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Stapleton, Heather M.

Overview:

Dr. Stapleton's research focuses on understanding the fate and transformation of organic contaminants in aquatic systems and in indoor environments. Her main focus has been on the bioaccumulation and biotransformation of brominated flame retardants, and specifically polybrominated diphenyl ethers,(PBDEs). Her current research projects explore the routes of human exposure to flame retardant chemicals and examine the way these compounds are photodegraded and metabolized using mass spectrometry to identify breakdown products/metabolites. She uses both in vivo techniques iwth fish, and in vitro techniques with cell cultures to examine metabolism of this varied class of chemicals. Also of interest to Dr. Stapleton is the study of the fate of PBDEs in the environment which may lead to bioaccumulation in aquatic systems and examining their bioavailability under different environmental conditions.

Positions:

Dan and Bunny Gabel Associate Professor of Environmental Ethics and Sustainable Environmental Management

Environmental Sciences and Policy
Nicholas School of the Environment

Associate Professor of Environmental Sciences and Policy in the Nicholas School of the Environment

Environmental Sciences and Policy
Nicholas School of the Environment

Associate Professor in the Department of Civil and Environmental Engineering

Civil and Environmental Engineering
Pratt School of Engineering

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

B.S. 1997

B.S. — Long Island University Southhampton College

M.S. 2000

M.S. — University of Maryland, College Park

Ph.D. 2003

Ph.D. — University of Maryland, College Park

News:

Grants:

The placenta: a novel target of sex specific neurotoxicity by fire retardants

Administered By
Environmental Sciences and Policy
AwardedBy
North Carolina State University
Role
Principal Investigator
Start Date
August 01, 2017
End Date
July 31, 2022

Superfund Research Center

Administered By
Environmental Sciences and Policy
AwardedBy
National Institute of Environmental Health Sciences
Role
Co-Principal Investigator
Start Date
June 01, 2000
End Date
March 31, 2022

Developmental Toxicity of Organophosphate-based Flame Retardants

Administered By
Environmental Sciences and Policy
AwardedBy
University of California - Riverside
Role
Principal Investigator
Start Date
March 01, 2017
End Date
February 28, 2022

Interrogation of molecular mechanisms involved in driving adipogenesis in environmental mixtures and novel analytical techniques for identifying putative causative chemicals

Administered By
Environmental Sciences and Policy
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
May 01, 2017
End Date
April 30, 2020

Children Exposure to SVOC Mixtures Indoors and Associations with Obesity

Administered By
Environmental Sciences and Policy
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 2007
End Date
June 30, 2019

Residential Exposure of Young Children to SVOCs

Administered By
Environmental Sciences and Policy
AwardedBy
Environmental Protection Agency
Role
Principal Investigator
Start Date
September 01, 2014
End Date
August 31, 2018

Duke University Program in Environmental Health

Administered By
Environmental Sciences and Policy
AwardedBy
National Institute of Environmental Health Sciences
Role
Mentor
Start Date
July 01, 2013
End Date
June 30, 2018

Maternal and Paternal Flame Retardant Exposure, Impact on Fertility and Pregnancy

Administered By
Environmental Sciences and Policy
AwardedBy
Harvard University
Role
Principal Investigator
Start Date
June 10, 2014
End Date
February 28, 2018

Prenatal Exposure to Organophosphates and Associations with Child Growth

Administered By
Environmental Sciences and Policy
AwardedBy
University of North Carolina - Chapel Hill
Role
Co Investigator
Start Date
December 01, 2014
End Date
November 30, 2017

Analysis of Flame Retardant Chemicals in Furniture Barriers

Administered By
Environmental Sciences and Policy
AwardedBy
Bureau of Electronic and Appliance Repair, Home Furnishings and Thermal Insulation
Role
Principal Investigator
Start Date
November 01, 2016
End Date
October 31, 2017

Developmental Toxicity of Organophosphate-based Flame Retardants

Administered By
Environmental Sciences and Policy
AwardedBy
University of California - Riverside
Role
Principal Investigator
Start Date
May 09, 2014
End Date
April 30, 2017

Evaluation of Changes in Flame Retardant Exposure in NYC

Administered By
Environmental Sciences and Policy
AwardedBy
Columbia University
Role
Principal Investigator
Start Date
December 31, 2015
End Date
December 30, 2016

Urinary Concentrations of Flame Retardant Metabolites in Mothers and Children

Administered By
Environmental Sciences and Policy
AwardedBy
Environmental Working Group
Role
Principal Investigator
Start Date
October 01, 2015
End Date
September 30, 2016

Toxicokinetics and Metabolic Disrupting Actions of the Flame Retardant Mixture Firemaster 550

Administered By
Environmental Sciences and Policy
AwardedBy
North Carolina State University
Role
Principal Investigator
Start Date
September 10, 2014
End Date
August 31, 2016

Exposure to Halogenated Aromatic Compounds and Risk of Thyroid Cancer

Administered By
Environmental Sciences and Policy
AwardedBy
Yale University
Role
Principal Investigator
Start Date
January 01, 2016
End Date
June 14, 2016

Evaluating Human Exposure to Triphenyl Phosphate from Nail Polish Applications

Administered By
Environmental Sciences and Policy
AwardedBy
Environmental Working Group
Role
Principal Investigator
Start Date
January 01, 2015
End Date
December 31, 2015

Developmental Toxicity of Organophosphate-based Flame Retardants

Administered By
Environmental Sciences and Policy
AwardedBy
University of South Carolina
Role
Principal Investigator
Start Date
May 09, 2014
End Date
June 30, 2015

Deiodinase Activity as a Biomarker of Response to Brominated Flame Retardants

Administered By
Nicholas School of the Environment
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 05, 2011
End Date
June 30, 2015

Current-Use Flame Retardants: Maternal Exposure and Neurodevelopment in Children

Administered By
Environmental Sciences and Policy
AwardedBy
University of California - Berkeley
Role
Principal Investigator
Start Date
June 17, 2013
End Date
May 31, 2015

Duke University Superfund Research Center (P42 ES010356)

Administered By
Environmental Sciences and Policy
AwardedBy
National Institute of Environmental Health Sciences
Role
Co Investigator
Start Date
June 01, 2000
End Date
March 31, 2014

Fate of Biosolid Derived Organic Contaminants in Soils and Effects on Soil Microbial Communities

Administered By
Civil and Environmental Engineering
AwardedBy
National Science Foundation
Role
Co-Principal Investigator
Start Date
July 01, 2009
End Date
June 30, 2013
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Publications:

The high-production volume fungicide pyraclostrobin induces triglyceride accumulation associated with mitochondrial dysfunction, and promotes adipocyte differentiation independent of PPARγ activation, in 3T3-L1 cells.

Pyraclostrobin is one of the most heavily used fungicides, and has been detected on a variety of produce, suggesting human exposure occurs regularly. Recently, pyraclostrobin exposure has been linked to a variety of toxic effects, including neurodegeneration and triglyceride (TG) accumulation. As pyraclostrobin inhibits electron transport chain complex III, and as mitochondrial dysfunction is associated with metabolic syndrome (cardiovascular disease, type II diabetes, obesity), we designed experiments to test the hypothesis that mitochondrial dysfunction underlies its adipogenic activity. 3T3-L1 cells were differentiated according to standard protocols in the presence of pyraclostrobin, resulting in TG accumulation. However, TG accumulation occurred without activation of the peroxisome proliferator activated nuclear receptor gamma (PPARγ), the canonical pathway mediating adipogenesis. Furthermore, cells failed to express many markers of adipogenesis (PPARγ, lpl, CEBPα), while co-exposure to pyraclostrobin and two different PPARγ antagonists (GW9662, T0070907) failed to mitigate TG accumulation, suggesting TG accumulation occurred through a PPARγ-independent mechanism. Instead, pyraclostrobin reduced steady-state ATP, mitochondrial membrane potential, basal mitochondrial respiration, ATP-linked respiration, and spare respiratory capacity, demonstrating mitochondrial dysfunction, while reduced expression of genes involved in glucose transport (Glut-4), glycolysis (Pkm, Pfkl, Pfkm), fatty acid oxidation (Cpt-1b), and lipogenesis (Fasn, Acacα, Acacβ) further suggested a disruption of metabolism. Finally, inhibition of cAMP responsive element binding protein (CREB), a PPARγ coactivator, partially mitigated pyraclostrobin-induced TG accumulation, suggesting TG accumulation is occurring through a CREB-driven mechanism. In contrast, rosiglitazone, a known PPARγ agonist, induced TG accumulation in a PPARγ-dependent manner and enhanced mitochondrial function. Collectively, these results suggest pyraclostrobin-induced mitochondrial dysfunction inhibits lipid homeostasis, resulting in TG accumulation. Exposures that disrupt mitochondrial function may have the potential to contribute to the rising incidence of metabolic syndrome, and thus more research is needed to understand the human health impact of pyraclostrobin exposure.

Authors
Luz, AL; Kassotis, CD; Stapleton, HM; Meyer, JN
MLA Citation
Luz, AL, Kassotis, CD, Stapleton, HM, and Meyer, JN. "The high-production volume fungicide pyraclostrobin induces triglyceride accumulation associated with mitochondrial dysfunction, and promotes adipocyte differentiation independent of PPARγ activation, in 3T3-L1 cells." Toxicology (November 7, 2017).
PMID
29127035
Source
epmc
Published In
TOXICOLOGY
Publish Date
2017
DOI
10.1016/j.tox.2017.11.010

Serum perfluoroalkyl acids (PFAAs) and associations with behavioral attributes.

The ubiquitous use of poly- and perfluoroalkyl substances (PFASs) in a variety of industrial and consumer products has resulted in chronic exposure in most industrialized nations, and led to measurable concentrations in blood and other tissues in humans across all life stages; however, behavioral attributes that relate to exposure are not well studied. To further investigate how behavior may relate to PFAS exposure, 37 adults were recruited from central North Carolina. Participants provided blood samples and behavioral questionnaires were administered, asking questions about a variety of household, dietary, and behavioral outcomes. Six PFAAs, including PFHxA (geometric mean: 0.14 ng/mL), PFOA (1.57 ng/mL), PFNA (0.67 ng/mL), PFDA (0.28 ng/mL), PFHxS (3.17 ng/mL) and PFOS (4.96 ng/mL) were detected in >50% of the samples. Generally, males had higher serum levels than females across all chemicals, and levels were very similar to NHANES levels; however, PFHxS and PFDA levels were higher in our study population. Several personal characteristics and behaviors were associated with serum PFAS levels. Reported use of filtration devices was associated with lower levels of PFOA (28% lower, p = 0.03), but higher levels of PFHxA (122% higher, p = 0.04). Serum PFHxS levels were also elevated in individuals that vacuumed less often, and in individuals that reported consuming more microwavable foods. These results suggest that personal behaviors may be important determinants of PFAS exposures.

Authors
Siebenaler, R; Cameron, R; Butt, CM; Hoffman, K; Higgins, CP; Stapleton, HM
MLA Citation
Siebenaler, R, Cameron, R, Butt, CM, Hoffman, K, Higgins, CP, and Stapleton, HM. "Serum perfluoroalkyl acids (PFAAs) and associations with behavioral attributes." Chemosphere 184 (October 2017): 687-693.
PMID
28633063
Source
epmc
Published In
Chemosphere
Volume
184
Publish Date
2017
Start Page
687
End Page
693
DOI
10.1016/j.chemosphere.2017.06.023

Associations between flame retardant applications in furniture foam, house dust levels, and residents' serum levels.

Polyurethane foam (PUF) in upholstered furniture frequently is treated with flame retardant chemicals (FRs) to reduce its flammability and adhere to rigorous flammability standards. For decades, a commercial mixture of polybrominated diphenyl ethers (PBDEs) called PentaBDE was commonly applied to foam to fulfill these regulations; however, concerns over toxicity, bioaccumulation, and persistence led to a global phase-out in the mid-2000s. Although PentaBDE is still detected in older furniture, other FR compounds such as tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and Firemaster® 550 (FM550) have been increasingly used as replacements. While biomonitoring studies suggest exposure is widespread, the primary sources of exposure are not clearly known. Here, we investigated the relationships between specific FR applications in furniture foam and human exposure. Paired samples of furniture foam, house dust and serum samples were collected from a cohort in North Carolina, USA and analyzed for FRs typically used in PUF. In general, the presence of a specific FR in the sofa of a home was associated with an increase in the concentration of that FR in house dust. For example, the presence of PentaBDE in sofas was associated with significantly higher levels of BDE-47, a major component of PentaBDE, in house dust (10β=6.4, p<0.001). A similar association was observed with a component of FM550, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), with levels that were approximately 3 times higher in house dust when FM550 was identified in the sofa foam (p<0.01). These relationships were modified by dust loading rates in the living room and the ratio of sofa size to room size. Interestingly, levels of TDCIPP and tris(1-chloro-2-isopropyl) phosphate (TCIPP) were also higher in dust with detections in sofa foam; however, these associations were not statistically significant and may suggest there are other prominent sources of these compounds in the home. In addition, the presence of PentaBDE in sofa foam was associated with significantly higher levels of BDE-47 in serum (p<0.01). These results suggest that FR applications in sofas are likely major sources of exposure to these compounds in the home.

Authors
Hammel, SC; Hoffman, K; Lorenzo, AM; Chen, A; Phillips, AL; Butt, CM; Sosa, JA; Webster, TF; Stapleton, HM
MLA Citation
Hammel, SC, Hoffman, K, Lorenzo, AM, Chen, A, Phillips, AL, Butt, CM, Sosa, JA, Webster, TF, and Stapleton, HM. "Associations between flame retardant applications in furniture foam, house dust levels, and residents' serum levels." Environment international 107 (October 2017): 181-189.
PMID
28750223
Source
epmc
Published In
Environment International
Volume
107
Publish Date
2017
Start Page
181
End Page
189
DOI
10.1016/j.envint.2017.07.015

Exposure to flame retardant chemicals and occurrence and severity of papillary thyroid cancer: A case-control study.

Thyroid cancer is the fastest increasing cancer in the U.S., and papillary thyroid cancer (PTC) accounts for >80% of incident cases. Increasing exposure to flame retardant chemicals (FRs) has raised concerns about their possible role in this 'epidemic'. The current study was designed to test the hypothesis that higher exposure to FRs is associated with increased odds of PTC.PTC patients at the Duke Cancer Institute were approached and invited to participate. Age- and gender-matched controls were recruited from the Duke Health System and surrounding communities. Because suitable biomarkers of long-term exposure do not exist for many common FRs, and levels of FRs in dust are significantly correlated with exposure, relationships between FRs in household dust and PTC were evaluated in addition to available biomarkers. PTC status, measures of aggressiveness (e.g. tumor size) and BRAF V600E mutation were included as outcomes.Higher levels of some FRs, particularly decabromodiphenyl ether (BDE-209) and tris(2-chloroethyl) phosphate in dust, were associated with increased odds of PTC. Participants with dust BDE-209 concentrations above the median level were 2.29 times as likely to have PTC [95% confidence interval: 1.03, 5.08] compared to those with low BDE-209 concentrations. Associations varied based on tumor aggressiveness and mutation status; TCEP was more strongly associated with larger, more aggressive tumors and BDE-209 was associated with smaller, less aggressive tumors.Taken together, these results suggest exposure to FRs in the home, particularly BDE-209 and TCEP, may be associated with PTC occurrence and severity, and warrant further study.

Authors
Hoffman, K; Lorenzo, A; Butt, CM; Hammel, SC; Henderson, BB; Roman, SA; Scheri, RP; Stapleton, HM; Sosa, JA
MLA Citation
Hoffman, K, Lorenzo, A, Butt, CM, Hammel, SC, Henderson, BB, Roman, SA, Scheri, RP, Stapleton, HM, and Sosa, JA. "Exposure to flame retardant chemicals and occurrence and severity of papillary thyroid cancer: A case-control study." Environment international 107 (October 2017): 235-242.
Website
http://hdl.handle.net/10161/15444
PMID
28772138
Source
epmc
Published In
Environment International
Volume
107
Publish Date
2017
Start Page
235
End Page
242
DOI
10.1016/j.envint.2017.06.021

Demographic and dietary risk factors in relation to urinary metabolites of organophosphate flame retardants in toddlers.

Organophosphate flame retardants (OPFRs), including Tris (1,3-dichloro-isopropyl) phosphate (TDCPP), triphenyl phosphate (TPP), and isopropylated triphenyl phosphate (ITP), are increasingly used in consumer products because of the recent phase out of polybrominated diphenyl ether (PBDE) flame retardants. OPFRs have been widely detected in adults and have been linked to reproductive and endocrine changes in adult males. Carcinogenicity and damage to immunologic, neurologic and developmental systems have been observed in human cell lines. Young children are especially vulnerable to OPFR exposure, but little is known about exposure levels or exposure risk factors in this population. We examined parent-reported demographic and dietary survey data in relation to OPFR urinary metabolite concentrations in 15- to 18-month old toddlers (n = 41). OPFR metabolites were detected in 100% of subjects. The metabolite of TPP, diphenyl phosphate (DPP) was detected most commonly (100%), with TDCPP metabolite, bis(1,3-dichloro-2-propyl) phosphate (BDCPP), detected in 85-95% of samples, and ITP metabolite, monoisopropylphenyl phenyl phosphate (ip-DPP), detected in 81% of samples (n = 21). Toddlers of mothers earning <$10,000 annually had geometric mean DPP concentrations 66% higher (p = 0.05) than toddlers of mothers earning >$10,000/year (7.8 ng/mL, 95% CI 5.03, 12.11 and 4.69 ng/mL, 95% CI 3.65-6.04, respectively). While no dietary factors were significantly associated with OPFR metabolite concentrations, results suggested meat and fish consumption may be associated with higher DPP and BDCPP levels while increased dairy and fresh food consumption may be associated with lower DPP, BDCPP, and ip-DPP levels. Research with larger sample sizes and more detailed dietary data is required to confirm these preliminary findings.

Authors
Thomas, MB; Stapleton, HM; Dills, RL; Violette, HD; Christakis, DA; Sathyanarayana, S
MLA Citation
Thomas, MB, Stapleton, HM, Dills, RL, Violette, HD, Christakis, DA, and Sathyanarayana, S. "Demographic and dietary risk factors in relation to urinary metabolites of organophosphate flame retardants in toddlers." Chemosphere 185 (October 2017): 918-925.
PMID
28763939
Source
epmc
Published In
Chemosphere
Volume
185
Publish Date
2017
Start Page
918
End Page
925
DOI
10.1016/j.chemosphere.2017.07.015

Biochar and activated carbon act as promising amendments for promoting the microbial debromination of tetrabromobisphenol A.

The increasing occurrence of tetrabromobisphenol A (TBBPA) in the environment is raising questions about its potential environmental health impacts as it has been shown to cause various deleterious effects in humans. The fact that the highest concentrations of TBBPA have been reported in wastewater sludge is concerning as effluent discharge and biosolids land application are likely a route by which TBBPA can be further disbursed to the environment. Our objectives in this study were to evaluate the effect of biochar (BC) and activated carbon (AC) in promoting the biodegradation of TBBPA, and characterize the response of anaerobic sludge microbial communities following amendments. Both carbonaceous amendments were found to promote the reductive debromination of TBBPA. Nearly complete transformation of TBBPA to BPA was observed in the amended reactors ∼20 days earlier than in the control reactors. In particular, the transformation of diBBPA to monoBBPA, which appears to be the rate-limiting step, was accelerated in the presence of either amendment. Overall, microbial taxa responding to the amendments, i.e., 'sensitive responders', represented a small proportion of the community (i.e., 7.2%), and responded positively. However, although both amendments had a similar effect on TBBPA degradation, the taxonomic profile of the sensitive responders differed greatly from one amendment to the other. BC had a taxonomically broader and slightly more pronounced effect than AC. This work suggests that BC and AC show great potential to promote the biodegradation of TBBPA in anaerobic sludge, and their integration into wastewater treatment processes may be helpful for removing TBBPA and possibly other emerging hydrophobic contaminants.

Authors
Lefèvre, E; Bossa, N; Gardner, CM; Gehrke, GE; Cooper, EM; Stapleton, HM; Hsu-Kim, H; Gunsch, CK
MLA Citation
Lefèvre, E, Bossa, N, Gardner, CM, Gehrke, GE, Cooper, EM, Stapleton, HM, Hsu-Kim, H, and Gunsch, CK. "Biochar and activated carbon act as promising amendments for promoting the microbial debromination of tetrabromobisphenol A." Water research 128 (September 30, 2017): 102-110.
PMID
29091801
Source
epmc
Published In
Water Research
Volume
128
Publish Date
2017
Start Page
102
End Page
110
DOI
10.1016/j.watres.2017.09.047

Brominated and organophosphate flame retardants target different neurodevelopmental stages, characterized with embryonic neural stem cells and neuronotypic PC12 cells.

In addition to their activity as endocrine disruptors, brominated and organophosphate flame retardants are suspected to be developmental neurotoxicants, although identifying their specific mechanisms for that activity has been elusive. In the current study, we evaluated the effects of several flame retardants on neurodifferentiation using two in vitro models that assess distinct "decision nodes" in neural cell development: embryonic rat neural stem cells (NSCs), which evaluate the origination of neurons and glia from precursors, and rat neuronotypic PC12 cells, which characterize a later stage where cells committed to a neuronal phenotype undergo neurite outgrowth and neurotransmitter specification. In NSCs, both brominated and organophosphate flame retardants diverted the phenotype in favor of glia and away from formation of neurons, leading to an increased glia/neuron ratio, a common hallmark of the in vivo effects of neurotoxicants. For this early decision node, the brominated flame retardants were far more potent than the organophosphates. In PC12 cells, the brominated flame retardants were far less effective, whereas tris (1,3-dichloro-2-propyl) phosphate, an organophosphate, was more effective. Thus, the two classes of flame retardants differentially impact the two distinct vulnerable periods of neurodifferentiation. Furthermore, the effects on neurodifferentiation were separable from outright cytotoxicity, an important requirement in establishing a specific effect of these agents on neural cell development. These results reinforce the likelihood that flame retardants act as developmental neurotoxicants via direct effects on neural cell differentiation, over and above other activities that can impact nervous system development, such as endocrine disruption.

Authors
Slotkin, TA; Skavicus, S; Stapleton, HM; Seidler, FJ
MLA Citation
Slotkin, TA, Skavicus, S, Stapleton, HM, and Seidler, FJ. "Brominated and organophosphate flame retardants target different neurodevelopmental stages, characterized with embryonic neural stem cells and neuronotypic PC12 cells." Toxicology 390 (September 2017): 32-42.
PMID
28851516
Source
epmc
Published In
TOXICOLOGY
Volume
390
Publish Date
2017
Start Page
32
End Page
42
DOI
10.1016/j.tox.2017.08.009

Estimated Tris(1,3-dichloro-2-propyl) Phosphate Exposure Levels for U.S. Infants Suggest Potential Health Risks

Authors
Hoffman, K; Gearhart-Serna, L; Lorber, M; Webster, TF; Stapleton, HM
MLA Citation
Hoffman, K, Gearhart-Serna, L, Lorber, M, Webster, TF, and Stapleton, HM. "Estimated Tris(1,3-dichloro-2-propyl) Phosphate Exposure Levels for U.S. Infants Suggest Potential Health Risks." Environmental Science & Technology Letters 4.8 (August 8, 2017): 334-338.
Source
crossref
Published In
Environmental Science and Technology Letters
Volume
4
Issue
8
Publish Date
2017
Start Page
334
End Page
338
DOI
10.1021/acs.estlett.7b00196

Sex Specific Placental Accumulation and Behavioral Effects of Developmental Firemaster 550 Exposure in Wistar Rats.

Firemaster® 550 (FM 550) is a commercial flame retardant mixture of brominated and organophosphate compounds applied to polyurethane foam used in furniture and baby products. Due to widespread human exposure, and structural similarities with known endocrine disruptors, concerns have been raised regarding possible toxicity. We previously reported evidence of sex specific behavioral effects in rats resulting from developmental exposure. The present study expands upon this prior finding by testing for a greater range of behavioral effects, and measuring the accumulation of FM 550 compounds in placental tissue. Wistar rat dams were orally exposed to FM 550 during gestation (0, 300 or 1000 µg/day; GD 9 - 18) for placental measurements or perinatally (0, 100, 300 or 1000 µg/day; GD 9 - PND 21) to assess activity and anxiety-like behaviors. Placental accumulation was dose dependent, and in some cases sex specific, with the brominated components reaching the highest levels. Behavioral changes were predominantly associated with a loss or reversal of sex differences in activity and anxiety-like behaviors. These findings demonstrate that environmental chemicals may sex-dependently accumulate in the placenta. That sex-biased exposure might translate to sex-specific adverse outcomes such as behavioral deficits is a possibility that merits further investigation.

Authors
Baldwin, KR; Phillips, AL; Horman, B; Arambula, SE; Rebuli, ME; Stapleton, HM; Patisaul, HB
MLA Citation
Baldwin, KR, Phillips, AL, Horman, B, Arambula, SE, Rebuli, ME, Stapleton, HM, and Patisaul, HB. "Sex Specific Placental Accumulation and Behavioral Effects of Developmental Firemaster 550 Exposure in Wistar Rats." Scientific reports 7.1 (August 2, 2017): 7118-.
Website
http://hdl.handle.net/10161/15445
PMID
28769031
Source
epmc
Published In
Scientific Reports
Volume
7
Issue
1
Publish Date
2017
Start Page
7118
DOI
10.1038/s41598-017-07216-6

Influence of storage vial material on measurement of organophosphate flame retardant metabolites in urine.

Use of organophosphate flame retardants (PFRs) has increased over the past decade with the phase out of polybrominated diphenyl ethers. Urinary metabolites of PFRs are used as biomarkers of exposure in epidemiologic research, which typically uses samples collected and stored in polypropylene plastic cryovials. However, a small study suggested that the storage vial material may influence reported concentrations. Therefore, we aimed to examine the influence of the storage vial material on analytical measurement of PFR urinary metabolites. Using urine samples collected from participants in the Environment and Reproductive Health (EARTH) Study, we analyzed the PFR metabolites in duplicate aliquots that were stored in glass and plastic vials (n = 31 pairs). Bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), diphenyl phosphate (DPHP) and isopropyl-phenyl phenyl phosphate (ip-PPP) were detected in 98%, 97% and 87% of duplicates. We observed high correlations between glass-plastic duplicates for BDCIPP (rs = 0.95), DPHP (rs = 0.79) and ip-PPP (rs = 0.82) (p < 0.0001). Urinary ip-PPP was an average of 0.04 ng/ml (p = 0.04) higher among samples stored in glass, with a mean relative difference of 14%. While this difference is statistically significant, it is small in magnitude. No differences were observed for BDCIPP or DPHP, however future research should seek to reduce the potential for type II error (false negatives). We conclude that storing urine samples in polypropylene plastic cryovials may result in slightly reduced concentrations of urinary ip-PPP relative to storage in glass vials and future research should seek to increase the sample size, reduce background variability and consider the material of the urine collection cup.

Authors
Carignan, CC; Butt, CM; Stapleton, HM; Meeker, JD; Minguez-Alarcón, L; Williams, PL; Hauser, R
MLA Citation
Carignan, CC, Butt, CM, Stapleton, HM, Meeker, JD, Minguez-Alarcón, L, Williams, PL, and Hauser, R. "Influence of storage vial material on measurement of organophosphate flame retardant metabolites in urine." Chemosphere 181 (August 2017): 440-446.
PMID
28458219
Source
epmc
Published In
Chemosphere
Volume
181
Publish Date
2017
Start Page
440
End Page
446
DOI
10.1016/j.chemosphere.2017.04.083

Characterization of Adipogenic Activity of House Dust Extracts and Semi-Volatile Indoor Contaminants in 3T3-L1 Cells.

Obesity and metabolic disorders are of great societal concern and generate significant human health care costs. Recently, attention has focused on the potential for environmental contaminants to act as metabolic disruptors. This study sought to evaluate the adipogenic activity of indoor house dust extracts and a suite of semivolatile organic chemicals (SVOCs) that are often ubiquitously detected in indoor environments. 3T3-L1 cells were exposed to extracts of indoor dust or individual SVOCs and assessed for triglyceride accumulation and preadipocyte proliferation. Ten of 11 house dust extracts exhibited significant triglyceride accumulation and/or proliferation at environmentally relevant levels (<20 μg of dust/well), and significant adipogenic activity was also exhibited by 28 of the SVOCs. Notably, pyraclostrobin, dibutyl phthalate, tert-butyl-phenyl diphenyl phosphate, and the isopropylated triaryl phosphates (ITPs) exhibited near maximal or supra-maximal triglyceride accumulation relative to the rosiglitazone-induced maximum. The adipogenic activity in house dust occurred at concentrations below EPA estimated child exposure levels, and raises concerns for human health impacts, particularly in children. Our results delineate a novel potential health threat and identify putative causative SVOCs that are likely contributing to this activity.

Authors
Kassotis, CD; Hoffman, K; Stapleton, HM
MLA Citation
Kassotis, CD, Hoffman, K, and Stapleton, HM. "Characterization of Adipogenic Activity of House Dust Extracts and Semi-Volatile Indoor Contaminants in 3T3-L1 Cells." Environmental science & technology 51.15 (August 2017): 8735-8745.
PMID
28699343
Source
epmc
Published In
Environmental Science & Technology
Volume
51
Issue
15
Publish Date
2017
Start Page
8735
End Page
8745
DOI
10.1021/acs.est.7b01788

Closing the Mass Balance on Fluorine on Papers and Textiles.

Papers and textiles that are treated with per- and polyfluoroalkyl substances (PFASs) are sources of human and environmental exposure. Data for individual PFASs, such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), are not placed into the context of total fluorine for papers and textiles. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to quantify volatile and ionic PFASs, respectively, and the total oxidizable precursor (TOP) assay was used to quantify precursors that form perfluoroalkyl carboxylates. Molar sums of PFASs obtained by GC-MS, LC-MS/MS, and precursors were compared to total fluorine (nmol F/cm2) determined by particle-induced gamma ray emission (PIGE) spectroscopy, measured before and after extraction. Volatile and ionic PFASs and unknown precursors accounted for 0-2.2%, 0-0.41%, and 0.021-14%, respectively, of the total nmol F/cm2 determined by PIGE. After extraction, papers and textiles retained 64 ± 28% to 110 ± 30% of the original nmol F/cm2 as determined by PIGE, indicating that the majority of fluorine remains associated with the papers and textiles. The sum of PFASs in the volatile, ionic, and precursor fraction, and total fluorine after extraction indicate that mass balance was achieved (within analytical error) of the initial total fluorine measured by PIGE.

Authors
Robel, AE; Marshall, K; Dickinson, M; Lunderberg, D; Butt, C; Peaslee, G; Stapleton, HM; Field, JA
MLA Citation
Robel, AE, Marshall, K, Dickinson, M, Lunderberg, D, Butt, C, Peaslee, G, Stapleton, HM, and Field, JA. "Closing the Mass Balance on Fluorine on Papers and Textiles." Environmental science & technology 51.16 (August 2017): 9022-9032.
PMID
28712295
Source
epmc
Published In
Environmental Science & Technology
Volume
51
Issue
16
Publish Date
2017
Start Page
9022
End Page
9032
DOI
10.1021/acs.est.7b02080

Flame retardants and their metabolites in the homes and urine of pregnant women residing in California (the CHAMACOS cohort).

Organophosphate flame retardants (PFRs), used in consumer products since the 1970s, persist in the environment. Restrictions on penta-polybrominated diphenyl ether (PBDE) flame retardants resulted in increased use of Firemaster® 550 (FM® 550), and the organophosphate triesters: tris(1,3- dichloro-2-propyl) phosphate (TDCIPP); tris(chloropropyl) phosphate (TCIPP); tris(2-chloroethyl) phosphate (TCEP); and triphenyl phosphate (TPHP). The objectives of this study were to (1) identify determinants of flame retardants (4 PFRs, PentaBDEs and FM® 550) in house dust, (2) measure urinary PFR metabolites in pregnant women, and (3) estimate health risks from PFR exposure. We measured flame retardants in house dust (n = 125) and metabolites in urine (n = 310) collected in 2000-2001 from Mexican American women participating in the CHAMACOS birth cohort study in California. We detected FM® 550 and PFRs, including two (TCEP and TDCIPP) known to the state of California to cause cancer, in most dust samples. The maximum TCEP and TDCIPP dust levels were among the highest ever reported although the median levels were generally lower compared to other U.S. cohorts. Metabolites of TDCIPP (BDCIPP: bis(1,3-dichloro-2-propyl) phosphate) and TPHP (DPHP: diphenyl phosphate) were detected in 78% and 79% of prenatal urine samples, respectively. We found a weak but positive correlation between TPHP in dust and DPHP in 124 paired prenatal urine samples (Spearman rho = 0.17; p = 0.06). These results provide information on PFR exposure and risk in pregnant women from the early 2000's and are also valuable to assess trends in exposure and risk given changing fire safety regulations and concomitant changes in chemical flame retardant use.

Authors
Castorina, R; Butt, C; Stapleton, HM; Avery, D; Harley, KG; Holland, N; Eskenazi, B; Bradman, A
MLA Citation
Castorina, R, Butt, C, Stapleton, HM, Avery, D, Harley, KG, Holland, N, Eskenazi, B, and Bradman, A. "Flame retardants and their metabolites in the homes and urine of pregnant women residing in California (the CHAMACOS cohort)." Chemosphere 179 (July 2017): 159-166.
PMID
28365501
Source
epmc
Published In
Chemosphere
Volume
179
Publish Date
2017
Start Page
159
End Page
166
DOI
10.1016/j.chemosphere.2017.03.076

Impacts of Unregulated Novel Brominated Flame Retardants on Human Liver Thyroid Deiodination and Sulfotransferation.

The inhibitory effects of five novel brominated flame retardants, 1,2-bis(2,4,5-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP), and β-tetrabromoethylcyclohexane (β-TBECH), on thyroid hormone deiodinase (DIO) and sulfotransferase (SULT) activity were investigated using human in vitro liver microsomal and cytosolic bioassays. Enzymatic activity was measured by incubating active human liver subcellular fractions with thyroid hormones (T4 and rT3 separately) and measuring changes in thyroid hormone (T4, T3, rT3, and 3,3'-T2) concentrations. Only DBDPE showed inhibition of both outer and inner ring deiodination (O and IRD) of T3 and 3,3'-T2 formation from T4, respectively, with an estimated IC50 of 160 nM; no statistically significant inhibition of SULT activity was observed. ORD inhibition of 3,3'-T2 formation from rT3 was also observed (IC50 ∼ 100 nM). The kinetics of T4 O and IRD were also investigated, although a definitive mechanism could not be identified as the Michaelis-Menten parameters and maximal rate constants were not significantly different. Concentrations tested were intentionally above expected environmental levels, and this study suggests that these NBFRs are not potent human liver DIO and SULT inhibitors. To our knowledge, DBDPE is the first example of a nonhydroxylated contaminant inhibiting DIO activity, and further study of the mechanism of action is warranted.

Authors
Smythe, TA; Butt, CM; Stapleton, HM; Pleskach, K; Ratnayake, G; Song, CY; Riddell, N; Konstantinov, A; Tomy, GT
MLA Citation
Smythe, TA, Butt, CM, Stapleton, HM, Pleskach, K, Ratnayake, G, Song, CY, Riddell, N, Konstantinov, A, and Tomy, GT. "Impacts of Unregulated Novel Brominated Flame Retardants on Human Liver Thyroid Deiodination and Sulfotransferation." Environmental science & technology 51.12 (June 2017): 7245-7253.
PMID
28541672
Source
epmc
Published In
Environmental Science & Technology
Volume
51
Issue
12
Publish Date
2017
Start Page
7245
End Page
7253
DOI
10.1021/acs.est.7b01143

Associations between urinary diphenyl phosphate and thyroid function.

Triphenyl phosphate (TPHP) is a commonly used organophosphate flame retardant and plasticizer with widespread human exposure. Data on health effects of TPHP are limited. Recent toxicological studies suggest TPHP may alter thyroid function. We used repeated measures to assess the temporal variability in urinary concentrations of the TPHP metabolite, diphenyl phosphate (DPHP), and to examine relationships between DPHP concentrations and thyroid hormones. We sampled 51 adults at months 1, 6, and 12 from 2010 to 2011. Urine samples were analyzed for DPHP. Serum samples were analyzed for free and total thyroxine (fT4, TT4), total triiodothyronine (TT3), and thyroid stimulating hormone (TSH). We assessed variability in DPHP using intraclass correlation coefficients (ICCs) and kappa statistics. We used linear mixed-effects models to examine associations between DPHP and thyroid hormones. DPHP was detected in 95% of urine samples. Mean DPHP concentrations were 43% higher in women than men. DPHP showed high within-subject variability (ICC range, 0.13-0.39; kappa range, 0.16-0.39). High versus low (≥2.65 vs. <2.65ng/mL) DPHP in all participants was associated with a 0.43μg/dL (95% confidence interval: 0.15, 0.72) increase in mean TT4 levels. In sex-stratified analyses, high versus low DPHP was associated with a 0.91μg/dL (95% CI: 0.47, 1.36) increase in mean TT4 in women. The association was attenuated in men (βeta=0.19; 95% CI: -0.15, 0.52). We found no significant associations between DPHP and fT4, TT3, or TSH. We found evidence that TPHP exposure may be associated with increased TT4 levels, especially in women.

Authors
Preston, EV; McClean, MD; Claus Henn, B; Stapleton, HM; Braverman, LE; Pearce, EN; Makey, CM; Webster, TF
MLA Citation
Preston, EV, McClean, MD, Claus Henn, B, Stapleton, HM, Braverman, LE, Pearce, EN, Makey, CM, and Webster, TF. "Associations between urinary diphenyl phosphate and thyroid function." Environment international 101 (April 2017): 158-164.
PMID
28162782
Source
epmc
Published In
Environment International
Volume
101
Publish Date
2017
Start Page
158
End Page
164
DOI
10.1016/j.envint.2017.01.020

Associations between urinary diphenyl phosphate and thyroid function

Authors
Preston, EV; McClean, MD; Henn, BC; Stapleton, HM; Braverman, LE; Pearce, EN; Makey, CM; Webster, TF
MLA Citation
Preston, EV, McClean, MD, Henn, BC, Stapleton, HM, Braverman, LE, Pearce, EN, Makey, CM, and Webster, TF. "Associations between urinary diphenyl phosphate and thyroid function." ENVIRONMENT INTERNATIONAL 101 (April 2017): 158-164.
Source
wos-lite
Published In
Environment International
Volume
101
Publish Date
2017
Start Page
158
End Page
164
DOI
10.1016/j.envint.2017.01.020

Comment on "Mutagenic Azo Dyes, Rather Than Flame Retardants, Are the Predominant Brominated Compounds in House Dust".

Authors
Ferguson, PL; Stapleton, HM
MLA Citation
Ferguson, PL, and Stapleton, HM. "Comment on "Mutagenic Azo Dyes, Rather Than Flame Retardants, Are the Predominant Brominated Compounds in House Dust"." Environmental Science & Technology 51.6 (March 10, 2017): 3588-3590.
PMID
28282131
Source
epmc
Published In
Environmental Science & Technology
Volume
51
Issue
6
Publish Date
2017
Start Page
3588
End Page
3590
DOI
10.1021/acs.est.7b00372

Toddler's behavior and its impacts on exposure to polybrominated diphenyl ethers.

Children have higher polybrominated diphenyl ether (PBDE) body burdens than adults, which may be related to hand-to-mouth behavior. We investigate associations between children's behavior, including hand-to-mouth contacts, and markers of PBDE exposure. In addition, we investigate associations between characteristics of the home environment and exposure. Eighty-three children aged 12-36 months were recruited from North Carolina (2009-2010). Children provided blood and handwipes samples, which were analyzed for PBDEs. Parents completed questionnaires, providing demographic, behavioral, and environmental data. More active children had higher levels of PBDEs on their hands and in their bodies. For example, children who spent more time sleeping had lower exposures to PBDEs; each additional hour of sleep resulted in a 30% decrease in handwipe BDE-99 levels (P<0.001) and a 15% decrease in serum (P=0.03). After accounting for handwipe PBDE levels, children who licked their fingers while eating had higher serum PBDEs. Other behaviors were not consistently associated with serum levels. Playing with plastic toys was associated with higher handwipe levels of PBDEs, while frequent vacuuming decreased handwipe PBDE levels. Characteristics of the home environment generally were not associated with serum PBDEs. Our results suggest that certain aspects of children's behavior and their environment impact exposure to PBDEs.

Authors
Hoffman, K; Webster, TF; Sjödin, A; Stapleton, HM
MLA Citation
Hoffman, K, Webster, TF, Sjödin, A, and Stapleton, HM. "Toddler's behavior and its impacts on exposure to polybrominated diphenyl ethers." Journal of exposure science & environmental epidemiology 27.2 (March 2017): 193-197.
PMID
26956938
Source
epmc
Published In
Journal of Exposure Science and Environmental Epidemiology
Volume
27
Issue
2
Publish Date
2017
Start Page
193
End Page
197
DOI
10.1038/jes.2016.11

Temporal Trends in Exposure to Organophosphate Flame Retardants in the United States.

During the past decade, use of organophosphate compounds as flame retardants and plasticizers has increased. Numerous studies investigating biomarkers (i.e., urinary metabolites) demonstrate ubiquitous human exposure and suggest that human exposure may be increasing. To formally assess temporal trends, we combined data from 14 U.S. epidemiologic studies for which our laboratory group previously assessed exposure to two commonly used organophosphate compounds, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP). Using individual-level data and samples collected between 2002 and 2015, we assessed temporal and seasonal trends in urinary bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), the metabolites of TDCIPP and TPHP, respectively. Data suggest that BDCIPP concentrations have increased dramatically since 2002. Samples collected in 2014 and 2015 had BDCIPP concentrations that were more than 15 times higher than those collected in 2002 and 2003 (10β = 16.5; 95% confidence interval from 9.64 to 28.3). Our results also demonstrate significant increases in DPHP levels; however, increases were much smaller than for BDCIPP. Additionally, results suggest that exposure varies seasonally, with significantly higher levels of exposure in summer for both TDCIPP and TPHP. Given these increases, more research is needed to determine whether the levels of exposure experienced by the general population are related to adverse health outcomes.

Authors
Hoffman, K; Butt, CM; Webster, TF; Preston, EV; Hammel, SC; Makey, C; Lorenzo, AM; Cooper, EM; Carignan, C; Meeker, JD; Hauser, R; Soubry, A; Murphy, SK; Price, TM; Hoyo, C; Mendelsohn, E; Congleton, J; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Butt, CM, Webster, TF, Preston, EV, Hammel, SC, Makey, C, Lorenzo, AM, Cooper, EM, Carignan, C, Meeker, JD, Hauser, R, Soubry, A, Murphy, SK, Price, TM, Hoyo, C, Mendelsohn, E, Congleton, J, Daniels, JL, and Stapleton, HM. "Temporal Trends in Exposure to Organophosphate Flame Retardants in the United States." Environmental science & technology letters 4.3 (March 2017): 112-118.
PMID
28317001
Source
epmc
Published In
Environmental Science and Technology Letters
Volume
4
Issue
3
Publish Date
2017
Start Page
112
End Page
118
DOI
10.1021/acs.estlett.6b00475

Temporal Trends in Exposure to Organophosphate Flame Retardants in the United States

Authors
Hoffman, K; Butt, CM; Webster, TF; Preston, EV; Hammel, SC; Makey, C; Lorenzo, AM; Cooper, EM; Carignan, C; Meeker, JD; Hauser, R; Soubry, A; Murphy, SK; Price, TM; Hoyo, C; Mendelsohn, E; Congleton, J; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Butt, CM, Webster, TF, Preston, EV, Hammel, SC, Makey, C, Lorenzo, AM, Cooper, EM, Carignan, C, Meeker, JD, Hauser, R, Soubry, A, Murphy, SK, Price, TM, Hoyo, C, Mendelsohn, E, Congleton, J, Daniels, JL, and Stapleton, HM. "Temporal Trends in Exposure to Organophosphate Flame Retardants in the United States." ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 4.3 (March 2017): 112-118.
Source
wos-lite
Published In
Environmental Science and Technology Letters
Volume
4
Issue
3
Publish Date
2017
Start Page
112
End Page
118
DOI
10.1021/acs.estletr.6b00475

Prevalence of historical and replacement brominated flame retardant chemicals in New York City homes.

Until their phase-out between 2005 and 2013, polybrominated diphenyl ethers (PBDEs) were added to household products including furniture, rugs, and electronics to meet flammability standards. Replacement brominated flame retardant (BFR) chemicals, including 2-ethylhexyl-2,3,4,5 tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH), which are components of the Firemaster 550® commercial mixture, are now being used to meet some flammability standards in furniture. The objective of this analysis was to evaluate the extent to which mothers and their children living in New York City are exposed to PBDEs, TBB, and TBPH.We measured PBDEs, TBB, and TBPH using gas chromatography mass spectrometry in dust (n = 25) and handwipe (n = 11) samples collected between 2012 and 2013 from mothers and children living in New York City. We defined dust as enriched if the proportional distribution for a given BFR exceeded two-thirds of the total BFR content.We detected PBDEs and TBPH in 100% of dust and handwipe samples and TBB in 100% of dust samples and 95% of handwipe samples. Dust from approximately two-thirds of households was enriched for either PBDEs (n = 9) or for TBB + TBPH (n = 8). Overall, the median house dust concentration of TBB + TBPH (1318 ng/g dust) was higher than that of ΣPentaBDE (802 ng/g dust) and BDE-209 (1171 ng/g dust). Children generally had higher BFR handwipe concentrations compared to mothers (ΣPentaBDE: 73%, BDE-209: 64%, TBB + TBPH: 55%) and within households, BFR concentrations from paired maternal-child handwipes were highly correlated. Among mothers, we found a significant positive relation between house dust and handwipe BDE-209 and TBB + TBPH concentrations.PBDEs, TBB and TBPH are ubiquitous in house dust and handwipes in a sample of mother-child pairs residing in New York City.

Authors
Cowell, WJ; Stapleton, HM; Holmes, D; Calero, L; Tobon, C; Perzanowski, M; Herbstman, JB
MLA Citation
Cowell, WJ, Stapleton, HM, Holmes, D, Calero, L, Tobon, C, Perzanowski, M, and Herbstman, JB. "Prevalence of historical and replacement brominated flame retardant chemicals in New York City homes." Emerging contaminants 3.1 (March 2017): 32-39.
PMID
28989983
Source
epmc
Published In
Emerging Contaminants
Volume
3
Issue
1
Publish Date
2017
Start Page
32
End Page
39
DOI
10.1016/j.emcon.2017.01.001

Characterization of Adipogenic Chemicals in Three Different Cell Culture Systems: Implications for Reproducibility Based on Cell Source and Handling.

The potential for chemical exposures to exacerbate the development and/or prevalence of metabolic disorders, such as obesity, is currently of great societal concern. Various in vitro assays are available to assess adipocyte differentiation, though little work has been done to standardize protocols and compare models effectively. This study compares several adipogenic cell culture systems under a variety of conditions to assess variability in responses. Two sources of 3T3-L1 preadipocytes as well as OP9 preadipocytes were assessed for cell proliferation and triglyceride accumulation following different induction periods and using various tissue culture plates. Both cell line and cell source had a significant impact on potencies and efficacies of adipogenic chemicals. Gene expression analyses suggested that differential expression of nuclear receptors involved in adipogenesis underlie the differences between OP9 and 3T3-L1 cells; however, there were also differences based on 3T3-L1 cell source. Induction period modulated potency and efficacy of response depending on cell line and test chemical, and large variations were observed in triglyceride accumulation and cell proliferation between brands of tissue culture plates. Our results suggest that the selection of a cell system and differentiation protocol significantly impacts the detection of adipogenic chemicals, and therefore, influences reproducibility of these studies.

Authors
Kassotis, CD; Masse, L; Kim, S; Schlezinger, JJ; Webster, TF; Stapleton, HM
MLA Citation
Kassotis, CD, Masse, L, Kim, S, Schlezinger, JJ, Webster, TF, and Stapleton, HM. "Characterization of Adipogenic Chemicals in Three Different Cell Culture Systems: Implications for Reproducibility Based on Cell Source and Handling." Scientific Reports 7 (February 8, 2017): 42104-.
PMID
28176856
Source
epmc
Published In
Scientific Reports
Volume
7
Publish Date
2017
Start Page
42104
DOI
10.1038/srep42104

Exposure to a PBDE/OH-BDE mixture alters juvenile zebrafish (Danio rerio) development.

Polybrominated diphenyl ethers (PBDEs) and their metabolites (e.g., hydroxylated BDEs [OH-BDEs]) are contaminants frequently detected together in human tissues and are structurally similar to thyroid hormones. Thyroid hormones partially mediate metamorphic transitions between life stages in zebrafish, making this a critical developmental window that may be vulnerable to chemicals disrupting thyroid signaling. In the present study, zebrafish were exposed to 6-OH-BDE-47 (30 nM; 15 μg/L) alone, or to a low-dose (30 μg/L) or high-dose (600 μg/L) mixture of PentaBDEs, 6-OH-BDE-47 (0.5-6 μg/L), and 2,4,6-tribromophenol (5-100 μg/L) during juvenile development (9-23 d postfertilization) and evaluated for developmental endpoints mediated by thyroid hormone signaling. Fish were sampled at 3 time points and examined for developmental and skeletal morphology, apical thyroid and skeletal gene markers, and modifications in swimming behavior (as adults). Exposure to the high-dose mixture resulted in >85% mortality within 1 wk of exposure, despite being below reported acute toxicity thresholds for individual congeners. The low-dose mixture and 6-OH-BDE-47 groups exhibited reductions in body length and delayed maturation, specifically relating to swim bladder, fin, and pigmentation development. Reduced skeletal ossification was also observed in 6-OH-BDE-47-treated fish. Assessment of thyroid and osteochondral gene regulatory networks demonstrated significantly increased expression of genes that regulate skeletal development and thyroid hormones. Overall, these results indicate that exposures to PBDE/OH-BDE mixtures adversely impact zebrafish maturation during metamorphosis. Environ Toxicol Chem 2017;36:36-48. © 2016 SETAC.

Authors
Macaulay, LJ; Chernick, M; Chen, A; Hinton, DE; Bailey, JM; Kullman, SW; Levin, ED; Stapleton, HM
MLA Citation
Macaulay, LJ, Chernick, M, Chen, A, Hinton, DE, Bailey, JM, Kullman, SW, Levin, ED, and Stapleton, HM. "Exposure to a PBDE/OH-BDE mixture alters juvenile zebrafish (Danio rerio) development." Environmental toxicology and chemistry 36.1 (January 2017): 36-48.
PMID
27329031
Source
epmc
Published In
Environmental Toxicology & Chemistry
Volume
36
Issue
1
Publish Date
2017
Start Page
36
End Page
48
DOI
10.1002/etc.3535

Do flame retardant chemicals increase the risk for thyroid dysregulation and cancer?

Flame retardant chemicals are added to consumer products to reduce fire incidence and severity; approximately 1.5 million tons of these chemicals are used annually. However, their widespread use has led to their ubiquitous presence in the environment and chronic accumulation in human tissues. We summarize current trends in human flame retardant chemical exposure, and review recent data highlighting concerns for thyroid dysregulation and cancer risk in human populations.Polybrominated diphenyl ethers were once commonly used as flame retardant chemicals, but recently were phased out. Exposure is associated with thyroid dysregulation (mainly T4 reductions) in animals, with new work focusing on specific mechanisms of action. Polybrominated diphenyl ethers also impact human thyroid regulation and are related to clinical thyroid disease, but associations appear both dose and life-stage dependent. Emerging data suggest that common alternate flame retardant chemicals may be more potent thyroid disruptors than their predecessors, which is particularly concerning given increasing levels of exposure.Potential health impacts of flame retardant chemicals are only beginning to be understood for 'legacy flame retardant chemicals' (i.e., polybrominated diphenyl ethers), and are largely unevaluated for newer-use chemicals. Cumulatively, current data suggest impact on thyroid regulation is likely, potentially implicating flame retardant chemicals in thyroid disease and cancers for which thyroid dysregulation impacts risk or prognosis.

Authors
Hoffman, K; Sosa, JA; Stapleton, HM
MLA Citation
Hoffman, K, Sosa, JA, and Stapleton, HM. "Do flame retardant chemicals increase the risk for thyroid dysregulation and cancer?." Current opinion in oncology 29.1 (January 2017): 7-13. (Review)
PMID
27755165
Source
epmc
Published In
Current Opinion in Oncology
Volume
29
Issue
1
Publish Date
2017
Start Page
7
End Page
13
DOI
10.1097/cco.0000000000000335

Predictors of urinary flame retardant concentration among pregnant women.

Organophosphate compounds are commonly used in residential furniture, electronics, and baby products as flame retardants and are also used in other consumer products as plasticizers. Although the levels of exposure biomarkers are generally higher among children and decrease with age, relatively little is known about the individual characteristics associated with higher levels of exposure. Here, we investigate urinary metabolites of several organophosphate flame retardants (PFRs) in a cohort of pregnant women to evaluate patterns of exposure.Pregnant North Carolina women (n=349) provided information on their individual characteristics (e.g. age and body mass index (BMI)) as a part of the Pregnancy Infection and Nutrition Study (2002-2005). Women also provided second trimester urine samples in which six PFR metabolites were measured using mass spectrometry methods.PFR metabolites were detected in every urine sample, with BDCIPP, DHPH, ip-PPP and BCIPHIPP detected in >80% of samples. Geometric mean concentrations were higher than what has been reported previously for similarly-timed cohorts. Women with higher pre-pregnancy BMI tended to have higher levels of urinary metabolites. For example, those classified as obese at the start of pregnancy had ip-PPP levels that were 1.52 times as high as normal weight range women (95% confidence interval: 1.23, 1.89). Women without previous children also tended to have higher urinary levels of DPHP, but lower levels of ip-PPP. In addition, we saw strong evidence of seasonal trends in metabolite concentrations (e.g. higher DPHP, BDCIPP, and BCIPHIPP in summer, and evidence of increasing ip-PPP between 2002 and 2005).Our results indicate ubiquitous exposure to PFRs among NC women in the early 2000s. Additionally, our work suggests that individual characteristics are related to exposure and that temporal variation, both seasonal and annual, may exist.

Authors
Hoffman, K; Lorenzo, A; Butt, CM; Adair, L; Herring, AH; Stapleton, HM; Daniels, JL
MLA Citation
Hoffman, K, Lorenzo, A, Butt, CM, Adair, L, Herring, AH, Stapleton, HM, and Daniels, JL. "Predictors of urinary flame retardant concentration among pregnant women." Environment international 98 (January 2017): 96-101.
PMID
27745946
Source
epmc
Published In
Environment International
Volume
98
Publish Date
2017
Start Page
96
End Page
101
DOI
10.1016/j.envint.2016.10.007

Biogas Stoves Reduce Firewood Use, Household Air Pollution, and Hospital Visits in Odisha, India.

Traditional cooking using biomass is associated with ill health, local environmental degradation, and regional climate change. Clean stoves (liquefied petroleum gas (LPG), biogas, and electric) are heralded as a solution, but few studies have demonstrated their environmental health benefits in field settings. We analyzed the impact of mainly biogas (as well as electric and LPG) stove use on social, environmental, and health outcomes in two districts in Odisha, India, where the Indian government has promoted household biogas. We established a cross-sectional observational cohort of 105 households that use either traditional mud stoves or improved cookstoves (ICS). Our multidisciplinary team conducted surveys, environmental air sampling, fuel weighing, and health measurements. We examined associations between traditional or improved stove use and primary outcomes, stratifying households by proximity to major industrial plants. ICS use was associated with 91% reduced use of firewood (p < 0.01), substantial time savings for primary cooks, a 72% reduction in PM2.5, a 78% reduction in PAH levels, and significant reductions in water-soluble organic carbon and nitrogen (p < 0.01) in household air samples. ICS use was associated with reduced time in the hospital with acute respiratory infection and reduced diastolic blood pressure but not with other health measurements. We find many significant gains from promoting rural biogas stoves in a context in which traditional stove use persists, although pollution levels in ICS households still remained above WHO guidelines.

Authors
Lewis, JJ; Hollingsworth, JW; Chartier, RT; Cooper, EM; Foster, WM; Gomes, GL; Kussin, PS; MacInnis, JJ; Padhi, BK; Panigrahi, P; Rodes, CE; Ryde, IT; Singha, AK; Stapleton, HM; Thornburg, J; Young, CJ; Meyer, JN; Pattanayak, SK
MLA Citation
Lewis, JJ, Hollingsworth, JW, Chartier, RT, Cooper, EM, Foster, WM, Gomes, GL, Kussin, PS, MacInnis, JJ, Padhi, BK, Panigrahi, P, Rodes, CE, Ryde, IT, Singha, AK, Stapleton, HM, Thornburg, J, Young, CJ, Meyer, JN, and Pattanayak, SK. "Biogas Stoves Reduce Firewood Use, Household Air Pollution, and Hospital Visits in Odisha, India." Environmental science & technology 51.1 (January 2017): 560-569.
PMID
27785914
Source
epmc
Published In
Environmental Science & Technology
Volume
51
Issue
1
Publish Date
2017
Start Page
560
End Page
569
DOI
10.1021/acs.est.6b02466

Brominated flame retardants in placental tissues: associations with infant sex and thyroid hormone endpoints.

Brominated flame retardants (BFRs) are endocrine disruptors that bioaccumulate in the placenta, but it remains unclear if they disrupt tissue thyroid hormone (TH) metabolism. Our primary goal was to investigate associations between placental BFRs, TH levels, Type 3 deiodinase (DIO3) activity and TH sulfotransferase (SULT) activities.Placenta samples collected from 95 women who delivered term (>37 weeks) infants in Durham, NC, USA (enrolled 2010-2011) were analyzed for polybrominated diphenyl ethers (PBDEs), 2,4,6-tribromophenol (2,4,6-TBP), THs (T4, T3 and rT3), and DIO3 and TH SULT activities.PBDEs and 2,4,6-TBP were detected in all placenta samples. PBDEs were higher in placental tissues from male infants compared to female infants, with 2,4,6-TBP and BDE-209 levels approximately twice as high. Among male infants, placental BDE-99 and BDE-209 were negatively associated with rT3 placental levels. For female infants, placental BDE-99 and 2,4,6-TBP were positively associated with T3 concentrations. DIO3 activity was also significantly higher in placental tissues from male infants compared to females, while 3,3'-T2 SULT activity was significantly higher in placental tissues from females compared to males. Among males, several PBDE congeners were positively correlated with T3 SULT, while BDE-99 was negatively associated with T3 SULT among females. Associations generally remained after adjustment for potential confounding by maternal age and gestational age at delivery.These results suggest BFRs accumulate in the placenta and potentially alter TH function in a sex-specific manner, a possible mechanism to explain the sex-dependent impacts of environmental exposure on children's growth and development. More research is needed to elucidate the effects of BFRs on placenta function during pregnancy, as well as the biological consequences of exposure and thyroid disruption.

Authors
Leonetti, C; Butt, CM; Hoffman, K; Hammel, SC; Miranda, ML; Stapleton, HM
MLA Citation
Leonetti, C, Butt, CM, Hoffman, K, Hammel, SC, Miranda, ML, and Stapleton, HM. "Brominated flame retardants in placental tissues: associations with infant sex and thyroid hormone endpoints." Environmental health : a global access science source 15.1 (November 25, 2016): 113-.
PMID
27884139
Source
epmc
Published In
Environmental Health
Volume
15
Issue
1
Publish Date
2016
Start Page
113
DOI
10.1186/s12940-016-0199-8

Editor's Highlight: Transplacental and Lactational Transfer of Firemaster® 550 Components in Dosed Wistar Rats.

Firemaster® 550 (FM 550) is a commercial mixture of organophosphate and brominated flame retardants currently in use as a replacement for pentaBDE. Its organophosphate components include triphenyl phosphate (TPHP) and a suite of isopropylated triarylphosphate isomers (ITPs); its brominated components include 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEH-TEBP). Taken together, these chemicals have been shown to be endocrine disrupting and potentially toxic, and human exposure to them is widespread. In this study, maternal transfer of FM 550 components, and in some cases their metabolites, was investigated in dosed Wistar rats. Gestational and lactational transfer were examined separately, with dams orally exposed to 300 or 1000 µg of FM 550 for 10 consecutive days during gestation (gestational day [GD] 9-18) or lactation (postnatal day [PND] 3-12). Levels of parent compounds were measured in fetus and whole pup tissue homogenates, and in dam and pup serum, and several metabolites were measured in dam and pup urine. EH-TBB body burdens resulting from lactational transfer were approximately 200- to 300-fold higher than those resulting from placental transfer, whereas low levels of BEH-TEBP were transferred during both lactation and gestation. TPHP and ITPs were rapidly metabolized by the dams and were not detected in whole tissue homogenates. However, diphenyl phosphate (DPHP) and mono-isopropylphenyl phenyl phosphate (ip-PPP) were detected in urine from the dosed animals. This study is the first to confirm ip-PPP as a urinary metabolite of ITPs and establish a pharmacokinetic profile of FM 550 in a mammalian model.Firemaster 550 ;: lactational transfer ;: gestational transfer; metabolites; rodent.

Authors
Phillips, AL; Chen, A; Rock, KD; Horman, B; Patisaul, HB; Stapleton, HM
MLA Citation
Phillips, AL, Chen, A, Rock, KD, Horman, B, Patisaul, HB, and Stapleton, HM. "Editor's Highlight: Transplacental and Lactational Transfer of Firemaster® 550 Components in Dosed Wistar Rats." Toxicological sciences : an official journal of the Society of Toxicology 153.2 (October 2016): 246-257.
PMID
27370412
Source
epmc
Published In
Toxicological Sciences (Elsevier)
Volume
153
Issue
2
Publish Date
2016
Start Page
246
End Page
257
DOI
10.1093/toxsci/kfw122

Results from Screening Polyurethane Foam Based Consumer Products for Flame Retardant Chemicals: Assessing Impacts on the Change in the Furniture Flammability Standards.

Flame retardant (FR) chemicals have often been added to polyurethane foam to meet required state and federal flammability standards. However, some FRs (e.g., PBDEs and TDCIPP) are associated with health hazards and are now restricted from use in some regions. In addition, California's residential furniture flammability standard (TB-117) has undergone significant amendments over the past few years, and TDCIPP has been added to California's Proposition 65 list. These events have likely led to shifts in the types of FRs used, and the products to which they are applied. To provide more information on the use of FRs in products containing polyurethane foam (PUF), we established a screening service for the general public. Participants residing in the US were allowed to submit up to 5 samples from their household for analysis, free of charge, and supplied information on the product category, labeling, and year and state of purchase. Between February 2014 and June 2016, we received 1141 PUF samples for analysis from various products including sofas, chairs, mattresses, car seats and pillows. Of these samples tested, 52% contained a FR at levels greater than 1% by weight. Tris(1,3-dichloroisopropyl)phosphate (TDCIPP) was the most common FR detected in PUF samples, and was the most common FR detected in all product categories. Analysis of the data by purchasing date suggests that the use of TDCIPP decreased in recent years, paralleled with an increase in the use of TCIPP and a nonhalogenated aryl phosphate mixture we call "TBPP." In addition, we observed significant decreases in FR applications in furniture products and child car seats, suggesting the use of additive FRs in PUF may be declining, perhaps as a reflection of recent changes to TB-117 and Proposition 65. More studies are needed to determine how these changes in FR use relate to changes in exposure among the general population.

Authors
Cooper, EM; Kroeger, G; Davis, K; Clark, CR; Ferguson, PL; Stapleton, HM
MLA Citation
Cooper, EM, Kroeger, G, Davis, K, Clark, CR, Ferguson, PL, and Stapleton, HM. "Results from Screening Polyurethane Foam Based Consumer Products for Flame Retardant Chemicals: Assessing Impacts on the Change in the Furniture Flammability Standards." Environmental science & technology 50.19 (October 2016): 10653-10660.
PMID
27552529
Source
epmc
Published In
Environmental Science & Technology
Volume
50
Issue
19
Publish Date
2016
Start Page
10653
End Page
10660
DOI
10.1021/acs.est.6b01602

Regional comparison of organophosphate flame retardant (PFR) urinary metabolites and tetrabromobenzoic acid (TBBA) in mother-toddler pairs from California and New Jersey.

Authors
Butt, CM; Hoffman, K; Chen, A; Lorenzo, A; Congleton, J; Stapleton, HM
MLA Citation
Butt, CM, Hoffman, K, Chen, A, Lorenzo, A, Congleton, J, and Stapleton, HM. "Regional comparison of organophosphate flame retardant (PFR) urinary metabolites and tetrabromobenzoic acid (TBBA) in mother-toddler pairs from California and New Jersey." Environment international 94 (September 2016): 627-634.
PMID
27397928
Source
epmc
Published In
Environment International
Volume
94
Publish Date
2016
Start Page
627
End Page
634
DOI
10.1016/j.envint.2016.06.029

Urinary biomarkers of flame retardant exposure among collegiate U.S. gymnasts.

Flame retardants are widely used in polyurethane foam materials including gymnastics safety equipment such as pit cubes and landing mats. We previously reported elevated concentrations of flame retardants in the air and dust of a U.S. gymnastics training facility and elevated PentaBDE in the serum of collegiate gymnasts. Our objective in this pilot study was to compare urinary biomarkers of exposure to other flame retardants and additives of polyurethane foam including tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), triphenyl phosphate (TPHP) and 2-ethylhexyl- 2,3,4,5-tetrabromobenzoate (EH-TBB) in samples collected from 11 collegiate gymnasts before and after a gymnastics practice (n=53 urine samples total). We identified a 50% increase in the TPHP biomarker (p=0.03) from before to after practice, a non-significant 22% increase in the TDCIPP biomarker (p=0.14) and no change for the EH-TBB biomarker. These preliminary results indicate that the gymnastics training environment can be a source of recreational exposure to flame retardants. Such exposures are likely widespread, as we identified flame retardants in 89% of foam samples collected from gyms across the U.S.

Authors
Carignan, CC; Fang, M; Stapleton, HM; Heiger-Bernays, W; McClean, MD; Webster, TF
MLA Citation
Carignan, CC, Fang, M, Stapleton, HM, Heiger-Bernays, W, McClean, MD, and Webster, TF. "Urinary biomarkers of flame retardant exposure among collegiate U.S. gymnasts." Environment international 94 (September 2016): 362-368.
PMID
27395335
Source
epmc
Published In
Environment International
Volume
94
Publish Date
2016
Start Page
362
End Page
368
DOI
10.1016/j.envint.2016.06.030

Tris(1,3-dichloro-2-propyl)phosphate Induces Genome-Wide Hypomethylation within Early Zebrafish Embryos.

Tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) is a high-production volume organophosphate-based plasticizer and flame retardant widely used within the United States. Using zebrafish as a model, the objectives of this study were to determine whether (1) TDCIPP inhibits DNA methyltransferase (DNMT) within embryonic nuclear extracts; (2) uptake of TDCIPP from 0.75 h postfertilization (hpf, 2-cell) to 2 hpf (64-cell) or 6 hpf (shield stage) leads to impacts on the early embryonic DNA methylome; and (3) TDCIPP-induced impacts on cytosine methylation are localized to CpG islands within intergenic regions. Within this study, 5-azacytidine (5-azaC, a DNMT inhibitor) was used as a positive control. Although 5-azaC significantly inhibited zebrafish DNMT, TDCIPP did not affect DNMT activity in vitro at concentrations as high as 500 μM. However, rapid embryonic uptake of 5-azaC and TDCIPP from 0.75 to 2 hpf resulted in chemical- and chromosome-specific alterations in cytosine methylation at 2 hpf. Moreover, TDCIPP exposure predominantly resulted in hypomethylation of positions outside of CpG islands and within intragenic (exon) regions of the zebrafish genome. Overall, these findings provide the foundation for monitoring DNA methylation dynamics within zebrafish as well as identifying potential associations among TDCIPP exposure, adverse health outcomes, and DNA methylation status within human populations.

Authors
Volz, DC; Leet, JK; Chen, A; Stapleton, HM; Katiyar, N; Kaundal, R; Yu, Y; Wang, Y
MLA Citation
Volz, DC, Leet, JK, Chen, A, Stapleton, HM, Katiyar, N, Kaundal, R, Yu, Y, and Wang, Y. "Tris(1,3-dichloro-2-propyl)phosphate Induces Genome-Wide Hypomethylation within Early Zebrafish Embryos." Environmental science & technology 50.18 (September 2016): 10255-10263.
PMID
27574916
Source
epmc
Published In
Environmental Science & Technology
Volume
50
Issue
18
Publish Date
2016
Start Page
10255
End Page
10263
DOI
10.1021/acs.est.6b03656

Correction to Measuring Personal Exposure to Organophosphate Flame Retardants using Silicone Wristbands and Hand Wipes.

Authors
Hammel, SC; Hoffman, K; Webster, TF; Anderson, KA; Stapleton, HM
MLA Citation
Hammel, SC, Hoffman, K, Webster, TF, Anderson, KA, and Stapleton, HM. "Correction to Measuring Personal Exposure to Organophosphate Flame Retardants using Silicone Wristbands and Hand Wipes." Environmental science & technology 50.18 (September 2016): 10291-.
PMID
27563931
Source
epmc
Published In
Environmental Science & Technology
Volume
50
Issue
18
Publish Date
2016
Start Page
10291
DOI
10.1021/acs.est.6b04169

Characterizing Flame Retardant Applications and Potential Human Exposure in Backpacking Tents.

Flame retardant (FR) chemicals are applied to products to meet flammability standards; however, exposure to some additive FRs has been shown to be associated with adverse health effects. Previous research on FR exposure has primarily focused on chemicals applied to furniture and electronics; however, camping tents sold in the United States, which often meet flammability standard CPAI-84, remain largely unstudied in regards to their chemical treatments. In this study, FRs from five brands of CPAI-84-compliant, two-person backpacking tents were measured and potential exposure was assessed. Dermal and inhalation exposure levels were assessed by collecting hand wipes from 20 volunteers before and after tent setup and by using active air samplers placed inside assembled tents, respectively. Organophosphate flame retardants (OPFRs) were the most commonly detected FR in the tent materials and included triphenyl phosphate (TPHP), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tris(2-chloroethyl)phosphate (TCEP). Levels of OPFRS measured on hand wipes were significantly higher post-tent setup compared to pre setup, and in the case of TDCIPP, levels were 29 times higher post setup. OPFRs were also detected at measurable concentrations in the air inside of treated tents. Significant, positive correlations were found between FR levels in treated textiles and measures of dermal and inhalation exposure. These results demonstrate that dermal exposure to FRs occurs from handling camping tents and that inhalation exposure will likely occur while inside a tent.

Authors
Gomes, G; Ward, P; Lorenzo, A; Hoffman, K; Stapleton, HM
MLA Citation
Gomes, G, Ward, P, Lorenzo, A, Hoffman, K, and Stapleton, HM. "Characterizing Flame Retardant Applications and Potential Human Exposure in Backpacking Tents." Environmental science & technology 50.10 (May 2016): 5338-5345.
PMID
27082445
Source
epmc
Published In
Environmental Science & Technology
Volume
50
Issue
10
Publish Date
2016
Start Page
5338
End Page
5345
DOI
10.1021/acs.est.6b00923

Development of an analytical method to quantify PBDEs, OH-BDEs, HBCDs, 2,4,6-TBP, EH-TBB, and BEH-TEBP in human serum.

Polybrominated diphenyl ethers (PBDEs) flame retardants (FRs) were phased-out in the mid-2000s (penta- and octaBDE) and 2013 (decaBDE); however, their hydroxylated metabolites (OH-BDEs) are still commonly detected in human serum. Today, novel FRs such as Firemaster® 550, a mixture that contains two brominated compounds, EH-TBB and BEH-TEBP are used as replacements for PBDEs in some applications, and there is a need to develop a comprehensive analytical method to assess exposure to both legacy PBDEs and novel FRs. This study developed a solid-phase extraction (SPE)-based method to analyze PBDEs, OH-BDEs, 2,4,6-tribromophenol (TBP), hexabromocylcododecane isomers (HBCDs), EH-TBB, and BEH-TEBP in human serum. Briefly, serum proteins were first denatured with formic acid, and then the target analytes were isolated using a SPE column. Finally, the extract was cleaned and fractioned using a silica SPE column. Method performance was assessed by spiking fetal bovine serum with 1-2 ng of the target analytes, and method accuracy was quantified by comparison to a serum Standard Reference Material (SRM). The developed method showed good recovery and accuracy for all target analytes with the exception of the very low and very high molecular weight PBDE congeners. Using this method, 43 serum samples collected from the Healthy Pregnancy, Healthy Baby Study (HPHB) cohort in Durham, NC, USA were analyzed for FRs. A novel finding was the ubiquitous detection of 2,4,6-TBP, at levels greater than the individual PBDE congeners. Furthermore, 2,4,6-TBP was positively correlated with PBDEs, suggesting that they may have a similar source of exposure, or that 2,4,6-TBP may result from metabolism of PBDEs in vivo.

Authors
Butt, CM; Miranda, ML; Stapleton, HM
MLA Citation
Butt, CM, Miranda, ML, and Stapleton, HM. "Development of an analytical method to quantify PBDEs, OH-BDEs, HBCDs, 2,4,6-TBP, EH-TBB, and BEH-TEBP in human serum." Analytical and Bioanalytical Chemistry 408.10 (April 2016): 2449-2459.
PMID
26864867
Source
epmc
Published In
Analytical and Bioanalytical Chemistry
Volume
408
Issue
10
Publish Date
2016
Start Page
2449
End Page
2459
DOI
10.1007/s00216-016-9340-3

Determination of glucuronide conjugates of hydroxyl triphenyl phosphate (OH-TPHP) metabolites in human urine and its use as a biomarker of TPHP exposure.

In vitro studies using avian hepatocytes or human liver microsomes suggest that hydroxylation is an important pathway in the metabolism of triphenyl phosphate (TPHP), a chemical used as a flame retardant and plasticizer. TPHP metabolism can lead to the formation of para(p)- and meta(m)-hydroxyl-(OH-)TPHP products as well as their glucuronide conjugates. To determine whether the TPHP hydroxylation and depuration pathway also occurs in vivo in humans, the present study developed a sensitive method for quantification of p- and m-OH-TPHP glucuronides in human urine samples. In n = 1 pooled urine sample and n = 12 individual urine samples collected from four human volunteers from Ottawa (ON, Canada), p- and m-OH-TPHP glucuronides were detectable in 13 and 9 of the 13 analyzed samples and at concentrations ranging from

Authors
Su, G; Letcher, RJ; Yu, H; Gooden, DM; Stapleton, HM
MLA Citation
Su, G, Letcher, RJ, Yu, H, Gooden, DM, and Stapleton, HM. "Determination of glucuronide conjugates of hydroxyl triphenyl phosphate (OH-TPHP) metabolites in human urine and its use as a biomarker of TPHP exposure." Chemosphere 149 (April 2016): 314-319.
PMID
26874059
Source
epmc
Published In
Chemosphere
Volume
149
Publish Date
2016
Start Page
314
End Page
319
DOI
10.1016/j.chemosphere.2016.01.114

Measuring Personal Exposure to Organophosphate Flame Retardants Using Silicone Wristbands and Hand Wipes.

Organophosphate flame retardants (PFRs) are widely used as replacements for polybrominated diphenyl ethers in consumer products. With high detection in indoor environments and increasing toxicological evidence suggesting a potential for adverse health effects, there is a growing need for reliable exposure metrics to examine individual exposures to PFRs. Silicone wristbands have been used as passive air samplers for quantifying exposure in the general population and occupational exposure to polycyclic aromatic hydrocarbons. Here we investigated the utility of silicone wristbands in measuring exposure and internal dose of PFRs through measurement of urinary metabolite concentrations. Wristbands were also compared to hand wipes as metrics of exposure. Participants wore wristbands for 5 consecutive days and collected first morning void urine samples on 3 alternating days. Urine samples were pooled across 3 days and analyzed for metabolites of the following PFRs: tris(1,3-dichloroisopropyl) phosphate (TDCIPP), tris(1-chloro-2-isopropyl) phosphate (TCIPP), triphenyl phosphate (TPHP), and monosubstituted isopropylated triaryl phosphate (mono-ITP). All four PFRs and their urinary metabolites were ubiquitously detected. Correlations between TDCIPP and TCIPP and their corresponding urinary metabolites were highly significant on the wristbands (rs = 0.5-0.65, p < 0.001), which suggest that wristbands can serve as strong predictors of cumulative, 5-day exposure and may be an improved metric compared to hand wipes.

Authors
Hammel, SC; Hoffman, K; Webster, TF; Anderson, KA; Stapleton, HM
MLA Citation
Hammel, SC, Hoffman, K, Webster, TF, Anderson, KA, and Stapleton, HM. "Measuring Personal Exposure to Organophosphate Flame Retardants Using Silicone Wristbands and Hand Wipes." Environmental Science & Technology 50.8 (April 2016): 4483-4491.
PMID
26975559
Source
epmc
Published In
Environmental Science & Technology
Volume
50
Issue
8
Publish Date
2016
Start Page
4483
End Page
4491
DOI
10.1021/acs.est.6b00030

Concentrations of polybrominated diphenyl ethers (PBDEs) and 2,4,6-tribromophenol in human placental tissues.

Legacy environmental contaminants such as polybrominated diphenyl ethers (PBDEs) are widely detected in human tissues. However, few studies have measured PBDEs in placental tissues, and there are no reported measurements of 2,4,6-tribromophenol (2,4,6-TBP) in placental tissues. Measurements of these contaminants are important for understanding potential fetal exposures, as these compounds have been shown to alter thyroid hormone regulation in vitro and in vivo. In this study, we measured a suite of PBDEs and 2,4,6-TBP in 102 human placental tissues collected between 2010 and 2011 in Durham County, North Carolina, USA. The most abundant PBDE congener detected was BDE-47, with a mean concentration of 5.09ng/g lipid (range: 0.12-141ng/g lipid; detection frequency 91%); however, 2,4,6-TBP was ubiquitously detected and present at higher concentrations with a mean concentration of 15.4ng/g lipid (range:1.31-316ng/g lipid; detection frequency 100%). BDE-209 was also detected in more than 50% of the samples, and was significantly associated with 2,4,6-TBP in placental tissues, suggesting they may have a similar source, or that 2,4,6-TBP may be a degradation product of BDE-209. Interestingly, BDE-209 and 2,4,6-TBP were negatively associated with age (rs=-0.16; p=0.10 and rs=-0.17; p=0.08, respectively). The results of this work indicate that PBDEs and 2,4,6-TBP bioaccumulate in human placenta tissue and likely contribute to prenatal exposures to these environmental contaminants. Future studies are needed to determine if these joint exposures are associated with any adverse health measures in infants and children.

Authors
Leonetti, C; Butt, CM; Hoffman, K; Miranda, ML; Stapleton, HM
MLA Citation
Leonetti, C, Butt, CM, Hoffman, K, Miranda, ML, and Stapleton, HM. "Concentrations of polybrominated diphenyl ethers (PBDEs) and 2,4,6-tribromophenol in human placental tissues." Environment international 88 (March 2016): 23-29.
PMID
26700418
Source
epmc
Published In
Environment International
Volume
88
Publish Date
2016
Start Page
23
End Page
29
DOI
10.1016/j.envint.2015.12.002

Nail polish as a source of exposure to triphenyl phosphate.

Triphenyl phosphate (TPHP) is primarily used as either a flame retardant or plasticizer, and is listed as an ingredient in nail polishes. However, the concentration of TPHP in nail polish and the extent of human exposure following applications have not been previously studied. We measured TPHP in ten different nail polish samples purchased from department stores and pharmacies in 2013-2014. Concentrations up to 1.68% TPHP by weight were detected in eight samples, including two that did not list TPHP as an ingredient. Two cohorts (n=26 participants) were recruited to assess fingernail painting as a pathway of TPHP exposure. Participants provided urine samples before and after applying one brand of polish containing 0.97% TPHP by weight. Diphenyl phosphate (DPHP), a TPHP metabolite, was then measured in urine samples (n=411) and found to increase nearly seven-fold 10-14h after fingernail painting (p<0.001). To determine relative contributions of inhalation and dermal exposure, ten participants also painted their nails and painted synthetic nails adhered to gloves on two separate occasions, and collected urine for 24h following applications. Urinary DPHP was significantly diminished when wearing gloves, suggesting that the primary exposure route is dermal. Our results indicate that nail polish may be a significant source of short-term TPHP exposure and a source of chronic exposure for frequent users or those occupationally exposed.

Authors
Mendelsohn, E; Hagopian, A; Hoffman, K; Butt, CM; Lorenzo, A; Congleton, J; Webster, TF; Stapleton, HM
MLA Citation
Mendelsohn, E, Hagopian, A, Hoffman, K, Butt, CM, Lorenzo, A, Congleton, J, Webster, TF, and Stapleton, HM. "Nail polish as a source of exposure to triphenyl phosphate." Environment international 86 (January 2016): 45-51.
PMID
26485058
Source
epmc
Published In
Environment International
Volume
86
Publish Date
2016
Start Page
45
End Page
51
DOI
10.1016/j.envint.2015.10.005

A New Perspective on Sustainable Soil Remediation-Case Study Suggests Novel Fungal Genera Could Facilitate in situ Biodegradation of Hazardous Contaminants.

Deciding upon a cost effective and sustainable method to address soil pollution is a challenge for many remedial project managers. High pressure to quickly achieve cleanup goals pushes for energy-intensive remedies that rapidly address the contaminants of concern with established technologies, often leaving little room for research and development especially for slower treatment technologies, such as bioremediation, for the more heavily polluted sites. In the present case study, new genomic approaches have been leveraged to assess fungal biostimulation potential in soils polluted with particularly persistent hydrophobic contaminants. This new approach provides insights into the genetic functions available at a given site in a way never before possible. In particular, this article presents a case study where next generation sequencing (NGS) has been used to categorize fungi in soils from the Atlantic Wood Industries Superfund site in Portsmouth, Virginia. Data suggest that original attempts to harness fungi for bioremediation may have focused on fungal genera poorly suited to survive under heavily polluted site conditions, and that more targeted approaches relying on native indigenous fungi which are better equipped to survive under site specific conditions may be more appropriate.

Authors
Czaplicki, LM; Cooper, E; Ferguson, PL; Stapleton, HM; Vilgalys, R; Gunsch, CK
MLA Citation
Czaplicki, LM, Cooper, E, Ferguson, PL, Stapleton, HM, Vilgalys, R, and Gunsch, CK. "A New Perspective on Sustainable Soil Remediation-Case Study Suggests Novel Fungal Genera Could Facilitate in situ Biodegradation of Hazardous Contaminants." Remediation (New York, N.Y.) 26.2 (January 2016): 59-72.
PMID
27917031
Source
epmc
Published In
Remediation
Volume
26
Issue
2
Publish Date
2016
Start Page
59
End Page
72
DOI
10.1002/rem.21458

Characterization and Adaptation of Anaerobic Sludge Microbial Communities Exposed to Tetrabromobisphenol A.

The increasing occurrence of tetrabromobisphenol A (TBBPA) in the environment is raising questions about its potential ecological and human health impacts. TBBPA is microbially transformed under anaerobic conditions to bisphenol A (BPA). However, little is known about which taxa degrade TBBPA and the adaptation of microbial communities exposed to TBBPA. The objectives of this study were to characterize the effect of TBBPA on microbial community structure during the start-up phase of a bench-scale anaerobic sludge reactor, and identify taxa that may be associated with TBBPA degradation. TBBPA degradation was monitored using LC/MS-MS, and the microbial community was characterized using Ion Torrent sequencing and qPCR. TBBPA was nearly completely transformed to BPA via reductive debromination in 55 days. Anaerobic reactor performance was not negatively affected by the presence of TBBPA and the bulk of the microbial community did not experience significant shifts. Several taxa showed a positive response to TBBPA, suggesting they may be associated with TBBPA degradation. Some of these taxa had been previously identified as dehalogenating bacteria including Dehalococcoides, Desulfovibrio, Propionibacterium, and Methylosinus species, but most had not previously been identified as having dehalogenating capacities. This study is the first to provide in-depth information on the microbial dynamics of anaerobic microbial communities exposed to TBBPA.

Authors
Lefevre, E; Cooper, E; Stapleton, HM; Gunsch, CK
MLA Citation
Lefevre, E, Cooper, E, Stapleton, HM, and Gunsch, CK. "Characterization and Adaptation of Anaerobic Sludge Microbial Communities Exposed to Tetrabromobisphenol A." PloS one 11.7 (January 2016): e0157622-.
PMID
27463972
Source
epmc
Published In
PloS one
Volume
11
Issue
7
Publish Date
2016
Start Page
e0157622
DOI
10.1371/journal.pone.0157622

Associations of birth outcomes with maternal polybrominated diphenyl ethers and thyroid hormones during pregnancy.

Previous research has linked polybrominated diphenyl ether (PBDE) exposure to poor birth outcomes and altered thyroid hormone levels.We examined whether maternal PBDE serum levels were associated with infant birth weight (g), head circumference (cm), birth length (cm), and birth weight percentile for gestational age. We explored the potential for a mediating role of thyroid hormone levels.During 2008-2010, we recruited 140 pregnant women in their third trimester as part of a larger clinical obstetrics study known as Healthy Pregnancy, Healthy Baby. Blood samples were collected during a routine prenatal clinic visit. Serum was analyzed for PBDEs, phenolic metabolites, and thyroid hormones. Birth outcome information was abstracted from medical records.In unadjusted models, a two-fold increase in maternal BDE 153 was associated with an average decrease in head circumference of 0.32cm (95% CI: -0.53, -0.12); however, this association was attenuated after control for maternal risk factors. BDE 47 and 99 were similarly negatively associated but with 95% confidence intervals crossing the null. Associations were unchanged in the presence of thyroid hormones.Our data suggest a potential deleterious association between maternal PBDE levels and infant head circumference; however, confirmatory studies are needed in larger sample sizes. A mediating role of thyroid hormones was not apparent.

Authors
Miranda, ML; Anthopolos, R; Wolkin, A; Stapleton, HM
MLA Citation
Miranda, ML, Anthopolos, R, Wolkin, A, and Stapleton, HM. "Associations of birth outcomes with maternal polybrominated diphenyl ethers and thyroid hormones during pregnancy." Environment international 85 (December 2015): 244-253.
PMID
26431883
Source
epmc
Published In
Environment International
Volume
85
Publish Date
2015
Start Page
244
End Page
253
DOI
10.1016/j.envint.2015.09.015

High Exposure to Organophosphate Flame Retardants in Infants: Associations with Baby Products.

Infant products containing polyurethane foam are commonly treated with organophosphate flame retardants (PFRs), including tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and triphenyl phosphate (TPHP). Infants may have greater exposure due to greater contact with these products, yet little is known about levels of exposure or the factors contributing to higher exposure. We recruited children age 2-18 months from North Carolina to investigate PFR exposure (n = 43; recruited 2014-2015). Parents provided information on potential sources and modifiers of exposure, and reported whether they owned common infant products. We measured five PFR metabolites in urine samples collected from children. TDCIPP and TPHP metabolites (bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP)) were most commonly detected (>93% detect). Other metabolites were detected infrequently (<35% detect). Although we did not observe a clear age trend for infants, BDCIPP levels were substantially higher than those reported for adults (geometric mean = 7.3 ng/mL). The number of infant products owned was strongly associated with BDCIPP; children with >16 products had BDCIPP levels that were 6.8 times those with <13 (p = 0.02). Infants attending daycare centers also had higher BDCIPP levels (3.7 times those of others; p = 0.07), suggesting time spent in this microenvironment contributes to higher exposure. In contrast, DPHP levels were not related to products owned, time in different microenvironments, or behavior.

Authors
Hoffman, K; Butt, CM; Chen, A; Limkakeng, AT; Stapleton, HM
MLA Citation
Hoffman, K, Butt, CM, Chen, A, Limkakeng, AT, and Stapleton, HM. "High Exposure to Organophosphate Flame Retardants in Infants: Associations with Baby Products." Environmental science & technology 49.24 (December 2015): 14554-14559.
PMID
26551726
Source
epmc
Published In
Environmental Science & Technology
Volume
49
Issue
24
Publish Date
2015
Start Page
14554
End Page
14559
DOI
10.1021/acs.est.5b03577

Persisting effects of a PBDE metabolite, 6-OH-BDE-47, on larval and juvenile zebrafish swimming behavior.

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants that are widely detected in the environment, biota, and humans. In mammals, PBDEs can be oxidatively metabolized to form hydroxylated polybrominated diphenyl ethers (OH-BDEs). While studies have examined behavioral deficits or alterations induced by exposure to PBDEs in both rodents and fish, no study to date has explored behavioral effects from exposure to OH-BDEs, which have been shown to have greater endocrine disrupting potential compared to PBDEs. In the present study, zebrafish (Danio rerio) were exposed during embryonic and larval development (0-6 days post fertilization, dpf) to a PBDE metabolite, 6-hydroxy, 2,2',4,4' tetrabromodiphenyl ether (10-50 nM) and then examined for short and long-term behavioral effects. Exposed zebrafish tested as larvae (6 dpf) showed an altered swimming response to light-dark transitions, exhibiting hypoactivity in light periods compared to control fish. When fish exposed from 0-6 dpf were tested as juveniles (45 dpf), they showed an increased fear response and hyperactivity in response to tests of novel environment exploration and habituation learning. These results demonstrate that early life exposure to a PBDE metabolite can have immediate or later life (more than a month after exposure) effects on activity levels, habituation, and fear/anxiety.

Authors
Macaulay, LJ; Bailey, JM; Levin, ED; Stapleton, HM
MLA Citation
Macaulay, LJ, Bailey, JM, Levin, ED, and Stapleton, HM. "Persisting effects of a PBDE metabolite, 6-OH-BDE-47, on larval and juvenile zebrafish swimming behavior." Neurotoxicology and teratology 52.Pt B (November 2015): 119-126.
PMID
25979796
Source
epmc
Published In
Neurotoxicology and Teratology
Volume
52
Issue
Pt B
Publish Date
2015
Start Page
119
End Page
126
DOI
10.1016/j.ntt.2015.05.002

Developmental toxicity of the PBDE metabolite 6-OH-BDE-47 in zebrafish and the potential role of thyroid receptor β.

6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) is both a polybrominated diphenyl ether (PBDE) flame retardant metabolite and a marine natural product. It has been identified both as a neurotoxicant in cell-based studies and as a developmental toxicant in zebrafish. However, hydroxylated PBDE metabolites are also considered thyroid hormone disruptors due to their structural similarity to endogenous thyroid hormones. The purpose of this study was to evaluate the effects of 6-OH-BDE-47 on a developmental pathway regulated by thyroid hormones in zebrafish. Morphological measurements of development (head trunk angle, otic vesicle length, and eye pigmentation) were recorded in embryos at 30h post fertilization (hpf) and detailed craniofacial morphology was examined in 4 day old larvae using cartilage staining. Exposure to 6-OH-BDE-47 resulted in severe developmental delays. A 100nM concentration resulted in a 26% decrease in head trunk angle, a 54% increase in otic vesicle length, and a 42% decrease in eye pigmentation. Similarly, altered developmental morphology was observed following thyroid receptor β morpholino knockdown, exposure to the thyroid hormone triiodothyronine (T3) or to thyroid disrupting chemicals (TDC; iopanoic acid and propylthiouracil). The threshold for lower jaw deformities and craniofacial cartilage malformations was at doses greater than 50nM. Of interest, these developmental delays and effects were rescued by microinjection of TRβ mRNA during the 1-2 cell stage. These data indicate that OH-BDEs can adversely affect early life development of zebrafish and suggest they may be impacting thyroid hormone regulation in vivo through downregulation of the thyroid hormone receptor.

Authors
Macaulay, LJ; Chen, A; Rock, KD; Dishaw, LV; Dong, W; Hinton, DE; Stapleton, HM
MLA Citation
Macaulay, LJ, Chen, A, Rock, KD, Dishaw, LV, Dong, W, Hinton, DE, and Stapleton, HM. "Developmental toxicity of the PBDE metabolite 6-OH-BDE-47 in zebrafish and the potential role of thyroid receptor β." Aquatic toxicology (Amsterdam, Netherlands) 168 (November 2015): 38-47.
PMID
26433919
Source
epmc
Published In
Aquatic Toxicology
Volume
168
Publish Date
2015
Start Page
38
End Page
47
DOI
10.1016/j.aquatox.2015.09.007

Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission

Authors
Maley, AM; Falk, KA; Hoover, L; Earlywine, EB; Seymour, MD; DeYoung, PA; Blum, A; Stapleton, HM; Peaslee, GF
MLA Citation
Maley, AM, Falk, KA, Hoover, L, Earlywine, EB, Seymour, MD, DeYoung, PA, Blum, A, Stapleton, HM, and Peaslee, GF. "Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 358 (September 2015): 21-25.
Source
crossref
Published In
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Volume
358
Publish Date
2015
Start Page
21
End Page
25
DOI
10.1016/j.nimb.2015.05.006

Effect-Directed Analysis of Human Peroxisome Proliferator-Activated Nuclear Receptors (PPARγ1) Ligands in Indoor Dust.

Agonism of human peroxisome proliferator-activated nuclear receptor gamma (PPARγ1) was recently observed in 15 of 25 samples of indoor dust extracts at environmentally relevant exposure levels. In this study, an effect-directed analysis approach was used to identify the primary contributors of PPARγ1 activity in the dust extracts. Three dust extracts showing significant PPARγ1 activity were fractionated with normal phase high-performance liquid chromatography (NP-HPLC) and each fraction was tested for PPARγ1 activity. Three dust extracts showed a similar PPARγ1 activity distribution in the NP-HPLC fractions. In most active fractions, fatty acids (FAs), including oleic acid, stearic acid, palmitic acid and myristic acid, were the primary chemicals identified using gas-chromatography mass spectrometry (GC-MS). Chemical measurements of the FAs in house dust extracts revealed a positive and significant correlation with the observed PPARγ1 activity. To test the role of FAs in the activity, a mixture of four FAs was prepared in the ratios measured in the dust samples and tested for activity. The activity of this mixture was 30-50% of the activity observed in the dust extracts, suggesting they were contributing to the observed activity, but also suggesting additional unknown compounds are likely still present in the dust extracts. To tentatively identify sources of FAs in the dust samples, FAs were quantified in human/animal hair, dead skin cells, and cooking oil. FAs were abundant in all samples and our data indicate that all of these may be sources to indoor dust.

Authors
Fang, M; Webster, TF; Stapleton, HM
MLA Citation
Fang, M, Webster, TF, and Stapleton, HM. "Effect-Directed Analysis of Human Peroxisome Proliferator-Activated Nuclear Receptors (PPARγ1) Ligands in Indoor Dust." Environmental Science & Technology 49.16 (August 2015): 10065-10073.
PMID
26172369
Source
epmc
Published In
Environmental Science & Technology
Volume
49
Issue
16
Publish Date
2015
Start Page
10065
End Page
10073
DOI
10.1021/acs.est.5b01524

Activation of Human Peroxisome Proliferator-Activated Nuclear Receptors (PPARγ1) by Semi-Volatile Compounds (SVOCs) and Chemical Mixtures in Indoor Dust.

Recently, we reported that several semi-volatile compounds (SVOCs) were competitive ligands for human peroxisome proliferator-activated nuclear receptor gamma (PPARγ1). We also observed significant binding from chemicals extracted from house dust at a concentration of 3 mg dust/mL in the dosing medium. To follow up on this study, a commercially available reporter gene assay (GeneBLAzer PPARγ1 non-DA Assay, Invitrogen) was used to investigate the PPARγ1 activation by 30 common SVOCs (e.g., brominated flame retardants, organophosphates, and phthalates) and in house dust extracts. Twenty-eight SVOCs or their metabolites were either confirmed or for the first time were found to be weak or moderate PPARγ1 agonists. We also observed activation in 15 of 25 dust extracts examined. In some cases, activation was as high as 50% of the activation of the positive control (rosiglitazone). Furthermore, there was a significant and positive correlation (r = 0.7, p < 0.003) between data collected from this reporter assay and our previous ligand binding assay tested on the same dust extracts. Our results suggest that many SVOCs ubiquitous in house dust, or their metabolites, are possible PPARγ1 agonists. Also, chemical mixtures present in house dust at environmentally relevant levels can activate human PPARγ1 in a transfected cell culture system, and further research is needed to identify the primary chemical(s) driving this activity.

Authors
Fang, M; Webster, TF; Stapleton, HM
MLA Citation
Fang, M, Webster, TF, and Stapleton, HM. "Activation of Human Peroxisome Proliferator-Activated Nuclear Receptors (PPARγ1) by Semi-Volatile Compounds (SVOCs) and Chemical Mixtures in Indoor Dust." Environmental science & technology 49.16 (August 2015): 10057-10064.
PMID
26172262
Source
epmc
Published In
Environmental Science & Technology
Volume
49
Issue
16
Publish Date
2015
Start Page
10057
End Page
10064
DOI
10.1021/acs.est.5b01523

Disruption of type 2 iodothyronine deiodinase activity in cultured human glial cells by polybrominated diphenyl ethers.

Polybrominated diphenyl ether (PBDE) flame retardants are endocrine disruptors and suspected neurodevelopmental toxicants. While the direct mechanisms of neurodevelopmental toxicity have not been fully elucidated, it is conceivable that alterations in thyroid hormone levels in the developing brain may contribute to these effects. Cells within the brain locally convert thyroxine (T4) to the biologically active triiodothyronine (T3) through the action of the selenodeiodinase type 2 iodothyronine deiodinase (DIO2). Previous studies have demonstrated that PBDEs can alter hepatic deiodinase activity both in vitro and in vivo; however, the effects of PBDEs on the deiodinase isoforms expressed in the brain are not well understood. Here, we studied the effects of several individual PBDEs and hydroxylated metabolites (OH-BDEs) on DIO2 activity in astrocytes, a specialized glial cell responsible for production of more than 50% of the T3 required by the brain. Primary human astrocytes and H4 glioma cells were exposed to individual PBDEs or OH-BDEs at concentrations up to 5 μM. BDE-99 decreased DIO2 activity by 50% in primary astrocyte cells and by up to 80% in the H4 cells at doses of ≥500 nM. 3-OH-BDE-47, 6-OH-BDE-47, and 5'-OH-BDE-99 also decreased DIO2 activity in cultured H4 glioma cells by 45-80% at doses of approximately 1-5 μM. Multiple mechanisms appear to contribute to the decreased DIO2 activity, including weakened expression of DIO2 mRNA, competitive inhibition of DIO2, and enhanced post-translational degradation of DIO2. We conclude that decreases in DIO2 activity caused by exposure to PBDEs may play a role in the neurodevelopmental deficits caused by these toxicants.

Authors
Roberts, SC; Bianco, AC; Stapleton, HM
MLA Citation
Roberts, SC, Bianco, AC, and Stapleton, HM. "Disruption of type 2 iodothyronine deiodinase activity in cultured human glial cells by polybrominated diphenyl ethers." Chemical research in toxicology 28.6 (June 2, 2015): 1265-1274.
PMID
26004626
Source
epmc
Published In
Chemical Research in Toxicology
Volume
28
Issue
6
Publish Date
2015
Start Page
1265
End Page
1274
DOI
10.1021/acs.chemrestox.5b00072

Gene transcription, metabolite and lipid profiling in eco-indicator daphnia magna indicate diverse mechanisms of toxicity by legacy and emerging flame-retardants.

The use of chemical flame-retardants (FR) in consumer products has steadily increased over the last 30 years. Toxicity data exist for legacy FRs such as pentabromodiphenyl ether (pentaBDE), but less is known about effects of new formulations. To address this issue, the toxicity of seven FR chemicals and formulations was assessed on the freshwater crustacean Daphnia magna. Acute 48-h nominal LC50 values for penta- and octabromodiphenyl ether (pentaBDE, octaBDE), Firemaster 550 (FM550), Firemaster BZ-54 (BZ54), bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), triphenyl phosphate (TPhP), and nonbrominated BEH-TEBP analog bis(2-ethylhexyl) phthalate (BEHP) ranged from 0.058 mg/L (pentaBDE) to 3.96 mg/L (octaBDE). mRNA expression, (1)H NMR-based metabolomic and lipidomic profiling at 1/10 LC50 revealed distinct patterns of molecular response for each exposure, suggesting pentaPBDE affects transcription and translation, octaBDE and BEH-TEBP affect glycosphingolipid biosynthesis and BZ54 affects Wnt and Hedgehog signal pathways as well as glycosaminoglycan degradation. Brominated components of FM550 (i.e., BZ54) were significantly higher in Daphnia after 48 h following 1/10 LC50 exposure. FM550 elicited significant mRNA changes at five concentrations across a range from 1/10(6) LC50 to 1/2 LC50. Analyses suggest FM550 impairs nutrient utilization or uptake in Daphnia.

Authors
Scanlan, LD; Loguinov, AV; Teng, Q; Antczak, P; Dailey, KP; Nowinski, DT; Kornbluh, J; Lin, XX; Lachenauer, E; Arai, A; Douglas, NK; Falciani, F; Stapleton, HM; Vulpe, CD
MLA Citation
Scanlan, LD, Loguinov, AV, Teng, Q, Antczak, P, Dailey, KP, Nowinski, DT, Kornbluh, J, Lin, XX, Lachenauer, E, Arai, A, Douglas, NK, Falciani, F, Stapleton, HM, and Vulpe, CD. "Gene transcription, metabolite and lipid profiling in eco-indicator daphnia magna indicate diverse mechanisms of toxicity by legacy and emerging flame-retardants." Environmental science & technology 49.12 (June 2015): 7400-7410.
PMID
25985095
Source
epmc
Published In
Environmental Science & Technology
Volume
49
Issue
12
Publish Date
2015
Start Page
7400
End Page
7410
DOI
10.1021/acs.est.5b00977

Fate of flame retardants and the antimicrobial agent triclosan in planted and unplanted biosolid-amended soils.

A comprehensive understanding of the fate of contaminant-laden biosolids is needed to fully evaluate the environmental impacts of biosolid land application. The present study examined the fate of several flame retardants and triclosan in biosolid-amended soil in a 90-d greenhouse experiment. Objectives included evaluating the persistence of these compounds in soil, their phytoaccumulation potential by alfalfa (Medicago sativa), and potential degradation reactions. Concentrations of the polybrominated diphenyl ether (PBDE) congeners BDE-47 and BDE-209 and the antimicrobial triclosan declined significantly over time in biosolid-amended soil planted with alfalfa and then reached a steady state by day 28. In contrast, no significant losses of those analytes were observed from soil in nonvegetated pots. The amount of an analyte lost from vegetated soil ranged from 43% for the flame retardant di(2-ethylhexyl)-2,3,4,5-tetrabromophthalate to 61% for triclosan and was significantly and negatively related to the log octanol-water partition coefficient. Alfalfa roots and shoots were monitored for the compounds, but no clear evidence of phytoaccumulation was observed. Methyl triclosan formation was observed in the biosolid-amended soils during the study period, indicating in situ biotransformation of triclosan. The present study demonstrates that, although they are highly recalcitrant, PBDEs, selected alternate brominated flame retardants, and triclosan are capable of undergoing dissipation from biosolid-amended soils in the presence of plants.

Authors
Davis, EF; Gunsch, CK; Stapleton, HM
MLA Citation
Davis, EF, Gunsch, CK, and Stapleton, HM. "Fate of flame retardants and the antimicrobial agent triclosan in planted and unplanted biosolid-amended soils." Environmental toxicology and chemistry 34.5 (May 2015): 968-976.
PMID
25546022
Source
epmc
Published In
Environmental Toxicology & Chemistry
Volume
34
Issue
5
Publish Date
2015
Start Page
968
End Page
976
DOI
10.1002/etc.2854

In Vitro Metabolism of the Flame Retardant Triphenyl Phosphate in Chicken Embryonic Hepatocytes and the Importance of the Hydroxylation Pathway

Authors
Su, G; Letcher, RJ; Crump, D; Gooden, DM; Stapleton, HM
MLA Citation
Su, G, Letcher, RJ, Crump, D, Gooden, DM, and Stapleton, HM. "In Vitro Metabolism of the Flame Retardant Triphenyl Phosphate in Chicken Embryonic Hepatocytes and the Importance of the Hydroxylation Pathway." Environmental Science & Technology Letters 2.4 (April 14, 2015): 100-104.
Source
crossref
Published In
Environmental Science and Technology Letters
Volume
2
Issue
4
Publish Date
2015
Start Page
100
End Page
104
DOI
10.1021/acs.estlett.5b00041

Triphenyl phosphate-induced developmental toxicity in zebrafish: potential role of the retinoic acid receptor.

Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) - a high-production volume organophosphate-based flame retardant - results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) - a nuclear receptor that regulates vertebrate heart morphogenesis - in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5-72h post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) - a primary TPP metabolite - were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) - a major target gene for RA-induced RAR activation in zebrafish - and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may interact with human RARs, we then exposed Chinese hamster ovary cells stably transfected with chimeric human RARα-, RARβ-, or RARγ to TPP in the presence of RA, and found that TPP significantly inhibited RA-induced luciferase activity in a concentration-dependent manner. Overall, our findings suggest that zebrafish RARs may be involved in mediating TPP-induced developmental toxicity, a mechanism of action that may have relevance to humans.

Authors
Isales, GM; Hipszer, RA; Raftery, TD; Chen, A; Stapleton, HM; Volz, DC
MLA Citation
Isales, GM, Hipszer, RA, Raftery, TD, Chen, A, Stapleton, HM, and Volz, DC. "Triphenyl phosphate-induced developmental toxicity in zebrafish: potential role of the retinoic acid receptor." Aquatic toxicology (Amsterdam, Netherlands) 161 (April 2015): 221-230.
PMID
25725299
Source
epmc
Published In
Aquatic Toxicology
Volume
161
Publish Date
2015
Start Page
221
End Page
230
DOI
10.1016/j.aquatox.2015.02.009

Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding potential of several major flame retardants, their metabolites, and chemical mixtures in house dust.

Accumulating evidence has shown that some environmental contaminants can alter adipogenesis and act as obesogens. Many of these contaminants act via the activation of the peroxisome proliferator-activated receptor γ (PPARγ) nuclear receptor.Our goal was to determine the PPARγ ligand binding potency of several major flame retardants, including polybrominated diphenyl ethers (PBDEs), halogenated phenols and bisphenols, and their metabolites. Ligand binding activity of indoor dust and its bioactivated extracts were also investigated.We used a commercially available fluorescence polarization ligand binding assay to investigate the binding potency of flame retardants and dust extracts to human PPARγ ligand-binding domain. Rosiglitazone was used as a positive control.Most of the tested compounds exhibited dose-dependent binding to PPARγ. Mono(2-ethylhexyl) tetrabromophthalate, halogenated bisphenols and phenols, and hydroxylated PBDEs were found to be potent PPARγ ligands. The most potent compound was 3-OH-BDE-47, with an IC50 (concentration required to reduce effect by 50%) of 0.24 μM. The extent of halogenation and the position of the hydroxyl group strongly affected binding. In the dust samples, 21 of the 24 samples tested showed significant binding potency at a concentration of 3 mg dust equivalent (DEQ)/mL. A 3-16% increase in PPARγ binding potency was observed following bioactivation of the dust using rat hepatic S9 fractions.Our results suggest that several flame retardants are potential PPARγ ligands and that metabolism may lead to increased binding affinity. The PPARγ binding activity of house dust extracts at levels comparable to human exposure warrants further studies into agonistic or antagonistic activities and their potential health effects.

Authors
Fang, M; Webster, TF; Ferguson, PL; Stapleton, HM
MLA Citation
Fang, M, Webster, TF, Ferguson, PL, and Stapleton, HM. "Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding potential of several major flame retardants, their metabolites, and chemical mixtures in house dust." Environmental health perspectives 123.2 (February 2015): 166-172.
PMID
25314719
Source
epmc
Published In
Environmental health perspectives
Volume
123
Issue
2
Publish Date
2015
Start Page
166
End Page
172
DOI
10.1289/ehp.1408522

Monitoring indoor exposure to organophosphate flame retardants: hand wipes and house dust.

Organophosphate flame retardants (PFRs) are becoming popular replacements for the phased-out polybrominated diphenyl ether (PBDE) mixtures, and they are now commonly detected in indoor environments. However, little is known about human exposure to PFRs because they cannot be easily measured in blood or serum.To investigate relationships between the home environment and internal exposure, we assessed associations between two PFRs, tris(1,3-dichloropropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP), in paired hand wipe and dust samples and concentrations of their metabolites in urine samples (n = 53). We also assessed short-term variation in urinary metabolite concentrations (n = 11 participants; n = 49 samples).Adult volunteers in North Carolina, USA, completed questionnaires and provided urine, hand wipe, and household dust samples. PFRs and PBDEs were measured in hand wipes and dust, and bis(1,3-dichloropropyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), metabolites of TDCIPP and TPHP, were measured in urine.TDCIPP and TPHP were detected frequently in hand wipes and dust (> 86.8%), with geometric mean concentrations exceeding those of PBDEs. Unlike PBDEs, dust TDCIPP and TPHP levels were not associated with hand wipes. However, hand wipe levels were associated with urinary metabolites. Participants with the highest hand wipe TPHP mass, for instance, had DPHP levels 2.42 times those of participants with the lowest levels (95% CI: 1.23, 4.77). Women had higher levels of DPHP, but not BDCIPP. BDCIPP and DPHP concentrations were moderately to strongly reliable over 5 consecutive days (intraclass correlation coefficients of 0.81 and 0.51, respectively).PFR exposures are widespread, and hand-to-mouth contact or dermal absorption may be important pathways of exposure.

Authors
Hoffman, K; Garantziotis, S; Birnbaum, LS; Stapleton, HM
MLA Citation
Hoffman, K, Garantziotis, S, Birnbaum, LS, and Stapleton, HM. "Monitoring indoor exposure to organophosphate flame retardants: hand wipes and house dust." Environmental health perspectives 123.2 (February 2015): 160-165.
PMID
25343780
Source
epmc
Published In
Environmental health perspectives
Volume
123
Issue
2
Publish Date
2015
Start Page
160
End Page
165
DOI
10.1289/ehp.1408669

Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding potential of several major flame retardants, their metabolites, and chemical mixtures in house dust

© 2015, Public Health Services, US Dept of Health and Human Services. All rights reserved. Background: Accumulating evidence has shown that some environmental contaminants can alter adipogenesis and act as obesogens. Many of these contaminants act via the activation of the peroxisome proliferator-activated receptor γ (PPARγ) nuclear receptor. oBjectives: Our goal was to determine the PPARγ ligand binding potency of several major flame retardants, including polybrominated diphenyl ethers (PBDEs), halogenated phenols and bisphenols, and their metabolites. Ligand binding activity of indoor dust and its bioactivated extracts were also investigated. Methods: We used a commercially available fluorescence polarization ligand binding assay to investigate the binding potency of flame retardants and dust extracts to human PPARγ ligand-binding domain. Rosiglitazone was used as a positive control. results: Most of the tested compounds exhibited dose-dependent binding to PPARγ. Mono(2-ethyl hexyl) tetrabromophthalate, halogenated bisphenols and phenols, and hydroxylated PBDEs were found to be potent PPARγ ligands. The most potent compound was 3-OH-BDE-47, with an IC 50 (concentration required to reduce effect by 50%) of 0.24 μM. The extent of halogenation and the position of the hydroxyl group strongly affected binding. In the dust samples, 21 of the 24 samples tested showed significant binding potency at a concentration of 3 mg dust equivalent (DEQ)/mL. A 3–16% increase in PPARγ binding potency was observed following bioactivation of the dust using rat hepatic S9 fractions. conclusion: Our results suggest that several flame retardants are potential PPARγ ligands and that metabolism may lead to increased binding affinity. The PPARγ binding activity of house dust extracts at levels comparable to human exposure warrants further studies into agonistic or antagonistic activities and their potential health effects.

Authors
Fang, M; Webster, TF; Ferguson, PL; Stapleton, HM
MLA Citation
Fang, M, Webster, TF, Ferguson, PL, and Stapleton, HM. "Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding potential of several major flame retardants, their metabolites, and chemical mixtures in house dust." Environmental Health Perspectives 123.2 (January 1, 2015): 166-172.
Source
scopus
Published In
Environmental health perspectives
Volume
123
Issue
2
Publish Date
2015
Start Page
166
End Page
172
DOI
10.1289/ehp.1408522.

Effects of elevated nitrate on endocrine function in Atlantic salmon, Salmo salar

Authors
Freitag, AR; Thayer, LR; Leonetti, C; Stapleton, HM; Hamlin, HJ
MLA Citation
Freitag, AR, Thayer, LR, Leonetti, C, Stapleton, HM, and Hamlin, HJ. "Effects of elevated nitrate on endocrine function in Atlantic salmon, Salmo salar." Aquaculture 436 (January 2015): 8-12.
Source
crossref
Published In
Aquaculture
Volume
436
Publish Date
2015
Start Page
8
End Page
12
DOI
10.1016/j.aquaculture.2014.10.041

Polybrominated diphenyl ether congener, BDE-47, impairs insulin sensitivity in mice with liver-specific Pten deficiency.

BACKGROUND: The potential health effects of polybrominated diphenyl ethers (PBDEs) that are widely used as flame-retardants in consumer products have been attributed, in part, to their endocrine disrupting properties. The purpose of this study is to examine the in vivo effects of an early exposure to PBDEs on the development of insulin resistance in mice. RESULTS: The metabolic consequences of BDE-47 in mice with varying insulin sensitivities secondary to liver-specific activation of Akt (Pten (fl/fl);Alb (Cre)) and mTORC1 (Tsc1 (fl/fl);Alb (Cre)) as well as wild-type littermates, were studied. BDE-47, a dominant congener of PBDE, was given daily (1 mg/kg/day) for six weeks by oral gavage in young mice following weaning. At the end of the exposure, there were no significant differences in total body, liver, or white adipose tissue weights between the BDE-47-treated vs. DMSO-treated mice for each respective genotype. Metabolic studies revealed significant impairment in insulin sensitivity in the BDE-47-treated Pten (fl/fl);Alb (Cre) mice, but not in wild-type or Tsc1 (fl/fl);Alb (Cre) mice. This was not accompanied by significant alterations in plasma insulin levels or hepatic triglyceride accumulation in the Pten (fl/fl);Alb (Cre) mice. The mean plasma BDE-47 level in the wild-type mice was 11.7 ± 2.9 ng/g (wet weight). CONCLUSIONS: Our findings indicate that BDE-47 exposure during the early post-natal period induces a mild disturbance in glucose metabolism in susceptible mice with increased baseline insulin sensitivity. These results suggest an interaction between BDE-47 and genetic factors that regulate insulin signaling, which may result in long-term consequences.

Authors
McIntyre, RL; Kenerson, HL; Subramanian, S; Wang, SA; Kazami, M; Stapleton, HM; Yeung, RS
MLA Citation
McIntyre, RL, Kenerson, HL, Subramanian, S, Wang, SA, Kazami, M, Stapleton, HM, and Yeung, RS. "Polybrominated diphenyl ether congener, BDE-47, impairs insulin sensitivity in mice with liver-specific Pten deficiency." BMC obesity 2 (January 2015): 3-.
PMID
26217518
Source
epmc
Published In
BMC Obesity
Volume
2
Publish Date
2015
Start Page
3
DOI
10.1186/s40608-014-0031-3

Persisting effects of a PBDE metabolite, 6-OH-BDE-47, on larval and juvenile zebrafish swimming behavior

Authors
Macaulay, LJ; Bailey, JM; Levin, ED; Stapleton, HM
MLA Citation
Macaulay, LJ, Bailey, JM, Levin, ED, and Stapleton, HM. "Persisting effects of a PBDE metabolite, 6-OH-BDE-47, on larval and juvenile zebrafish swimming behavior." NEUROTOXICOLOGY AND TERATOLOGY 52 (2015): 119-126.
Source
wos-lite
Published In
Neurotoxicology and Teratology
Volume
52
Publish Date
2015
Start Page
119
End Page
126
DOI
10.1016/j.ntr.2015.05.002

Flame retardant associations between children's handwipes and house dust.

Polybrominated diphenyl ether (PBDE), flame retardants (FRs) have been ubiquitously detected at high concentrations in indoor environments; however, with their recent phase-out, more attention is being focused on measurements of exposure to alternative FRs such as organophosphate FRs (OPFRs). In our previous research, we found that PBDE residues measured on children's handwipes were a strong predictor of serum PBDE levels. Here we build upon this research to examine longitudinal changes in PBDEs in indoor dust and children's handwipes, and explore the associations between handwipes and dust for alternative FRs. Children from our previous study were re-contacted after approximately two years and new samples of indoor dust and handwipes were collected. PBDE dust-levels were significantly correlated between two different sampling rounds separated by two years; however, PBDE levels in handwipes were not correlated, perhaps suggesting that the sources of PBDEs remained relatively constant in the home, but that behavioral differences in children are changing with age and influencing handwipe levels. OPFRs [i.e. tris(1,3-dichloroisopropyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP)], 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB, also known as TBB), di(2-ethylhexyl) tetrabromophthalate (BEH-TEBP, also known as TBPH), and 1,2,5,6,9,10-hexabromocyclododecane (HBCD) were also ubiquitously detected in house dust samples and geometric mean levels were similar to PBDE levels, or higher in the case of the OPFRs. Significant associations between handwipes and house dust were observed for these alternative FRs, particularly for EH-TBB (rs=0.54; p<0.001). Increasing house dust levels and age were associated with higher levels of FRs in handwipes, and high hand washing frequency (>5 times d(-1)) was associated with lower FR levels in handwipes. Overall these data suggest that exposure to these alternative FRs will be similar to PBDE exposure, and the influence of hand-to-mouth behavior in children's exposure needs to be further examined to better estimate exposure potential.

Authors
Stapleton, HM; Misenheimer, J; Hoffman, K; Webster, TF
MLA Citation
Stapleton, HM, Misenheimer, J, Hoffman, K, and Webster, TF. "Flame retardant associations between children's handwipes and house dust." Chemosphere 116 (December 2014): 54-60.
PMID
24485814
Source
epmc
Published In
Chemosphere
Volume
116
Publish Date
2014
Start Page
54
End Page
60
DOI
10.1016/j.chemosphere.2013.12.100

Effect-directed analysis of Elizabeth River porewater: developmental toxicity in zebrafish (Danio rerio).

In the present study, effect-directed analysis was used to identify teratogenic compounds in porewater collected from a Superfund site along the Elizabeth River estuary (VA, USA). Zebrafish (Danio rerio) exposed to the porewater displayed acute developmental toxicity and cardiac teratogenesis, presumably because of elevated sediment levels of polycyclic aromatic hydrocarbons (PAHs) from historical creosote use. Pretreatment of porewater with several physical and chemical particle removal methods revealed that colloid-bound chemicals constituted the bulk of the observed toxicity. Size-exclusive chromatography and normal-phase high-performance liquid chromatography were used to fractionate Elizabeth River porewater. Acute toxicity of porewater extracts and extract fractions was assessed as the pericardial area in embryonic zebrafish. The most toxic fraction contained several known aryl hydrocarbon receptor (AhR) agonists (e.g., 1,2-benzofluorene and 1,2-benzanthracene) and cytochrome P450 A1 (CPY1A) inhibitors (e.g., dibenzothiophene and fluoranthene). The second most toxic fraction contained known AhR agonists (e.g., benzo[a]pyrene and indeno[1,2,3-cd]pyrene). Addition of a CYP1A inhibitor, fluoranthene, increased toxicity in all active porewater fractions, suggesting synergism between several contaminants present in porewaters. The results indicate that the observed acute toxicity associated with Elizabeth River porewater results from high concentrations of AhR agonistic PAHs and mixture effects related to interactions between compounds co-occurring at the Elizabeth River site. However, even after extensive fractionation and chemical characterization, it remains plausible that some active compounds in Elizabeth River porewater remain unidentified.

Authors
Fang, M; Getzinger, GJ; Cooper, EM; Clark, BW; Garner, LVT; Di Giulio, RT; Ferguson, PL; Stapleton, HM
MLA Citation
Fang, M, Getzinger, GJ, Cooper, EM, Clark, BW, Garner, LVT, Di Giulio, RT, Ferguson, PL, and Stapleton, HM. "Effect-directed analysis of Elizabeth River porewater: developmental toxicity in zebrafish (Danio rerio)." Environmental toxicology and chemistry 33.12 (December 2014): 2767-2774.
PMID
25196082
Source
epmc
Published In
Environmental Toxicology & Chemistry
Volume
33
Issue
12
Publish Date
2014
Start Page
2767
End Page
2774
DOI
10.1002/etc.2738

Developmental exposure to organophosphate flame retardants elicits overt toxicity and alters behavior in early life stage zebrafish (Danio rerio).

Organophosphate flame retardants (OPFRs) are common replacements for the phased-out polybrominated diphenyl ethers (PBDEs) and have been detected at high concentrations in environmental samples. OPFRs are structurally similar to organophosphate pesticides and may adversely affect the developing nervous system. This study evaluated the overt toxicity, uptake, and neurobehavioral effects of tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tris (2-chloroethyl) phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCPP), and tris (2,3-dibromopropyl) phosphate (TDBPP) in early life stage zebrafish. Chlorpyrifos was used as a positive control. For overt toxicity and neurobehavioral assessments, zebrafish were exposed from 0 to 5 days postfertilization (dpf). Hatching, death, or malformations were evaluated daily. Teratogenic effects were scored by visual examination on 6 dpf. To evaluate uptake and metabolism, zebrafish were exposed to 1 µM of each organophosphate (OP) flame retardant and collected on 1 and 5 dpf to monitor accumulation. Larval swimming activity was measured in 6 dpf larvae to evaluate neurobehavioral effects of exposures below the acute toxicity threshold. TDBPP elicited the greatest toxicity at >1 µM. TDCPP and chlorpyrifos were overtly toxic at concentrations ≥10 µM, TCEP, and TCPP were not overtly toxic at the doses tested. Tissue concentrations increased with increasing hydrophobicity of the parent chemical after 24 h exposures. TDCPP and TDBPP and their respective metabolites were detected in embryos on 5 dpf. For all chemicals tested, developmental exposures that were not overtly toxic significantly altered larval swimming activity. These data indicate that OPFRs adversely affect development of early life stage zebrafish.

Authors
Dishaw, LV; Hunter, DL; Padnos, B; Padilla, S; Stapleton, HM
MLA Citation
Dishaw, LV, Hunter, DL, Padnos, B, Padilla, S, and Stapleton, HM. "Developmental exposure to organophosphate flame retardants elicits overt toxicity and alters behavior in early life stage zebrafish (Danio rerio)." Toxicological sciences : an official journal of the Society of Toxicology 142.2 (December 2014): 445-454.
PMID
25239634
Source
epmc
Published In
Toxicological Sciences (Elsevier)
Volume
142
Issue
2
Publish Date
2014
Start Page
445
End Page
454
DOI
10.1093/toxsci/kfu194

Exposures, mechanisms, and impacts of endocrine-active flame retardants.

This review summarizes the endocrine and neurodevelopmental effects of two current-use additive flame retardants (FRs), tris (1,3-dichloro-isopropyl) phosphate (TDCPP) and Firemaster(®) 550 (FM 550), and the recently phased-out polybrominated diphenyl ethers (PBDEs), all of which were historically or are currently used in polyurethane foam applications. Use of these chemicals in consumer products has led to widespread exposure in indoor environments. PBDEs and their hydroxylated metabolites appear to primarily target the thyroid system, likely due to their structural similarity to endogenous thyroid hormones. In contrast, much less is known about the toxicity of TDCPP and FM 550. However, recent in vitro and in vivo studies suggest that both should be considered endocrine disruptors as studies have linked TDCPP exposure with changes in circulating hormone levels, and FM 550 exposure with changes in adipogenic and osteogenic pathways.

Authors
Dishaw, LV; Macaulay, LJ; Roberts, SC; Stapleton, HM
MLA Citation
Dishaw, LV, Macaulay, LJ, Roberts, SC, and Stapleton, HM. "Exposures, mechanisms, and impacts of endocrine-active flame retardants." Current opinion in pharmacology 19 (December 2014): 125-133. (Review)
PMID
25306433
Source
epmc
Published In
Current Opinion in Pharmacology
Volume
19
Publish Date
2014
Start Page
125
End Page
133
DOI
10.1016/j.coph.2014.09.018

Evaluating the bioaccessibility of flame retardants in house dust using an in vitro Tenax bead-assisted sorptive physiologically based method.

Exposure to house dust is a significant source of exposure to flame retardant chemicals (FRs), particularly in the US. Given the high exposure there is a need to understand the bioaccessibility of FRs from dust. In this study, Tenax beads (TA) encapsulated within a stainless steel insert were used as an adsorption sink to estimate the dynamic absorption of a suite of FRs commonly detected in indoor dust samples (n = 17), and from a few polyurethane foam samples for comparison. Organophosphate flame retardants (OPFRs) had the highest estimated bioaccessibility (∼ 80%) compared to brominated compounds (e.g., PBDEs), and values generally decreased with increasing Log K(ow), with <30% bioaccessibility measured for BDE209. These measurements were in very close agreement with reported PBDE bioavailability measures from an in vivo rat exposure study using indoor dust. The bioaccessibility of very hydrophobic FRs (Log K(ow) > 6) in foam was much less than that in house dust, and increasing bioaccessibility was observed with decreasing particle size. In addition, we examined the stability of more labile FRs containing ester groups (e.g., OPFRs and 2-ethylhexyl-tetrabromo-benzoate (EH-TBB)) in a mock-digestive fluid matrix. No significant changes in the OPFR concentrations were observed in this fluid; however, EH-TBB was found to readily hydrolyze to tetrabromobenzoic acid (TBBA) in the intestinal fluid in the presence of lipases. In conclusion, our study demonstrates that the bioaccessibility and stability of FRs following ingestion varies by chemical and sample matrix and thus should be considered in exposure assessments.

Authors
Fang, M; Stapleton, HM
MLA Citation
Fang, M, and Stapleton, HM. "Evaluating the bioaccessibility of flame retardants in house dust using an in vitro Tenax bead-assisted sorptive physiologically based method." Environmental science & technology 48.22 (November 5, 2014): 13323-13330.
PMID
25330458
Source
epmc
Published In
Environmental Science & Technology
Volume
48
Issue
22
Publish Date
2014
Start Page
13323
End Page
13330
DOI
10.1021/es503918m

Ligand binding and activation of PPARγ by Firemaster® 550: effects on adipogenesis and osteogenesis in vitro.

The use of alternative flame retardants has increased since the phase out of pentabromodiphenyl ethers (pentaBDEs). One alternative, Firemaster® 550 (FM550), induces obesity in rats. Triphenyl phosphate (TPP), a component of FM550, has a structure similar to that of organotins, which are obesogenic in rodents.We tested the hypothesis that components of FM550 are biologically active peroxisome proliferator-activated receptor γ (PPARγ) ligands and estimated indoor exposure to TPP.FM550 and its components were assessed for ligand binding to and activation of human PPARγ. Solvent mapping was used to model TPP in the PPARγ binding site. Adipocyte and osteoblast differentiation were assessed in bone marrow multipotent mesenchymal stromal cell models. We estimated exposure of children to TPP using a screening-level indoor exposure model and house dust concentrations determined previously.FM550 bound human PPARγ, and binding appeared to be driven primarily by TPP. Solvent mapping revealed that TPP interacted with binding hot spots within the PPARγ ligand binding domain. FM550 and its organophosphate components increased human PPARγ1 transcriptional activity in a Cos7 reporter assay and induced lipid accumulation and perilipin protein expression in BMS2 cells. FM550 and TPP diverted osteogenic differentiation toward adipogenesis in primary mouse bone marrow cultures. Our estimates suggest that dust ingestion is the major route of exposure of children to TPP.Our findings suggest that FM550 components bind and activate PPARγ. In addition, in vitro exposure initiated adipocyte differentiation and antagonized osteogenesis. TPP likely is a major contributor to these biological actions. Given that TPP is ubiquitous in house dust, further studies are warranted to investigate the health effects of FM550.

Authors
Pillai, HK; Fang, M; Beglov, D; Kozakov, D; Vajda, S; Stapleton, HM; Webster, TF; Schlezinger, JJ
MLA Citation
Pillai, HK, Fang, M, Beglov, D, Kozakov, D, Vajda, S, Stapleton, HM, Webster, TF, and Schlezinger, JJ. "Ligand binding and activation of PPARγ by Firemaster® 550: effects on adipogenesis and osteogenesis in vitro." Environmental health perspectives 122.11 (November 2014): 1225-1232.
PMID
25062436
Source
epmc
Published In
Environmental health perspectives
Volume
122
Issue
11
Publish Date
2014
Start Page
1225
End Page
1232
DOI
10.1289/ehp.1408111

Response to comment on "Determining the ecological impacts of organic contaminants in biosolids using a high-throughput colorimetric denitrification assay: a case study with antimicrobial agents".

Authors
Holzem, RM; Stapleton, HM; Gunsch, CK
MLA Citation
Holzem, RM, Stapleton, HM, and Gunsch, CK. "Response to comment on "Determining the ecological impacts of organic contaminants in biosolids using a high-throughput colorimetric denitrification assay: a case study with antimicrobial agents"." Environmental science & technology 48.20 (October 2014): 12470-12471. (Letter)
PMID
25271770
Source
epmc
Published In
Environmental Science & Technology
Volume
48
Issue
20
Publish Date
2014
Start Page
12470
End Page
12471
DOI
10.1021/es5036305

Urinary tetrabromobenzoic acid (TBBA) as a biomarker of exposure to the flame retardant mixture Firemaster® 550.

Firemaster® 550 (FM550) is commonly added to residential furniture to reduce its flammability. Recent toxicological evidence suggests that FM550 may be endocrine disrupting and obesogenic.Our objectives were to develop methods to assess exposure to FM550 in human populations and to identify potential routes of exposure.Using mass spectrometry methods, we developed a method to measure 2,3,4,5-tetrabromobenzoic acid (TBBA), a urinary metabolite of the major brominated FM550 component 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB). The method was applied to a cohort of adult volunteers (n = 64). Participants completed questionnaires, provided urine and handwipe samples, and collected dust samples from their homes. We measured TBB and the other major brominated FM550 component, bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), in paired dust and handwipe samples.TBBA was detected in 72.4% of urine samples. Although TBBA is a rapidly formed metabolite, analyses indicated moderate temporal reliability (interclass correlation coefficient = 0.56; 95% confidence interval: 0.46, 0.66). TBB and TBPH were detected frequently in dust samples [geometric mean (GM) = 315.1 and 364.7 ng/g, respectively] and in handwipes (GM = 31.4 and 23.4 ng, respectively). Levels of TBB and TBPH in dust were positively correlated with levels in handwipes. In addition, levels of TBB in handwipes were positively correlated with urinary TBBA. Results suggest frequent hand washing may reduce the mass of TBB on participants' hands and reduce urinary TBBA levels.Cumulatively, our data indicate that exposures to FM550 are widespread and that the home environment may be an important source of exposure. Urinary TBBA provides a potentially useful biomarker of FM550 exposure for epidemiologic studies.

Authors
Hoffman, K; Fang, M; Horman, B; Patisaul, HB; Garantziotis, S; Birnbaum, LS; Stapleton, HM
MLA Citation
Hoffman, K, Fang, M, Horman, B, Patisaul, HB, Garantziotis, S, Birnbaum, LS, and Stapleton, HM. "Urinary tetrabromobenzoic acid (TBBA) as a biomarker of exposure to the flame retardant mixture Firemaster® 550." Environmental Health Perspectives 122.9 (September 2014): 963-969.
PMID
24823833
Source
epmc
Published In
Environmental health perspectives
Volume
122
Issue
9
Publish Date
2014
Start Page
963
End Page
969
DOI
10.1289/ehp.1308028

Metabolites of organophosphate flame retardants and 2-ethylhexyl tetrabromobenzoate in urine from paired mothers and toddlers.

As a result of the polybrominated diphenyl ether (PBDE) ban in the mid-2000s, the chemical flame retardant market has moved toward alterative compounds including chlorinated alkyl and nonchlorinated aryl organophosphate flame retardants (OPFRs) as well as aromatic brominated compounds such as Firemaster 550 (FM550). Recent studies have shown that the OPFRs and Firemaster 550 components are frequently detected in polyurethane foams and in indoor dust. Some OPFRs are considered carcinogenic and/or neurodevelopmental toxicants, and children's exposure to these compounds is a concern. OPFRs are readily metabolized and excreted in the urine as their dialkyl and diaryl compounds which function as biomarkers for OPFR exposure. Limited research has shown that adults are broadly exposed to OPFRs, but nothing is known about children's exposure. Similarly, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), a FM550 component, is metabolized to tetrabromobenzoic acid (TBBA). The current study measured levels of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(1-chloro-2-propyl) phosphate (BCIPP), diphenyl phosphate (DPHP), 2 alkylated DPHPs, and TBBA in urine collected in 2013 from 21 US mother-toddler pairs. BDCIPP, DPHP, and ip-DPHP were detected in 100%, 98%, and 96% of all individuals, whereas BCIPP and tert-butyl-DPHP (tb-DPHP) were only detected in 8% and 13%. Further, TBBA was detected in 27% of adults but 70% of children. Overall, children had higher urinary levels of BDCIPP, DPHP, ip-DPHP, and TBBA as compared to their mothers, suggesting higher exposure. For example, on average, BDCIPP levels in children were 4.9 times those of mothers. BDCIPP and DPHP levels in mother's urine were also significantly correlated with levels in children's urine, suggesting similar exposure routes, likely in the home environment. Various potential predictors of OPFR exposure were assessed using a questionnaire. In children some predictors of hand-mouth exposure were associated with elevated BDCIPP and DPHP levels (e.g., less frequent hand washing for BDCIPP). Overall, these trends are consistent with higher flame retardant levels in children as a result of increased hand-mouth behavior and elevated dust exposure.

Authors
Butt, CM; Congleton, J; Hoffman, K; Fang, M; Stapleton, HM
MLA Citation
Butt, CM, Congleton, J, Hoffman, K, Fang, M, and Stapleton, HM. "Metabolites of organophosphate flame retardants and 2-ethylhexyl tetrabromobenzoate in urine from paired mothers and toddlers." Environmental science & technology 48.17 (September 2014): 10432-10438.
PMID
25090580
Source
epmc
Published In
Environmental Science & Technology
Volume
48
Issue
17
Publish Date
2014
Start Page
10432
End Page
10438
DOI
10.1021/es5025299

A rapid cytoplasmic mechanism for PI3 kinase regulation by the nuclear thyroid hormone receptor, TRβ, and genetic evidence for its role in the maturation of mouse hippocampal synapses in vivo.

Several rapid physiological effects of thyroid hormone on mammalian cells in vitro have been shown to be mediated by the phosphatidylinositol 3-kinase (PI3K), but the molecular mechanism of PI3K regulation by nuclear zinc finger receptor proteins for thyroid hormone and its relevance to brain development in vivo have not been elucidated. Here we show that, in the absence of hormone, the thyroid hormone receptor TRβ forms a cytoplasmic complex with the p85 subunit of PI3K and the Src family tyrosine kinase, Lyn, which depends on two canonical phosphotyrosine motifs in the second zinc finger of TRβ that are not conserved in TRα. When hormone is added, TRβ dissociates and moves to the nucleus, and phosphatidylinositol (3, 4, 5)-trisphosphate production goes up rapidly. Mutating either tyrosine to a phenylalanine prevents rapid signaling through PI3K but does not prevent the hormone-dependent transcription of genes with a thyroid hormone response element. When the rapid signaling mechanism was blocked chronically throughout development in mice by a targeted point mutation in both alleles of Thrb, circulating hormone levels, TRβ expression, and direct gene regulation by TRβ in the pituitary and liver were all unaffected. However, the mutation significantly impaired maturation and plasticity of the Schaffer collateral synapses on CA1 pyramidal neurons in the postnatal hippocampus. Thus, phosphotyrosine-dependent association of TRβ with PI3K provides a potential mechanism for integrating regulation of development and metabolism by thyroid hormone and receptor tyrosine kinases.

Authors
Martin, NP; Marron Fernandez de Velasco, E; Mizuno, F; Scappini, EL; Gloss, B; Erxleben, C; Williams, JG; Stapleton, HM; Gentile, S; Armstrong, DL
MLA Citation
Martin, NP, Marron Fernandez de Velasco, E, Mizuno, F, Scappini, EL, Gloss, B, Erxleben, C, Williams, JG, Stapleton, HM, Gentile, S, and Armstrong, DL. "A rapid cytoplasmic mechanism for PI3 kinase regulation by the nuclear thyroid hormone receptor, TRβ, and genetic evidence for its role in the maturation of mouse hippocampal synapses in vivo." Endocrinology 155.9 (September 2014): 3713-3724.
PMID
24932806
Source
epmc
Published In
Endocrinology
Volume
155
Issue
9
Publish Date
2014
Start Page
3713
End Page
3724
DOI
10.1210/en.2013-2058

In vitro assessment of human nuclear hormone receptor activity and cytotoxicity of the flame retardant mixture FM 550 and its triarylphosphate and brominated components.

Firemaster(®) 550 (FM 550) is a mixture of brominated and triarylphosphate flame retardants used in polyurethane foam-based products. The primary components are also used in numerous other applications and are thus common household and industrial contaminants. Our previous animal studies suggested that FM 550 exposure may alter metabolism and cause weight gain. Employing human nuclear receptor (NR) luciferase reporter assays, the goal of this study was to evaluate the agonist actions of FM 550 and its constituent compounds at NRs with known roles in establishing or regulating energy balance. FM 550 was found to have significant agonist activity only at the master regulator of adipocyte differentiation PPARγ. As a result, the concentration response relationships and relative activities of FM 550 at PPARγ were investigated in more detail with the contribution of each chemical component defined and compared to the activities of the prototypical PPARγ environmental ligands triphenyltin and tributyltin. The resulting data indicated that the primary metabolic disruptive effects of FM 550 were likely mediated by the activity of the triarylphosphates at PPARγ, and have identified TPP as a candidate metabolic disruptor that also acts as a cytotoxicant.

Authors
Belcher, SM; Cookman, CJ; Patisaul, HB; Stapleton, HM
MLA Citation
Belcher, SM, Cookman, CJ, Patisaul, HB, and Stapleton, HM. "In vitro assessment of human nuclear hormone receptor activity and cytotoxicity of the flame retardant mixture FM 550 and its triarylphosphate and brominated components." Toxicology letters 228.2 (July 2014): 93-102.
PMID
24786373
Source
epmc
Published In
Toxicology Letters
Volume
228
Issue
2
Publish Date
2014
Start Page
93
End Page
102
DOI
10.1016/j.toxlet.2014.04.017

Activation of Human Peroxisome Proliferator-Activated Receptor-Gamma (PPAR gamma) by House Dust Extracts

Authors
Wolf, CJ; Fang, M; Stapleton, HM; Abbott, BD
MLA Citation
Wolf, CJ, Fang, M, Stapleton, HM, and Abbott, BD. "Activation of Human Peroxisome Proliferator-Activated Receptor-Gamma (PPAR gamma) by House Dust Extracts." BIRTH DEFECTS RESEARCH PART A-CLINICAL AND MOLECULAR TERATOLOGY 100.5 (May 2014): 393-393.
Source
wos-lite
Published In
Birth Defects Research Part A: Clinical and Molecular Teratology
Volume
100
Issue
5
Publish Date
2014
Start Page
393
End Page
393

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
epmc
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environ Int 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women.

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Authors
Hoffman, K; Daniels, JL; Stapleton, HM
MLA Citation
Hoffman, K, Daniels, JL, and Stapleton, HM. "Urinary metabolites of organophosphate flame retardants and their variability in pregnant women." Environment international 63 (February 2014): 169-172.
PMID
24316320
Source
pubmed
Published In
Environment International
Volume
63
Publish Date
2014
Start Page
169
End Page
172
DOI
10.1016/j.envint.2013.11.013

Flame Retardant Applications in Camping Tents and Potential Exposure.

Concern has mounted over health effects caused by exposure to flame retardant additives used in consumer products. Significant research efforts have focused particularly on exposure to polybrominated diphenyl ethers (PBDEs) used in furniture and electronic applications. However, little attention has focused on applications in textiles, particularly textiles meeting a flammability standard known as CPAI-84. In this study, we investigated flame retardant applications in camping tents that met CPAI-84 standards by analyzing 11 samples of tent fabrics for chemical flame retardant additives. Furthermore, we investigated potential exposure by collecting paired samples of tent wipes and hand wipes from 27 individuals after tent setup. Of the 11 fabric samples analyzed, 10 contained flame retardant additives, which included tris(1,3-dichloroisopropyl) phosphate (TDCPP), decabromodiphenyl ether (BDE-209), triphenyl phosphate, and tetrabromobisphenol-A. Flame retardant concentrations were discovered to be as high as 37.5 mg/g (3.8% by weight) in the tent fabric samples, and TDCPP and BDE-209 were the most frequently detected in these samples. We also observed a significant association between TDCPP levels in tent wipes and those in paired hand wipes, suggesting that human contact with the tent fabric material leads to the transfer of the flame retardant to the skin surface and human exposure. These results suggest that direct contact with flame retardant-treated textiles may be a source of exposure. Future studies will be needed to better characterize exposure, including via inhalation and dermal sorption from air.

Authors
Keller, AS; Raju, NP; Webster, TF; Stapleton, HM
MLA Citation
Keller, AS, Raju, NP, Webster, TF, and Stapleton, HM. "Flame Retardant Applications in Camping Tents and Potential Exposure." Environmental science & technology letters 1.2 (February 2014): 152-155.
PMID
24804279
Source
epmc
Published In
Environmental Science and Technology Letters
Volume
1
Issue
2
Publish Date
2014
Start Page
152
End Page
155
DOI
10.1021/ez400185y

Determining the ecological impacts of organic contaminants in biosolids using a high-throughput colorimetric denitrification assay: a case study with antimicrobial agents.

Land application accounts for ∼ 50% of wastewater solid disposal in the United States. Still, little is known regarding the ecological impacts of nonregulated contaminants found in biosolids. Because of the myriad of contaminants, there is a need for a rapid, high-throughput method to evaluate their ecotoxicity. Herein, we developed a novel assay that measures denitrification inhibition in a model denitrifier, Paracoccus denitrificans Pd1222. Two common (triclosan and triclocarban) and four emerging (2,4,5 trichlorophenol, 2-benzyl-4-chlorophenol, 2-chloro-4-phenylphenol, and bis(5-chloro-2-hydroxyphenyl)methane) antimicrobial agents found in biosolids were analyzed. Overall, the assay was reproducible and measured impacts on denitrification over 3 orders of magnitude exposure. The lowest observable adverse effect concentrations (LOAECs) were 1.04 μM for triclosan, 3.17 μM for triclocarban, 0.372 μM for bis-(5-chloro-2-hydroxyphenyl)methane, 4.89 μM for 2-chloro-4-phenyl phenol, 45.7 μM for 2-benzyl-4-chorophenol, and 50.6 μM for 2,4,5-trichlorophenol. Compared with gene expression and cell viability based methods, the denitrification assay was more sensitive and resulted in lower LOAECs. The increased sensitivity, low cost, and high-throughput adaptability make this method an attractive alternative for meeting the initial testing regulatory framework for the Federal Insecticide, Fungicide, and Rodenticide Act, and recommended for the Toxic Substances Control Act, in determining the ecotoxicity of biosolids-derived emerging contaminants.

Authors
Holzem, RM; Stapleton, HM; Gunsch, CK
MLA Citation
Holzem, RM, Stapleton, HM, and Gunsch, CK. "Determining the ecological impacts of organic contaminants in biosolids using a high-throughput colorimetric denitrification assay: a case study with antimicrobial agents." Environmental science & technology 48.3 (January 23, 2014): 1646-1655.
PMID
24410196
Source
epmc
Published In
Environmental Science & Technology
Volume
48
Issue
3
Publish Date
2014
Start Page
1646
End Page
1655
DOI
10.1021/es404431k

Tissue distribution and thyroid hormone effects on mRNA abundance for membrane transporters Mct8, Mct10, and organic anion-transporting polypeptides (Oatps) in a teleost fish

Many of the actions of thyroid hormones (THs) occur via TH binding to intracellular receptors. Although it was long thought that THs diffused passively across plasma membranes, it is now recognized that cellular entry is mediated by a variety of membrane transporter proteins. In this study, we identified cDNAs encoding the TH transporters monocarboxylate transferases 8 (mct8) and 10 (mct10) as well as eight distinct organic anion-transporting polypeptide (oatp) proteins from fathead minnow (Pimephales promelas). Analysis of the tissue distribution of transporter mRNAs revealed that mct8 and mct10 transcripts were both abundant in liver, but also present at lower levels in brain, gonad and other tissues. Transcripts encoding oatp1c1 were highly abundant in brain, liver and gonad, and exhibited significant sex differences in the liver and gonad. Treatment of adult male minnows with 3,5,3'-triiodothyronine (T 3 ) or the goitrogen methimazole altered gene transcript abundance for several transporters. Fish given exogenous T 3 had reduced mct8 and oapt1c1 mRNA levels in the liver compared to methimazole-treated fish. In the brain, transcripts for mct8, mct10, oatp2b1, and oatp3a1 were each reduced in abundance in fish wit h elevated T 3 . As a whole, these results provide evidence that TH status influences the transcriptional dynamics of mct8, mct10 and several Oatp genes including oatp1c1 in teleost fish. © 2013 Elsevier Inc.

Authors
Muzzio, AM; Noyes, PD; Stapleton, HM; Lema, SC
MLA Citation
Muzzio, AM, Noyes, PD, Stapleton, HM, and Lema, SC. "Tissue distribution and thyroid hormone effects on mRNA abundance for membrane transporters Mct8, Mct10, and organic anion-transporting polypeptides (Oatps) in a teleost fish." Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology 167 (January 1, 2014): 77-89.
PMID
24113777
Source
scopus
Published In
Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology
Volume
167
Publish Date
2014
Start Page
77
End Page
89
DOI
10.1016/j.cbpa.2013.09.019

Flame retardant associations between children's handwipes and house dust

© 2014 Elsevier Ltd. Polybrominated diphenyl ether (PBDE), flame retardants (FRs) have been ubiquitously detected at high concentrations in indoor environments; however, with their recent phase-out, more attention is being focused on measurements of exposure to alternative FRs such as organophosphate FRs (OPFRs). In our previous research, we found that PBDE residues measured on children's handwipes were a strong predictor of serum PBDE levels. Here we build upon this research to examine longitudinal changes in PBDEs in indoor dust and children's handwipes, and explore the associations between handwipes and dust for alternative FRs. Children from our previous study were re-contacted after approximately two years and new samples of indoor dust and handwipes were collected. PBDE dust-levels were significantly correlated between two different sampling rounds separated by two years; however, PBDE levels in handwipes were not correlated, perhaps suggesting that the sources of PBDEs remained relatively constant in the home, but that behavioral differences in children are changing with age and influencing handwipe levels. OPFRs [i.e. tris(1,3-dichloroisopropyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP)], 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB, also known as TBB), di(2-ethylhexyl) tetrabromophthalate (BEH-TEBP, also known as TBPH), and 1,2,5,6,9,10-hexabromocyclododecane (HBCD) were also ubiquitously detected in house dust samples and geometric mean levels were similar to PBDE levels, or higher in the case of the OPFRs. Significant associations between handwipes and house dust were observed for these alternative FRs, particularly for EH-TBB (r s =0.54; p < 0.001). Increasing house dust levels and age were associated with higher levels of FRs in handwipes, and high hand washing frequency ( > 5timesd -1 ) was associated with lower FR levels in handwipes. Overall these data suggest that exposure to these alternative FRs will be similar to PBDE exposure, and the influence of hand-to-mouth behavior in children's exposure needs to be further examined to better estimate exposure potential.

Authors
Stapleton, HM; Misenheimer, J; Hoffman, K; Webster, TF
MLA Citation
Stapleton, HM, Misenheimer, J, Hoffman, K, and Webster, TF. "Flame retardant associations between children's handwipes and house dust." Chemosphere 116 (January 1, 2014): 54-60.
Source
scopus
Published In
Chemosphere
Volume
116
Publish Date
2014
Start Page
54
End Page
60
DOI
10.1016/j.chemosphere.2013.12.100

Rapid method for the measurement of circulating thyroid hormones in low volumes of teleost fish plasma by LC-ESI/MS/MS.

Thyroid hormones are critical regulators of normal development and physiological functioning in all vertebrates. Radioimmunoassay (RIA) approaches have been the method of choice for measuring circulating levels of thyroid hormones in vertebrates. While sensitive, RIA-based approaches only allow for a single analyte measurement per assay, can lack concordance across platforms and laboratories, and can be prone to analytical interferences especially when used with fish plasma. Ongoing advances in liquid chromatography tandem mass spectrometry (LC/MS/MS) have led to substantial decreases in detection limits for thyroid hormones and other biomolecules in complex matrices, including human plasma. Despite these advances, current analytical approaches do not allow for the measurement of native thyroid hormone in teleost fish plasma by mass spectrometry and continue to rely on immunoassay. In this study, we developed a new method that allows for the rapid extraction and simultaneous measurement of total T4 (TT4) and total T3 (TT3) in low volumes (50 μL) of fish plasma by LC/MS/MS. Methods were optimized initially in plasma from rainbow trout (Oncorhynchus mykiss) and applied to plasma from other teleost fishes, including fathead minnows (Pimephales promelas), mummichogs (Fundulus heteroclitus), sockeye salmon (Oncorhynchus nerka), and coho salmon (Oncorhynchus kisutch). Validation of method performance with T4- and T3-spiked rainbow trout plasma at 2 and 4 ng/mL produced mean recoveries ranging from 82 to 95 % and 97 to 105 %, respectively. Recovery of (13)C12-T4 internal standard in plasma extractions was: 99 ± 1.8 % in rainbow trout, 85 ± 11 % in fathead minnow, 73 ± 5.0 % in mummichog, 73 ± 1.7 % in sockeye salmon, and 80 ± 8.4 % in coho salmon. While absolute levels of thyroid hormones measured in identical plasma samples by LC/MS/MS and RIA varied depending on the assay used, T4/T3 ratios were generally consistent across both techniques. Less variability was measured among samples subjected to LC/MS/MS suggesting a more precise estimate of thyroid hormone homeostasis in the species targeted. Overall, a sensitive and reproducible method was established that takes advantage of LC/MS/MS techniques to rapidly measure TT4 and TT3 with negligible interferences in low volumes of plasma across a variety of teleost fishes.

Authors
Noyes, PD; Lema, SC; Roberts, SC; Cooper, EM; Stapleton, HM
MLA Citation
Noyes, PD, Lema, SC, Roberts, SC, Cooper, EM, and Stapleton, HM. "Rapid method for the measurement of circulating thyroid hormones in low volumes of teleost fish plasma by LC-ESI/MS/MS." Anal Bioanal Chem 406.3 (January 2014): 715-726.
PMID
24343452
Source
pubmed
Published In
Analytical and Bioanalytical Chemistry
Volume
406
Issue
3
Publish Date
2014
Start Page
715
End Page
726
DOI
10.1007/s00216-013-7528-3

The PBDE metabolite 6-OH-BDE 47 affects melanin pigmentation and THRβ MRNA expression in the eye of zebrafish embryos.

Polybrominated diphenyl ethers and their hydroxyl-metabolites (OH-BDEs) are commonly detected contaminants in human serum in the US population. They are also considered to be endocrine disruptors, and are specifically known to affect thyroid hormone regulation. In this study, we investigated and compared the effects of a PBDE and its OH-BDE metabolite on developmental pathways regulated by thyroid hormones using zebrafish as a model. Exposure to 6-OHBDE 47 (10-100 nM), but not BDE 47 (1-50 μM), led to decreased melanin pigmentation and increased apoptosis in the retina of zebrafish embryos in a concentration-dependent manner in short-term exposures (4 - 30 hours). Six-OH-BDE 47 exposure also significantly decreased thyroid hormone receptor β (THRβ) mRNA expression, which was confirmed using both RT-PCR and in situ hybridization (whole mount and paraffin- section). Interestingly, exposure to the native thyroid hormone, triiodothyronine (T3) also led to similar responses: decreased THRβ mRNA expression, decreased melanin pigmentation and increased apoptosis, suggesting that 6-OH-BDE 47 may be acting as a T3 mimic. To further investigate short-term effects that may be regulated by THRβ, experiments using a morpholino gene knock down and THRβ mRNA over expression were conducted. Knock down of THRβ led to decreases in melanin pigmentation and increases in apoptotic cells in the eye of zebrafish embryos, similar to exposure to T3 and 6-OH-BDE 47, but THRβ mRNA overexpression rescued these effects. Histological analysis of eyes at 22 hpf from each group revealed that exposure to T3 or to 6-OH-BDE 47 was associated with a decrease of melanin and diminished proliferation of cells in layers of retina near the choroid. This study suggests that 6-OH-BDE 47 disrupts the activity of THRβ in early life stages of zebrafish, and warrants further studies on effects in developing humans.

Authors
Dong, W; Macaulay, LJ; Kwok, KW; Hinton, DE; Ferguson, PL; Stapleton, HM
MLA Citation
Dong, W, Macaulay, LJ, Kwok, KW, Hinton, DE, Ferguson, PL, and Stapleton, HM. "The PBDE metabolite 6-OH-BDE 47 affects melanin pigmentation and THRβ MRNA expression in the eye of zebrafish embryos." Endocrine disruptors (Austin, Tex.) 2.1 (January 2014).
PMID
25767823
Source
epmc
Published In
Endocrine Disruptors
Volume
2
Issue
1
Publish Date
2014

Prenatal dexamethasone augments the neurobehavioral teratology of chlorpyrifos: significance for maternal stress and preterm labor.

Glucocorticoids are the consensus treatment given in preterm labor and are also elevated by maternal stress; organophosphate exposures are virtually ubiquitous, so human developmental coexposures to these two agents are common. This study explores how prenatal dexamethasone exposure modifies the neurobehavioral teratology of chlorpyrifos, one of the most widely used organophosphates. We administered dexamethasone to pregnant rats on gestational days 17-19 at a standard therapeutic dose (0.2 mg/kg); offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1 mg/kg) that produces barely-detectable (<10%) inhibition of brain cholinesterase activity. Dexamethasone did not alter brain chlorpyrifos concentrations, nor did either agent alone or in combination affect brain thyroxine levels. Assessments were carried out from adolescence through adulthood encompassing T-maze alternation, Figure 8 maze (locomotor activity, habituation), novelty-suppressed feeding and novel object recognition tests. For behaviors where chlorpyrifos or dexamethasone individually had small effects, the dual exposure produced larger, significant effects that reflected additivity (locomotor activity, novelty-suppressed feeding, novel object recognition). Where the individual effects were in opposite directions or were restricted to only one agent, we found enhancement of chlorpyrifos' effects by prenatal dexamethasone (habituation). Finally, for behaviors where controls displayed a normal sex difference in performance, the combined treatment either eliminated or reversed the difference (locomotor activity, novel object recognition). Combined exposure to dexamethasone and chlorpyrifos results in a worsened neurobehavioral outcome, providing a proof-of-principle that prenatal glucocorticoids can create a subpopulation with enhanced vulnerability to environmental toxicants.

Authors
Levin, ED; Cauley, M; Johnson, JE; Cooper, EM; Stapleton, HM; Ferguson, PL; Seidler, FJ; Slotkin, TA
MLA Citation
Levin, ED, Cauley, M, Johnson, JE, Cooper, EM, Stapleton, HM, Ferguson, PL, Seidler, FJ, and Slotkin, TA. "Prenatal dexamethasone augments the neurobehavioral teratology of chlorpyrifos: significance for maternal stress and preterm labor." Neurotoxicol Teratol 41 (January 2014): 35-42.
PMID
24177596
Source
pubmed
Published In
Neurotoxicology and Teratology
Volume
41
Publish Date
2014
Start Page
35
End Page
42
DOI
10.1016/j.ntt.2013.10.004

Flame retardant exposure among collegiate United States gymnasts

Gymnastics training facilities contain large volumes of polyurethane foam, a material that often contains additive flame retardants such as PentaBDE. While investigations of human exposure to flame retardants have focused on the general population, potentially higher than background exposures may occur in gymnasts and certain occupational groups. Our objectives were to compare PentaBDE body burden among gymnasts to the general United States population and characterize flame retardants levels in gym equipment, air, and dust. We recruited 11 collegiate female gymnasts (ages 18-22) from one gym in the eastern United States. The geometric mean (GM) concentration of BDE-153 in gymnast sera (32.5 ng/g lipid) was 4-6.5 times higher than in the general United States population groups. Median concentrations of PentaBDE, TBB, and TBPH in paired handwipe samples were 2-3 times higher after practice compared to before, indicating the gymnasts contacted these flame retardants during practice. GM concentrations of PentaBDE, TBB, and TBPH were 1-3 orders of magnitude higher in gym air and dust than in residences. Our findings suggest that these collegiate gymnasts experienced higher exposures to PentaBDE flame retardants compared to the general United States population and that gymnasts may also have increased exposure to other additive flame retardants used in polyurethane foam such as TBB and TBPH. © 2013 American Chemical Society.

Authors
Carignan, CC; Heiger-Bernays, W; McClean, MD; Roberts, SC; Stapleton, HM; Sjödin, A; Webster, TF
MLA Citation
Carignan, CC, Heiger-Bernays, W, McClean, MD, Roberts, SC, Stapleton, HM, Sjödin, A, and Webster, TF. "Flame retardant exposure among collegiate United States gymnasts." Environmental Science and Technology 47.23 (December 3, 2013): 13848-13856.
PMID
24195753
Source
scopus
Published In
Environmental Science & Technology
Volume
47
Issue
23
Publish Date
2013
Start Page
13848
End Page
13856
DOI
10.1021/es4037868

Inhibition of thyroid hormone sulfotransferase activity by brominated flame retardants and halogenated phenolics.

Many halogenated organic contaminants (HOCs) are considered endocrine disruptors and affect the hypothalamic-pituitary-thyroid axis, often by interfering with circulating levels of thyroid hormones (THs). We investigated one potential mechanism for TH disruption, inhibition of sulfotransferase activity. One of the primary roles of TH sulfation is to support the regulation of biologically active T3 through the formation of inactive THs. We investigated TH sulfotransferase inhibition by 14 hydroxylated polybrominated diphenyl ethers (OH BDEs), BDE 47, triclosan, and fluorinated, chlorinated, brominated, and iodinated analogues of 2,4,6-trihalogenated phenol and bisphenol A (BPA). A new mass spectrometry-based method was also developed to measure the formation rates of 3,3'-T2 sulfate (3,3'-T2S). Using pooled human liver cytosol, we investigated the influence of these HOCs on the sulfation of 3,3'-T2, a major substrate for TH sulfation. For the formation of 3,3'-T2S, the Michaelis constant (Km) was 1070 ± 120 nM and the Vmax was 153 ± 6.6 pmol min(-1) (mg of protein)(-1). All chemicals investigated inhibited sulfotransferase activity with the exception of BDE 47. The 2,4,6-trihalogenated phenols were the most potent inhibitors followed by the OH BDEs and then halogenated BPAs. The IC50 values for the OH BDEs were primarily in the low nanomolar range, which may be environmentally relevant. In silico molecular modeling techniques were also used to simulate the binding of OH BDE to SULT1A1. This study suggests that some HOCs, including antimicrobial chemicals and metabolites of flame retardants, may interfere with TH regulation through inhibition of sulfotransferase activity.

Authors
Butt, CM; Stapleton, HM
MLA Citation
Butt, CM, and Stapleton, HM. "Inhibition of thyroid hormone sulfotransferase activity by brominated flame retardants and halogenated phenolics." Chem Res Toxicol 26.11 (November 18, 2013): 1692-1702.
PMID
24089703
Source
pubmed
Published In
Chemical Research in Toxicology
Volume
26
Issue
11
Publish Date
2013
Start Page
1692
End Page
1702
DOI
10.1021/tx400342k

Exploratory analysis of urinary metabolites of phosphorus-containing flame retardants in relation to markers of male reproductive health.

The use of phosphorus-containing flame retardants (PFRs) has increased over the past decade. Widespread human exposure has been reported, but information on the safety or potential health risks of PFRs is lacking. We assessed the relationship between urinary concentrations of two PFR metabolites [bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPHP)] and semen quality, sperm motion parameters, and serum hormone levels in 33 men. BDCPP and DPHP concentrations were significantly greater in urine samples collected in the afternoon compared to those collected in the morning (p <0.05). In multivariable models, a number of statistically significant or suggestive associations were observed between the reproductive health measures and both PFR metabolites. While the study was limited by a small sample size, these results warrant further investigation in a larger study population. Additional studies on sources, pathways, and routes of PFR exposure, along with research on toxicokinetics and exposure measure utility, are also needed.

Authors
Meeker, JD; Cooper, EM; Stapleton, HM; Hauser, R
MLA Citation
Meeker, JD, Cooper, EM, Stapleton, HM, and Hauser, R. "Exploratory analysis of urinary metabolites of phosphorus-containing flame retardants in relation to markers of male reproductive health." Endocrine disruptors (Austin, Tex.) 1.1 (October 2013): e26306-.
PMID
24795899
Source
epmc
Published In
Endocrine Disruptors
Volume
1
Issue
1
Publish Date
2013
Start Page
e26306
DOI
10.4161/endo.26306

Compound- and mixture-specific differences in resistance to polycyclic aromatic hydrocarbons and PCB-126 among Fundulus heteroclitus subpopulations throughout the Elizabeth River estuary (Virginia, USA).

Atlantic killifish (Fundulus heteroclitus) inhabiting the Atlantic Wood Industries Superfund Site (Elizabeth River, Portsmouth, VA, USA) are resistant to the acute toxicity and cardiac teratogenesis caused by high levels of polycyclic aromatic hydrocarbons (PAHs) from creosote. The resistance is linked to down regulation of the aryl hydrocarbon receptor (AHR) pathway. We investigated the association between CYP1 activity, as a marker of potential AHR pathway suppression, and contaminant resistance in killifish subpopulations from sites throughout the estuary that varied significantly in PAH contamination level. Adult killifish and sediments were collected from seven sites across approximately 13.7 km in river length within the estuary and from a nearby reference site. Sediment PAH levels were determined using gas chromatography mass spectrometry. Embryos obtained via manual spawning were exposed to individual AHR agonists and PAH mixtures 24 h post fertilization (hpf); CYP1 activity was determined by in ovo ethoxyresorufin-o-deethylase (EROD) at 96 hpf, and cardiac deformity severity was scored at 144 hpf. The total PAH levels measured among the sites varied from approximately 200 to 125,000 ng/g dry sediment. Overall, the resistance to teratogenesis was strongest in the subpopulations from sites in or closest to the major PAH contamination sites, but even embryos from less-contaminated sites within the Elizabeth River demonstrated at least partial resistance to many challenges. Surprisingly, all of the subpopulations tested were highly resistant to PCB-126 (3,3',4,4',5-pentachlorobiphenyl). However, the degree of CYP1 activity response varied significantly among subpopulations and did not always correlate strongly with resistance to teratogenesis; some subpopulations resisted the cardiac teratogenesis caused by the challenges at doses that still elicited strong EROD induction. Our results suggest that there is variation in the adaptive phenotype exhibited by laboratory-spawned embryos from killifish subpopulations throughout the estuary. Furthermore, the results show that contaminants have affected killifish subpopulations throughout the estuary, even in sites with lower levels of PAHs.

Authors
Clark, BW; Cooper, EM; Stapleton, HM; Di Giulio, RT
MLA Citation
Clark, BW, Cooper, EM, Stapleton, HM, and Di Giulio, RT. "Compound- and mixture-specific differences in resistance to polycyclic aromatic hydrocarbons and PCB-126 among Fundulus heteroclitus subpopulations throughout the Elizabeth River estuary (Virginia, USA)." Environ Sci Technol 47.18 (September 17, 2013): 10556-10566.
PMID
24003986
Source
pubmed
Published In
Environmental Science & Technology
Volume
47
Issue
18
Publish Date
2013
Start Page
10556
End Page
10566
DOI
10.1021/es401604b

Low level exposure to the flame retardant BDE-209 reduces thyroid hormone levels and disrupts thyroid signaling in fathead minnows.

Polybrominated diphenyl ether (PBDE) flame retardants have been shown to disrupt thyroid hormone regulation, neurodevelopment, and reproduction in some animals. However, effects of the most heavily used PBDE, decabromodiphenyl ether (BDE-209), on thyroid functioning remain unclear. This study examined low-dose effects of BDE-209 on thyroid hormone levels and signaling in fathead minnows. Adult males received dietary exposures of BDE-209 at a low dose (∼3 ng/g bw-day) and high dose (∼300 ng/g bw-day) for 28 days followed by a 14-day depuration to evaluate recovery. Compared to controls, fish exposed to the low dose for 28 days experienced a 53% and 46% decline in circulating total thyroxine (TT4) and 3,5,3'-triiodothyronine (TT3), respectively, while TT4 and TT3 deficits at the high dose were 59% and 62%. Brain deiodinase activity (T4-ORD) was reduced by ∼65% at both doses. BDE-209 elevated the relative mRNA expression of genes encoding deiodinases, nuclear thyroid receptors, and membrane transporters in the brain and liver in patterns that varied with time and dose, likely in compensation to hypothyroidism. Declines in the gonadal-somatic index (GSI) and increased mortality were also measured. Effects at the low dose were consistent with the high dose, suggesting nonlinear relationships between BDE-209 exposures and thyroid dysfunction.

Authors
Noyes, PD; Lema, SC; Macaulay, LJ; Douglas, NK; Stapleton, HM
MLA Citation
Noyes, PD, Lema, SC, Macaulay, LJ, Douglas, NK, and Stapleton, HM. "Low level exposure to the flame retardant BDE-209 reduces thyroid hormone levels and disrupts thyroid signaling in fathead minnows." Environ Sci Technol 47.17 (September 3, 2013): 10012-10021.
PMID
23899252
Source
pubmed
Published In
Environmental Science & Technology
Volume
47
Issue
17
Publish Date
2013
Start Page
10012
End Page
10021
DOI
10.1021/es402650x

Does thyroid disruption contribute to the developmental neurotoxicity of chlorpyrifos?

Although organophosphate pesticides are not usually characterized as "endocrine disruptors," recent work points to potential, long-term reductions of circulating thyroid hormones after developmental exposures to chlorpyrifos that are devoid of observable toxicity. We administered chlorpyrifos to developing rats on gestational days 17-20 or postnatal days 1-4, regimens that produce distinctly different, sex-selective effects on neurobehavioral performance. The prenatal regimen produced a small, but statistically significant reduction in brain thyroxine levels from juvenile stages through adulthood; in contrast, postnatal exposure produced a transient elevation in young adulthood. However, in neither case did we observe the sex-selectivity noted earlier for neurobehavioral outcomes of these specific treatment regimens, or as reported earlier for effects on serum T4 in developing mice. Thus, although chlorpyrifos has the potential to disrupt thyroid status sufficiently to alter brain thyroid hormone levels, the effect is small, and any potential contribution to neurobehavioral abnormalities remains to be proven.

Authors
Slotkin, TA; Cooper, EM; Stapleton, HM; Seidler, FJ
MLA Citation
Slotkin, TA, Cooper, EM, Stapleton, HM, and Seidler, FJ. "Does thyroid disruption contribute to the developmental neurotoxicity of chlorpyrifos?." Environ Toxicol Pharmacol 36.2 (September 2013): 284-287.
PMID
23686008
Source
pubmed
Published In
Environmental Toxicology and Pharmacology
Volume
36
Issue
2
Publish Date
2013
Start Page
284
End Page
287
DOI
10.1016/j.etap.2013.04.003

Science Should Guide TSCA Reform

Authors
Lohmann, R; Stapleton, HM; Hites, RA
MLA Citation
Lohmann, R, Stapleton, HM, and Hites, RA. "Science Should Guide TSCA Reform." ENVIRONMENTAL SCIENCE & TECHNOLOGY 47.16 (August 20, 2013): 8995-8996.
PMID
23899100
Source
wos-lite
Published In
Environmental Science & Technology
Volume
47
Issue
16
Publish Date
2013
Start Page
8995
End Page
8996
DOI
10.1021/es403027y

Science In TSCA Reform

Authors
Lohmann, R; Stapleton, HM; Hites, RA
MLA Citation
Lohmann, R, Stapleton, HM, and Hites, RA. "Science In TSCA Reform." CHEMICAL & ENGINEERING NEWS 91.32 (August 12, 2013): 3-3.
Source
wos-lite
Published In
Chemical & Engineering News
Volume
91
Issue
32
Publish Date
2013
Start Page
3
End Page
3

Using whole mount in situ hybridization to examine thyroid hormone deiodinase expression in embryonic and larval zebrafish: a tool for examining OH-BDE toxicity to early life stages.

Polybrominated diphenyl ethers (PBDEs) and their oxidative metabolites (hydroxylated PBDEs; OH-BDEs) are known endocrine disrupting contaminants that have been shown to disrupt thyroid hormone regulation both in mammals and in fish. The purpose of this study was to determine the precise organ and tissue locations that express genes critical to thyroid hormone regulation in developing zebrafish (Danio rerio), and to determine the effects of an OH-BDE on their expression. While RT-PCR can provide quantitative data on gene expression, it lacks spatial sensitivity to examine localized gene expression; and, isolation of organs from zebrafish embryos is technically difficult, if not impossible. For this reason, the present study used whole mount in situ hybridization to simultaneously localize and quantify gene expression in vivo. While PBDEs and OH-BDEs have been shown to inhibit the activity and expression of deiodionases, a family of enzymes that regulate thyroid hormone concentrations intracellularly, it is unclear whether or not they can affect regional expression of the different isoforms during early development. In this study we investigated deiodinase 1 (Dio1), deiodinase 2 (Dio2), and deiodinase 3 (Dio3) mRNA expression at the following life stages (2, 8, and 1k-cells; 50%-epiboly, 6 and 18-somites, 22, 24, 48, 72 hpf and/or 10 dpf) in zebrafish and found life stage specific expression of these genes that were highly localized. To demonstrate the use of this technique for investigating potential endocrine disrupting effects, zebrafish embryos were exposed to 1, 10 and 100nM 6-OH-BDE-47. Significant increases in mean intensity of Dio1 and Dio3 expression in the periventricular zone of brain and pronephric duct, respectively (quantified by measuring intensity of coloration using ImageJ analysis software) were observed, suggesting localized response at the HPT axis with the possibility of impacting neurodevelopment. Our results demonstrate effects of OH-BDEs on thyroid regulating gene expression and provide more insight into potential sites of injury during early life stages.

Authors
Dong, W; Macaulay, LJ; Kwok, KWH; Hinton, DE; Stapleton, HM
MLA Citation
Dong, W, Macaulay, LJ, Kwok, KWH, Hinton, DE, and Stapleton, HM. "Using whole mount in situ hybridization to examine thyroid hormone deiodinase expression in embryonic and larval zebrafish: a tool for examining OH-BDE toxicity to early life stages." Aquat Toxicol 132-133 (May 15, 2013): 190-199.
PMID
23531416
Source
pubmed
Published In
Aquatic Toxicology
Volume
132-133
Publish Date
2013
Start Page
190
End Page
199
DOI
10.1016/j.aquatox.2013.02.008

Investigating a novel flame retardant known as V6: measurements in baby products, house dust, and car dust.

With the phase-out of polybrominated diphenyl ether (PBDE) flame retardants, the use of new and alternate flame retardants has been increasing. 2,2-bis(chloromethyl)propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate, known as V6, is a flame retardant applied to polyurethane foam commonly found in furniture and automobile foam. However, to the authors' knowledge, no research has been conducted on V6 levels in the environment. The intention of this study was to measure the concentration of V6 in foam collected from baby products where it was recently detected and measure levels in dust samples collected from homes and automobiles in the Boston, MA area. To accomplish this, a pure V6 commercial standard was purchased from a Chinese manufacturer and purified (>98%). An analytical method to measure V6 in dust samples using liquid chromatography tandem mass spectrometry (LC/MS-MS) was developed. Extraction was conducted using accelerated solvent extraction (ASE) and extracts were purified using an ENVI-Florisil SPE column (500 mg, 3 mL). V6 was measured in foam samples collected from baby products with a concentration ranging from 24,500,000 to 59,500,000 ng/g of foam (n = 12, average ± sd: 46,500,000 ± 12,000,000 ng/g; i.e., on average, 4.6% of the foam mass was V6). V6 was also detected in 19 of 20 car dust samples and 14 of 20 house dust samples analyzed. The concentration of V6 in the house dust ranged from <5 ng/g to 1110 ng/g with a median of 12.5 ng/g, and <5 ng/g to 6160 ng/g in the car dust with a median of 103.0 ng/g. Concentrations in car dust were significantly higher than in the house dust potentially indicating higher use of V6 in automobiles compared to products found in the home. Furthermore, tris (2-chloroethyl) phosphate (TCEP), a known carcinogen, was found in the V6 commercial mixture (14% by weight) as an impurity and was consistently detected with V6 in the foam samples analyzed. A significant correlation was also observed between V6 and TCEP in the dust samples suggesting that the use of V6 is a significant source of TCEP in the indoor environment.

Authors
Fang, M; Webster, TF; Gooden, D; Cooper, EM; McClean, MD; Carignan, C; Makey, C; Stapleton, HM
MLA Citation
Fang, M, Webster, TF, Gooden, D, Cooper, EM, McClean, MD, Carignan, C, Makey, C, and Stapleton, HM. "Investigating a novel flame retardant known as V6: measurements in baby products, house dust, and car dust." Environ Sci Technol 47.9 (May 7, 2013): 4449-4454.
PMID
23565680
Source
pubmed
Published In
Environmental Science & Technology
Volume
47
Issue
9
Publish Date
2013
Start Page
4449
End Page
4454
DOI
10.1021/es400032v

Aryl Phosphate Esters Within a Major PentaBDE Replacement Product Induce Cardiotoxicity in Developing Zebrafish Embryos: Potential Role of the Aryl Hydrocarbon Receptor

Authors
McGee, SP; Konstantinov, A; Stapleton, HM; Volz, DC
MLA Citation
McGee, SP, Konstantinov, A, Stapleton, HM, and Volz, DC. "Aryl Phosphate Esters Within a Major PentaBDE Replacement Product Induce Cardiotoxicity in Developing Zebrafish Embryos: Potential Role of the Aryl Hydrocarbon Receptor." TOXICOLOGICAL SCIENCES 133.1 (May 2013): 144-156.
PMID
23377616
Source
wos-lite
Published In
Toxicological Sciences (Elsevier)
Volume
133
Issue
1
Publish Date
2013
Start Page
144
End Page
156
DOI
10.1093/toxsci/kft020

The Organic Anion Transporting Protein (OATP) Family in a Teleost Fish Model

Authors
Muzzio, AM; Noyes, PD; Stapleton, HM; Lema, SC
MLA Citation
Muzzio, AM, Noyes, PD, Stapleton, HM, and Lema, SC. "The Organic Anion Transporting Protein (OATP) Family in a Teleost Fish Model." April 2013.
Source
wos-lite
Published In
Integrative and Comparative Biology (BioOne)
Volume
53
Publish Date
2013
Start Page
E340
End Page
E340

Exposure to flame retardant chemicals on commercial airplanes

Authors
Allen, JG; Stapleton, HM; Vallarino, J; McNeely, E; McClean, MD; Harrad, SJ; Rauert, CB; Spengler, JD
MLA Citation
Allen, JG, Stapleton, HM, Vallarino, J, McNeely, E, McClean, MD, Harrad, SJ, Rauert, CB, and Spengler, JD. "Exposure to flame retardant chemicals on commercial airplanes." ENVIRONMENTAL HEALTH 12 (February 16, 2013).
PMID
23413926
Source
wos-lite
Published In
Environmental Health
Volume
12
Publish Date
2013
DOI
10.1186/1476-069X-12-17

Exposure to Polybrominated Diphenyl Ethers in the Indoor Environment

© 2013, Springer Science+Business Media New York. Polybrominated diphenyl ethers (PBDEs) are fire retardants used in consumer products such as foam-containing furniture and electronics. This paper reviews human exposure to PBDEs in North America, applying the source to exposure paradigm, and arrives to the following five conclusions. (1) PentaBDE concentrations in residential house dust are associated with the amount of bromine contained in furniture as measured by X-ray fluorescence; similarly, DecaBDE in dust is associated with bromine in electronics. (2) Microscopic analysis of dust suggests that physical breakdown of products may be an important source of DecaBDE in dust. (3) Concentrations of PentaBDE in people were associated with PentaBDE levels in dust from their homes. (4) Inhalation appears to be a minor route of exposure for most of the population. PentaBDEs on handwipes are associated with both dust concentrations and body burdens, suggesting hand-to-mouth activity (or dermal absorption) as important routes of exposure. (5) Diet appears to be another, independent source of exposure. Fire fighters may be exposed via dust, ash or air, particularly in the aftermath of a fire. The existing literature suggests that human health effects may be associated with PentaBDE exposures in the general population. Manufacture of PentaBDE has been banned; replacement fire retardants can be measured in products and dust. The use of PBDEs and related flame retardants poses a potential risk–risk trade-off that requires the joint efforts of environmental scientists and the fire science community.

Authors
Webster, TF; Stapleton, HM; McClean, MD
MLA Citation
Webster, TF, Stapleton, HM, and McClean, MD. "Exposure to Polybrominated Diphenyl Ethers in the Indoor Environment." Fire Technology 51.1 (January 1, 2013): 85-95.
Source
scopus
Published In
Fire Technology
Volume
51
Issue
1
Publish Date
2013
Start Page
85
End Page
95
DOI
10.1007/s10694-013-0334-9

Human exposure assessment of indoor dust: Webster and Stapleton respond.

Authors
Webster, TF; Stapleton, HM
MLA Citation
Webster, TF, and Stapleton, HM. "Human exposure assessment of indoor dust: Webster and Stapleton respond." Environmental health perspectives 121.4 (2013): A110-A111.
Source
scival
Published In
Environmental health perspectives
Volume
121
Issue
4
Publish Date
2013
Start Page
A110
End Page
A111
DOI
10.1289/ehp.1206470R

Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster® 550 in Rats: An Exploratory Assessment

Firemaster® 550 (FM 550), a fire-retardant mixture used in foam-based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 μg/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels. © 2012 Wiley Periodicals, Inc.

Authors
Patisaul, HB; Roberts, SC; Mabrey, N; Mccaffrey, KA; Gear, RB; Braun, J; Belcher, SM; Stapleton, HM
MLA Citation
Patisaul, HB, Roberts, SC, Mabrey, N, Mccaffrey, KA, Gear, RB, Braun, J, Belcher, SM, and Stapleton, HM. "Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster® 550 in Rats: An Exploratory Assessment." Journal of Biochemical and Molecular Toxicology 27.2 (2013): 124-136.
Source
scival
Published In
Journal of Biochemical and Molecular Toxicology
Volume
27
Issue
2
Publish Date
2013
Start Page
124
End Page
136
DOI
10.1002/jbt.21439

Predictors of tris(1,3-dichloro-2-propyl) phosphate metabolite in the urine of office workers

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is a flame retardant widely used in furniture containing polyurethane foam. It is a carcinogen, endocrine disruptor, and potentially neurotoxic. Our objectives were to characterize exposure of adult office workers (n = 29) to TDCPP by measuring its primary metabolite, bis(1,3-dichloro-2-propyl) phosphate (BDCPP), in their urine; measuring TDCPP in dust from their homes; offices and vehicles; and assessing possible predictors of exposure. We identified TDCPP in 99% of dust (GM = 4.43. μg/g) and BDCPP in 100% of urine samples (GM = 408. pg/mL). Concentrations of TDCPP were significantly higher in dust from vehicles (GM = 12.5. μg/g) and offices (GM = 6.06. μg/g) than in dust from the main living area (GM = 4.21. μg/g) or bedrooms (GM = 1.40. μg/g) of worker homes. Urinary BDCPP concentrations among participants who worked in a new office building were 26% of those who worked in older buildings (p = 0.01). We found some evidence of a positive trend between urinary BDCPP and TDCPP in office dust that was not observed in the other microenvironments and may be related to the timing of urine sample collection during the afternoon of a workday. Overall our findings suggest that exposure to TDCPP in the work environment is one of the contributors to the personal exposure for office workers. Further research is needed to confirm specific exposure sources (e.g., polyurethane foam), determine the importance of exposure in other microenvironments such as homes and vehicles, and address the inhalation and dermal exposure pathways. © 2013 Elsevier Ltd.

Authors
Carignan, CC; McClean, MD; Cooper, EM; Watkins, DJ; Fraser, AJ; Heiger-Bernays, W; Stapleton, HM; Webster, TF
MLA Citation
Carignan, CC, McClean, MD, Cooper, EM, Watkins, DJ, Fraser, AJ, Heiger-Bernays, W, Stapleton, HM, and Webster, TF. "Predictors of tris(1,3-dichloro-2-propyl) phosphate metabolite in the urine of office workers." Environment International 55 (2013): 56-61.
PMID
23523854
Source
scival
Published In
Environment International
Volume
55
Publish Date
2013
Start Page
56
End Page
61
DOI
10.1016/j.envint.2013.02.004

Human exposure assessment of indoor dust: Webster and stapleton respond

Authors
Webster, TF; Stapleton, HM
MLA Citation
Webster, TF, and Stapleton, HM. "Human exposure assessment of indoor dust: Webster and stapleton respond." Environmental Health Perspectives 121.4 (2013): A109-A110.
PMID
23548261
Source
scival
Published In
Environmental health perspectives
Volume
121
Issue
4
Publish Date
2013
Start Page
A109
End Page
A110
DOI
10.1289/ehp.1206470R

Exposure to Polybrominated Diphenyl Ethers in the Indoor Environment

Polybrominated diphenyl ethers (PBDEs) are fire retardants used in consumer products such as foam-containing furniture and electronics. This paper reviews human exposure to PBDEs in North America, applying the source to exposure paradigm, and arrives to the following five conclusions. (1) PentaBDE concentrations in residential house dust are associated with the amount of bromine contained in furniture as measured by X-ray fluorescence; similarly, DecaBDE in dust is associated with bromine in electronics. (2) Microscopic analysis of dust suggests that physical breakdown of products may be an important source of DecaBDE in dust. (3) Concentrations of PentaBDE in people were associated with PentaBDE levels in dust from their homes. (4) Inhalation appears to be a minor route of exposure for most of the population. PentaBDEs on handwipes are associated with both dust concentrations and body burdens, suggesting hand-to-mouth activity (or dermal absorption) as important routes of exposure. (5) Diet appears to be another, independent source of exposure. Fire fighters may be exposed via dust, ash or air, particularly in the aftermath of a fire. The existing literature suggests that human health effects may be associated with PentaBDE exposures in the general population. Manufacture of PentaBDE has been banned; replacement fire retardants can be measured in products and dust. The use of PBDEs and related flame retardants poses a potential risk-risk trade-off that requires the joint efforts of environmental scientists and the fire science community. © 2013 Springer Science+Business Media New York.

Authors
Webster, TF; Stapleton, HM; McClean, MD
MLA Citation
Webster, TF, Stapleton, HM, and McClean, MD. "Exposure to Polybrominated Diphenyl Ethers in the Indoor Environment." Fire Technology (2013): 1-11.
Source
scival
Published In
Fire Technology
Publish Date
2013
Start Page
1
End Page
11
DOI
10.1007/s10694-013-0334-9

Associations between serum levels of polybrominated diphenyl ether (PBDE) flame retardants and environmental and behavioral factors in pregnant women

Polybrominated diphenyl ethers (PBDE) are flame retardants that were previously used in upholstery, fabrics, and household appliances. PBDEs have been linked to adverse health outcomes, including neurotoxicity, thyroid hormone dysregulation, endocrine disruption, and poor semen quality. Because PBDEs pass into placental circulation, maternal exposures can approximate fetal exposures. Our objectives were to determine whether diet and specific human behaviors were significantly associated with PBDE exposures in a cohort of pregnant women. Women between the 34th and 38th week of pregnancy were given a questionnaire about behavioral, environmental, and dietary factors and asked to provide blood samples. Serum PBDE levels were measured using GS-MS and lipid adjusted. An adjusted ordinary least squares regression model was run to identify potential associations between behaviors and serum PBDE levels. Serum concentrations of BDEs 47, 99, 100, and 153 were found above the limit of detection in at least 50% of study participants and used in our models. Associations with serum PBDEs were observed with self-reported hand-to-mouth behaviors, including biting nails and licking fingers. Serum BDE levels of 47, 99, 153, and total PBDEs were also significantly higher in those individuals owning a large-screen TV compared with those who did not. Serum PBDE levels were comparable to levels reported in the general population. Hand-to-mouth behaviors may influence serum PBDE concentrations in adults. Household electronics such as large-screen TVs appear to serve as a significant source of PBDEs in pregnant women. Together, hand-to-mouth behaviors and TV ownership may serve as a route of exposure to PBDEs in adults.© 2013 Nature America, Inc. All rights reserved.

Authors
Buttke, DE; Wolkin, A; Stapleton, HM; Miranda, ML
MLA Citation
Buttke, DE, Wolkin, A, Stapleton, HM, and Miranda, ML. "Associations between serum levels of polybrominated diphenyl ether (PBDE) flame retardants and environmental and behavioral factors in pregnant women." Journal of Exposure Science and Environmental Epidemiology 23.2 (2013): 176-182.
Source
scival
Published In
Journal of Exposure Science and Environmental Epidemiology
Volume
23
Issue
2
Publish Date
2013
Start Page
176
End Page
182
DOI
10.1038/jes.2012.67

Urinary metabolites of organophosphate flame retardants: Temporal variability and correlations with house dust concentrations

Background: A reduction in the use of polybrominated diphenyl ethers (PBDEs) because of human health concerns may result in an increased use of and human exposure to organophosphate flame retardants (OPFRs). Human exposure and health studies of OPFRs are lacking. Objectives: We sought to define the degree of temporal variability in urinary OPFR metabolites in order to inform epidemiologic study design, and to explore a potential primary source of exposure by examining the relationship between OPFRs in house dust and their metabolites in urine. Methods: Nine repeated urine samples were collected from 7 men over the course of 3 months and analyzed for bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPP), metabolites of the OPFRs tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), respectively. Intraclass correlation coefficients (ICCs) were calculated to characterize temporal reliability. Paired house dust and urine samples were collected from 45 men. Results: BDCPP was detected in 91% of urine samples, and DPP in 96%. Urinary BDCPP showed moderate-to-strong temporal reliability (ICC range, 0.55-0.72). ICCs for DPP were lower, but moderately reliable (range, 0.35-0.51). There was a weak [Spearman r (rS) = 0.31] but significant (p = 0.03) correlation between urinary BDCPP and TDCPP concentrations in house dust that strengthened when nondetects (rS = 0.47) were excluded. There was no correlation between uncorrected DPP and TPP measured in house dust (rS < 0.1). Conclusions: Household dust may be an important source of exposure to TDCPP but not TPP. Urinary concentrations of BDCPP and DPP were moderately to highly reliable within individuals over 3 months.

Authors
Meeker, JD; Cooper, EM; Stapleton, HM; Hauser, R
MLA Citation
Meeker, JD, Cooper, EM, Stapleton, HM, and Hauser, R. "Urinary metabolites of organophosphate flame retardants: Temporal variability and correlations with house dust concentrations." Environmental Health Perspectives 121.5 (2013): 580-585.
PMID
23461877
Source
scival
Published In
Environmental health perspectives
Volume
121
Issue
5
Publish Date
2013
Start Page
580
End Page
585
DOI
10.1289/ehp.1205907

Associations between PBDEs in office air, dust, and surface wipes

Increased use of flame-retardants in office furniture may increase exposure to PBDEs in the office environment. However, partitioning of PBDEs within the office environment is not well understood. Our objectives were to examine relationships between concurrent measures of PBDEs in office air, floor dust, and surface wipes.We collected air, dust, and surface wipe samples from 31 offices in Boston, MA. Correlation and linear regression were used to evaluate associations between variables. Geometric mean (GM) concentrations of individual BDE congeners in air and congener specific octanol-air partition coefficients (Koa) were used to predict GM concentrations in dust and surface wipes and compared to the measured concentrations.GM concentrations of PentaBDEs in office air, dust, and surface wipes were 472pg/m3, 2411ng/g, and 77pg/cm2, respectively. BDE209 was detected in 100% of dust samples (GM=4202ng/g), 93% of surface wipes (GM=125pg/cm2), and 39% of air samples. PentaBDEs in dust and air were moderately correlated with each other (r=0.60, p=0.0003), as well as with PentaBDEs in surface wipes (r=0.51, p=0.003 for both dust and air). BDE209 in dust was correlated with BDE209 in surface wipes (r=0.69, p=0.007). Building (three categories) and PentaBDEs in dust were independent predictors of PentaBDEs in both air and surface wipes, together explaining 50% (p=0.0009) and 48% (p=0.001) of the variation respectively. Predicted and measured concentrations of individual BDE congeners were highly correlated in dust (r=0.98, p<0.0001) and surface wipes (r=0.94, p=002). BDE209 provided an interesting test of this equilibrium partitioning model as it is a low volatility compound.Associations between PentaBDEs in multiple sampling media suggest that collecting dust or surface wipes may be a convenient method of characterizing exposure in the indoor environment. The volatility of individual congeners, as well as physical characteristics of the indoor environment, influence relationships between PBDEs in air, dust, and surface wipes. © 2013 Elsevier Ltd.

Authors
Watkins, DJ; McClean, MD; Fraser, AJ; Weinberg, J; Stapleton, HM; Webster, TF
MLA Citation
Watkins, DJ, McClean, MD, Fraser, AJ, Weinberg, J, Stapleton, HM, and Webster, TF. "Associations between PBDEs in office air, dust, and surface wipes." Environment International 59 (2013): 124-132.
PMID
23797055
Source
scival
Published In
Environment International
Volume
59
Publish Date
2013
Start Page
124
End Page
132
DOI
10.1016/j.envint.2013.06.001

Novel and high volume use flame retardants in US couches reflective of the 2005 PentaBDE phase out.

California's furniture flammability standard Technical Bulletin 117 (TB 117) is believed to be a major driver of chemical flame retardant (FR) use in residential furniture in the United States. With the phase-out of the polybrominated diphenyl ether (PBDE) FR mixture PentaBDE in 2005, alternative FRs are increasingly being used to meet TB 117; however, it was unclear which chemicals were being used and how frequently. To address this data gap, we collected and analyzed 102 samples of polyurethane foam from residential couches purchased in the United States from 1985 to 2010. Overall, we detected chemical flame retardants in 85% of the couches. In samples purchased prior to 2005 (n = 41) PBDEs associated with the PentaBDE mixture including BDEs 47, 99, and 100 (PentaBDE) were the most common FR detected (39%), followed by tris(1,3-dichloroisopropyl) phosphate (TDCPP; 24%), which is a suspected human carcinogen. In samples purchased in 2005 or later (n = 61) the most common FRs detected were TDCPP (52%) and components associated with the Firemaster550 (FM 550) mixture (18%). Since the 2005 phase-out of PentaBDE, the use of TDCPP increased significantly. In addition, a mixture of nonhalogenated organophosphate FRs that included triphenyl phosphate (TPP), tris(4-butylphenyl) phosphate (TBPP), and a mix of butylphenyl phosphate isomers were observed in 13% of the couch samples purchased in 2005 or later. Overall the prevalence of flame retardants (and PentaBDE) was higher in couches bought in California compared to elsewhere, although the difference was not quite significant (p = 0.054 for PentaBDE). The difference was greater before 2005 than after, suggesting that TB 117 is becoming a de facto standard across the U.S. We determined that the presence of a TB 117 label did predict the presence of a FR; however, lack of a label did not predict the absence of a flame retardant. Following the PentaBDE phase out, we also found an increased number of flame retardants on the market. Given these results, and the potential for human exposure to FRs, health studies should be conducted on the types of FRs identified here.

Authors
Stapleton, HM; Sharma, S; Getzinger, G; Ferguson, PL; Gabriel, M; Webster, TF; Blum, A
MLA Citation
Stapleton, HM, Sharma, S, Getzinger, G, Ferguson, PL, Gabriel, M, Webster, TF, and Blum, A. "Novel and high volume use flame retardants in US couches reflective of the 2005 PentaBDE phase out." Environ Sci Technol 46.24 (December 18, 2012): 13432-13439.
PMID
23186002
Source
pubmed
Published In
Environmental Science & Technology
Volume
46
Issue
24
Publish Date
2012
Start Page
13432
End Page
13439
DOI
10.1021/es303471d

Rodent Thyroid, Liver, and Fetal Testis Toxicity of the Monoester Metabolite of Bis-(2-ethylhexyl) Tetrabromophthalate (TBPH), a Novel Brominated Flame Retardant Present in Indoor Dust

Authors
Springer, C; Dere, E; Hall, SJ; McDonnell, EV; Roberts, SC; Butt, CM; Stapleton, HM; Watkins, DJ; McClean, MD; Webster, TF; Schlezinger, JJ; Boekelheide, K
MLA Citation
Springer, C, Dere, E, Hall, SJ, McDonnell, EV, Roberts, SC, Butt, CM, Stapleton, HM, Watkins, DJ, McClean, MD, Webster, TF, Schlezinger, JJ, and Boekelheide, K. "Rodent Thyroid, Liver, and Fetal Testis Toxicity of the Monoester Metabolite of Bis-(2-ethylhexyl) Tetrabromophthalate (TBPH), a Novel Brominated Flame Retardant Present in Indoor Dust." ENVIRONMENTAL HEALTH PERSPECTIVES 120.12 (December 2012): 1711-1719.
PMID
23014847
Source
wos-lite
Published In
Environmental health perspectives
Volume
120
Issue
12
Publish Date
2012
Start Page
1711
End Page
1719
DOI
10.1289/ehp.1204932

In vitro metabolism of the brominated flame retardants 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH) in human and rat tissues.

Due to the phaseout of polybrominated diphenyl ether (PBDE) flame retardants, new chemicals, such as 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH), have been used as replacements in some commercial flame retardant mixtures. Both chemicals have been detected in indoor dust at concentrations approaching the concentrations of PBDEs; however, little is known about their fate, metabolism, or toxicity. The goal of this study was to investigate the potential metabolism of these two brominated flame retardants in human and rat tissues by conducting in vitro experiments with liver and intestinal subcellular fractions. In all the experiments, TBB was consistently metabolized to 2,3,4,5-tetrabromobenzoic acid (TBBA) via cleavage of the 2-ethylhexyl chain without requiring any added cofactors. TBBA was also formed in purified porcine carboxylesterase but at a much faster rate of 6.29 ± 0.58 nmol min(-1) mg protein(-1). The estimated K(m) and V(max) values for TBB metabolism in human microsomes were 11.1 ± 3.9 μM and 0.644 ± 0.144 nmol min(-1) mg protein(-1), respectively. A similar K(m) of 9.3 ± 2.2 μM was calculated for porcine carboxylesterase, indicating similar enzyme specificity. While the rapid formation of TBBA may reduce the bioaccumulation potential of TBB in mammals and may be useful as a biomarker of TBB exposure, the toxicity of this brominated benzoic acid is unknown and may be a concern based on its structural similarity to other toxic pollutants. In contrast to TBB, no metabolites of TBPH were detected in human or rat subcellular fractions. However, a metabolic product of TBPH, mono(2-ethylhexyl) tetrabromophthalate (TBMEHP), was formed in purified porcine carboxylesterase at an approximate rate of 1.08 pmol min(-1) mg protein(-1). No phase II metabolites of TBBA or TBMEHP were observed. More research is needed to understand the in vivo toxicokinetics and health effects of these compounds given their current ubiquitous presence in most US households and the resulting probability of chronic exposure, particularly to young children.

Authors
Roberts, SC; Macaulay, LJ; Stapleton, HM
MLA Citation
Roberts, SC, Macaulay, LJ, and Stapleton, HM. "In vitro metabolism of the brominated flame retardants 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH) in human and rat tissues." Chem Res Toxicol 25.7 (July 16, 2012): 1435-1441.
PMID
22575079
Source
pubmed
Published In
Chemical Research in Toxicology
Volume
25
Issue
7
Publish Date
2012
Start Page
1435
End Page
1441
DOI
10.1021/tx300086x

Serum PBDEs in a North Carolina toddler cohort: associations with handwipes, house dust, and socioeconomic variables.

BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are persistent, bioaccumulative, and endocrine-disrupting chemicals. OBJECTIVES: We used handwipes to estimate exposure to PBDEs in house dust among toddlers and examined sex, age, breast-feeding, race, and parents' education as predictors of serum PBDEs. METHODS: Eighty-three children from 12 to 36 months of age were enrolled in North Carolina between May 2009 and November 2010. Blood, handwipe, and house dust samples were collected and analyzed for PBDEs. A questionnaire was administered to collect demographic data. RESULTS: PBDEs were detected in all serum samples (geometric mean for ΣpentaBDE in serum was 43.3 ng/g lipid), 98% of the handwipe samples, and 100% of the dust samples. Serum ΣpentaBDEs were significantly correlated with both handwipe and house dust ΣpentaBDE levels, but were more strongly associated with handwipe levels (r = 0.57; p < 0.001 vs. r = 0.35; p < 0.01). Multivariate model estimates revealed that handwipe levels, child's sex, child's age, and father's education accounted for 39% of the variation in serum ΣBDE3 levels (sum of BDEs 47, 99, and 100). In contrast, age, handwipe levels, and breast-feeding duration explained 39% of the variation in serum BDE 153. CONCLUSIONS: Our study suggests that hand-to-mouth activity may be a significant source of exposure to PBDEs. Furthermore, age, socioeconomic status, and breast-feeding were significant predictors of exposure, but associations varied by congener. Specifically, serum ΣBDE3 was inversely associated with socioeconomic status, whereas serum BDE-153 was positively associated with duration of breast-feeding and mother's education.

Authors
Stapleton, HM; Eagle, S; Sjödin, A; Webster, TF
MLA Citation
Stapleton, HM, Eagle, S, Sjödin, A, and Webster, TF. "Serum PBDEs in a North Carolina toddler cohort: associations with handwipes, house dust, and socioeconomic variables." Environ Health Perspect 120.7 (July 2012): 1049-1054.
PMID
22763040
Source
pubmed
Published In
Environmental health perspectives
Volume
120
Issue
7
Publish Date
2012
Start Page
1049
End Page
1054
DOI
10.1289/ehp.1104802

Measurement of flame retardants and triclosan in municipal sewage sludge and biosolids.

As polybrominated diphenyl ethers (PBDEs) face increasing restrictions worldwide, several alternate flame retardants are expected to see increased use as replacement compounds in consumer products. Chemical analysis of biosolids collected from wastewater treatment plants (WWTPs) can help determine whether these flame retardants are migrating from the indoor environment to the outdoor environment, where little is known about their ultimate fate and effects. The objective of this study was to measure concentrations of a suite of flame retardants, and the antimicrobial compound triclosan, in opportunistic samples of municipal biosolids and the domestic sludge Standard Reference Material (SRM) 2781. Grab samples of biosolids were collected from two WWTPs in North Carolina and two in California. Biosolids samples were also obtained during three subsequent collection events at one of the North Carolina WWTPs to evaluate fluctuations in contaminant levels within a given facility over a period of three years. The biosolids and SRM 2781 were analyzed for PBDEs, hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), di(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), the chlorinated flame retardant Dechlorane Plus (syn- and anti-isomers), and the antimicrobial agent 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan). PBDEs were detected in every sample analyzed, and ΣPBDE concentrations ranged from 1750 to 6358ng/g dry weight. Additionally, the PBDE replacement chemicals TBB and TBPH were detected at concentrations ranging from 120 to 3749 ng/g dry weight and from 206 to 1631 ng/g dry weight, respectively. Triclosan concentrations ranged from 490 to 13,866 ng/g dry weight. The detection of these contaminants of emerging concern in biosolids suggests that these chemicals have the potential to migrate out of consumer products and enter the outdoor environment.

Authors
Davis, EF; Klosterhaus, SL; Stapleton, HM
MLA Citation
Davis, EF, Klosterhaus, SL, and Stapleton, HM. "Measurement of flame retardants and triclosan in municipal sewage sludge and biosolids." Environ Int 40 (April 2012): 1-7.
PMID
22280921
Source
pubmed
Published In
Environment International
Volume
40
Publish Date
2012
Start Page
1
End Page
7
DOI
10.1016/j.envint.2011.11.008

Flame Retardants: Polybrominated Diphenyl Ethers and their Replacements

Authors
Webster, TF; Stapleton, HM
MLA Citation
Webster, TF, and Stapleton, HM. "Flame Retardants: Polybrominated Diphenyl Ethers and their Replacements." (March 30, 2012): 89-108. (Chapter)
Source
scopus
Publish Date
2012
Start Page
89
End Page
108
DOI
10.1002/9781118184141.ch4

Impact of dust from multiple microenvironments and diet on PentaBDE body burden

Our objectives were to determine relative contributions of diet and dust exposure from multiple microenvironments to PentaBDE body burden, and to explore the role of handwipes as a measure of personal exposure to PentaBDE. We administered a food frequency questionnaire and collected serum, dust (office, main living area, bedroom, and vehicle), and handwipe samples from 31 participants. ∑PentaBDEs (sum of BDE 28/33, 47, 99, 100, and 153) in handwipes collected in the office environment were weakly correlated with dust collected from offices (r = 0.35, p = 0.06) and bedrooms (r = 0.39, p = 0.04), but not with dust from main living areas (r = -0.05, p = 0.77) or vehicles (r = 0.17, p = 0.47). ∑PentaBDEs in serum were correlated with dust from main living areas (r = 0.42, p = 0.02) and bedrooms (r = 0.49, p = 0.008), but not with dust from offices (r = 0.22, p = 0.25) or vehicles (r = 0.20, p = 0.41). Our final regression model included variables for main living area dust and handwipes, and predicted 55% of the variation in serum ∑PentaBDE concentrations (p = 0.0004). Diet variables were not significant predictors of ∑PentaBDEs in serum. Our research suggests that exposure to dust in the home environment may be the most important factor in predicting PentaBDE body burden in North Americans, and potential exposure pathways may involve PBDE residues on hands. © 2011 American Chemical Society.

Authors
Watkins, DJ; McClean, MD; Fraser, AJ; Weinberg, J; Stapleton, HM; Sjödin, A; Webster, TF
MLA Citation
Watkins, DJ, McClean, MD, Fraser, AJ, Weinberg, J, Stapleton, HM, Sjödin, A, and Webster, TF. "Impact of dust from multiple microenvironments and diet on PentaBDE body burden." Environmental Science and Technology 46.2 (2012): 1192-1200.
PMID
22142368
Source
scival
Published In
Environmental Science & Technology
Volume
46
Issue
2
Publish Date
2012
Start Page
1192
End Page
1200
DOI
10.1021/es203314e

Polyfluorinated compounds in serum linked to indoor air in office environments

We aimed to investigate the role of indoor office air on exposure to polyfluorinated compounds (PFCs) among office workers. Week-long, active air sampling was conducted during the winter of 2009 in 31 offices in Boston, MA. Air samples were analyzed for fluorotelomer alcohols (FTOHs), sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs). Serum was collected from each participant (n = 31) and analyzed for 12 PFCs including PFOA and PFOS. In air, FTOHs were present in the highest concentrations, particularly 8:2-FTOH (GM = 9920 pg/m 3). FTOHs varied significantly by building with the highest levels observed in a newly constructed building. PFOA in serum was significantly correlated with air levels of 6:2-FTOH (r = 0.43), 8:2-FTOH (r = 0.60), and 10:2-FTOH (r = 0.62). Collectively, FTOHs in air significantly predicted PFOA in serum (p < 0.001) and explained approximately 36% of the variation in serum PFOA concentrations. PFOS in serum was not associated with air levels of FOSAs/FOSEs. In conclusion, FTOH concentrations in office air significantly predict serum PFOA concentrations in office workers. Variation in PFC air concentrations by building is likely due to differences in the number, type, and age of potential sources such as carpeting, furniture, and/or paint. © 2011 American Chemical Society.

Authors
Fraser, AJ; Webster, TF; Watkins, DJ; Nelson, JW; Stapleton, HM; Calafat, AM; Kato, K; Shoeib, M; Vieira, VM; McClean, MD
MLA Citation
Fraser, AJ, Webster, TF, Watkins, DJ, Nelson, JW, Stapleton, HM, Calafat, AM, Kato, K, Shoeib, M, Vieira, VM, and McClean, MD. "Polyfluorinated compounds in serum linked to indoor air in office environments." Environmental Science and Technology 46.2 (2012): 1209-1215.
PMID
22148395
Source
scival
Published In
Environmental Science & Technology
Volume
46
Issue
2
Publish Date
2012
Start Page
1209
End Page
1215
DOI
10.1021/es2038257

BDE 49 and developmental toxicity in zebrafish

The polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants. Human health concerns of these agents have largely centered upon their potential to elicit reproductive and developmental effects. Of the various congeners, BDE 49 (2,2′,4,5′-tetrabromodiphenyl ether) has been poorly studied, despite the fact that it is often detected in the tissues of fish and wildlife species. Furthermore, we have previously shown that BDE 49 is a metabolic debromination product of BDE 99 hepatic metabolism in salmon, carp and trout, underscoring the need for a better understanding of biological effects. In the current study, we investigated the developmental toxicity of BDE 49 using the zebrafish (Danio rerio) embryo larval model. Embryo and larval zebrafish were exposed to BDE 49 at either 5 hours post fertilization (hpf) or 24 hpf and monitored for developmental and neurotoxicity. Exposure to BDE 49 at concentrations of 4iμ-32 μM caused a dose-dependent loss in survivorship at 6 days post fertilization (dpf). Morphological impairments were observed prior to the onset of mortality, the most striking of which included severe dorsal curvatures of the tail. The incidence of dorsal tail curvatures was dose and time dependent. Exposure to BDE 49 caused cardiac toxicity as evidenced by a significant reduction in zebrafish heart rates at 6 dpf but not earlier, suggesting that cardiac toxicity was non-specific and associated with physiological stress. Neurobehavioral injury from BDE 49 was evidenced by an impairment of touch-escape responses observed at 5 dpf. Our results indicate that BDE 49 is a developmental toxicant in larval zebrafish that can cause morphological abnormalities and adversely affect neurobehavior. The observed toxicities from BDE 49 were similar in scope to those previously reported for the more common tetrabrominated congener, BDE 47, and also for other lower brominated PBDEs, suggest that these compounds may share similarities in risk to aquatic species. © 2011 Elsevier Inc. All rights reserved.

Authors
McClain, V; Stapleton, HM; Tilton, F; Gallagher, EP
MLA Citation
McClain, V, Stapleton, HM, Tilton, F, and Gallagher, EP. "BDE 49 and developmental toxicity in zebrafish." Comparative Biochemistry and Physiology - C Toxicology and Pharmacology 155.2 (2012): 253-258.
PMID
21951712
Source
scival
Published In
Comparative Biochemistry and Physiology - Part C: Toxicology & Pharmacology
Volume
155
Issue
2
Publish Date
2012
Start Page
253
End Page
258
DOI
10.1016/j.cbpc.2011.09.004

Trophic transfer of polybrominated diphenyl ethers and polychlorinated biphenyls in a tidal freshwater marsh

The John Heinz National Wildlife Refuge (NWR) at Tinicum Marsh contains one of the last remaining tidal freshwater marsh communities along the Pennsylvania side of the Delaware River Estuary. The marsh receives a significant load of nutrients and sediment-associated contaminants and is hypothesised to act as an effective trap for these chemicals. The goal of this study was to quantify the levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) at various trophic levels at two sites within Tinicum Marsh and assess the factors important in determining their bioaccumulation and trophic transfer. For both PCBs and PBDEs, lipid variation for all species was a large factor in determining contaminant body burden. Also, concentrations in biota increased with increasing trophic level as determined by nitrogen isotope analysis (δ15N values) at the downstream site within Tinicum Marsh. This trend was less apparent at the upstream site and may be due to differences in feeding behaviours among species between the two sites and/or differences in carbon and nitrogen sources and recycling. These data are valuable in assisting bioaccumulation/trophic transfer studies and serve as benchmarks to which future PCB and PBDE concentrations will be compared. © 2012 Copyright Taylor and Francis Group, LLC.

Authors
Ashley, JTF; Vasquez, MA; Zelanko, P; McKinley, E; Schafer, M; Zaoudeh, L; Horwitz, R; Stapleton, HM; Velinsky, DJ
MLA Citation
Ashley, JTF, Vasquez, MA, Zelanko, P, McKinley, E, Schafer, M, Zaoudeh, L, Horwitz, R, Stapleton, HM, and Velinsky, DJ. "Trophic transfer of polybrominated diphenyl ethers and polychlorinated biphenyls in a tidal freshwater marsh." Chemistry and Ecology 28.4 (2012): 305-325.
Source
scival
Published In
Chemistry and Ecology
Volume
28
Issue
4
Publish Date
2012
Start Page
305
End Page
325
DOI
10.1080/02757540.2012.656608

Species specific differences in the in vitro metabolism of the flame retardant mixture, Firemaster® BZ-54

Firemaster® BZ-54 is a flame retardant additive and consists of a brominated benzoate (2-ethylhexyl 2,3,4,5-tetrabromobenzoate; TBB) and a brominated phthalate (bis (2-ethylhexyl) 2,3,4,5-tetrabromophthalate; TBPH). Previous research has shown that fathead minnows exposed in vivo to Firemaster® BZ-54 accumulate TBB and TBPH. This study examined the in vitro biotransformation potential of TBB and TBPH in hepatic subcellular fractions (i.e., S9, microsomes and cytosol) in the fathead minnow, common carp, mouse and snapping turtle. Metabolism was evaluated by measuring the loss of the parent TBB or TBPH and identifying potential metabolites in the sample extracts. Metabolic loss of TBPH was measured for all species, while TBB loss was observed for all species except for the snapping turtle. Several metabolites were observed in all of the incubations except for snapping turtle. Metabolites observed appeared to be derived from TBB, given their structures and lack of appearance in the snapping turtle incubations. One of these metabolites, 2,3,4,5-tetrabromomethylbenzoate has been identified for the first time in a biological system. When metabolized, TBB and TBPH loss was found in each subcellular fraction suggesting that the enzyme(s) involved are present in both soluble and membrane-bound forms. It can be concluded that a broad range of species are capable of metabolizing TBB and TBPH to various metabolites and further research should be carried out to ascertain the specific products formed from metabolism of TBB and TBPH. © 2012 Elsevier B.V.

Authors
Bearr, JS; Mitchelmore, CL; Roberts, SC; Stapleton, HM
MLA Citation
Bearr, JS, Mitchelmore, CL, Roberts, SC, and Stapleton, HM. "Species specific differences in the in vitro metabolism of the flame retardant mixture, Firemaster® BZ-54." Aquatic Toxicology 124-125 (2012): 41-47.
PMID
22889877
Source
scival
Published In
Aquatic Toxicology
Volume
124-125
Publish Date
2012
Start Page
41
End Page
47
DOI
10.1016/j.aquatox.2012.06.006

Brominated and chlorinated flame retardants in San Francisco Bay sediments and wildlife

Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the use of alternative flame retardants in consumer products to comply with flammability standards. In contrast to PBDEs, information on the occurrence and fate of these alternative compounds in the environment is limited, particularly in the United States. In this study, a survey of flame retardants in San Francisco Bay was conducted to evaluate whether PBDE replacement chemicals and other current use flame retardants were accumulating in the Bay food web. In addition to PBDEs, brominated and chlorinated flame retardants (hexabromocyclododecane (HBCD) and Dechlorane Plus (DP)) were detected in Bay sediments and wildlife. Median concentrations of PBDEs, HBCD, and DP, respectively, were 4.3, 0.3, and 0.2ngg-1 dry weight (dw) in sediments; 1670, <6.0, and 0.5ngg-1 lipid weight (lw) in white croaker (Genyonemus lineatus); 1860, 6.5, and 1.3ngg-1 lw in shiner surfperch (Cymatogaster aggregata); 5500, 37.4, and 0.9ngg-1 lw in eggs of double-crested cormorant (Phalacrocorax auritus); 770, 7.1, and 0.9ngg-1 lw in harbor seal (Phoca vitulina) adults; and 330, 3.5, and <0.1ngg-1 lw in harbor seal (P. vitulina) pups. Two additional flame retardants, pentabromoethylbenzene (PBEB) and 1,2-bis(2,4,6 tribromophenoxy)ethane (BTBPE) were detected in sediments but with less frequency and at lower concentrations (median concentrations of 0.01 and 0.02ngg-1 dw, respectively) compared to the other flame retardants. PBEB was also detected in each of the adult harbor seals and in 83% of the pups (median concentrations 0.2 and 0.07ngg-1 lw, respectively). The flame retardants hexabromobenzene (HBB), decabromodiphenyl ethane (DBDPE), bis(2-ethylhexyl) tetrabromophthalate (TBPH), and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), were not detected in sediments and BTBPE, HBB and TBB were not detected in wildlife samples. Elevated concentrations of some flame retardants were likely associated with urbanization and Bay hydrodynamics. Compared to other locations, concentrations of PBDEs in Bay wildlife were comparable or higher, while concentrations of the alternatives were generally lower. This study is the first to determine concentrations of PBDE replacement products and other flame retardants in San Francisco Bay, providing some of the first data on the food web occurrence of these flame retardants in a North American urbanized estuary. © 2012 Elsevier Ltd.

Authors
Klosterhaus, SL; Stapleton, HM; Guardia, MJL; Greig, DJ
MLA Citation
Klosterhaus, SL, Stapleton, HM, Guardia, MJL, and Greig, DJ. "Brominated and chlorinated flame retardants in San Francisco Bay sediments and wildlife." Environment International 47 (2012): 56-65.
PMID
22766500
Source
scival
Published In
Environment International
Volume
47
Publish Date
2012
Start Page
56
End Page
65
DOI
10.1016/j.envint.2012.06.005

Early Zebrafish Embryogenesis Is Susceptible to Developmental TDCPP Exposure

Authors
McGee, SP; Cooper, E; Stapleton, HM; Volz, D
MLA Citation
McGee, SP, Cooper, E, Stapleton, HM, and Volz, D. "Early Zebrafish Embryogenesis Is Susceptible to Developmental TDCPP Exposure." Environmental Health Perspectives 120.11 (2012): 1586-1591. (Academic Article)
Source
manual
Published In
Environmental Health Perspectives
Volume
120
Issue
11
Publish Date
2012
Start Page
1586
End Page
1591

Associations between serum levels of polybrominated diphenyl ether (PBDE) flame retardants and environmental and behavioral factors in pregnant women

Polybrominated diphenyl ethers (PBDE) are flame retardants that were previously used in upholstery, fabrics, and household appliances. PBDEs have been linked to adverse health outcomes, including neurotoxicity, thyroid hormone dysregulation, endocrine disruption, and poor semen quality. Because PBDEs pass into placental circulation, maternal exposures can approximate fetal exposures. Our objectives were to determine whether diet and specific human behaviors were significantly associated with PBDE exposures in a cohort of pregnant women. Women between the 34th and 38th week of pregnancy were given a questionnaire about behavioral, environmental, and dietary factors and asked to provide blood samples. Serum PBDE levels were measured using GS-MS and lipid adjusted. An adjusted ordinary least squares regression model was run to identify potential associations between behaviors and serum PBDE levels. Serum concentrations of BDEs 47, 99, 100, and 153 were found above the limit of detection in at least 50% of study participants and used in our models. Associations with serum PBDEs were observed with self-reported hand-to-mouth behaviors, including biting nails and licking fingers. Serum BDE levels of 47, 99, 153, and total PBDEs were also significantly higher in those individuals owning a large-screen TV compared with those who did not. Serum PBDE levels were comparable to levels reported in the general population. Hand-to-mouth behaviors may influence serum PBDE concentrations in adults. Household electronics such as large-screen TVs appear to serve as a significant source of PBDEs in pregnant women. Together, hand-to-mouth behaviors and TV ownership may serve as a route of exposure to PBDEs in adults.Journal of Exposure Science and Environmental Epidemiology advance online publication, 4 July 2012; doi:10.1038/jes.2012.67.

Authors
Buttke, DE; Wolkin, A; Stapleton, HM; Miranda, ML
MLA Citation
Buttke, DE, Wolkin, A, Stapleton, HM, and Miranda, ML. "Associations between serum levels of polybrominated diphenyl ether (PBDE) flame retardants and environmental and behavioral factors in pregnant women." Journal of Exposure Science and Environmental Epidemiology (2012).
PMID
22760441
Source
scival
Published In
Journal of Exposure Science and Environmental Epidemiology
Publish Date
2012
DOI
10.1038/jes.2012.67

Associations between brominated flame retardants in house dust and hormone levels in men.

Authors
Johnson, PJ; Stapleton, HM; Mukherjee, B; Hauser, R; Meeker, JD
MLA Citation
Johnson, PJ, Stapleton, HM, Mukherjee, B, Hauser, R, and Meeker, JD. "Associations between brominated flame retardants in house dust and hormone levels in men. (Accepted)" Sci Total Environ (2012). (Academic Article)
PMID
23333513
Source
manual
Published In
Sci Total Environ
Publish Date
2012

Early zebrafish embryogenesis is susceptible to developmental TDCPP exposure

Background: Chlorinated phosphate esters (CPEs) are widely used as additive flame retardants for low-density polyurethane foams and have frequently been detected at elevated concentrations within indoor environmental media. Objectives: To begin characterizing the potential toxicity of CPEs on early vertebrate development, we examined the developmental toxicity of four CPEs used in polyurethane foam: tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and 2,2-bis(chloromethyl)propane-1,3-diyl tetrakis(2-chlorethyl) bis(phosphate) (V6). Methods: Using zebrafish as a model for vertebrate embryogenesis, we first screened the potential teratogenic effects of TDCPP, TCEP, TCPP, and V6 using a developmental toxicity assay. Based on these results, we focused on identification of susceptible windows of developmental TDCPP exposure as well as evaluation of uptake and elimination of TDCPP and bis(1,3-dichloro-2-propyl)phosphate (BDCPP, the primary metabolite) within whole embryos. Finally, because TDCPP-specific genotoxicity assays have, for the most part, been negative in vivo and because zygotic genome remethylation is a key biological event during cleavage, we investigated whether TDCPP altered the status of zygotic genome methylation during early zebrafish embryogenesis. R esults: Overall, our findings suggest that the cleavage period during zebrafish embryogenesis is susceptible to TDCPP-induced delays in remethylation of the zygotic genome, a mechanism that may be associated with enhanced developmental toxicity following initiation of TDCPP exposure at the start of cleavage. C onclusions: Our results suggest that further research is needed to better understand the effects of a widely used and detected CPE within susceptible windows of early vertebrate development.

Authors
McGee, SP; Cooper, EM; Stapleton, HM; Volz, DC
MLA Citation
McGee, SP, Cooper, EM, Stapleton, HM, and Volz, DC. "Early zebrafish embryogenesis is susceptible to developmental TDCPP exposure." Environmental Health Perspectives 120.11 (2012): 1585-1591.
PMID
23017583
Source
scival
Published In
Environmental health perspectives
Volume
120
Issue
11
Publish Date
2012
Start Page
1585
End Page
1591
DOI
10.1289/ehp.1205316

Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster ® 550 in Rats: An Exploratory Assessment

Firemaster® 550 (FM 550), a fire-retardant mixture used in foam-based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 μg/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels. © 2012 Wiley Periodicals, Inc.

Authors
Patisaul, HB; Roberts, SC; Mabrey, N; Mccaffrey, KA; Gear, RB; Braun, J; Belcher, SM; Stapleton, HM
MLA Citation
Patisaul, HB, Roberts, SC, Mabrey, N, Mccaffrey, KA, Gear, RB, Braun, J, Belcher, SM, and Stapleton, HM. "Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster ® 550 in Rats: An Exploratory Assessment." Journal of Biochemical and Molecular Toxicology (2012).
PMID
23139171
Source
scival
Published In
Journal of Biochemical and Molecular Toxicology
Publish Date
2012
DOI
10.1002/jbt.21439

Halogenated phenolic contaminants inhibit the in vitro activity of the thyroid-regulating deiodinases in human liver.

Halogenated contaminants, particularly brominated flame retardants, disrupt circulating levels of thyroid hormones (THs), potentially affecting growth and development. Disruption may be mediated by impacts on deiodinase (DI) activity, which regulate the levels of active hormones available to bind to nuclear receptors. The goal of this study was to develop a mass spectrometry-based method for measuring the activity of DIs in human liver microsomes and to examine the effect of halogenated phenolic contaminants on DI activity. Thyroxine (T4) and reverse triiodothyronine (rT3) deiodination kinetics were measured by incubating pooled human liver microsomes with T4 or rT3 and monitoring the production of T3, rT3, 3,3'-diiodothyronine, and 3-monoiodothyronine by liquid chromatography tandem mass spectrometry. Using this method, we examined the effects of several halogenated contaminants, including 2,2',4,4',5-pentabromodiphenyl ether (BDE 99), several hydroxylated polybrominated diphenyl ethers (OH-BDEs), tribromophenol, tetrabromobisphenol A, and triclosan, on DI activity. The Michaelis constants (K(M)) of rT3 and T4 deiodination were determined to be 3.2 ± 0.7 and 17.3 ± 2.3μM. The V(max) was 160 ± 5.8 and 2.8 ± 0.10 pmol/min.mg protein, respectively. All studied contaminants inhibited DI activity in a dose-response manner, with the exception of BDE 99 and two OH-BDEs. 5'-Hydroxy 2,2',4,4',5-pentabromodiphenyl ether was found to be the most potent inhibitor of DI activity, and phenolic structures containing iodine were generally more potent inhibitors of DI activity relative to brominated, chlorinated, and fluorinated analogues. This study suggests that some halogenated phenolics, including current use compounds such as plastic monomers, flame retardants, and their metabolites, may disrupt TH homeostasis through the inhibition of DI activity in vivo.

Authors
Butt, CM; Wang, D; Stapleton, HM
MLA Citation
Butt, CM, Wang, D, and Stapleton, HM. "Halogenated phenolic contaminants inhibit the in vitro activity of the thyroid-regulating deiodinases in human liver." Toxicol Sci 124.2 (December 2011): 339-347.
PMID
21565810
Source
pubmed
Published In
Toxicological Sciences (Elsevier)
Volume
124
Issue
2
Publish Date
2011
Start Page
339
End Page
347
DOI
10.1093/toxsci/kfr117

Is the PentaBDE replacement, tris (1,3-dichloro-2-propyl) phosphate (TDCPP), a developmental neurotoxicant? Studies in PC12 cells.

Organophosphate flame retardants (OPFRs) are used as replacements for the commercial PentaBDE mixture that was phased out in 2004. OPFRs are ubiquitous in the environment and detected at high concentrations in residential dust, suggesting widespread human exposure. OPFRs are structurally similar to neurotoxic organophosphate pesticides, raising concerns about exposure and toxicity to humans. This study evaluated the neurotoxicity of tris (1,3-dichloro-2-propyl) phosphate (TDCPP) compared to the organophosphate pesticide, chlorpyrifos (CPF), a known developmental neurotoxicant. We also tested the neurotoxicity of three structurally similar OPFRs, tris (2-chloroethyl) phosphate (TCEP), tris (1-chloropropyl) phosphate (TCPP), and tris (2,3-dibromopropyl) phosphate (TDBPP), and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a major component of PentaBDE. Using undifferentiated and differentiating PC12 cells, changes in DNA synthesis, oxidative stress, differentiation into dopaminergic or cholinergic neurophenotypes, cell number, cell growth and neurite growth were assessed. TDCPP displayed concentration-dependent neurotoxicity, often with effects equivalent to or greater than equimolar concentrations of CPF. TDCPP inhibited DNA synthesis, and all OPFRs decreased cell number and altered neurodifferentiation. Although TDCPP elevated oxidative stress, there was no adverse effect on cell viability or growth. TDCPP and TDBPP promoted differentiation into both neuronal phenotypes, while TCEP and TCPP promoted only the cholinergic phenotype. BDE-47 had no effect on cell number, cell growth or neurite growth. Our results demonstrate that different OPFRs show divergent effects on neurodifferentiation, suggesting the participation of multiple mechanisms of toxicity. Additionally, these data suggest that OPFRs may affect neurodevelopment with similar or greater potency compared to known and suspected neurotoxicants.

Authors
Dishaw, LV; Powers, CM; Ryde, IT; Roberts, SC; Seidler, FJ; Slotkin, TA; Stapleton, HM
MLA Citation
Dishaw, LV, Powers, CM, Ryde, IT, Roberts, SC, Seidler, FJ, Slotkin, TA, and Stapleton, HM. "Is the PentaBDE replacement, tris (1,3-dichloro-2-propyl) phosphate (TDCPP), a developmental neurotoxicant? Studies in PC12 cells." Toxicol Appl Pharmacol 256.3 (November 1, 2011): 281-289.
PMID
21255595
Source
pubmed
Published In
Toxicology and Applied Pharmacology
Volume
256
Issue
3
Publish Date
2011
Start Page
281
End Page
289
DOI
10.1016/j.taap.2011.01.005

Genotoxicity in Atlantic killifish (Fundulus heteroclitus) from a PAH-contaminated Superfund site on the Elizabeth River, Virginia.

The Atlantic Wood Industries Superfund site (AWI) on the Elizabeth River in Portsmouth, VA is heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) from a wood treatment facility. Atlantic killifish, or mummichog (Fundulus heteroclitus), at this Superfund site are exposed to very high concentrations of several carcinogens. In this study, we measured PAH concentrations in both fish tissues and sediments. Concurrently, we assessed different aspects of genotoxicity in the killifish exposed in situ. Both sediment and tissue PAH levels were significantly higher in AWI samples, relative to a reference site, but the chemistry profile was different between sediments and tissues. Killifish at AWI exhibited higher levels of DNA damage compared to reference fish, as measured via the flow cytometric method (FCM), and the damage was consistent with sediment PAH concentrations. Covalent binding of benzo[a]pyrene (BaP) metabolites to DNA, as measured via LC-MS/MS adduct detection methods, were also elevated and could be partially responsible for the DNA damage. Using similar LC-MS/MS methods, we found no evidence that oxidative DNA adducts had a role in observed genotoxicity.

Authors
Jung, D; Matson, CW; Collins, LB; Laban, G; Stapleton, HM; Bickham, JW; Swenberg, JA; Di Giulio, RT
MLA Citation
Jung, D, Matson, CW, Collins, LB, Laban, G, Stapleton, HM, Bickham, JW, Swenberg, JA, and Di Giulio, RT. "Genotoxicity in Atlantic killifish (Fundulus heteroclitus) from a PAH-contaminated Superfund site on the Elizabeth River, Virginia." Ecotoxicology 20.8 (November 2011): 1890-1899.
PMID
21706406
Source
pubmed
Published In
Ecotoxicology
Volume
20
Issue
8
Publish Date
2011
Start Page
1890
End Page
1899
DOI
10.1007/s10646-011-0727-9

Analysis of the flame retardant metabolites bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPP) in urine using liquid chromatography-tandem mass spectrometry.

Organophosphate triesters tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate are widely used flame retardants (FRs) present in many products common to human environments, yet understanding of human exposure and health effects of these compounds is limited. Monitoring urinary metabolites as biomarkers of exposure can be a valuable aid for improving this understanding; however, no previously published method exists for the analysis of the primary TDCPP metabolite, bis(1,3-dichloro-2-propyl) phosphate (BDCPP), in human urine. Here, we present a method to extract the metabolites BDCPP and diphenyl phosphate (DPP) in human urine using mixed-mode anion exchange solid phase extraction and mass-labeled internal standards with analysis by atmospheric pressure chemical ionization liquid chromatography tandem mass spectrometry. The method detection limit was 8 pg mL(-1) urine for BDCPP and 204 pg mL(-1) for DPP. Recoveries of analytes spiked into urine ranged from 82 ± 10% to 91 ± 4% for BDCPP and from 72 ± 12% to 76 ± 8% for DPP. Analysis of a small number of urine samples (n=9) randomly collected from non-occupationally exposed adults revealed the presence of both BDCPP and DPP in all samples. Non-normalized urinary concentrations ranged from 46-1,662 pg BDCPP mL(-1) to 287-7,443 pg DPP mL(-1), with geometric means of 147 pg BDCPP mL(-1) and 1,074 pg DPP mL(-1). Levels of DPP were higher than those of BDCPP in 89% of samples. The presented method is simple and sufficiently sensitive to detect these FR metabolites in humans and may be applied to future studies to increase our understanding of exposure to and potential health effects from FRs.

Authors
Cooper, EM; Covaci, A; van Nuijs, ALN; Webster, TF; Stapleton, HM
MLA Citation
Cooper, EM, Covaci, A, van Nuijs, ALN, Webster, TF, and Stapleton, HM. "Analysis of the flame retardant metabolites bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPP) in urine using liquid chromatography-tandem mass spectrometry." Anal Bioanal Chem 401.7 (October 2011): 2123-2132.
PMID
21830137
Source
pubmed
Published In
Analytical and Bioanalytical Chemistry
Volume
401
Issue
7
Publish Date
2011
Start Page
2123
End Page
2132
DOI
10.1007/s00216-011-5294-7

Associations between polybrominated diphenyl ether (PBDE) flame retardants, phenolic metabolites, and thyroid hormones during pregnancy.

BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are chemical additives used as flame retardants in commercial products. PBDEs are bioaccumulative and persistent and have been linked to several adverse health outcomes. OBJECTIVES: This study leverages an ongoing pregnancy cohort to measure PBDEs and PBDE metabolites in serum collected from an understudied population of pregnant women late in their third trimester. A secondary objective was to determine whether the PBDEs or their metabolites were associated with maternal thyroid hormones. METHODS: One hundred forty pregnant women > 34 weeks into their pregnancy were recruited into this study between 2008 and 2010. Blood samples were collected during a routine prenatal clinic visit. Serum was analyzed for a suite of PBDEs, three phenolic metabolites (i.e., containing an -OH moiety), and five thyroid hormones. RESULTS: PBDEs were detected in all samples and ranged from 3.6 to 694 ng/g lipid. Two hydroxylated BDE congeners (4´-OH-BDE 49 and 6-OH-BDE 47) were detected in > 67% of the samples. BDEs 47, 99, and 100 were significantly and positively associated with free and total thyroxine (T4) levels and with total triiodothyronine levels above the normal range. Associations between T4 and PBDEs remained after controlling for smoking status, maternal age, race, gestational age, and parity. CONCLUSIONS: PBDEs and OH-BDEs are prevalent in this cohort, and levels are similar to those in the general population. Given their long half-lives, PBDEs may be affecting thyroid regulation throughout pregnancy. Further research is warranted to determine mechanisms through which PBDEs affect thyroid hormone levels in developing fetuses and newborn babies.

Authors
Stapleton, HM; Eagle, S; Anthopolos, R; Wolkin, A; Miranda, ML
MLA Citation
Stapleton, HM, Eagle, S, Anthopolos, R, Wolkin, A, and Miranda, ML. "Associations between polybrominated diphenyl ether (PBDE) flame retardants, phenolic metabolites, and thyroid hormones during pregnancy." Environ Health Perspect 119.10 (October 2011): 1454-1459.
PMID
21715241
Source
pubmed
Published In
Environmental health perspectives
Volume
119
Issue
10
Publish Date
2011
Start Page
1454
End Page
1459
DOI
10.1289/ehp.1003235

Accumulation and debromination of decabromodiphenyl ether (BDE-209) in juvenile fathead minnows (Pimephales promelas) induces thyroid disruption and liver alterations.

Polybrominated diphenyl ether (PBDE) flame retardants are known to affect thyroid hormone (TH) regulation. The TH-regulating deiodinases have been implicated in these impacts; however, PBDE effects on the fish thyroid system are largely unknown. Moreover, the liver as a potential target of PBDE toxicity has not been explored in young fish. This study measured decabromodiphenyl ether (BDE-209) effects on TH regulation by measuring deiodinase activity in juvenile fathead minnows (Pimephales promelas). Dietary accumulations and debromination of BDE-209 were also measured, and the morphology of thyroid and liver tissues was examined. Juvenile fathead minnows (28 days old) received a 28-day dietary treatment of BDE-209 at 9.8 ± 0.16 μg/g of food at 5% of their body weight per day followed by a 14-day depuration period in which they were fed clean food. Chemical analysis revealed that BDE-209 accumulated in tissues and was metabolized to reductive products ranging from penta- to octaBDEs with 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154) being the most accumulative metabolite. By day 28 of the exposure, rates of outer and inner ring deiodination (ORD and IRD, respectively) of thyroxine (T4) were each reduced by ∼74% among treatments. Effects on T4-ORD and T4-IRD remained significant even after the 14-day depuration period. Histological examination of treated fish showed significantly increased thyroid follicular epithelial cell heights and vacuolated hepatocyte nuclei. Enlarged biliary passageways may be the cause of the distinctive liver phenotype observed, although further testing is needed. Altogether, these results suggest that juvenile fish may be uniquely susceptible to thyroid disruptors like PBDEs.

Authors
Noyes, PD; Hinton, DE; Stapleton, HM
MLA Citation
Noyes, PD, Hinton, DE, and Stapleton, HM. "Accumulation and debromination of decabromodiphenyl ether (BDE-209) in juvenile fathead minnows (Pimephales promelas) induces thyroid disruption and liver alterations." Toxicol Sci 122.2 (August 2011): 265-274.
PMID
21546348
Source
pubmed
Published In
Toxicological Sciences (Elsevier)
Volume
122
Issue
2
Publish Date
2011
Start Page
265
End Page
274
DOI
10.1093/toxsci/kfr105

Identification of flame retardants in polyurethane foam collected from baby products.

With the phase-out of PentaBDE in 2004, alternative flame retardants are being used in polyurethane foam to meet flammability standards. However, insufficient information is available on the identity of the flame retardants currently in use. Baby products containing polyurethane foam must meet California state furniture flammability standards, which likely affects the use of flame retardants in baby products throughout the U.S. However, it is unclear which products contain flame retardants and at what concentrations. In this study we surveyed baby products containing polyurethane foam to investigate how often flame retardants were used in these products. Information on when the products were purchased and whether they contained a label indicating that the product meets requirements for a California flammability standard were recorded. When possible, we identified the flame retardants being used and their concentrations in the foam. Foam samples collected from 101 commonly used baby products were analyzed. Eighty samples contained an identifiable flame retardant additive, and all but one of these was either chlorinated or brominated. The most common flame retardant detected was tris(1,3-dichloroisopropyl) phosphate (TDCPP; detection frequency 36%), followed by components typically found in the Firemaster550 commercial mixture (detection frequency 17%). Five samples contained PBDE congeners commonly associated with PentaBDE, suggesting products with PentaBDE are still in-use. Two chlorinated organophosphate flame retardants (OPFRs) not previously documented in the environment were also identified, one of which is commercially sold as V6 (detection frequency 15%) and contains tris(2-chloroethyl) phosphate (TCEP) as an impurity. As an addition to this study, we used a portable X-ray fluorescence (XRF) analyzer to estimate the bromine and chlorine content of the foam and investigate whether XRF is a useful method for predicting the presence of halogenated flame retardant additives in these products. A significant correlation was observed for bromine; however, there was no significant relationship observed for chlorine. To the authors knowledge, this is the first study to report on flame retardants in baby products. In addition, we have identified two chlorinated OPFRs not previously documented in the environment or in consumer products. Based on exposure estimates conducted by the Consumer Product Safety Commission (CPSC), we predict that infants may receive greater exposure to TDCPP from these products compared to the average child or adult from upholstered furniture, all of which are higher than acceptable daily intake levels of TDCPP set by the CPSC. Future studies are therefore warranted to specifically measure infants exposure to these flame retardants from intimate contact with these products and to determine if there are any associated health concerns.

Authors
Stapleton, HM; Klosterhaus, S; Keller, A; Ferguson, PL; van Bergen, S; Cooper, E; Webster, TF; Blum, A
MLA Citation
Stapleton, HM, Klosterhaus, S, Keller, A, Ferguson, PL, van Bergen, S, Cooper, E, Webster, TF, and Blum, A. "Identification of flame retardants in polyurethane foam collected from baby products." Environ Sci Technol 45.12 (June 15, 2011): 5323-5331.
PMID
21591615
Source
pubmed
Published In
Environmental Science & Technology
Volume
45
Issue
12
Publish Date
2011
Start Page
5323
End Page
5331
DOI
10.1021/es2007462

Species-specific differences and structure-activity relationships in the debromination of PBDE congeners in three fish species.

Previous studies have suggested that there may be species-specific differences in the metabolism of polybrominated diphenyl ethers (PBDEs) among different fish species. In this study, we investigated the in vitro hepatic metabolism of eleven individual PBDE congeners (tri- through decaBDEs) in three different fish species: rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), and Chinook salmon (O. tschwatcha). In addition, we evaluated the influence of PBDE structural characteristics (i.e., bromine substitution patterns) on metabolism. Six of the eleven congeners we evaluated, BDEs 99, 153, 183, 203, 208, and 209, were metabolically debrominated to lower brominated congeners. All of the congeners that were metabolized contained at least one meta-substituted bromine. Metabolites were not detected for congeners without one meta-substituted bromine (e.g., BDEs 28, 47, and 100). Metabolite formation rates were generally 10 to 100 times faster in carp than in trout and salmon. BDEs 47, 49, 101, 154, and 183 were the major metabolites observed in all three species with the exception of BDE 47, which was only detected in carp. Carp demonstrated a preference toward meta-debromination, while trout and salmon debrominated meta- and para-bromine atoms to an equal extent. We compared glutathione-S-transferase (GST) and deiodinase (DI) activity among all three species as these enzyme systems have been hypothesized to play a role in PBDE debromination in teleosts. Carp exhibited a preference for meta-deiodination of the thyroid hormone thyroxine, which was consistent with the preference for meta-debromination of PBDEs observed in carp.

Authors
Roberts, SC; Noyes, PD; Gallagher, EP; Stapleton, HM
MLA Citation
Roberts, SC, Noyes, PD, Gallagher, EP, and Stapleton, HM. "Species-specific differences and structure-activity relationships in the debromination of PBDE congeners in three fish species." Environ Sci Technol 45.5 (March 1, 2011): 1999-2005.
PMID
21291240
Source
pubmed
Published In
Environmental Science & Technology
Volume
45
Issue
5
Publish Date
2011
Start Page
1999
End Page
2005
DOI
10.1021/es103934x

Biotransformation of HBCD in biological systems can confound temporal-trend studies

Authors
Tomy, GT; Palace, V; Marvin, C; Stapleton, HM; Covaci, A; Harrad, S
MLA Citation
Tomy, GT, Palace, V, Marvin, C, Stapleton, HM, Covaci, A, and Harrad, S. "Biotransformation of HBCD in biological systems can confound temporal-trend studies." Environmental Science and Technology 45.2 (2011): 364-365.
PMID
21155584
Source
scival
Published In
Environmental Science & Technology
Volume
45
Issue
2
Publish Date
2011
Start Page
364
End Page
365
DOI
10.1021/es1039369

Exposure to PBDEs in the office environment: Evaluating the relationships between dust, handwipes, and serum

Background: Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants in consumer products and are ubiquitous in residential indoor air and dust. However, little is known about exposure in the office environment. Objectives: We examined relationships between PBDE concentrations in the office environment and internal exposure using concurrent measurements of PBDEs in serum, handwipes, and office dust. Methods: We collected serum, dust, and handwipe samples from 31 participants who spent at least 20 hr/week in an office. We used a questionnaire to collect information about work and personal habits. Results: We found positive associations between PBDEs in room dust, handwipes (a measure of personal exposure), and serum. PBDE office dust concentrations were weakly correlated with measurements in handwipes: r = 0.35 (p = 0.06) for pentaBDE (sum of BDE congeners 28/33, 47, 99, 100, and 153) and 0.33 (p = 0.07) for BDE-209. Hand washing also predicted pentaBDE levels in handwipes: low hand-washers had 3.3 times the pentaBDE levels in their handwipes than did high hand-washers (p = 0.02). PentaBDE in handwipes predicted pentaBDE levels in serum (p = 0.03): Serum concentrations in the highest handwipe tertile were on average 3.5 times the lowest hand-wipe tertile. The geometric mean concentration of pentaBDEs in serum was 27 ng/g lipid. We detected BDE-209 in 20% of serum samples, at levels ranging from < 4.8 to 9.7 ng/g lipid. Conclusion: Our research suggests that exposure to pentaBDE in the office environment contrib.-utes to pentaBDE body burden, with exposure likely linked to PBDE residues on hands. In addi-tion, hand washing may decrease exposure to PBDEs.

Authors
Watkins, DJ; McClean, MD; Fraser, AJ; Weinberg, J; Stapleton, HM; Sjödin, A; Webster, TF
MLA Citation
Watkins, DJ, McClean, MD, Fraser, AJ, Weinberg, J, Stapleton, HM, Sjödin, A, and Webster, TF. "Exposure to PBDEs in the office environment: Evaluating the relationships between dust, handwipes, and serum." Environmental Health Perspectives 119.9 (2011): 1247-1252.
PMID
21715243
Source
scival
Published In
Environmental health perspectives
Volume
119
Issue
9
Publish Date
2011
Start Page
1247
End Page
1252
DOI
10.1289/ehp.1003271

Serum PBDEs in US Toddlers: Associations with Hand Wipes, House Dust and Socioeconomic Variables

Authors
Stapleton, HM; Eagle, SD; Sjodin, A; Webster, TF
MLA Citation
Stapleton, HM, Eagle, SD, Sjodin, A, and Webster, TF. "Serum PBDEs in US Toddlers: Associations with Hand Wipes, House Dust and Socioeconomic Variables (Submitted)." Environmental Health Perspectives (2011). (Academic Article)
Source
manual
Published In
Environmental Health Perspectives
Publish Date
2011

Ultraviolet treatment and biodegradation of dibenzothiophene: Identification and toxicity of products.

Biodegradation of pollutants often results in incomplete mineralization and formation of degradation products with unknown chemical and toxicological characteristics. Ultraviolet (UV) irradiation, a common technology used in water and wastewater treatment, may help reduce aqueous concentrations of degradation products produced during biological treatment and their associated hazards. Combined biological and UV transformations may be important in natural systems as well. We investigated the effects of UV irradiation (254 nm) on dibenzothiophene (DBT), a sulfur-containing polyaromatic hydrocarbon, in artificial seawater, and its effects on biodegradation products produced from mixed-community microbial transformations of DBT, including DBT sulfone, DBT sulfoxide, hydroxylated and carboxylated benzothiophenes, thiosalicylic acid, and others. Toxicity of solutions after UV exposure was monitored using bioluminescent bacteria (Vibrio fischeri) and by evaluating cardiac deformities in Fundulus heteroclitus embryos. The highest UV fluence reduced DBT concentration by 28% when DBT was present as the sole organic solute. In postbiodegradation solution, the same fluence reduced the initial concentration of DBT by 81%, and 11 DBT biodegradation products to trace levels. Regardless of UV fluence, DBT by itself produced minimal effects in Fundulus embryos but was moderately toxic to V. fischeri. Postbiodegradation solutions were highly toxic to both test organisms. The highest UV fluence slightly reduced toxicity of postbiodegradation solution to V. fischeri but exacerbated cardiac deformities in Fundulus embryos. Toxicity could not be attributed to specific products and was likely a result of mixture effects. These results emphasize that toxicity can increase during remediation and that multiple assays may be necessary for evaluation. The novel approach of combined biodegradation/UV treatment is promising, although further research is needed to reduce toxicity in the case of DBT.

Authors
Cooper, EM; Stapleton, HM; Matson, CW; Di Giulio, RT; Schuler, AJ
MLA Citation
Cooper, EM, Stapleton, HM, Matson, CW, Di Giulio, RT, and Schuler, AJ. "Ultraviolet treatment and biodegradation of dibenzothiophene: Identification and toxicity of products." Environ Toxicol Chem 29.11 (November 2010): 2409-2416.
PMID
20862751
Source
pubmed
Published In
Environmental Toxicology & Chemistry
Volume
29
Issue
11
Publish Date
2010
Start Page
2409
End Page
2416
DOI
10.1002/etc.312

Analysis of thyroid hormones in serum by liquid chromatography-tandem mass spectrometry.

Thyroid hormones are essential hormones for regulating growth and development in humans and wildlife. Methods to monitor precise and low levels of these hormones in serum and tissues are needed to assess overall health, whether from disease considerations or possibly from environmental contaminant exposures. Common and routine methods typically rely upon radioimmunoassays, which can be expensive, and typically only measure thyroxine and 3,3',5-triidothyronine, which can be a limitation in fully evaluating impacts on thyroid regulation. In this study we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous analysis of five thyroid hormones--thyroxine, 3,3',5-triidothyronine, 3,3',5'-triiodothyronine, 3,3'-diiodothyronine, and 3,5-diiodothyronine--in serum samples. The LC-MS/MS parameters were optimized and calibrated over a wide concentration range (1.0-500 ng/mL) with on-column detection limits of 1.5-7.0 pg. With use of spiked bovine serum samples, the mean method recoveries were calculated to be 81.3-111.9% with relative standard deviations of 1.2-9.6% at spiking levels ranging from 10 to 100 ng/mL. This method was compared with measurements made by standard radioimmunoassays and with measurements made in a serum Standard Reference Material (SRM 1951b). Development of this method expands the capacity to measure thyroid hormones by including a larger suite of thyroid hormones, and has promising applications for measuring catabolism of thyroid hormones in vitro.

Authors
Wang, D; Stapleton, HM
MLA Citation
Wang, D, and Stapleton, HM. "Analysis of thyroid hormones in serum by liquid chromatography-tandem mass spectrometry." Anal Bioanal Chem 397.5 (July 2010): 1831-1839.
PMID
20437035
Source
pubmed
Published In
Analytical and Bioanalytical Chemistry
Volume
397
Issue
5
Publish Date
2010
Start Page
1831
End Page
1839
DOI
10.1007/s00216-010-3705-9

Characterizing the in vitro hepatic biotransformation of the flame retardant BDE 99 by common carp.

Polybrominated diphenyl ethers (PBDEs) are a class of flame retardant chemicals known to biomagnify in aquatic foodwebs. However, significant biotransformation of some congeners via reductive dehalogenation has been observed during in vivo and in vitro laboratory exposures, particularly in fish models. Little information is available on the enzyme systems responsible for catalyzing this metabolic pathway in fish. This study was undertaken to characterize the biotransformation of one primary BDE congener, 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), using in vitro techniques. Hepatic sub-cellular fractions were first prepared from individual adult common carp (Cyprinus carpio) to examine metabolism in both microsomal and cytosolic sub-cellular fractions. Debromination rates (i.e. BDE-99 biotransformation to BDE-47) were generally higher in the microsomal fraction than in the cytosolic fraction, and some intra-species variability was observed. Further experiments were conducted to determine the biotransformation kinetics and the influence of specific co-factors, inhibitors and competitive substrates on metabolism using pooled carp liver microsomes. The apparent K(m) and V(max) values were 19.4microM and 1120pmolesh(-1)mgprotein(-1), respectively. Iodoacetate (IaC) and the two thyroid hormones, reverse triodothyronine (rT3) and thyroxine (T4), significantly inhibited the debromination of BDE-99 in microsomal sub-cellular fractions with IC(50) values of 2.2microM, 0.83microM, and >1.0microM, respectively. These results support our hypothesis that deiodinase enzymes may be catalyzing the metabolism of PBDEs in fish liver tissues. Further studies are needed to evaluate metabolic activity in other species and tissues that contain these enzymes.

Authors
Noyes, PD; Kelly, SM; Mitchelmore, CL; Stapleton, HM
MLA Citation
Noyes, PD, Kelly, SM, Mitchelmore, CL, and Stapleton, HM. "Characterizing the in vitro hepatic biotransformation of the flame retardant BDE 99 by common carp." Aquat Toxicol 97.2 (April 15, 2010): 142-150.
PMID
20080306
Source
pubmed
Published In
Aquatic Toxicology
Volume
97
Issue
2
Publish Date
2010
Start Page
142
End Page
150
DOI
10.1016/j.aquatox.2009.12.013

Accumulation and DNA damage in fathead minnows (Pimephales promelas) exposed to 2 brominated flame-retardant mixtures, firemaster® 550 and firemaster® BZ-54

Firemaster® 550 and Firemaster® BZ-54 are two brominated formulations that are in use as replacements for polybrominated diphenyl ether (PBDE) flame retardants. Two major components of these mixtures are 2,3,4,5-tetrabromo-ethylhexylbenzoate (TBB) and 2,3,4,5-tetrabromo-bis(2- ethylhexyl) phthalate (TBPH). Both have been measured in environmental matrices; however, scant toxicological information exists. The present study aimed to determine if these brominated flame-retardant formulations are bioavailable and adversely affect DNA integrity in fish. Fathead minnows (Pimephales promelas) were orally exposed to either FM 550, FM BZ54, or the nonbrominated form of TBPH, di-(2-ethylhexyl) phthalate (DEHP) for 56 d and depurated (e.g., fed clean food) for 22 d. At several time points, liver and blood cells were collected and assessed for DNA damage. Homogenized fish tissues were extracted and analyzed on day 0 and day 56 to determine the residue of TBB and TBPH and the appearance of any metabolites using gas chromatography-electron-capture negative ion mass spectrometry (GC/ECNI-MS). Significant increases (p < 0.05) in DNA strand breaks from liver cells (but not blood cells) were observed during the exposure period compared with controls, although during depuration these levels returned to control. Both parent compounds, TBB and TBPH, were detected in tissues at approximately 1% of daily dosage along with brominated metabolites. The present study provides evidence for accumulation, metabolism, and genotoxicity of these new formulation flame retardants in fish and highlights the potential adverse effects of TBB- and TBPH-formulated fire retardants to aquatic species. © 2009 SETAC.

Authors
Bearr, JS; Stapleton, HM; Mitchelmore, CL
MLA Citation
Bearr, JS, Stapleton, HM, and Mitchelmore, CL. "Accumulation and DNA damage in fathead minnows (Pimephales promelas) exposed to 2 brominated flame-retardant mixtures, firemaster® 550 and firemaster® BZ-54." Environmental Toxicology and Chemistry 29.3 (2010): 722-729.
PMID
20821500
Source
scival
Published In
Environmental Toxicology & Chemistry
Volume
29
Issue
3
Publish Date
2010
Start Page
722
End Page
729
DOI
10.1002/etc.94

House dust concentrations of organophosphate flame retardants in relation to hormone levels and semen quality parameters

BACKGROUND: Organophosphate (OP) compounds, such as tris(1,3-dichloro-2- propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), are commonly used as additive flame retardants and plasticizers in a wide range of materials. Although widespread human exposure to OP flame retardants is likely, there is a lack of human and animal data on potential health effects. OBJECTIVE: We explored relationships of TDCPP and TPP concentrations in house dust with hormone levels and semen quality parameters. METHODS: We analyzed house dust from 50 men recruited through a U.S. infertility clinic for TDCPP and TPP. Relationships with reproductive and thyroid hormone levels, as well as semen quality parameters, were assessed using crude and multivariable linear regression. RESULTS: TDCPP and TPP were detected in 96% and 98% of samples, respectively, with widely varying concentrations up to 1.8 mg/g. In models adjusted for age and body mass index, an interquartile range (IQR) increase in TDCPP was associated with a 3% [95% confidence interval (CI), -5% to -1%) decline in free thyroxine and a 17% (95% CI, 4-32%) increase in prolactin. There was a suggestive inverse association between TDCPP and free androgen index that became less evident in adjusted models. In the adjusted models, an IQR increase in TPP was associated with a 10% (95% CI, 2-19%) increase in prolactin and a 19% (95% CI, -30% to -5%) decrease in sperm concentration. CONCLUSION: OP flame retardants may be associated with altered hormone levels and decreased semen quality in men. More research on sources and levels of human exposure to OP flame retardants and associated health outcomes are needed.

Authors
Meeker, JD; Stapleton, HM
MLA Citation
Meeker, JD, and Stapleton, HM. "House dust concentrations of organophosphate flame retardants in relation to hormone levels and semen quality parameters." Environmental Health Perspectives 118.3 (2010): 318-323.
PMID
20194068
Source
scival
Published In
Environmental health perspectives
Volume
118
Issue
3
Publish Date
2010
Start Page
318
End Page
323
DOI
10.1289/ehp.0901332

PBDEs, methoxylated PBDEs and HBCDs in Japanese common squid (Todarodes pacificus) from Korean offshore waters

Little information is available on the levels of brominated compounds found in biota from the Korean Peninsula. In this study, Japanese common squids (Todarodes pacificus) were analyzed for 38 polybrominated diphenyl ethers, two methoxylated polybrominated diphenyl ethers and three stereoisomers of hexabromocyclododecane (α, β, and γ-HBCD) from the east and western coasts of the Korean Peninsula. Among 38 PBDEs, 10 PBDEs were detected and their total concentrations ranged from 21 to 292. ng/g lipid wt with a mean concentration of 108. ng/g lipid wt, while two MeO-BDEs and three isomers of HBCDs were detected in all samples. BDE47 showed the highest residual level, followed by BDE99, 154, 153, 28/33. Concentrations of PBDEs and MeO-BDEs were not significantly different between the both sides of the Korean Peninsula; however, HBCD concentrations were higher levels in the East/Japan Sea than the Yellow Sea, indicating that HBCD sources possibly exist in Japan. © 2010 Elsevier Ltd.

Authors
Kim, GB; Stapleton, HM
MLA Citation
Kim, GB, and Stapleton, HM. "PBDEs, methoxylated PBDEs and HBCDs in Japanese common squid (Todarodes pacificus) from Korean offshore waters." Marine Pollution Bulletin 60.6 (2010): 935-940.
PMID
20394952
Source
scival
Published In
Marine Pollution Bulletin
Volume
60
Issue
6
Publish Date
2010
Start Page
935
End Page
940
DOI
10.1016/j.marpolbul.2010.03.025

Evaluating daily exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in fish oil supplements

Fish oil supplements have become a popular means of increasing one's dietary intake of essential polyunsaturated fatty acids. However, there is growing concern that the levels and potential health effects of lipophilic organic contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may diminish some of the health benefits associated with the daily consumption of fish oil supplements. In this study, ten over-the-counter fish oil supplements available in the United States were analysed for PCBs and PBDEs and daily exposures calculated. Based on manufacturers' recommended dosages, daily intakes of PCBs and PBDEs ranged from 5 to 686 ng day-1 and from 1 to 13 ng day-1, respectively. Daily consumption offish oil supplements expose consumers to PCBs and PBDEs. However, in comparison with fish ingestion, fish supplements may decrease daily PCB exposure and provide a safer pathway for individuals seeking to maintain daily recommended levels of polyunsaturated fatty acids. © 2010 Taylor & Francis.

Authors
Ashley, JTF; Ward, JS; Schafer, MW; Stapleton, HM; Velinsky, DJ
MLA Citation
Ashley, JTF, Ward, JS, Schafer, MW, Stapleton, HM, and Velinsky, DJ. "Evaluating daily exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in fish oil supplements." Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 27.8 (2010): 1177-1185.
PMID
20496249
Source
scival
Published In
Food Additives & Contaminants: Part A - Chemistry, Analysis, Control, Exposure & Risk Assessment
Volume
27
Issue
8
Publish Date
2010
Start Page
1177
End Page
1185
DOI
10.1080/19440041003793298

Relationships between polybrominated diphenyl ether concentrations in house dust and serum

Polybrominated diphenyl ethers (PBDEs) have been measured in the home environment and in humans, but studies linking environmental levels to body burdens are limited. This study examines the relationship between PBDE concentrations in house dust and serum from adults residing in these homes. We measured PBDE concentrations in house dust from 50 homes and in serum of male-female couples from 12 of the homes. Detection rates, dust-serum, and within-matrix correlations varied by PBDE congener. There was a strong correlation (r = 0.65-0.89, p < 0.05) between dust and serum concentrations of several predominant PBDE congeners (BDE 47, 99, and 100). Dust and serum levels of BDE 153 were not correlated (r < 0.01). The correlation of dust and serum levels of BDE 209 could not be evaluated due to low detection rates of BDE 209 in serum. Serum concentrations of the sum of BDE 47, 99, and 100 were also strongly correlated within couples (r = 0.85, p = 0.0005). This study provides evidence that house dust is a primary exposure pathway of PBDEs and supports the use of dust PBDE concentrations as a marker for exposure to PBDE congeners other than BDE 153. © 2010 American Chemical Society.

Authors
Johnson, PI; Stapleton, HM; Sjodin, A; Meeker, JD
MLA Citation
Johnson, PI, Stapleton, HM, Sjodin, A, and Meeker, JD. "Relationships between polybrominated diphenyl ether concentrations in house dust and serum." Environmental Science and Technology 44.14 (2010): 5627-5632.
Website
http://hdl.handle.net/10161/4025
PMID
20521814
Source
scival
Published In
Environmental Science & Technology
Volume
44
Issue
14
Publish Date
2010
Start Page
5627
End Page
5632
DOI
10.1021/es100697q

Relationships Between Brominated Flame Retardant Concentrations in House Dust and Serum Hormone Levels in Men

Authors
Johnson, PI; Stapleton, HM; Hauser, R; Meeker, JD
MLA Citation
Johnson, PI, Stapleton, HM, Hauser, R, and Meeker, JD. "Relationships Between Brominated Flame Retardant Concentrations in House Dust and Serum Hormone Levels in Men." November 2009.
Source
wos-lite
Published In
Epidemiology
Volume
20
Issue
6
Publish Date
2009
Start Page
S162
End Page
S163

Response to "Comment on 'Photodegradation Pathways of Nonabrominated Diphenyl Ethers, 2-Ethylhexyltetrabromobenzoate, and Di(2-ethylhexyl)tetrabromophthalate: Identifying Potential Markers of Photodegradation'"

Authors
Stapleton, HM; Davis, EF
MLA Citation
Stapleton, HM, and Davis, EF. "Response to "Comment on 'Photodegradation Pathways of Nonabrominated Diphenyl Ethers, 2-Ethylhexyltetrabromobenzoate, and Di(2-ethylhexyl)tetrabromophthalate: Identifying Potential Markers of Photodegradation'"." Environ Sci Technol 43.20 (October 15, 2009): 7994-.
PMID
19921926
Source
pubmed
Published In
Environmental Science & Technology
Volume
43
Issue
20
Publish Date
2009
Start Page
7994
DOI
10.1021/es902576n

Detection of organophosphate flame retardants in furniture foam and U.S. house dust.

Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the increased use of alternate flame retardant chemicals to meet flammability standards. However, it has been difficult to determine which chemical formulations are currently being used in high volumes to meet flammability standards since the use of flame retardant formulations in consumer products is not transparent (i.e., not provided to customers). To investigate chemicals being used as replacements for PentaBDE in polyurethane foam, we analyzed foam samples from 26 different pieces of furniture purchased in the United States primarily between 2003 and 2009. Samples included foam from couches, chairs, mattress pads, pillows, and, in one case, foam from a sound-proofing system of a laboratory-grade dust sieve, and were analyzed using gas chromatography mass spectrometry. Fifteen of the foam samples contained the flame retardanttris(1,3-dichloro-2-propyl) phosphate (TDCPP; 1-5% by weight), four samples contained tris(1-chloro-2-propyl) phosphate (TCPP; 0.5 -22% by weight), one sample contained brominated chemicals found in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from a futon likely purchased prior to 2004 contained PentaBDE (0.5% by weight). Due to the high frequency of detection of the chlorinated phosphate compounds in furniture foam,we analyzed extracts from 50 house dust samples collected between 2002 and 2007 in the Boston, MA area for TDCPP, TCPP, and another high volume use organophosphate-based flame retardant used in foam, triphenylphosphate (TPP). Detection frequencies for TDCPP and TPP in the dust samples were > 96% and were log normally distributed, similar to observations for PBDEs. TCPP was positively detected in dust in only 24% of the samples, but detection was significantly limited by a coelution problem. The geometric mean concentrations for TCPP, TDCPP, and TPP in house dust were 570, 1890, and 7360 ng/g, respectively, and maximum values detected in dust were 5490, 56,080 and 1,798,000 ng/g, respectively. These data suggest that levels of these organophosphate flame retardants are comparable, or in some cases greater than, levels of PBDEs in house dust. The high prevalence of these chemicals in foam and the high concentrations measured in dust (as high as 1.8 mg/g) warrant further studies to evaluate potential health effects from dust exposure, particularly for children.

Authors
Stapleton, HM; Klosterhaus, S; Eagle, S; Fuh, J; Meeker, JD; Blum, A; Webster, TF
MLA Citation
Stapleton, HM, Klosterhaus, S, Eagle, S, Fuh, J, Meeker, JD, Blum, A, and Webster, TF. "Detection of organophosphate flame retardants in furniture foam and U.S. house dust." Environ Sci Technol 43.19 (October 1, 2009): 7490-7495.
PMID
19848166
Source
pubmed
Published In
Environmental Science & Technology
Volume
43
Issue
19
Publish Date
2009
Start Page
7490
End Page
7495

Photodegradation pathways of nonabrominated diphenyl ethers, 2-ethylhexyltetrabromobenzoate and di(2-ethylhexyl)tetrabromophthalate: identifying potential markers of photodegradation.

Photodegradation kinetics of several polybrominated diphenyl ethers (PBDEs), particularly decabromodiphenyl ether (BDE 209), have been reported in various matrixes, demonstrating that it photodegrades primarily via debromination. However, it has been difficult to determine the primary pathways by which bromine is cleaved from BDE 209 to form nona- and octabrominated congeners. In this study, photodegradation of the three nonaBDE congeners (i.e., BDE 206, 207, and 208) was examined individually in three different solvents exposed to natural sunlight and then analyzed to identify the primary degradation products. Rapid degradation of nonaBDEs (half-lives ranging from 4.25 to 12.78 min) was observed coincident with formation of octa- and heptabrominated PBDEs. BDE 207 photodegraded most rapidly while BDE 206 photodegraded the slowest. The photodegradation pathways of each nonaBDE congener were consistent among the different solvent matrixes tested; however, mass balances were found to vary with the type of solvent used in the experiment (recovery ranging from 76 to 95%). The octabrominated congener, BDE 202, and the ratio of BDE197 to BDE 201,were identified as congeners that may serve as environmental markers of photolytic debromination of decaBDE. Additional photodegradation studies were conducted with two new brominated flame retardants used in replacements for pentaBDE mixtures: 2-ethylhexyltetrabromobenzoate (TBB) and di(2-ethylhexyl)-tetrabromophthalate (TBPH). Both TBB and TBPH underwent photolysis more slowly than nonaBDEs (half-lives ranging from 85.70 to 220.17 min) and primarily formed debrominated products.

Authors
Davis, EF; Stapleton, HM
MLA Citation
Davis, EF, and Stapleton, HM. "Photodegradation pathways of nonabrominated diphenyl ethers, 2-ethylhexyltetrabromobenzoate and di(2-ethylhexyl)tetrabromophthalate: identifying potential markers of photodegradation." Environ Sci Technol 43.15 (August 1, 2009): 5739-5746.
PMID
19731671
Source
pubmed
Published In
Environmental Science & Technology
Volume
43
Issue
15
Publish Date
2009
Start Page
5739
End Page
5746

Metabolism of polybrominated diphenyl ethers (PBDEs) by human hepatocytes in vitro.

BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals that accumulate in human tissues and are potential toxicants. Concentrations of PBDEs in human tissues have increased recently, and body burdens in the U.S. and Canadian populations are higher than in any other region. OBJECTIVES: Although metabolism in animal laboratory studies has been examined, no studies have explored the metabolism of these contaminants in human tissues. We undertook this study to determine whether PBDEs could be metabolized by human liver cells in vitro and to identify what types of metabolites are formed. METHODS: We exposed hepatocytes from three different donors (two cryopreserved batches and one fresh batch) to solutions containing 10 muM of either of two environmentally relevant and prominent PBDE congeners-BDE-99 or BDE-209-for periods of 24-72 hr. We also conducted gene expression analysis to provide information on potential induction of xenobiotic metabolizing enzymes. RESULTS: Exposing hepatocytes to BDE-99 resulted in the formation of 2,4,5-tribromo phenol, two monohydroxylated pentabrominated diphenyl ether metabolites, and a yet unidentified tetrabrominated metabolite. No hydroxylated or debrominated metabolites were observed in the cells exposed to BDE-209. This suggests that BDE-209 was not metabolized, that nonextractable, covalently protein-bound metabolites were formed, or that the exposure time was not long enough for BDE-209 to diffuse into the cell to be metabolized. However, we observed up-regulation of genes encoding for cytochrome P450 monooxygenase (CYP) 1A2, CYP3A4, deiodinase type 1, and glutathione S-transferase M1 in hepatocyes exposed to both BDE-99 and BDE-209. CONCLUSIONS: Our in vitro results suggest that the human liver will likely metabolize some BDE congeners (e.g., BDE-99) in vivo. These metabolites have been shown to elicit greater toxicity than the parent BDE congeners in laboratory bioassays; thus, more research on body burdens and human health effects from these metabolites are warranted.

Authors
Stapleton, HM; Kelly, SM; Pei, R; Letcher, RJ; Gunsch, C
MLA Citation
Stapleton, HM, Kelly, SM, Pei, R, Letcher, RJ, and Gunsch, C. "Metabolism of polybrominated diphenyl ethers (PBDEs) by human hepatocytes in vitro." Environ Health Perspect 117.2 (February 2009): 197-202.
PMID
19270788
Source
pubmed
Published In
Environmental health perspectives
Volume
117
Issue
2
Publish Date
2009
Start Page
197
End Page
202
DOI
10.1289/ehp.11807

Identifying transfer mechanisms and sources of decabromodiphenyl ether (BDE 209) in indoor environments using environmental forensic microscopy

Although the presence of polybrominated diphenyl ethers (PBDEs) in house dust has been linked to consumer products, the mechanism of transfer remains poorly understood. We conjecture that volatilized PBDEs will be associated with dust particles containing organic matter and will be homogeneously distributed in house dust. In contrast, PBDEs arising from weathering or abrasion of polymers should remain bound to particlesoftheoriginalpolymermatrixandwillbeheterogeneously distributed within the dust. We used scanning electron microscopy and other tools of environmental forensic microscopy to investigate PBDEs in dust, examining U.S. and U.K. dust samples with extremely high levels of BDE 209 (260-2600 μ g/ g), a nonvolatile compound at room temperature. We found that the bromine in these samples was concentrated in widely scattered, highly contaminated particles. In the house dust samples from Boston (U.S.), bromine was associated with a polymer/organic matrix. These results suggest that the BDE 209 was transferred to dust via physical processes such as abrasion or weathering. In conjunction with more traditional tools of environmental chemistry, such as gas chromatography/ mass spectrometry (GC/MS), environmental for ensicmicroscopy provides novel insights into the origins of BDE 209 in dust and their mechanisms of transfer from products. © 2009 American Chemical Society.

Authors
Webster, TF; Harrad, S; Millette, JR; Holbrook, RD; Davis, JM; Stapleton, HM; Allen, JG; McClean, MD; Ibarra, C; Abdallah, MA-E; Covaci, A
MLA Citation
Webster, TF, Harrad, S, Millette, JR, Holbrook, RD, Davis, JM, Stapleton, HM, Allen, JG, McClean, MD, Ibarra, C, Abdallah, MA-E, and Covaci, A. "Identifying transfer mechanisms and sources of decabromodiphenyl ether (BDE 209) in indoor environments using environmental forensic microscopy." Environmental Science and Technology 43.9 (2009): 3067-3072.
PMID
19534115
Source
scival
Published In
Environmental Science & Technology
Volume
43
Issue
9
Publish Date
2009
Start Page
3067
End Page
3072
DOI
10.1021/es803139w

In vitro hepatic metabolism of 2,2′,4,4′,5-pentabromodiphenyl ether (BDE 99) in Chinook Salmon (Onchorhynchus tshawytscha)

Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants that persist in the environment and are present in geographically widespread fish species. PBDE concentrations can be particularly high in resident Chinook salmon (Onchorhynchus tshawytscha) in the Puget Sound, Washington. Although PBDE residues in salmon and other fish are often dominated by lower brominated congeners, these congeners are not produced commercially in the greatest quantity, suggesting bioaccumulation of the lower molecular weight PBDEs or debromination of more fully brominated congeners. We determined the capacity of Chinook liver fractions to debrominate 2,2′,4,4′,5-pentabromodiphenyl ether (BDE 99), a model PBDE congener readily debrominated by common carp (Cyprinus caprio). Liver subcellular fractions from two strains of Chinook were incubated with BDE 99 prior to liquid/liquid extraction followed by gas chromatography/mass spectrometry analysis (GC/MS analysis) to identify metabolites and debromination products. In contrast to common carp, debromination of BDE 99 to BDE 47 (2,2′,4,4′-tetrabromodiphenyl ether) was not observed in microsomal fractions from either strain of Chinook salmon. However, Chinook salmon liver microsomes from both Chinook strains slowly debrominated BDE 99 to BDE 49 (2,2′,4,5′-tetrabromodiphenyl ether), a unique debromination product whose formation has not been reported in other fish. Three-year-old males belonging to a Rapid River Spring Chinook salmon genetic strain showed a somewhat greater microsomal debromination capacity than older hatchery returning male Chinook, but were still inefficient in the debromination of BDE 99 relative to carp. Microsomal debromination of BDE 99 to BDE 49 was not NADPH-dependent, indicating a lack of cytochrome P450 involvement. By contrast, omission of the reductant dithiothreitol (DTT) from Chinook microsomal preparations resulted in a lack of BDE 99 debromination, suggesting the involvement of a microsomal reductase(s) or deiodinase (DI). Cytosolic fractions from Chinook salmon and Common carp debrominated BDE 99 to BDE 49 in vitro. However, carp cytosolic enzymes preferentially formed BDE 47. In summary, our data indicate significant differences among teleosts with respect to efficiency and metabolite profiles of BDE 99 debromination, and suggest that the high concentrations of BDE 47 in resident Chinook salmon from the Puget Sound are not a result of hepatic metabolism of BDE 99. The results of our study also suggest the involvement of an unidentified hepatic reductase or DI in PBDE debromination in fish. © 2009 Elsevier B.V. All rights reserved.

Authors
Browne, EP; Stapleton, HM; Kelly, SM; Tilton, SC; Gallagher, EP
MLA Citation
Browne, EP, Stapleton, HM, Kelly, SM, Tilton, SC, and Gallagher, EP. "In vitro hepatic metabolism of 2,2′,4,4′,5-pentabromodiphenyl ether (BDE 99) in Chinook Salmon (Onchorhynchus tshawytscha)." Aquatic Toxicology 92.4 (2009): 281-287.
PMID
19346012
Source
scival
Published In
Aquatic Toxicology
Volume
92
Issue
4
Publish Date
2009
Start Page
281
End Page
287
DOI
10.1016/j.aquatox.2009.02.017

Tissue Distribution of Polybrominated Diphenyl Ethers in Rats Following Oral Exposure and the Relationship to Body Burdens

Authors
Huwe, JK; Hakk, H; Stapleton, HM; Birnbaum, LS
MLA Citation
Huwe, JK, Hakk, H, Stapleton, HM, and Birnbaum, LS. "Tissue Distribution of Polybrominated Diphenyl Ethers in Rats Following Oral Exposure and the Relationship to Body Burdens." November 2008.
Source
wos-lite
Published In
Epidemiology
Volume
19
Issue
6
Publish Date
2008
Start Page
S76
End Page
S76

Televisions as Sources of DecaBDE in House Dust

Authors
Allen, JG; McClean, MD; Stapleton, HM; Webster, TF
MLA Citation
Allen, JG, McClean, MD, Stapleton, HM, and Webster, TF. "Televisions as Sources of DecaBDE in House Dust." November 2008.
Source
wos-lite
Published In
Epidemiology
Volume
19
Issue
6
Publish Date
2008
Start Page
S76
End Page
S76

Alternate and new brominated flame retardants detected in U.S. house dust.

Due to the voluntary withdrawals and/or bans on the use of two polybrominated diphenyl ether (PBDE) commercial mixtures, an increasing number of alternate flame retardant chemicals are being introduced in commercial applications. To determine if these alternate BFRs are present in indoor environments, we analyzed dust samples collected from 19 homes in the greater Boston, MA area during 2006. Using pure and commercial standards we quantified the following brominated flame retardant chemicals using GC/ECNI-MS methods: hexabromocyclododecane (sigma HBCD), bis(2,4,6,-tribromphenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and the brominated components found in Firemaster 550 (FM 550): 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB) and (2-ethylhexyl)tetrabromophthalate (TBPH), the latter compound being a brominated analogue of di(2-ethylhexyl)phthalate (DEHP). The concentrations of all compounds were log-normally distributed and the largest range in concentrations was observed for HBCD (sum of all isomers), with concentrations ranging from <4.5 ng/g to a maximum of 130,200 ng/g with a median value of 230 ng/g. BTBPE ranged from 1.6 to 789 ng/g with a median value of 30 ng/g and DBDPE ranged from <10.0 to 11,070 ng/g with a median value of 201 ng/g. Of the FM 550 components, TBB ranged from <6.6 to 15,030 ng/g with a median value of 133 ng/g; whereas TBPH ranged from 1.5 to 10,630 ng/g with a median value of 142 ng/g. Furthermore, the ratio of TBB/TBPH present in the dust samples ranged from 0.05 to 50 (average 4.4), varying considerably from the ratio observed in the FM 550 commercial mixture (4:1 by mass), suggesting different sources with different chemical compositions, and/or differential fate and transport within the home. Analysis of paired dust samples collected from different rooms in the same home suggests HBCD, TBB, and TBPH are higher in dust from the main living area compared to dust collected in bedrooms; however, BTBPE and DBDPE levels were comparable between rooms. This study highlights the fact that numerous types of brominated flame retardants are present in indoor environments, raising questions about exposure to mixtures of these contaminants.

Authors
Stapleton, HM; Allen, JG; Kelly, SM; Konstantinov, A; Klosterhaus, S; Watkins, D; McClean, MD; Webster, TF
MLA Citation
Stapleton, HM, Allen, JG, Kelly, SM, Konstantinov, A, Klosterhaus, S, Watkins, D, McClean, MD, and Webster, TF. "Alternate and new brominated flame retardants detected in U.S. house dust." Environ Sci Technol 42.18 (September 15, 2008): 6910-6916.
PMID
18853808
Source
pubmed
Published In
Environmental Science & Technology
Volume
42
Issue
18
Publish Date
2008
Start Page
6910
End Page
6916

Measurement of polybrominated diphenyl ethers on hand wipes: estimating exposure from hand-to-mouth contact.

Estimates of exposure to the flame-retardant polybrominated diphenyl ethers (PBDEs) in dust are very poor due to limited knowledge about dust ingestion. This study was undertaken to determine if PBDEs could be measured on hand wipes, and if so, to determine the distribution of levels present on the skin surface area to provide preliminary exposure estimates from hand-to-mouth contact. Hand wipes were collected from 33 individuals residing in the United States using sterile gauze pads soaked in isopropyl alcohol. The total PBDE residue collected on the wipes ranged from 2.60 to 1982 ng, with a median value of 130 ng, or normalized to hand surface area, a concentration of 135 pg/cm2. The fully brominated congener, BDE 209, was also detected and ranged from < DL to 270 ng with a median value of 26 ng. Congener patterns observed on the wipes were similar to patterns observed in house dust samples, consisting of congeners associated with the PentaBDE and DecaBDE mixtures, suggesting that the source of PBDEs to the hands may be dust particles. However, PBDE hand residues may also be a result of direct contact with PBDE-laden products, leading to adsorption to the skin surface oils. Repeated wipe sampling from three individuals suggests that sigmaPBDE levels on the hand may be relatively consistent for some individuals but not for others. Furthermore, levels of sigmaPBDEs were greater on the bottom of the hands relative to the top of the hands. Using these values we have calculated potential human exposure from hand-to-mouth contact. The median exposure estimates for children and adults are 1380 and 154 ng/day, respectively, whereas the 95th percentile exposure estimates were 6090 and 677 ng/day, respectively. These estimates are greater than dietary intake rates and suggest hand-to-mouth contact may be a key exposure route for PBDEs.

Authors
Stapleton, HM; Kelly, SM; Allen, JG; Mcclean, MD; Webster, TF
MLA Citation
Stapleton, HM, Kelly, SM, Allen, JG, Mcclean, MD, and Webster, TF. "Measurement of polybrominated diphenyl ethers on hand wipes: estimating exposure from hand-to-mouth contact." Environ Sci Technol 42.9 (May 1, 2008): 3329-3334.
PMID
18522114
Source
pubmed
Published In
Environmental Science & Technology
Volume
42
Issue
9
Publish Date
2008
Start Page
3329
End Page
3334

Serum levels of polybrominated diphenyl ethers (PBDEs) in foam recyclers and carpet installers working in the United States.

Increased exposure to the flame retardants known as polybrominated diphenyl ethers (PBDEs) may be expected to occur during the recycling of polyurethane foam containing these chemicals. To date, no studies in the United States have investigated occupational exposure to these flame retardants during recycling processes. The objective of the present study was to determine if individuals working in foam recycling facilities, and/or carpet installers who may install carpet padding manufactured from recycled foam, possess significantly higher PBDE serum levels relative to that of the general U.S. population. As a control group, serum was collected from four spouses and one clerical worker. In addition, levels in workers were also compared to the recently published national health and nutrition examination survey (NHANES) data set on PBDEs in the general U.S. population. Serum samples were collected in duplicate and analyzed by two different laboratories as quality control. Total PBDE levels were found to be significantly higher (p < 0.05) in the individuals recycling foam and installing carpet (n = 15) relative to the control group (n = 5). Median sigmaPBDE levels in the foam recyclers, carpet layers, and control group were 160, 178, and 19 ng/g lipid, respectively. In contrast, concentrations of a polybrominated biphenyl (BB-153) and a polychlorinated biphenyl (CB-153) were equivalent among all groups tested. The PBDE congeners BDE-47, 99, 100, and 153 contributed 90% of the sigmaPBDE concentration in serum and no differences in congener patterns were apparent among the different groups. Relative to concentrations measured in the NHANES, foam recyclers and carpet layers have body burdens that are an order of magnitude higher. These data suggest individuals recycling foam-containing products, and/ or using products manufactured from recycled foam (i.e., carpet padding), have higher body burdens of PBDEs, and thus may be at higher risk from adverse health effects associated with brominated flame retardant exposure.

Authors
Stapleton, HM; Sjödin, A; Jones, RS; Niehüser, S; Zhang, Y; Patterson, DG
MLA Citation
Stapleton, HM, Sjödin, A, Jones, RS, Niehüser, S, Zhang, Y, and Patterson, DG. "Serum levels of polybrominated diphenyl ethers (PBDEs) in foam recyclers and carpet installers working in the United States." Environ Sci Technol 42.9 (May 1, 2008): 3453-3458.
PMID
18522133
Source
pubmed
Published In
Environmental Science & Technology
Volume
42
Issue
9
Publish Date
2008
Start Page
3453
End Page
3458

Photodegradation of decabromodiphenyl ether in house dust by natural sunlight.

Photolytic degradation of decabromodiphenyl ether (BDE 209) has been observed in several matrices such as solvent/ water mixtures, sediments, and soil; however, no studies have investigated the degradation potential of BDE 209 in house dust. In the present study, both a natural and a BDE 209-spiked dust material were exposed to sunlight for 200 cumulative h. Degradation of BDE 209 was observed in both matrices but was 35% greater in the spiked dust relative to the natural dust material. The pseudo- first-order degradation rates were 2.3 x 10(-3) and 1.7 x 10(-3) per hour for the spiked and natural dust, respectively. During the 200-h exposure, as much as 38% of the original BDE 209 mass was degraded in the spiked dust, 25% of which could not be accounted for and was lost to unknown pathways and/or products. The remaining 13% was accounted for by the formation of lower brominated congeners. Debrominated products detected in the spiked dust included all three nonabrominated congeners (BDE 206, BDE 207, and BDE 208) and several octabrominated congeners (BDE 196, BDE 197, BDE 201, BDE 202, and BDE 203/200). In technical commercial octa-BDE mixtures, BDE 201 is a very small component (below detection limit to 0.8%), and BDE 202 is not detected. Therefore, the presence of these congeners in house dust may provide a marker of environmental debromination of BDE 209. The ratio of BDE 197 to BDE 201 may also be indicative of BDE 209 degradation. as the ratio of these two congeners appeared to reach a steady-state value (~1) in both exposure scenarios in the present study.

Authors
Stapleton, HM; Dodder, NG
MLA Citation
Stapleton, HM, and Dodder, NG. "Photodegradation of decabromodiphenyl ether in house dust by natural sunlight." Environ Toxicol Chem 27.2 (February 2008): 306-312.
PMID
18348638
Source
pubmed
Published In
Environmental Toxicology & Chemistry
Volume
27
Issue
2
Publish Date
2008
Start Page
306
End Page
312
DOI
10.1897/07-301R.1

Serum PBDE Levels in Occupationally Exposed Individuals in the United States

Authors
Stapleton, HM; Sjodin, A; Jones, RS; Niehauser, S; Zhang, Y; Patterson, DG
MLA Citation
Stapleton, HM, Sjodin, A, Jones, RS, Niehauser, S, Zhang, Y, and Patterson, DG. "Serum PBDE Levels in Occupationally Exposed Individuals in the United States." Environ Sci & Technol 42.9 (2008): 3453-3458. (Academic Article)
Source
manual
Published In
Environ Sci & Technol
Volume
42
Issue
9
Publish Date
2008
Start Page
3453
End Page
3458

Measurement of Polybrominated Diphenyl Ethers on Hand Wipes: Estimating Exposure from Hand to Mouth Contact

Authors
Stapleton, HM; Kelly, SM; Allen, JG; McClean, MD; Webster, TF
MLA Citation
Stapleton, HM, Kelly, SM, Allen, JG, McClean, MD, and Webster, TF. "Measurement of Polybrominated Diphenyl Ethers on Hand Wipes: Estimating Exposure from Hand to Mouth Contact." Environ Sci & Technol 49.9 (2008): 3329-3334. (Academic Article)
Source
manual
Published In
Environ Sci & Technol
Volume
49
Issue
9
Publish Date
2008
Start Page
3329
End Page
3334

Longitudinal Analysis of Polybrominated Diphenyl Ethers (PBDEs) in Household Microenvironments: Characterization of Dust and Relationship to Indoor Air.

Authors
Allen, JG; McClean, MD; Stapleton, HM; Webster, TF
MLA Citation
Allen, JG, McClean, MD, Stapleton, HM, and Webster, TF. "Longitudinal Analysis of Polybrominated Diphenyl Ethers (PBDEs) in Household Microenvironments: Characterization of Dust and Relationship to Indoor Air." Environment International 34.8 (2008): 1085-1091. (Academic Article)
Source
manual
Published In
Environment International
Volume
34
Issue
8
Publish Date
2008
Start Page
1085
End Page
1091

Linking PBDEs in house dust to consumer products using X-ray fluorescence

The indoor environment is an important source of exposure to polybrominated diphenyl ethers (PBDEs), a class of fire retardants used in many household products. Previous attempts to link PBDE concentrations in house dust to consumer products have been hampered by the inability to determine the presence of PBDEs in otherwise similar products. We used a portable X-ray fluorescence (XRF) analyzer to nondestructively quantify bromine concentrations in consumer goods. In the validation phase, XRF-measured bromine was highly correlated with GC/MS-measured bromine for furniture foam and plastic from electronics (n = 29, r = 0.93, p < 0.0001). In the field study phase, the XRF-measured bromine in room furniture was associated with pentaBDE concentrations in room dust in the bedroom (r = 0.68, p = 0.001) and main living area (r = 0.51, p = 0.02). We also found an association between XRF-measured bromine levels in electronics and decaBDE levels in dust, largely driven by the high levels in televisions (r = 0.64, p = 0.003 for bedrooms). For the main living area, predicting decaBDE in dust improved when we included an interaction effect between the bromine content of televisions and the number of persons in the house (p < 0.005), a potential surrogate for television usage. © 2008 American Chemical Society.

Authors
Allen, JG; Mcclean, MD; Stapleton, HM; Webster, TF
MLA Citation
Allen, JG, Mcclean, MD, Stapleton, HM, and Webster, TF. "Linking PBDEs in house dust to consumer products using X-ray fluorescence." Environmental Science and Technology 42.11 (2008): 4222-4228.
PMID
18589991
Source
scival
Published In
Environmental Science & Technology
Volume
42
Issue
11
Publish Date
2008
Start Page
4222
End Page
4228
DOI
10.1021/es702964a

Comparative absorption and bioaccumulation of polybrominated diphenyl ethers following ingestion via dust and oil in male rats

Household dust has been implicated as a major source of polybrominated diphenyl ether (PBDE) exposure in humans. This finding has important implications for young children, who tend to ingest more dust than adults and may be more susceptible to some of the putative developmental effects of PBDEs. Absorption parameters of PBDEs from ingested dust are unknown; therefore, the objectives of this study were to determine and to compare the uptake of PBDEs from either household dust (NIST Standard Reference Material 2585) or a corn oil solution. Male rats were administered dust or corn oil doses at 1 or 6 μg of PBDEs kg-1 body wt in the diet for 21 days (n = 4 rats per group). The concentrations of 15 PBDEs were measured in adipose tissue and liver from each treatment group and showed that bioconcentration was congener dependent, but for the majority of congeners, the concentrations did not differ with either dose level or dose vehicle. Hepatic Cyp2b1 and 2b2 mRNA expression increased in rats receiving the higher PBDE doses, suggesting potential effects on metabolic activity. Retention of PBDEs in tissues ranged from <5% of the dose for BDE-209 to 70% for BDEs-47, 100, and 153 but generally did not differ between the high dust and high oil treatment groups. Excretion via the feces was significantly lower in the high oil dosed rats suggesting differences in absorption, excretion, and/or metabolism. The present study shows that PBDEs in dust are readily bioavailable and are biologically active, as indicated by increased transcription of hepatic enzymes. © 2008 American Chemical Society.

Authors
Huwe, JK; Hakk, H; Smith, DJ; Diliberto, JJ; Richardson, V; Stapleton, HM; Birnbaum, LS
MLA Citation
Huwe, JK, Hakk, H, Smith, DJ, Diliberto, JJ, Richardson, V, Stapleton, HM, and Birnbaum, LS. "Comparative absorption and bioaccumulation of polybrominated diphenyl ethers following ingestion via dust and oil in male rats." Environmental Science and Technology 42.7 (2008): 2694-2700.
PMID
18505018
Source
scival
Published In
Environmental Science & Technology
Volume
42
Issue
7
Publish Date
2008
Start Page
2694
End Page
2700
DOI
10.1021/es702644k

Response to comment on "Altemate and new brominated flame retardants detected in U.S. house dust"

Authors
Stapleton, HM; Kelly, SM; Allen, JG; Watkins, DJ; Heiger-Bernays, WJ; McClean, MD; Webster, TF; Konstantinov, A; Klosterhaus, S
MLA Citation
Stapleton, HM, Kelly, SM, Allen, JG, Watkins, DJ, Heiger-Bernays, WJ, McClean, MD, Webster, TF, Konstantinov, A, and Klosterhaus, S. "Response to comment on "Altemate and new brominated flame retardants detected in U.S. house dust"." Environmental Science and Technology 42.24 (2008): 9455-9456.
Source
scival
Published In
Environmental Science & Technology
Volume
42
Issue
24
Publish Date
2008
Start Page
9455
End Page
9456
DOI
10.1021/es8026192

Critical factors in assessing exposure to PBDEs via house dust

Assessment of indoor exposure to polybrominated diphenyl ethers (PBDEs) requires a critical examination of methods that may influence exposure estimates and comparisons between studies. We measured PBDEs in residential dust collected from 20 homes in Boston, MA, to examine 5 key questions: 1) Does the choice of dust exposure metric-e.g., concentration (ng/g) or dust loading (ng/m2)-affect analysis and results? 2) To what degree do dust concentrations change over time? 3) Do dust concentrations vary between rooms? 4) Is the home vacuum bag an acceptable surrogate for researcher-collected dust? 5) Are air and dust concentrations correlated for the same room? We used linear mixed-effects models to analyze the data while accounting for within-home and within-room correlations. We found that PBDE dust concentration and surface loading were highly correlated (r = 0.86-0.95, p < 0.001). Average dust concentrations did not significantly differ over an 8-month period, possibly because home furnishings changed little over this time. We observed significant differences between rooms in the same home: PBDE concentrations in the main living area were 97% higher than the bedroom for decaBDE (p = 0.02) and 72% higher for pentaBDE (p = 0.05). Home vacuum bag dust concentrations were significantly lower than researcher-collected dust and not strongly correlated. Air (vapor and particulate phase) and dust concentrations were correlated for pentaBDE (p = 0.62, p < 0.01), but not for decaBDE (p = 0.25). In addition, potential markers of BDE 209 debromination (BDE 202 and the BDE197:BDE201 ratio) were also observed in household dust samples. One vacuum bag sample contained the highest concentrations of BDE 209 (527,000 ng/g) and total PBDEs (544,000 ng/g) that have been reported in house dust. © 2008 Elsevier Ltd. All rights reserved.

Authors
Allen, JG; McClean, MD; Stapleton, HM; Webster, TF
MLA Citation
Allen, JG, McClean, MD, Stapleton, HM, and Webster, TF. "Critical factors in assessing exposure to PBDEs via house dust." Environment International 34.8 (2008): 1085-1091.
PMID
18456330
Source
scival
Published In
Environment International
Volume
34
Issue
8
Publish Date
2008
Start Page
1085
End Page
1091
DOI
10.1016/j.envint.2008.03.006

Determination of polybrominated diphenyl ethers in environmental standard reference materials.

Standard reference materials (SRMs) are valuable tools in developing and validating analytical methods to improve quality assurance standards. The National Institute of Standards and Technology (NIST) has a long history of providing environmental SRMs with certified concentrations of organic and inorganic contaminants. Here we report on new certified and reference concentrations for 27 polybrominated diphenyl ether (PBDE) congeners in seven different SRMs: cod-liver oil, whale blubber, fish tissue (two materials), mussel tissue and sediment (two materials). PBDEs were measured in these SRMs, with the lowest concentrations measured in mussel tissue (SRM 1974b) and the highest in sediment collected from the New York/New Jersey Waterway (SRM 1944). Comparing the relative PBDE congener concentrations within the samples, we found the biota SRMs contained primarily tetrabrominated and pentabrominated diphenyl ethers, whereas the sediment SRMs contained primarily decabromodiphenyl ether (BDE 209). The cod-liver oil (SRM 1588b) and whale blubber (SRM 1945) materials were also found to contain measurable concentrations of two methoxylated PBDEs (MeO-BDEs). Certified and reference concentrations are reported for 12 PBDE congeners measured in the biota SRMs and reference values are available for two MeO-BDEs. Results from a sediment interlaboratory comparison PBDE exercise are available for the two sediment SRMs (1941b and 1944).

Authors
Stapleton, HM; Keller, JM; Schantz, MM; Kucklick, JR; Leigh, SD; Wise, SA
MLA Citation
Stapleton, HM, Keller, JM, Schantz, MM, Kucklick, JR, Leigh, SD, and Wise, SA. "Determination of polybrominated diphenyl ethers in environmental standard reference materials." Anal Bioanal Chem 387.7 (April 2007): 2365-2379.
PMID
17206409
Source
pubmed
Published In
Analytical and Bioanalytical Chemistry
Volume
387
Issue
7
Publish Date
2007
Start Page
2365
End Page
2379
DOI
10.1007/s00216-006-1054-5

Certification of SRM 1589a PCBs, pesticides, PBDEs, and dioxins/furans in human serum

The Certificate of Analysis for SRM 1589a PCBs, Pesticides, PBDEs, and Dioxins/Furans in Human Serum has been updated to include certified concentration values for 27 polychlorinated biphenyl (PCB) congeners, three chlorinated pesticides, and four polybrominated diphenyl ether (PBDE) congeners as well as reference concentration values for 27 additional PCB congeners, six additional chlorinated pesticides, three additional PBDE congeners, and selected polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). This represents an addition of concentration values for 29 PCB congeners and for PBDE congeners that were not quantified in the previous issue of SRM 1589a. With the increased number of certified and reference concentration values for PCBs and the inclusion of certified and reference concentration values for PBDEs, this serum material will be more useful as a reference material for contaminant monitoring in human tissues and fluids. © 2007 Springer-Verlag.

Authors
Schantz, MM; Keller, JM; Leigh, S; Jr, DGP; Sharpless, KE; Sjödin, A; Stapleton, HM; Swarthout, R; Turner, WE; Wise, SA
MLA Citation
Schantz, MM, Keller, JM, Leigh, S, Jr, DGP, Sharpless, KE, Sjödin, A, Stapleton, HM, Swarthout, R, Turner, WE, and Wise, SA. "Certification of SRM 1589a PCBs, pesticides, PBDEs, and dioxins/furans in human serum." Analytical and Bioanalytical Chemistry 389.4 (2007): 1201-1208.
PMID
17710387
Source
scival
Published In
Analytical and Bioanalytical Chemistry
Volume
389
Issue
4
Publish Date
2007
Start Page
1201
End Page
1208
DOI
10.1007/s00216-007-1519-1

New standard reference material (srm) 2585: Organic contaminants in house dust to support exposure assessment measurements

The National Institute of Standards and Technology (NIST), Gaithersburg, MD, US, produced two house dust Standard Reference Materials (SRM) for lead and other trace elements to address indoor exposure to such elements. SRM 2583: Trace Elements in Indoor Dust, Nominal 90 mg per kg Lead and SRM 2584: Trace Elements in Indoor Dust, Nominal 1% Lead were the two SRMs. SRM 2583 was issued in 1996 and updated in 1998 with certified concentration values for arsenic, cadmium, chromium, mercury, and lead. SRM 2584 was issued in 1999 with certified concentration values for the same five elements, reference concentration values for an additional 10 elements, and information concentration values for 22 additional elements. SRM 2585: Organics in House Dust was another SRM that was intended to be used in evaluating methodology used for the determination of selected PAHs, polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and PBDE congeners in house dust and similar matrices.

Authors
Schantz, BMM; Keller, JM; Kucklick, JR; Poster, DL; Stapleton, HM; Pol, SSV; Wise, SA
MLA Citation
Schantz, BMM, Keller, JM, Kucklick, JR, Poster, DL, Stapleton, HM, Pol, SSV, and Wise, SA. "New standard reference material (srm) 2585: Organic contaminants in house dust to support exposure assessment measurements." American Laboratory 39.15 (2007): 22-28.
Source
scival
Published In
American laboratory
Volume
39
Issue
15
Publish Date
2007
Start Page
22
End Page
28

Debromination of polybrominated diphenyl ether-99 (BDE-99) in carp (Cyprinus carpio) microflora and microsomes

Based on previous findings in dietary studies with carp (Cyprinus carpio), we investigated the mechanism of 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99) debromination to 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) using liver and intestinal components. In vitro aerobic and anaerobic experiments tested the ability of carp intestinal microflora to debrominate BDE-99. No debromination of BDE-99 to BDE-47 was observed in microfloral samples; therefore, carp enzymatic pathways were assessed for debromination ability. After sixty-min incubation, intestine and liver microsomes exhibited 83 ± 34% and 106 ± 18% conversions, respectively, of BDE-99 to BDE-47; with no significant (p > 0.05) difference between organ debromination capabilities. Microsomal incubations with BDE-99, enzyme cofactors and competing substrates assessed the potential mechanisms of debromination. The presence of NADPH in the microsomal assay did not significantly (p > 0.05) affect BDE-99 debromination, which suggest that cytochrome P450 enzymes are not the main debrominating pathway for BDE-99. Co-incubation of BDE-99 spiked microsomes with reverse thyronine (rT3) significantly (p < 0.05) decreased the debromination capacity of intestinal microsomes indicating the potential of catalytic mediation via thyroid hormone deiodinases. The significant findings of this study are that intestinal microflora are not responsible for BDE-99 debromination, however, it is an endogenous process which occurs with approximately equal activity in intestine and liver microsomes and it can be inhibited by rT3. © 2007 Elsevier Ltd. All rights reserved.

Authors
Benedict, RT; Stapleton, HM; Letcher, RJ; Mitchelmore, CL
MLA Citation
Benedict, RT, Stapleton, HM, Letcher, RJ, and Mitchelmore, CL. "Debromination of polybrominated diphenyl ether-99 (BDE-99) in carp (Cyprinus carpio) microflora and microsomes." Chemosphere 69.6 (2007): 987-993.
PMID
17640709
Source
scival
Published In
Chemosphere
Volume
69
Issue
6
Publish Date
2007
Start Page
987
End Page
993
DOI
10.1016/j.chemosphere.2007.05.010

Polybrominated diphenyl ethers in American eels (Anguilla rostrata) from the Delaware River, USA

Authors
Ashley, JTF; Libero, D; Halscheid, E; Zaoudeh, L; Stapleton, HM
MLA Citation
Ashley, JTF, Libero, D, Halscheid, E, Zaoudeh, L, and Stapleton, HM. "Polybrominated diphenyl ethers in American eels (Anguilla rostrata) from the Delaware River, USA." Bulletin of Environmental Contamination and Toxicology 79.1 (2007): 99-103.
PMID
17476449
Source
scival
Published In
Bulletin of Environmental Contamination and Toxicology
Volume
79
Issue
1
Publish Date
2007
Start Page
99
End Page
103
DOI
10.1007/s00128-007-9090-1

Personal exposure to Polybrominated Diphenyl Ethers (PBDEs) in residential indoor air

We used personal air samplers to measure indoor air exposure to polybrominated diphenyl ethers (PBDEs) for 20 residents of the Greater Boston Area (Massachusetts). Area air measures were simultaneously collected from two rooms in each participant's home. Total personal air concentrations (particulate + vapor) were 469 pg/m3 for non-209 BDEs and 174 pg/m3 for BDE 209, significantly higher than bedroom and main living room concentrations (p = 0.01). The ratio of personal air to room air increased from 1 for vapor-phase congeners to 4 for fully particulate-bound congeners, indicating a personal cloud effect. Bedroom and main living area air samples were moderately correlated for non-209 BDEs (r = 0.45, p = 0.045) and BDE 209 (r = 0.58, p = 0.008). Use of personal air concentrations increased estimates of inhalation exposure over those previously reported. Inhalation may account for up to 22% of the total BDE 209 exposure in U.S. adults. © 2007 American Chemical Society.

Authors
Allen, JG; Mcclean, MD; Stapleton, HM; Nelson, JW; Webster, TF
MLA Citation
Allen, JG, Mcclean, MD, Stapleton, HM, Nelson, JW, and Webster, TF. "Personal exposure to Polybrominated Diphenyl Ethers (PBDEs) in residential indoor air." Environmental Science and Technology 41.13 (2007): 4574-4579.
PMID
17695899
Source
scival
Published In
Environmental Science & Technology
Volume
41
Issue
13
Publish Date
2007
Start Page
4574
End Page
4579
DOI
10.1021/es0703170

Instrumental methods and challenges in quantifying polybrominated diphenyl ethers in environmental extracts: a review.

Increased interest in the fate, transport and toxicity of polybrominated diphenyl ethers (PBDEs) over the past few years has led to a variety of studies reporting different methods of analysis for these persistent organic pollutants. Because PBDEs encompass a range of vapor pressures, molecular weights and degrees of bromine substitution, various analytical methods can lead to discrimination of some PBDE congeners. Recent improvements in injection techniques and mass spectrometer ionization methods have led to a variety of options to determine PBDEs in environmental samples. The purpose of this paper is therefore to review the available literature describing the advantages and disadvantages in choosing an injection technique, gas chromatography column and detector. Additional discussion is given to the challenges in measuring PBDEs, including potential chromatographic interferences and the lack of commercial standards for higher brominated congeners, which provides difficulties in examining degradation and debromination of BDE congeners, particularly for BDE 209.

Authors
Stapleton, HM
MLA Citation
Stapleton, HM. "Instrumental methods and challenges in quantifying polybrominated diphenyl ethers in environmental extracts: a review." Anal Bioanal Chem 386.4 (October 2006): 807-817.
PMID
17165211
Source
pubmed
Published In
Analytical and Bioanalytical Chemistry
Volume
386
Issue
4
Publish Date
2006
Start Page
807
End Page
817

In vivo and in vitro debromination of decabromodiphenyl ether (BDE 209) by juvenile rainbow trout and common carp.

Decabromodiphenyl ether (BDE 209), the major congener in the high volume industrial flame retardant mixture "DecaBDE", has recently been shown to be metabolized by carp. To further explore this phenomenon, juvenile rainbow trout were exposed to BDE 209 via the diet for a five month period. Analysis of the whole body homogenate, liver, serum, and intestinal tissues revealed that BDE 209 accumulated in rainbow trout tissues and was most concentrated in the liver. In addition to BDE 209, several hepta-, octa-, and nonaBDE congeners also accumulated in rainbow trout tissues over the same period as a result of BDE 209 debromination. Based on the total body burden of the hepta- through decaBDE congeners, uptake of BDE 209 was estimated at 3.2%. Congener profiles were different among whole body homogenate, liver, and serum, with the whole body homogenates having a greater contribution of the debrominated biotransformation products. Extracts of the rainbow trout whole body homogenates were compared with extracts from a previous experiment with common carp. This comparison revealed that BDE 202 (2,2',3,3',5,5',6,6'-octabromodiphenyl ether) was a dominant debromination product in both studies. To determine whether the observed debromination was metabolically driven, liver microsomal fractions were prepared from both common carp and rainbow trout. Analysis of the microsomal fractions following incubation with BDE 209 revealed that rainbow trout biotransformed as much as 22% of the BDE 209 mass, primarily to octa- and nonaBDE congeners. In contrast, carp liver microsomes biotransformed up to 65% of the BDE 209 mass, primarily down to hexaBDE congeners. These microsomal incubations confirm a metabolic pathway for BDE 209 debromination.

Authors
Stapleton, HM; Brazil, B; Holbrook, RD; Mitchelmore, CL; Benedict, R; Konstantinov, A; Potter, D
MLA Citation
Stapleton, HM, Brazil, B, Holbrook, RD, Mitchelmore, CL, Benedict, R, Konstantinov, A, and Potter, D. "In vivo and in vitro debromination of decabromodiphenyl ether (BDE 209) by juvenile rainbow trout and common carp." Environ Sci Technol 40.15 (August 1, 2006): 4653-4658.
PMID
16913120
Source
pubmed
Published In
Environmental Science & Technology
Volume
40
Issue
15
Publish Date
2006
Start Page
4653
End Page
4658

Determination of HBCD, PBDEs and MeO-BDEs in California sea lions (Zalophus californianus) stranded between 1993 and 2003.

Blubber samples from male California sea lions (Zalphophus californianus) stranded between 1993 and 2003 were analyzed for 27 polybrominated diphenyl ether (PBDE) congeners, three isomers of hexabromocyclododecane (HBCD) and 14 methoxylated polybrominated diphenyl ether (MeO-BDE) congeners. Total PBDEs ranged from 450 ng/g to 4740 ng/g wet mass and total HBCD ranged from < 0.3 ng/g to 12 ng/g wet mass. The concentration of HBCD increased from 0.7 ng/g to12.0 ng/g wet mass in sea lion blubber between 1993 and 2003. However, no significant temporal trend was observed for any of the other brominated compounds over this 10 year period. Only one of the 14 MeO-BDE congeners was detected in the blubber samples, 6-methoxy-2,2',4,4'-tetrabromodiphenyl ether (6-MeO-BDE 47), and concentrations ranged from < 0.2 ng/g to 12 ng/g wet mass. A bromo-, chloro-heterocyclic compound, 1,1'-dimethyl-tetrabromo-dichloro-2,2'-bipyrrole (DBP-Br4Cl2), previously reported in marine species along the Pacific coast, was also identified in the sea lion blubber. DBP-Br4Cl2 ranged from 44 ng/g wet mass to 660 ng/g wet mass and was present at concentrations rivaling the dominant PBDE congener, BDE 47 (2,2',4,4'-tetrabromodiphenyl ether). Concentrations of DBP-Br4Cl2 were positively correlated with 6-MeO-BDE 47 (r = 0.7; p < 0.05). Both of these compounds have been identified in marine algae and sponges, and studies suggest they are both produced from natural sources. This study demonstrates that brominated compounds from both anthropogenic and biogenic sources can accumulate to similar levels in marine mammals. In addition, HBCD concentrations appear to be increasing in California sea lion populations, whereas PBDE concentrations, between 1993 and 2003, were highly variable.

Authors
Stapleton, HM; Dodder, NG; Kucklick, JR; Reddy, CM; Schantz, MM; Becker, PR; Gulland, F; Porter, BJ; Wise, SA
MLA Citation
Stapleton, HM, Dodder, NG, Kucklick, JR, Reddy, CM, Schantz, MM, Becker, PR, Gulland, F, Porter, BJ, and Wise, SA. "Determination of HBCD, PBDEs and MeO-BDEs in California sea lions (Zalophus californianus) stranded between 1993 and 2003." Mar Pollut Bull 52.5 (May 2006): 522-531.
PMID
16293266
Source
pubmed
Published In
Marine Pollution Bulletin
Volume
52
Issue
5
Publish Date
2006
Start Page
522
End Page
531
DOI
10.1016/j.marpolbul.2005.09.045

Determination of polybrominated diphenyl ethers in indoor dust standard reference materials.

Polybrominated diphenyl ethers (PBDEs) have been measured for the first time in three different indoor dust Standard Reference Materials (SRMs) prepared by the National Institute of Standards and Technology (NIST). Two of these, SRM 2583 (Trace Elements in Indoor Dust) and SRM 2584 (Trace Elements in Indoor Dust), have been certified previously for lead and other inorganic constituents. A third, SRM 2585 (Organics in Indoor Dust), is a new indoor dust reference material prepared by NIST which will be certified for various organic compounds (polycyclic aromatic hydrocarbons, pesticides and polychlorinated biphenyls) in 2005 including certified concentrations for 16 individual PBDE congeners and reference values for an additional three PBDE congeners. Dust SRMs were analyzed for 30 PBDE congeners using high-resolution gas chromatography combined with low-resolution mass spectrometry operated in both negative chemical ionization (GC/ECNI-MS) and electron impact ionization (GC/EI-MS) modes. Sensitivity was an order of magnitude higher using GC/ECNI-MS relative to GC/EI-MS. These SRMs have been characterized and compared to the three PBDE commercial products (pentaBDE, octaBDE and decaBDE). PentaBDE and DecaBDE were present in all three SRMs and were the dominant commercial products, making up approximately 33% and 58%, respectively. Recent studies suggest that house dust may be a leading source of human exposure to PBDEs. These SRMs are the first reference materials with certified concentrations for PBDEs, which will aid in validating future measurements of PBDEs in house dust and other similar matrices.

Authors
Stapleton, HM; Harner, T; Shoeib, M; Keller, JM; Schantz, MM; Leigh, SD; Wise, SA
MLA Citation
Stapleton, HM, Harner, T, Shoeib, M, Keller, JM, Schantz, MM, Leigh, SD, and Wise, SA. "Determination of polybrominated diphenyl ethers in indoor dust standard reference materials." Anal Bioanal Chem 384.3 (February 2006): 791-800.
PMID
16385413
Source
pubmed
Published In
Analytical and Bioanalytical Chemistry
Volume
384
Issue
3
Publish Date
2006
Start Page
791
End Page
800
DOI
10.1007/s00216-005-0227-y

Polybrominated diphenyl ethers in house dust and clothes dryer lint

Few studies have measured the flame retardants polybrominated diphenyl ethers (PBDEs) in the indoor environment. Here, we report measurements of PBDEs in house dust samples collected from the Washington, D.C. metropolitan area in the United States. Dust samples were analyzed for 22 individual PBDE congeners and our results found PBDEs present in every sample. Concentrations of total PBDEs ranged from 780 ng/g dry mass to 30 100 ng/g dry mass. The dominant congeners observed in the dust samples were congeners associated with the pentaBDE and decaBDE commercial mixtures. Ancillary data were collected on the homes and examined for any correlations with total PBDE concentrations. No correlations were observed with year of house construction, type of flooring (i.e., hardwood vs carpet) or the number of television sets or personal computers in the home. However, a significant inverse correlation (p < 0.05) was observed between the area of the home and the contribution of BDE 209 to the total PBDE concentration in dust. Using estimates of inadvertent dust ingestion (0.02-0.2 g/day) by young children (ages 1-4), we estimate ingestion of total PBDEs to range from 120 to 6000 ng/day. Clothes dryer lint was also sampled and analyzed for PBDEs from five of the homes and were present in all five samples ranging from 480 to 3080 ng/g dry mass. This study demonstrates that PBDEs are prevalent at relatively high concentrations within homes where people, and particularly young children, may be susceptible to exposure.

Authors
Stapleton, HM; Dodder, NG; Offenberg, JH; Schantz, MM; Wise, SA
MLA Citation
Stapleton, HM, Dodder, NG, Offenberg, JH, Schantz, MM, and Wise, SA. "Polybrominated diphenyl ethers in house dust and clothes dryer lint." Environmental Science and Technology 39.4 (2005): 925-931.
PMID
15773463
Source
scival
Published In
Environmental Science and Technology
Volume
39
Issue
4
Publish Date
2005
Start Page
925
End Page
931
DOI
10.1021/es0486824

Persistent organic pollutants in two dolphin species with focus on toxaphene and polybrominated diphenyl ethers

Assessing trends of persistent organic pollutants (POPs) in marine mammals is difficult due to age, gender, and metabolism influences on accumulation. To help elucidate these effects in dolphins, POP concentrations were determined in the Atlantic white-sided dolphin, Lagenorhynchus acutus, a pelagic delphinid inhabiting North Atlantic waters, and in the rough-toothed dolphin, Steno bredanensis, a pelagic delphinid inhabiting tropical and subtropical waters. The specific objectives of this study were to determine baseline POP concentrations in L. acutus and S. bredanensis blubber samples and to examine the effects of age, gender, and metabolism on POP concentrations in dolphin blubber. Focus was aimed at contaminants of emerging concern, specifically, toxaphene and polybrominated diphenyl ethers (PBDEs). Samples collected from L. acutus (n = 47) stranding events in Massachusetts (1993-2000) and S. bredanensis samples (n = 15) were analyzed for PCBs, toxaphene, and other organic pesticides by gas chromatography/mass spectrometry (GC/MS). Age and gender influences were similar between the two species, with adult females having significantly lower POP concentrations as compared to adult males and juveniles. Mean ∑toxaphene concentrations were highest in juvenile L. acutus, 13.0 (6.7) μg/g wet mass (1 SD), and lowest in adult female S. bredanensis, 1.49 (1.4) μg/g wet mass. ∑PBDE (sum of congeners 47, 99, 100, 153, and 154) concentrations were highest in juvenile L. acutus, 2.41 (1.2) μg/g wet mass, and lowest in adult female S. bredanensis, 0.51 (0.6) μg/g wet mass. POP concentrations did not significantly differ between adult males and juveniles, suggesting metabolism of congeners and/or dilution with growth. PBDE concentrations in juvenile white-sided dolphins were not significantly related to collection year, suggesting that there may be a lag period for higher concentrations to be detected in pelagic marine mammals such as L. acutus or that concentrations have already peaked in this species prior to the first collection in 1993.

Authors
Tuerk, KJS; Kucklick, JR; Becker, PR; Stapleton, HM; Baker, JE
MLA Citation
Tuerk, KJS, Kucklick, JR, Becker, PR, Stapleton, HM, and Baker, JE. "Persistent organic pollutants in two dolphin species with focus on toxaphene and polybrominated diphenyl ethers." Environmental Science and Technology 39.3 (2005): 692-698.
PMID
15757328
Source
scival
Published In
Environmental Science & Technology
Volume
39
Issue
3
Publish Date
2005
Start Page
692
End Page
698
DOI
10.1021/es0487675

Debromination of the Flame Retardant Decabromodiphenyl Ether by Juvenile Carp (Cyprinus carpio) following Dietary Exposure

The congener 2,2′,3,3′,4,4′,5,5′,6,6′ -decabromodiphenyl ether (BDE 209) is the primary component in a commonly used flame retardant known as decaBDE. This flame retardant constitutes approximately 80% of the world market demand for polybrominated diphenyl ethers (PBDEs). Because this compound is very hydrophobic (log Kow ∼ 10), it has been suggested that BDE 209 has very low bioavailability, although debromination to more bioavailable metabolites has also been suggested to occur in fish tissues. In the present study, juvenile carp were exposed to BDE 209 amended food on a daily basis for 60 days, followed by a 40-day depuration period in which the fate of BDE 209 was monitored in whole fish and liver tissues separately. No net accumulation of BDE 209 was observed throughoutthe experiment despite an exposure concentration of 940 ng/day/fish. However, seven apparent debrominated products of BDE 209 accumulated in whole fish and liver tissues over the exposure period. These debrominated metabolites of BDE 209 were identified as penta- to octaBDEs using both GC/ECNI-MS and GC/HRMS. Using estimation methods for relative retention times of phenyl substitution patterns, we have identified possible structures for the hexa- and heptabromodiphenyl ethers identified in the carp tissues. Although exposure of carp to BDE 209 did not result in the accumulation of BDE 209 in carp tissues, our results indicate evidence of limited BDE 209 bioavailability from food in the form of lower brominated metabolites.

Authors
Stapleton, HM; Alaee, M; Letcher, RJ; Baker, JE
MLA Citation
Stapleton, HM, Alaee, M, Letcher, RJ, and Baker, JE. "Debromination of the Flame Retardant Decabromodiphenyl Ether by Juvenile Carp (Cyprinus carpio) following Dietary Exposure." Environmental Science and Technology 38.1 (2004): 112-119.
PMID
14740725
Source
scival
Published In
Environmental Science and Technology
Volume
38
Issue
1
Publish Date
2004
Start Page
112
End Page
119
DOI
10.1021/es034746j

Dietary accumulation and metabolism of polybrominated diphenyl ethers by juvenile carp (Cyprinus carpio)

Polybrominated diphenyl ethers (PBDEs) are hydrophobic organic contaminants with properties and nomenclature similar to polychlorinated biphenyls (PCBs). While much information is available on the bioaccumulation and pharamcokinetics of PCBs, little information is available on PBDEs. In this study, juvenile carp were exposed to a diet spiked with a cocktail of four BDE congeners (2,4,4′-tribromoDE [BDE 28], 2,2′,4,4′-tetrabromoDE [BDE 47], 2,2′,4,4′,5-pentabromoDE [BDE 99], and 2,2′,4,4′,5, 5′-hexabromoDE [BDE 153]) for 60 d followed by a 40-d depuration period. As a positive control, three PCB congeners with similar log KOW values (2,2′,5,5′-tetrachlorobiphenyl [PCB 52], 2,2′,4, 4′,5,5′-hexachlorobiphenyl [PCB 153], and 2,2′,3,4,4′,5, 5′-heptachlorobiphenyl [PCB 180]) were included in the cocktail to compare their assimilation and fate with the model BDE congeners. Concentrations of BDEs and PCBs were monitored in whole-fish tissues and liver tissues over the duration of the experiment. In addition, blood serum samples were taken and pooled among replicates to determine if any phenolic metabolites of BDE and PCBs were formed. Rapid assimilation of BDE 47 was observed relative to all other BDE and PCB congeners, whereas apparently no accumulation of BDE 99 occurred over the course of the experiment. Assimilation efficiencies for BDE 47 suggest that approximately 100% of the BDE 47 exposure was absorbed by carp tissues after 60 d. However, based on the time course of BDE 47 assimilation, it is improbable that all BDE 47 was assimilated; more likely, production of BDE 47 in carp tissues occurred as a result of debromination of higher-brominated compounds, possibly BDE 99. The net assimilation efficiencies of BDE 28 and BDE 153 were also apparently low (20 and 4%, respectively) relative to the three PCBs (40% assimilated) examined in this study. The low assimilation efficiency and high depuration rates for BDEs suggest a higher potential for biotransformation. While all three PCB compounds displayed very similar assimilation and depuration rates, three of the four BDE compounds displayed significantly different assimilation rates among BDE congeners and relative to the PCBs. This study suggests that BDEs have significantly different fate dynamics relative to PCBs in wild carp and likely other species of fish.

Authors
Stapleton, HM; Letcher, RJ; Li, J; Baker, JE
MLA Citation
Stapleton, HM, Letcher, RJ, Li, J, and Baker, JE. "Dietary accumulation and metabolism of polybrominated diphenyl ethers by juvenile carp (Cyprinus carpio)." Environmental Toxicology and Chemistry 23.8 (2004): 1939-1946.
PMID
15352483
Source
scival
Published In
Environmental Toxicology and Chemistry
Volume
23
Issue
8
Publish Date
2004
Start Page
1939
End Page
1946
DOI
10.1897/03-462

Debromination of Polybrominated Diphenyl Ether Congeners BDE 99 and BDE 183 in the Intestinal Tract of the Common Carp (Cyprinus carpio)

Polybrominated diphenyl ether (PBDE) congener patterns in biota are often enriched in tetra-, penta-, and hexabrominated diphenyl ethers, which is believed to result from the use of the commercial "pentaBDE" formulation. However, our evidence suggests that debromination of PBDEs occurs within fish tissues leading to appreciable accumulation of less brominated congeners. This suggests that PBDE body burdens can reflect both direct uptake from exposure and debromination of more highly brominated congeners. We conducted two independent dietary exposure studies using the common carp (Cyprinus carpio) to trace the fate of 2,2′,4,4′ ,5-pentabromodiphenyl ether (BDE 99) and 2,2′,3,4,4′,5′ ,6-heptabromodiphenyl ether (BDE 183) in fish tissues. Carp were fed food spiked with individual BDE congeners for 62 d, and depuration was monitored during the following 37 d. Significant debromination was observed, converting BDE 99 to 2,2′,4,4′-tetrabromodiphenyl ether (BDE 47) and BDE 183 to 2,2′,4,4′,5,6-hexabromodiphenyl ether (BDE 154) and another as yet unidentified hexa-BDE congener. The BDE 99 concentration rapidly declined from 400 ± 40 ng/g ww in the food to 53 ± 12 ng/g ww in the gut content material sampled 2.5 ± 1 h following feeding. At least 9.5 ± 0.8% of the BDE 99 mass in the gut was debrominated to BDE 47 and assimilated in carp tissues. In the BDE 183 exposure, approximately 17% of the BDE 183 mass was debrominated and accumulated in carp tissues in the form of two hexa-BDE congeners. In both exposure studies, the concentration of the exposure compound decreased significantly in the gut within 2.5 ± 1 h following ingestion. This rapid decrease in the concentration of the BDE congeners could not be explained entirely by debromination to quantified products or fecal egestion. Reactions occurring within the gut transform BDE congeners to other products that may accumulate or be excreted. Further studies are needed to identify and determine the effects of these BDE metabolites.

Authors
Stapleton, HM; Letcher, RJ; Baker, JE
MLA Citation
Stapleton, HM, Letcher, RJ, and Baker, JE. "Debromination of Polybrominated Diphenyl Ether Congeners BDE 99 and BDE 183 in the Intestinal Tract of the Common Carp (Cyprinus carpio)." Environmental Science and Technology 38.4 (2004): 1054-1061.
PMID
14998018
Source
scival
Published In
Environmental Science and Technology
Volume
38
Issue
4
Publish Date
2004
Start Page
1054
End Page
1061

Sedimentary nonylphenol contamination in an urbanized, industrialized segment of the Delaware River estuary, USA

Authors
Ashley, JTF; Moore, A; Stapleton, HM; Velinsky, DJ; Wilhelm, MP
MLA Citation
Ashley, JTF, Moore, A, Stapleton, HM, Velinsky, DJ, and Wilhelm, MP. "Sedimentary nonylphenol contamination in an urbanized, industrialized segment of the Delaware River estuary, USA." Bulletin of Environmental Contamination and Toxicology 70.5 (2003): 978-984.
PMID
12719824
Source
scival
Published In
Bulletin of Environmental Contamination and Toxicology
Volume
70
Issue
5
Publish Date
2003
Start Page
978
End Page
984
DOI
10.1007/s00128-003-0078-1

Polybrominated diphenyl ether flame retardants in the North American environment

North America consumes over half of the world's production of polybrominated diphenyl ether (PBDE) flame retardants. About 98% of global demand for the Penta-BDE mixture, the constituents of which are the most bioaccumulative and environmentally widespread, resides here. However, research on the environmental distribution of PBDEs in North America has lagged behind that in Northern Europe. Examination of available governmentally maintained release data suggests that Deca-BDE use in the US substantially exceeds that in Canada. Penta-BDE use probably follows a similar pattern. PBDE demand in Mexico is uncertain, but is assumed to be comparatively modest. Recent research examining air, water, sediment, sewage sludge and aquatic biota suggests that Penta-BDE constituents are present in geographically disparate locations in the US and Canada. The less brominated congeners have been observed in areas distant from their known use or production, e.g. the Arctic. PBDEs have been detected in low concentrations in North American air, water and sediment, but much higher levels in aquatic biota. Increased burdens as a function of position in the food web have been noted. PBDE concentrations in US and Canadian sewage sludges appear to be at least 10-fold greater than European levels and may be a useful barometer of release. In general, PBDE concentrations in environmental media reported in North America are comparable or exceed those observed elsewhere in the world. In contrast to Europe, environmental burdens are increasing over time here, consistent with the greater consumption of the commercial mixtures. However, data remain relatively scarce. Deca-BDE in the North American environment appears largely restricted to points of release, e.g. urban areas and those where PBDE-containing sewage sludges have been applied. This lack of redistribution is likely due to its extremely low volatility and water solubility. Penta-BDE and Deca-BDE products are used in different applications and this may also be a factor controlling their environmental release. Crown Copyright © 2003 Published by Elsevier Science Ltd. All rights reserved.

Authors
Hale, RC; Alaee, M; Manchester-Neesvig, JB; Stapleton, HM; Ikonomou, MG
MLA Citation
Hale, RC, Alaee, M, Manchester-Neesvig, JB, Stapleton, HM, and Ikonomou, MG. "Polybrominated diphenyl ether flame retardants in the North American environment." Environment International 29.6 (2003): 771-779.
PMID
12850095
Source
scival
Published In
Environment International
Volume
29
Issue
6
Publish Date
2003
Start Page
771
End Page
779
DOI
10.1016/S0160-4120(03)00113-2

Comparing polybrominated diphenyl ether and polychlorinated biphenyl bioaccumulation in a food web in Grand Traverse Bay, Lake Michigan

Levels of polybrominated diphenyl ethers (BDEs) in Great Lakes salmonids and ambient air have been recently reported, but few studies worldwide have examined the accumulation of BDEs within aquatic food webs. Here we report some of the first measurements of six BDE congeners that are common components of the pentaBDE commercial mixture within an entire Lake Michigan food web. BDEs were detected in all samples and the dominant BDE congener was 2,2′,4,4′-tetrabromodiphenyl ether (BDE 47). BDE 47 levels were consistently greater than those of the 2,2′,4,4′,5-pentabromodiphenyl ether (BDE 99), despite similar levels of these two compounds in commercial mixtures, suggesting differences in the bioavailability of the BDE congeners or differences in their ability to be metabolized. Additionally, congener composition was significantly different among deepwater sculpin, bloater chub, and lake trout, indicating differences in exposure or differences in biotransformation capacities. Total BDE concentrations in this food web were positively correlated (r = 0.94) with levels of PCBs previously measured in these samples (Stapleton et al. 2001a). Levels of BDE 47 and PCB 153, compounds with similar physicochemical properties, were compared to examine the relative exposure and bioaccumulation of these two classes of chemicals that have different environmental loading histories. Food web magnification factors calculated for these two congeners were 3.2 and 4.0 for BDE 47 and PCB 153, respectively, indicating a comparable potential for biomagnification in food webs.

Authors
Stapleton, HM; Baker, JE
MLA Citation
Stapleton, HM, and Baker, JE. "Comparing polybrominated diphenyl ether and polychlorinated biphenyl bioaccumulation in a food web in Grand Traverse Bay, Lake Michigan." Archives of Environmental Contamination and Toxicology 45.2 (2003): 227-234.
PMID
14565581
Source
scival
Published In
Archives of Environmental Contamination and Toxicology
Volume
45
Issue
2
Publish Date
2003
Start Page
227
End Page
234
DOI
10.1007/s00244-003-0165-7

Seasonal dynamics of PCB and toxaphene bioaccumulation within a Lake Michigan food web

Seasonal variations in PCB and toxaphene concentrations were measured in bulk zooplankton, mysid shrimp, benthic amphipods, alewife, and bloater chub collected from Grand Traverse Bay, Lake Michigan between April and September of 1997 and 1998. Concentrations of PCBs in the dissolved phase of the water column were consistent over time; however, seasonal changes in contaminant concentrations within the biota were significant. Seasonal changes were most pronounced in zooplankton, which displayed highest PCB burdens in April and decreased by as much as 75% through September, coincident with changes in phytoplankton biomass, species composition, and changes in the particulate pools of PCBs within the water column. Mysis sp. display a similar PCB trend as zooplankton, while Diporeia sp. displayed maximal PCB concentrations in late summer during 1997. PCB trends in the primary forage fish alewife (Alosa pseudoharengus) and bloater (Coregonus hoyi) were correlated more to shifts in lipid content and seasonal diet preferences. PCB concentrations were higher (p < 0.01) in bloater (310 ± 98 ng/g wet weight) than alewife (233 ± 70 ng/g wet weight), however alewife possessed higher toxaphene burdens (198 ± 72 ng/g wet weight) than bloater (88 ± 36 ng/g wet weight). Alewife contaminant burdens were high in spring and fall of both years, decreasing by as much as 60% in midsummer, and were reflective of changes measured in their lipid content associated with gamete production and spawning. These results suggest that despite invariant concentrations of the dissolved pool of PCBs within the lake, accumulation of PCBs by the biota on seasonal scales is controlled appreciably by growth and lipid dynamics, and foraging behavior.

Authors
Stapleton, HM; Skubinna, J; Baker, JE
MLA Citation
Stapleton, HM, Skubinna, J, and Baker, JE. "Seasonal dynamics of PCB and toxaphene bioaccumulation within a Lake Michigan food web." Journal of Great Lakes Research 28.1 (2002): 52-64.
Source
scival
Published In
Journal of Great Lakes Research
Volume
28
Issue
1
Publish Date
2002
Start Page
52
End Page
64

Accumulation of atmospheric and sedimentary PCBs and toxaphene in a Lake Michigan food web

Seston, sediment, settling organic matter, and food web members were collected from Grand Traverse Bay, Lake Michigan, between April 1997 and September 1998 to examine PCB and toxaphene biomagnification. Stable isotopes of nitrogen and carbon were analyzed in samples and used to establish trophic structure of the food web and to determine the importance of atmospheric versus sedimentary sources in delivering PCBs to the food web. Nitrogen isotopes were confounded by multiple variables in this system, particularly seasonal variation, and did not display a simple pattern of enrichment among trophic levels. However, δ13C displayed little seasonal variation and was positively correlated with PCB concentrations among food web members (r2 = 0.69). Plots of δ13C vs PCBs separate food web members into three distinct groupings comprised of invertebrates, primary forage fish, and predatory fish. Stable isotope values of the primary organic sources indicate that the atmosphere, and not the sediment, is the most likely source of PCBs to the food web of Lake Michigan. Additionally, we suggest that seston may be important in delivering PCBs to pelagic food web members and species that receive a majority of their nutrition through pelagic sources. In contrast, settling particles are implicated in delivering PCBs to benthic organisms and Mysis relicta.

Authors
Stapleton, HM; Masterson, C; Skubinna, J; Ostrom, P; Ostrom, NE; Baker, JE
MLA Citation
Stapleton, HM, Masterson, C, Skubinna, J, Ostrom, P, Ostrom, NE, and Baker, JE. "Accumulation of atmospheric and sedimentary PCBs and toxaphene in a Lake Michigan food web." Environmental Science and Technology 35.16 (2001): 3287-3293.
PMID
11529566
Source
scival
Published In
Environmental Science & Technology
Volume
35
Issue
16
Publish Date
2001
Start Page
3287
End Page
3293
DOI
10.1021/es0019225

Metabolism of highly chlorinated PCBs by a Lake Michigan fish

Authors
Stapleton, HM; Letcher, RJ; Baker, JE
MLA Citation
Stapleton, HM, Letcher, RJ, and Baker, JE. "Metabolism of highly chlorinated PCBs by a Lake Michigan fish." Environ. Sci. Technol. 35.24 (2001): 4747-4752. (Academic Article)
Source
manual
Published In
Environ. Sci. Technol.
Volume
35
Issue
24
Publish Date
2001
Start Page
4747
End Page
4752

Metabolism of PCBs by the deepwater sculpin (Myoxocephalus thompsoni)

Methylsulfonyl-PCBs (MeSO2-PCBs) are hydrophobic organic contaminants that bioaccumulate in the environment similar to their parent molecules, PCBs. Previously, MeSO2PCBs have primarily been identified in tissues of birds, humans, and other mammals. However, evidence now supports formation of these metabolites in deepwater sculpin, Myoxocephalus thompsoni, a benthic forage fish predominant in the Great Lakes. The ability of deepwater sculpin to form MeSO2-PCBs is unprecedented for a freshwater fish species and presents a novel biochemical pathway for organochlorine metabolism. Additionally, this appears to be a unique PCB metabolic pathway resulting in a reduction of as much as 10% in the sculpin PCB burden, which is further transformed into another class of organic contaminants in the Great Lakes ecosystem.

Authors
Stapleton, HM; Letcher, RJ; Baker, JE
MLA Citation
Stapleton, HM, Letcher, RJ, and Baker, JE. "Metabolism of PCBs by the deepwater sculpin (Myoxocephalus thompsoni)." Environmental Science and Technology 35.24 (2001): 4747-4752.
PMID
11775148
Source
scival
Published In
Environmental Science & Technology
Volume
35
Issue
24
Publish Date
2001
Start Page
4747
End Page
4752
DOI
10.1021/es015571l

Recent declines in PAH, PCB, and toxaphene levels in the Northern Great Lakes as determined from high resolution sediment cores

Sediment cores were collected from two sites in Grand Traverse Bay, Lake Michigan in May 1998, dated using 210Pb geochronology, and analyzed for polychlorinated biphenyl (PCB) congeners, polycyclic aromatic hydrocarbons (PAHs), and toxaphene. The extraordinarily high sediment focusing and accumulation rates in these cores relative to other Great Lakes sediments allowed quantification of high-resolution temporal trends in the burial of hydrophobic organic contaminants. The focus-corrected accumulation rate of total PCBs (sum of 105 congeners) in 1998 was 0.50 ng/cm2-year at both sites. Toxaphene and total PAH (t-PAH; sum of 33 compounds) surficial accumulations varied at each site and ranged from 0.08 to 0.41 ng/cm2-year for toxaphene and 25 to 52 ng/cm2-yr for t-PAHs at the two sites. The maximum t-PAH accumulation rate was in sediment dated from 1942, and PAH accumulation decreased from 1942 to 1980 with a first-order rate of decline 0.017 yr-1. Both toxaphene and t-PCB accumulations peaked in sediment deposited in 1972, after which their accumulations decreased with nearly identical rates of decline (0.027 yr-1 and 0.028 yr-1, respectively).

Authors
Schneider, AR; Stapleton, HM; Cornwell, J; Baker, JE
MLA Citation
Schneider, AR, Stapleton, HM, Cornwell, J, and Baker, JE. "Recent declines in PAH, PCB, and toxaphene levels in the Northern Great Lakes as determined from high resolution sediment cores." Environmental Science and Technology 35.19 (2001): 3809-3815.
PMID
11642437
Source
scival
Published In
Environmental Science & Technology
Volume
35
Issue
19
Publish Date
2001
Start Page
3809
End Page
3815
DOI
10.1021/es002044d
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