151
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Liu X, Yu G, Cao Z, Wang B, Huang J, Deng S, Wang Y, Shen H, Peng X. WITHDRAWN: Estimation of human exposure to halogenated flame retardants through dermal adsorption by skin wipe. CHEMOSPHERE 2016:S0045-6535(16)31389-3. [PMID: 27817895 DOI: 10.1016/j.chemosphere.2016.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/05/2016] [Accepted: 10/05/2016] [Indexed: 06/06/2023]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.chemosphere.2016.10.015. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Xiaotu Liu
- School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China
| | - Gang Yu
- School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
| | - Zhiguo Cao
- School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang 453007, China
| | - Bin Wang
- School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China
| | - Jun Huang
- School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China
| | - Shubo Deng
- School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China
| | - Yujue Wang
- School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China
| | - Hongbo Shen
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Xue Peng
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China
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152
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Knudsen GA, Hughes MF, Sanders JM, Hall SM, Birnbaum LS. Estimation of human percutaneous bioavailability for two novel brominated flame retardants, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP). Toxicol Appl Pharmacol 2016; 311:117-127. [PMID: 27732871 DOI: 10.1016/j.taap.2016.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/04/2016] [Accepted: 10/07/2016] [Indexed: 01/07/2023]
Abstract
2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) are novel brominated flame retardants used in consumer products. A parallelogram approach was used to predict human dermal absorption and flux for EH-TBB and BEH-TEBP. [14C]-EH-TBB or [14C]-BEH-TEBP was applied to human or rat skin at 100nmol/cm2 using a flow-through system. Intact rats received analogous dermal doses. Treated skin was washed and tape-stripped to remove "unabsorbed" [14C]-radioactivity after continuous exposure (24h). "Absorbed" was quantified using dermally retained [14C]-radioactivity; "penetrated" was calculated based on [14C]-radioactivity in media (in vitro) or excreta+tissues (in vivo). Human skin absorbed EH-TBB (24±1%) while 0.2±0.1% penetrated skin. Rat skin absorbed more (51±10%) and was more permeable (2±0.5%) to EH-TBB in vitro; maximal EH-TBB flux was 11±7 and 102±24pmol-eq/cm2/h for human and rat skin, respectively. In vivo, 27±5% was absorbed and 13% reached systemic circulation after 24h (maximum flux was 464±65pmol-eq/cm2/h). BEH-TEBP in vitro penetrance was minimal (<0.01%) for rat or human skin. BEH-TEBP absorption was 12±11% for human skin and 41±3% for rat skin. In vivo, total absorption was 27±9%; 1.2% reached systemic circulation. In vitro maximal BEH-TEBP flux was 0.3±0.2 and 1±0.3pmol-eq/cm2/h for human and rat skin; in vivo maximum flux for rat skin was 16±7pmol-eq/cm2/h. EH-TBB was metabolized in rat and human skin to tetrabromobenzoic acid. BEH-TEBP-derived [14C]-radioactivity in the perfusion media could not be characterized. <1% of the dose of EH-TBB and BEH-TEHP is estimated to reach the systemic circulation following human dermal exposure under the conditions tested. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE 2-Ethylhexyl 2,3,4,5-tetrabromobenzoate (PubChem CID: 71316600; CAS No. 183658-27-7 FW: 549.92g/mol logPest: 7.73-8.75 (12)) Abdallah et al., 2015a. Other published abbreviations for 2-ethylhexyl-2,3,4,5-tetrabromobenzoate are TBB EHTeBB or EHTBB Abdallah and Harrad, 2011. bis(2-ethylhexyl) tetrabromophthalate (PubChem CID: 117291; CAS No. 26040-51-7 FW: 706.14g/mol logPest: 9.48-11.95 (12)). Other published abbreviations for bis(2-ethylhexyl)tetrabromophthalate are TeBrDEPH TBPH or BEHTBP.
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Affiliation(s)
- Gabriel A Knudsen
- NCI Laboratory of Toxicology and Toxicokinetics, 111 T W Alexander Dr., Research Triangle Park, NC, USA.
| | - Michael F Hughes
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - J Michael Sanders
- NCI Laboratory of Toxicology and Toxicokinetics, 111 T W Alexander Dr., Research Triangle Park, NC, USA
| | - Samantha M Hall
- NCI Laboratory of Toxicology and Toxicokinetics, 111 T W Alexander Dr., Research Triangle Park, NC, USA
| | - Linda S Birnbaum
- NCI Laboratory of Toxicology and Toxicokinetics, 111 T W Alexander Dr., Research Triangle Park, NC, USA
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153
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Mitro SD, Dodson RE, Singla V, Adamkiewicz G, Elmi AF, Tilly MK, Zota AR. Consumer Product Chemicals in Indoor Dust: A Quantitative Meta-analysis of U.S. Studies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10661-10672. [PMID: 27623734 PMCID: PMC5052660 DOI: 10.1021/acs.est.6b02023] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/29/2016] [Accepted: 08/05/2016] [Indexed: 05/19/2023]
Abstract
Indoor dust is a reservoir for commercial consumer product chemicals, including many compounds with known or suspected health effects. However, most dust exposure studies measure few chemicals in small samples. We systematically searched the U.S. indoor dust literature on phthalates, replacement flame retardants (RFRs), perfluoroalkyl substances (PFASs), synthetic fragrances, and environmental phenols and estimated pooled geometric means (GMs) and 95% confidence intervals for 45 chemicals measured in ≥3 data sets. In order to rank and contextualize these results, we used the pooled GMs to calculate residential intake from dust ingestion, inhalation, and dermal uptake from air, and then identified hazard traits from the Safer Consumer Products Candidate Chemical List. Our results indicate that U.S. indoor dust consistently contains chemicals from multiple classes. Phthalates occurred in the highest concentrations, followed by phenols, RFRs, fragrance, and PFASs. Several phthalates and RFRs had the highest residential intakes. We also found that many chemicals in dust share hazard traits such as reproductive and endocrine toxicity. We offer recommendations to maximize comparability of studies and advance indoor exposure science. This information is critical in shaping future exposure and health studies, especially related to cumulative exposures, and in providing evidence for intervention development and public policy.
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Affiliation(s)
- Susanna D. Mitro
- Milken
Institute School of Public Health, George
Washington University, Washington,
D.C. 20052, United States
| | | | - Veena Singla
- Health
and Environment Program, Natural Resources
Defense Council, San Francisco, California 94104, United States
| | - Gary Adamkiewicz
- Harvard T. H.
Chan School of Public Health, Boston, Massachusetts 02115, United States
| | - Angelo F. Elmi
- Milken
Institute School of Public Health, George
Washington University, Washington,
D.C. 20052, United States
| | - Monica K. Tilly
- Health
and Environment Program, Natural Resources
Defense Council, San Francisco, California 94104, United States
- Occupational
and Environmental Medicine Program, University
of California San Francisco, San
Francisco, California 94143, United States
| | - Ami R. Zota
- Milken
Institute School of Public Health, George
Washington University, Washington,
D.C. 20052, United States
- Phone: (202) 994-9289; fax: 2052-994-0082; e-mail:
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154
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Knudsen GA, Sanders JM, Birnbaum LS. Disposition of the Emerging Brominated Flame Retardant, 2-Ethylhexyl 2,3,4,5-Tetrabromobenzoate, in Female SD Rats and Male B6C3F1 Mice: Effects of Dose, Route, and Repeated Administration. Toxicol Sci 2016; 154:392-402. [PMID: 27613714 DOI: 10.1093/toxsci/kfw176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB; MW 549.92 g/mol; CAS 183658-27-7) is a brominated component of flame retardant mixtures used as substitutes for some PBDEs. EH-TBB is added to various consumer products, including polyurethane foams, and has been detected in humans. The present study characterized the fate of EH-TBB in rodents. [14C]-labeled EH-TBB was absorbed, metabolized, and eliminated via the urine and feces following single administrations of 0.1-100 µmol/kg (∼0.05-55 mg/kg) or repeated administration (0.1 µmol/kg/day × 5-10 days) by gavage to female Hsd:Sprague DawleySD (SD) rats. Cumulative excretion via feces increased (39-60%) with dose (0.1-10 µmol/kg) with corresponding decreases in urinary excretion (54 to 37%) after 72 h. Delayed excretion of [14C]-radioactivity in urine and feces of a 100 µmol/kg oral dose was noted. Recovery was complete for all doses by 72 h. IV-injected rats excreted more of the 0.1 µmol/kg dose in urine and less in feces than did gavaged rats, indicating partial biliary elimination of systemically available compound. No tissue bioaccumulation was found for rats given 5 oral daily doses of EH-TBB. Parent molecule was not detected in urine whereas 2 metabolites, tetrabromobenzoic acid (TBBA), a TBBA-sulfate conjugate, and a TBBA-glycine conjugate were identified. EH-TBB and TBBA were identified in extracts from feces. Data from gavaged male B6C3F1/Tac mice indicated minimal sex- or species differences are likely for the disposition of EH-TBB. Approximately 85% of a 0.1 µmol/kg dose was absorbed from the gut. Overall absorption of EH-TBB is expected to be even greater at lower levels.
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Affiliation(s)
- Gabriel A Knudsen
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, North Carolina
| | - J Michael Sanders
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, North Carolina
| | - Linda S Birnbaum
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, North Carolina
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155
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Saini A, Thaysen C, Jantunen L, McQueen RH, Diamond ML. From Clothing to Laundry Water: Investigating the Fate of Phthalates, Brominated Flame Retardants, and Organophosphate Esters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9289-97. [PMID: 27507188 DOI: 10.1021/acs.est.6b02038] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The accumulation of phthalate esters, brominated flame retardants (BFRs) and organophosphate esters (OPEs) by clothing from indoor air and transfer via laundering to outdoors were investigated. Over 30 days cotton and polyester fabrics accumulated 3475 and 1950 ng/dm(2) ∑5phthalates, 65 and 78 ng/dm(2) ∑10BFRs, and 1200 and 310 ng/dm(2) ∑8OPEs, respectively. Planar surface area concentrations of OPEs and low molecular weight phthalates were significantly greater in cotton than polyester and similar for BFRs and high molecular weight phthalates. This difference was significantly and inversely correlated with KOW, suggesting greater sorption of polar compounds to polar cotton. Chemical release from cotton and polyester to laundry water was >80% of aliphatic OPEs (log KOW < 4), < 50% of OPEs with an aromatic structure, 50-100% of low molecular weight phthalates (log KOW 4-6), and < detection-35% of higher molecular weight phthalates (log KOW > 8) and BFRs (log KOW > 6). These results support the hypothesis that clothing acts an efficient conveyer of soluble semivolatile organic compounds (SVOCs) from indoors to outdoors through accumulation from air and then release during laundering. Clothes drying could as well contribute to the release of chemicals emitted by electric dryers. The results also have implications for dermal exposure.
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Affiliation(s)
- Amandeep Saini
- Department of Physical and Environmental Sciences, University of Toronto Scarborough , 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada
| | - Clara Thaysen
- Department of Earth Sciences, 22 Russell Street, University of Toronto , Toronto, Ontario M5S 3B1 Canada
| | - Liisa Jantunen
- Department of Earth Sciences, 22 Russell Street, University of Toronto , Toronto, Ontario M5S 3B1 Canada
- Air Quality Processes Research Section, Environment and Climate Change Canada , 6248 Eighth Line, Egbert, Ontario L0L 1N0 Canada
| | - Rachel H McQueen
- Department of Human Ecology, University of Alberta , Edmonton, Alberta T6G 2N1 Canada
| | - Miriam L Diamond
- Department of Physical and Environmental Sciences, University of Toronto Scarborough , 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada
- Department of Earth Sciences, 22 Russell Street, University of Toronto , Toronto, Ontario M5S 3B1 Canada
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156
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Behl M, Rice JR, Smith MV, Co CA, Bridge MF, Hsieh JH, Freedman JH, Boyd WA. Editor's Highlight: Comparative Toxicity of Organophosphate Flame Retardants and Polybrominated Diphenyl Ethers to Caenorhabditis elegans. Toxicol Sci 2016; 154:241-252. [PMID: 27566445 DOI: 10.1093/toxsci/kfw162] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
With the phasing-out of the polybrominated diphenyl ether (PBDE) flame retardants due to concerns regarding their potential developmental toxicity, the use of replacement compounds such as organophosphate flame retardants (OPFRs) has increased. Limited toxicity data are currently available to estimate the potential adverse health effects of the OPFRs. The toxicological effects of 4 brominated flame retardants, including 3 PBDEs and 3,3',5,5'-tetrabromobisphenol A, were compared with 6 aromatic OPFRs and 2 aliphatic OPFRs. The effects of these chemicals were determined using 3 biological endpoints in the nematode Caenorhabditis elegans (feeding, larval development, and reproduction). Because C. elegans development was previously reported to be sensitive to mitochondrial function, results were compared with those from an in vitro mitochondrial membrane permeabilization (MMP) assay. Overall 11 of the 12 flame retardants were active in 1 or more C. elegans biological endpoints, with only tris(2-chloroethyl) phosphate inactive across all endpoints including the in vitro MMP assay. For 2 of the C. elegans endpoints, at least 1 OPFR had similar toxicity to the PBDEs: triphenyl phosphate (TPHP) inhibited larval development at levels comparable to the 3 PBDEs; whereas TPHP and isopropylated phenol phosphate (IPP) affected C. elegans reproduction at levels similar to the PBDE commercial mixture, DE-71. The PBDEs reduced C. elegans feeding at lower concentrations than any OPFR. In addition, 9 of the 11 chemicals that inhibited C. elegans larval development also caused significant mitochondrial toxicity. These results suggest that some of the replacement aromatic OPFRs may have levels of toxicity comparable to PBDEs.
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Affiliation(s)
- Mamta Behl
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina
| | - Julie R Rice
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina
| | - Marjo V Smith
- Social & Scientific Systems, Inc., Durham, North Carolina
| | - Caroll A Co
- Social & Scientific Systems, Inc., Durham, North Carolina
| | | | - Jui-Hua Hsieh
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina
| | - Jonathan H Freedman
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Windy A Boyd
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina
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157
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Xu F, Giovanoulis G, van Waes S, Padilla-Sanchez JA, Papadopoulou E, Magnér J, Haug LS, Neels H, Covaci A. Comprehensive Study of Human External Exposure to Organophosphate Flame Retardants via Air, Dust, and Hand Wipes: The Importance of Sampling and Assessment Strategy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7752-60. [PMID: 27350238 DOI: 10.1021/acs.est.6b00246] [Citation(s) in RCA: 181] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We compared the human exposure to organophosphate flame retardants (PFRs) via inhalation, dust ingestion, and dermal absorption using different sampling and assessment strategies. Air (indoor stationary air and personal ambient air), dust (floor dust and surface dust), and hand wipes were sampled from 61 participants and their houses. We found that stationary air contains higher levels of ΣPFRs (median = 163 ng/m(3), IQR = 161 ng/m(3)) than personal air (median = 44 ng/m(3), IQR = 55 ng/m(3)), suggesting that the stationary air sample could generate a larger bias for inhalation exposure assessment. Tris(chloropropyl) phosphate isomers (ΣTCPP) accounted for over 80% of ΣPFRs in both stationary and personal air. PFRs were frequently detected in both surface dust (ΣPFRs median = 33 100 ng/g, IQR = 62 300 ng/g) and floor dust (ΣPFRs median = 20 500 ng/g, IQR = 30 300 ng/g). Tris(2-butoxylethyl) phosphate (TBOEP) accounted for 40% and 60% of ΣPFRs in surface and floor dust, respectively, followed by ΣTCPP (30% and 20%, respectively). TBOEP (median = 46 ng, IQR = 69 ng) and ΣTCPP (median = 37 ng, IQR = 49 ng) were also frequently detected in hand wipe samples. For the first time, a comprehensive assessment of human exposure to PFRs via inhalation, dust ingestion, and dermal absorption was conducted with individual personal data rather than reference factors of the general population. Inhalation seems to be the major exposure pathway for ΣTCPP and tris(2-chloroethyl) phosphate (TCEP), while participants had higher exposure to TBOEP and triphenyl phosphate (TPHP) via dust ingestion. Estimated exposure to ΣPFRs was the highest with stationary air inhalation (median =34 ng·kg bw(-1)·day(-1), IQR = 38 ng·kg bw(-1)·day(-1)), followed by surface dust ingestion (median = 13 ng·kg bw(-1)·day(-1), IQR = 28 ng·kg bw(-1)·day(-1)), floor dust ingestion and personal air inhalation. The median dermal exposure on hand wipes was 0.32 ng·kg bw(-1)·day(-1) (IQR = 0.58 ng·kg bw(-1)·day(-1)) for ΣTCPP. The selection of sampling and assessment strategies could significantly affect the results of exposure assessment.
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Affiliation(s)
- Fuchao Xu
- Toxicological Centre, University of Antwerp , Universiteitsplein 1, 2610 Wilrijk, Belgium
| | | | - Sofie van Waes
- Toxicological Centre, University of Antwerp , Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Juan Antonio Padilla-Sanchez
- Division of Environmental Medicine, Norwegian Institute of Public Health , Lovisenberggata 8, Oslo N-0403, Norway
| | - Eleni Papadopoulou
- Division of Environmental Medicine, Norwegian Institute of Public Health , Lovisenberggata 8, Oslo N-0403, Norway
| | - Jorgen Magnér
- IVL Swedish Environmental Research Institute , SE-100 31 Stockholm, Sweden
| | - Line Småstuen Haug
- Division of Environmental Medicine, Norwegian Institute of Public Health , Lovisenberggata 8, Oslo N-0403, Norway
| | - Hugo Neels
- Toxicological Centre, University of Antwerp , Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp , Universiteitsplein 1, 2610 Wilrijk, Belgium
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158
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Ding J, Xu Z, Huang W, Feng L, Yang F. Organophosphate ester flame retardants and plasticizers in human placenta in Eastern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 554-555:211-7. [PMID: 26950635 DOI: 10.1016/j.scitotenv.2016.02.171] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 02/24/2016] [Accepted: 02/24/2016] [Indexed: 05/24/2023]
Abstract
Organophosphate esters (OPEs) have been widely used in various products as alternatives to brominated flame retardants. Although widespread OPE exposure is expected in humans, the accumulation of OPEs has seldom been studied in the human body. In this study, 12 OPE analogs were analyzed in 50 human placentas collected in Eastern China. The concentrations of the 9 most frequently detected OPEs (Σ9OPEs) ranged from 34.4 to 862ng/g lipid weight (lw), with a median of 301ng/g lw. Tri(2-chloroethyl) phosphate (TCEP) was identified as the most abundant analog, with a median concentration of 142ng/g lw, followed by tributoxyethyl phosphate (TBEP) and triphenyl phosphate (TPhP). Statistical analysis showed no analog of OPEs or Σ9OPEs was positively correlated with the lipid content of the placentas. There were no correlations observed between the OPE concentrations and maternal characteristics. Food consumption habits exhibited weak effects on OPE levels in the placentas. Further investigation is required to determine the effects of OPEs on fetuses due to the expected increase in maternal exposure to these esters.
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Affiliation(s)
- Jinjian Ding
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; Research Center for Air Pollution and Health, Zhejiang University, Hangzhou, 310058, China
| | - Zemin Xu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Wei Huang
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Limin Feng
- Department of Laboratory Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, China
| | - Fangxing Yang
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; Research Center for Air Pollution and Health, Zhejiang University, Hangzhou, 310058, China.
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159
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Kile ML, Scott RP, O'Connell SG, Lipscomb S, MacDonald M, McClelland M, Anderson KA. Using silicone wristbands to evaluate preschool children's exposure to flame retardants. ENVIRONMENTAL RESEARCH 2016; 147:365-72. [PMID: 26945619 PMCID: PMC4821754 DOI: 10.1016/j.envres.2016.02.034] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 05/18/2023]
Abstract
Silicone wristbands can be used as passive sampling tools for measuring personal environmental exposure to organic compounds. Due to the lightweight and simple design, the wristband may be a useful technique for measuring children's exposure. In this study, we tested the stability of flame retardant compounds in silicone wristbands and developed an analytical approach for measuring 41 flame retardants in the silicone wristband in order to evaluate exposure to these compounds in preschool-aged children. To evaluate the robustness of using wristbands to measure flame retardants, we evaluated the stability of 3 polybrominated diphenyl ethers (BDEs), and 2 organophosphate flame retardants (OPFRs) in wristbands over 84 days and did not find any evidence of significant loss over time at either 4 or -20°C (p>0.16). We recruited a cohort of 92 preschool aged children in Oregon to wear the wristband for 7 days in order to characterize children's acceptance of the technology, and to characterize their exposure to flame retardants. Seventy-seven parents returned the wristbands for analysis of 35 BDEs, 4 OPFRs, and 2 other brominated flame retardants although 5 were excluded from the exposure assessment due to protocol deviations (n=72). A total of 20 compounds were detected above the limit of quantitation, and 11 compounds including 4 OPFRs and 7 BDEs were detected in over 60% of the samples. Children's gender, age, race, recruitment site, and family context were not significantly associated with returning wristbands or compliance with protocols. Comparisons between flame retardant data and socio-demographic information revealed significant differences in total exposures to both ΣBDEs and ΣOPFRs based on age of house, vacuuming frequency, and family context. These results demonstrate that preschool children in Oregon are exposed to BDEs that are no longer being produced in the United States and to OPFRs that have been used as an alternative to polybrominated compounds. Silicone wristbands were well tolerated by young children and were useful for characterizing personal exposure to flame retardants that were not bound to particulate matter.
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Affiliation(s)
- Molly L Kile
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, United States
| | - Richard P Scott
- Department of Environmental and Molecular Toxicology, Corvallis, OR 97331, United States
| | - Steven G O'Connell
- Department of Environmental and Molecular Toxicology, Corvallis, OR 97331, United States
| | - Shannon Lipscomb
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, United States; Oregon State University Cascades Campus, Bend, OR 97701, United States
| | - Megan MacDonald
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, United States
| | - Megan McClelland
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, United States
| | - Kim A Anderson
- Department of Environmental and Molecular Toxicology, Corvallis, OR 97331, United States.
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160
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Knudsen GA, Sanders JM, Birnbaum LS. Disposition of the emerging brominated flame retardant, bis(2-ethylhexyl) tetrabromophthalate, in female Sprague Dawley rats: effects of dose, route and repeated administration. Xenobiotica 2016; 47:245-254. [PMID: 27098498 DOI: 10.1080/00498254.2016.1174793] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
1. Bis(2-ethylhexyl)-tetrabromophthalate (BEH-TEBP; CAS No. 26040-51-7; PubChem CID: 117291; MW 706.15 g/mol, elsewhere: TeBrDEPH, TBPH, or BEHTBP) is used as an additive brominated flame retardant in consumer products. 2. Female Sprague Dawley rats eliminated 92-98% of [14C]-BEH-TEBP unchanged in feces after oral administration (0.1 or 10 μmol/kg). A minor amount of each dose (0.8-1%) was found in urine after 72 h. Disposition of orally administered BEH-TEBP in male B6C3F1/Tac mice was similar to female rats. 3. Bioaccumulation of [14C]-radioactivity was observed in liver and adrenals following 10 daily oral administrations (0.1 μmol/kg/day). These tissues contained 5- and 10-fold higher concentrations of [14C]-radioactivity, respectively, versus a single dose. 4. IV-administered [14C]-BEH-TEBP (0.1 μmol/kg) was slowly eliminated in feces, with >15% retained in tissues after 72 h. Bile and fecal extracts from these rats contained the metabolite mono-ethylhexyl tetrabromophthalate (TBMEHP). 5. BEH-TEBP was poorly absorbed, minimally metabolized and eliminated mostly by the fecal route after oral administration. Repeated exposure to BEH-TEBP led to accumulation in some tissues. The toxicological significance of this effect remains to be determined. This work was supported by the Intramural Research Program of the National Cancer Institute at the National Institutes of Health (Project ZIA BC 011476).
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161
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Hammel SC, Hoffman K, Webster TF, Anderson KA, Stapleton HM. Measuring Personal Exposure to Organophosphate Flame Retardants Using Silicone Wristbands and Hand Wipes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:4483-91. [PMID: 26975559 PMCID: PMC4872512 DOI: 10.1021/acs.est.6b00030] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
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.
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Affiliation(s)
- Stephanie C. Hammel
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
| | - Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
| | - Thomas F. Webster
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, United States
| | - Kim A. Anderson
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, United States
| | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
- Corresponding Author: Phone: 919-613-8717. Fax: 919-684-8741.
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162
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Fan X, Kubwabo C, Rasmussen PE, Wu F. Non-PBDE halogenated flame retardants in Canadian indoor house dust: sampling, analysis, and occurrence. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:7998-8007. [PMID: 26780041 DOI: 10.1007/s11356-015-5956-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/10/2015] [Indexed: 05/22/2023]
Abstract
An analytical method was developed for the measurement of 18 novel halogenated flame retardants in house dust. Sample preparation was based on ultrasound-assisted solvent extraction and clean up with solid phase extraction (SPE). Sample extracts were analyzed by gas chromatography-mass spectrometry (GC/MS) operated in electron capture negative ion (ECNI) chemical ionization mode. Baseline data from 351 fresh (active) dust samples collected under the Canadian House Dust Study (CHDS) revealed that five out of 18 target chemicals were present with detection frequencies higher than 90 %. Median (range) concentrations for these five compounds were as follows: 104 (<1.5-13,000) ng/g for 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), 8.5 (<1.7-2390) ng/g for 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 10.2 (<1.7-430) ng/g for hexabromobenzene (HBB), 2.9 (<1.2-1410) ng/g for syn-dechlorane plus (syn-DP) and 5.6 (<1.9-1570) ng/g for anti-dechlorane plus (anti-DP). A comparison of two sampling methods in a subset of 40 homes showed significant positive correlations between samples of "active" dust and samples taken directly from the household vacuum cleaner for all target compounds having median values above their corresponding method detection limits (MDLs). In addition, the method was also applied to the analysis of the targeted compounds in National Institute of Standards and Technology (NIST) standard reference material (SRM 2585, organic contaminants in house dust). Results from the current study could contribute to the potential certification of target chemicals in SRM 2585.
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Affiliation(s)
- Xinghua Fan
- Healthy Environments and Consumer Safety Branch, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Cariton Kubwabo
- Healthy Environments and Consumer Safety Branch, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada.
| | - Pat E Rasmussen
- Healthy Environments and Consumer Safety Branch, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Fang Wu
- Ministry of the Environment of Ontario and Climate Change, Toronto, ON, M9P 3V6, Canada
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163
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Keimowitz AR, Strunsky N, Wovkulich K. Organophosphate flame retardants in household dust before and after introduction of new furniture. CHEMOSPHERE 2016; 148:467-472. [PMID: 26841288 DOI: 10.1016/j.chemosphere.2016.01.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/11/2016] [Accepted: 01/12/2016] [Indexed: 06/05/2023]
Abstract
Flame retardant compounds originating from household items collect in household dust, a reasonable proxy for human exposure. Contributions of specific items or behaviors to dust are difficult to separate. This study examined standardized college housing before and after the introduction of new, flame retardant couches in order to explore any effect that changing upholstered furniture may have on flame retardant concentrations in dust. Two contradictory hypotheses were posited: (1) that new furniture might increase flame retardant releases immediately after introduction due to initial off-gassing of new materials or (2) that older furniture would release more flame retardants due to mechanical breakdown of polyurethane foam. This study was designed to determine which of these processes dominated. Prior to the introduction of new furniture, TDCIPP was detected in 12/20 samples at a median concentration of 22 μg/g and TCEP was detected in 1/20 samples at a concentration of 16 μg/g. TDCIPP and TCEP were not detected in any samples (N = 29) after the introduction of new couches. TPHP was detected both before (in 11/20 samples) and after (in 5/29 samples) introduction of new couches; the median concentrations before and after were 63 ± 49 and 16 ± 11 μg/g (standard deviation shown). Introduced couches contained TDCIPP (and not TPHP) at ∼1.25% (w/w). These data support the second hypothesis and indicate that removal of older furniture decreases TDCIPP and TCEP concentrations in dust and may potentially reduce total flame retardant concentrations in dust, at least immediately after introduction of the new furniture.
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Affiliation(s)
- A R Keimowitz
- Vassar College, Department of Chemistry, 124 Raymond Avenue, Poughkeepsie, NY 12508, USA.
| | - N Strunsky
- Vassar College, Department of Chemistry, 124 Raymond Avenue, Poughkeepsie, NY 12508, USA.
| | - K Wovkulich
- Vassar College, Department of Chemistry, 124 Raymond Avenue, Poughkeepsie, NY 12508, USA.
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164
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Zhao F, Wang J, Fang Y, Ding J, Yang H, Li L, Xi Z, Qiao H. Effects of tris(1,3-dichloro-2-propyl)phosphate on pathomorphology and gene/protein expression related to thyroid disruption in rats. Toxicol Res (Camb) 2016; 5:921-930. [PMID: 30090400 DOI: 10.1039/c5tx00374a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/03/2016] [Indexed: 11/21/2022] Open
Abstract
Previous studies demonstrated that tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) caused adverse effects on thyroid hormone (TH) imbalance in aquatic and avian organisms. This study focused on the effects of TDCIPP on thyroid function and hormone homeostasis in mammals. Pubertal female Sprague-Dawley rats were orally administered 50, 100, or 250 mg per kg per d of TDCIPP from postnatal day (PND) 22 to PND42 for 21 days. The serum triiodothyronine (T3) levels increased significantly at 250 mg per kg per d of TDCIPP. There were no significant differences in the body weight, serum thyroxine (T4) and free thyroxine (FT4) levels between the control and TDCIPP treated groups. There were significant dose-dependent increases in the mRNA and protein expression levels of genes related to drug metabolism (cytochrome-p450-3A1, CYP3A1) and TH clearance (udp-glucuronosyltransferase-1A6, UGT1A6) in the liver. Treatment with TDCIPP increased hepatic type 1 deiodinase (DIO1) mRNA at 250 mg per kg per d but down-regulated hepatic TH receptor beta (TRβ) mRNA expression. In addition, TDCIPP exposure induced slight thyroid follicular hyperplasia, and several genes involved in TH biosynthesis (NIS, TPO, Tg) were altered at 100 and 250 mg per kg per d of TDCIPP. Nevertheless, serum thyroid stimulating hormone (TSH) levels and the receptor (TSHr) mRNA significantly decreased at only the low dose group. Based on these results, we certified that TDCIPP disturbs the normal bioprocess on TH synthesis, biotransformation or clearance, and hepatic detoxification of pubertal female SD rats, causing thyroid function disorder.
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Affiliation(s)
- Fei Zhao
- School of Biomedical Engineering and Technology , Tianjin Medical University , 300070 , Tianjin , China . ; ; Tel: +86 22 23541744.,Tianjin Institute of Health and Environmental Medicine , A Key Laboratory of Risk Assessment & Control for Environment & Food Safety , 300050 , Tianjin , China . ; ; ; Tel: +86 22 84655424
| | - Jing Wang
- Tianjin Institute of Health and Environmental Medicine , A Key Laboratory of Risk Assessment & Control for Environment & Food Safety , 300050 , Tianjin , China . ; ; ; Tel: +86 22 84655424
| | - Yanjun Fang
- Tianjin Institute of Health and Environmental Medicine , A Key Laboratory of Risk Assessment & Control for Environment & Food Safety , 300050 , Tianjin , China . ; ; ; Tel: +86 22 84655424
| | - Jia Ding
- School of Biomedical Engineering and Technology , Tianjin Medical University , 300070 , Tianjin , China . ; ; Tel: +86 22 23541744
| | - Honglian Yang
- Tianjin Institute of Health and Environmental Medicine , A Key Laboratory of Risk Assessment & Control for Environment & Food Safety , 300050 , Tianjin , China . ; ; ; Tel: +86 22 84655424
| | - Li Li
- Tianjin Institute of Health and Environmental Medicine , A Key Laboratory of Risk Assessment & Control for Environment & Food Safety , 300050 , Tianjin , China . ; ; ; Tel: +86 22 84655424
| | - Zhuge Xi
- Tianjin Institute of Health and Environmental Medicine , A Key Laboratory of Risk Assessment & Control for Environment & Food Safety , 300050 , Tianjin , China . ; ; ; Tel: +86 22 84655424
| | - Haixuan Qiao
- School of Biomedical Engineering and Technology , Tianjin Medical University , 300070 , Tianjin , China . ; ; Tel: +86 22 23541744
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165
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Abbasi G, Saini A, Goosey E, Diamond ML. Product screening for sources of halogenated flame retardants in Canadian house and office dust. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 545-546:299-307. [PMID: 26747994 DOI: 10.1016/j.scitotenv.2015.12.028] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 11/30/2015] [Accepted: 12/06/2015] [Indexed: 05/22/2023]
Abstract
Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing.
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Affiliation(s)
- Golnoush Abbasi
- Department of Geography, University of Toronto, 100 St. George St., Toronto M5S 3G3, Canada
| | - Amandeep Saini
- Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4, Canada
| | - Emma Goosey
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto M5S 3B1, Canada
| | - Miriam L Diamond
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto M5S 3B1, Canada; Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4, Canada.
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166
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Zhang W, Zhang Y, Xu T, Wang Z, Wang J, Xiong W, Lu W, Zheng H, Yuan J. Involvement of ROS-mediated mitochondrial dysfunction and SIRT3 down-regulation in tris(2-chloroethyl)phosphate-induced cell cycle arrest. Toxicol Res (Camb) 2016; 5:461-470. [PMID: 30090360 PMCID: PMC6062305 DOI: 10.1039/c5tx00229j] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 12/13/2015] [Indexed: 01/22/2023] Open
Abstract
Tris(2-chloroethyl)phosphate (TCEP) is a flame retardant in plastics. It is bio-accumulative and persistent in the environment and has been detected in ambient and indoor air, surface and groundwater, food, house dust, and consumer products. Studies showed that TCEP can cause damage to the liver and kidneys of rats. However, the mechanisms underlying TCEP remain unclear. To investigate the effect of TCEP on mitochondrial function and cell fate, Chang liver cells were treated with TCEP (3.12, 12.50, 50.00, and 200.00 mg L-1) for 24 and 48 h. The results showed that TCEP increased mitochondrial reactive oxygen species production, disrupted mitochondrial integrity and caused mitochondrial dysfunction, representing increased intercellular free Ca2+ levels, decreased mitochondrial membrane potential and mitochondrial DNA copies as well as reduced ATP synthesis, and G2/M cell cycle arrest with down-regulation of SIRT3, forkhead box O3a and manganese superoxide dismutase proteins. The findings suggest that TCEP caused cell cycle arrest through down-regulation of SIRT3 is involved in mitochondrial oxidative stress.
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Affiliation(s)
- Wenjuan Zhang
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Youjian Zhang
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Tian Xu
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Zhiyuan Wang
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Jing Wang
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Wei Xiong
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Wenhong Lu
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Hongyan Zheng
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
| | - Jing Yuan
- Department of Occupational and Environmental Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China . ; ; Tel: +86 27 83693209
- Key Laboratory of Environment and Health , Ministry of Education & Ministry of Environmental Protection , and State Key Laboratory of Environmental Health (Incubating) , School of Public Health , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei , P. R. China
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167
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Hirsch C, Striegl B, Mathes S, Adlhart C, Edelmann M, Bono E, Gaan S, Salmeia KA, Hoelting L, Krebs A, Nyffeler J, Pape R, Bürkle A, Leist M, Wick P, Schildknecht S. Multiparameter toxicity assessment of novel DOPO-derived organophosphorus flame retardants. Arch Toxicol 2016; 91:407-425. [PMID: 26928308 PMCID: PMC5225203 DOI: 10.1007/s00204-016-1680-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/09/2016] [Indexed: 01/06/2023]
Abstract
Halogen-free organophosphorus flame retardants are considered as replacements for the phased-out class of polybrominated diphenyl ethers (PBDEs). However, toxicological information on new flame retardants is still limited. Based on their excellent flame retardation potential, we have selected three novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivatives and assessed their toxicological profile using a battery of in vitro test systems in order to provide toxicological information before their large-scale production and use. PBDE-99, applied as a reference compound, exhibited distinct neuro-selective cytotoxicity at concentrations ≥10 µM. 6-(2-((6-oxido-6H-dibenzo[c,e][1,2]oxaphosphinin-6-yl)amino)ethoxy)-6H-dibenzo[c,e][1,2]oxaphosphinine 6-oxide (ETA-DOPO) and 6,6′-(ethane-1,2-diylbis(oxy))bis(6H-dibenzo[c,e][1,2]oxaphosphinine-6-oxide) (EG-DOPO) displayed adverse effects at concentrations >10 µM in test systems reflecting the properties of human central and peripheral nervous system neurons, as well as in a set of non-neuronal cell types. DOPO and its derivative 6,6′-(ethane-1,2-diylbis(azanediyl))bis(6H-dibenzo[c,e][1,2]oxaphosphinine-6-oxide) (EDA-DOPO) were neither neurotoxic, nor did they exhibit an influence on neural crest cell migration, or on the integrity of human skin equivalents. The two compounds furthermore displayed no inflammatory activation potential, nor did they affect algae growth or daphnia viability at concentrations ≤400 µM. Based on the superior flame retardation properties, biophysical features suited for use in polyurethane foams, and low cytotoxicity of EDA-DOPO, our results suggest that it is a candidate for the replacement of currently applied flame retardants.
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Affiliation(s)
- Cordula Hirsch
- Particles-Biology Interactions Laboratory, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
| | - Britta Striegl
- ZHAW, Life Sciences and Facility Management, Einsiedlerstr. 31, 8820, Waedenswil, Switzerland
| | - Stephanie Mathes
- ZHAW, Life Sciences and Facility Management, Einsiedlerstr. 31, 8820, Waedenswil, Switzerland
| | - Christian Adlhart
- ZHAW, Life Sciences and Facility Management, Einsiedlerstr. 31, 8820, Waedenswil, Switzerland
| | - Michael Edelmann
- ZHAW, Life Sciences and Facility Management, Einsiedlerstr. 31, 8820, Waedenswil, Switzerland
| | - Epifania Bono
- ZHAW, Life Sciences and Facility Management, Einsiedlerstr. 31, 8820, Waedenswil, Switzerland
| | - Sabyasachi Gaan
- Additives and Chemistry Group, Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland
| | - Khalifah A Salmeia
- Additives and Chemistry Group, Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland
| | - Lisa Hoelting
- University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Alice Krebs
- University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Johanna Nyffeler
- University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Regina Pape
- University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Alexander Bürkle
- University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Marcel Leist
- University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Peter Wick
- Particles-Biology Interactions Laboratory, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland
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168
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Butt CM, Miranda ML, 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. Anal Bioanal Chem 2016; 408:2449-59. [PMID: 26864867 DOI: 10.1007/s00216-016-9340-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/08/2016] [Accepted: 01/14/2016] [Indexed: 12/30/2022]
Abstract
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.
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Affiliation(s)
- Craig M Butt
- Nicholas School of the Environment, Levine Science Research Center, Duke University, Room A220, Box 90328, Durham, NC, 27708, USA
| | - Marie Lynn Miranda
- Department of Statistics, Rice University, 6100 Main St. MS-138, Duncan Hall, Box 1892, Houston, TX, 77005-1827, USA.,Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Heather M Stapleton
- Nicholas School of the Environment, Levine Science Research Center, Duke University, Room A220, Box 90328, Durham, NC, 27708, USA.
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169
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Neurite outgrowth in human induced pluripotent stem cell-derived neurons as a high-throughput screen for developmental neurotoxicity or neurotoxicity. Neurotoxicology 2016; 53:271-281. [PMID: 26854185 DOI: 10.1016/j.neuro.2016.02.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 11/21/2022]
Abstract
Due to the increasing prevalence of neurological disorders and the large number of untested compounds in the environment, there is a need to develop reliable and efficient screening tools to identify environmental chemicals that could potentially affect neurological development. Herein, we report on a library of 80 compounds screened for their ability to inhibit neurite outgrowth, a process by which compounds may elicit developmental neurotoxicity, in a high-throughput, high-content assay using human neurons derived from induced pluripotent stem cells (iPSC). The library contains a diverse set of compounds including those that have been known to be associated with developmental neurotoxicity (DNT) and/or neurotoxicity (NT), environmental compounds with unknown neurotoxic potential (e.g., polycyclic aromatic hydrocarbons (PAHs) and flame retardants (FRs)), as well as compounds with no documented neurotoxic potential. Neurons were treated for 72h across a 6-point concentration range (∼0.3-100μM) in 384-well plates. Effects on neurite outgrowth were assessed by quantifying total outgrowth, branches, and processes. We also assessed the number ofviable cells per well. Concentration-response profiles were evaluated using a Hill model to derive benchmark concentration (BMC) values. Assay performance was evaluated using positive and negative controls and test replicates. Compounds were ranked by activity and selectivity (i.e., specific effects on neurite outgrowth in the absence of concomitant cytotoxicity) and repeat studies were conducted to confirm selectivity. Among the 80 compounds tested, 38 compounds were active, of which 16 selectively inhibited neurite outgrowth. Of these 16 compounds, 12 were known to cause DNT/NT and the remaining 4 compounds included 3 PAHs and 1 FR. In independent repeat studies, 14/16 selective compounds were reproducibly active in the assay, of which only 6 were selective for inhibition of neurite outgrowth. These 6 compounds were previously shown in the literature to be neurotoxic. These studies shed light on the current status of human iPSCs in DNT/NT screening and their utility in identifying, ranking, and prioritizing compounds with DNT/NT potential for further in vivo testing.
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170
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Ionas AC, Ulevicus J, Gómez AB, Brandsma SH, Leonards PEG, van de Bor M, Covaci A. Children's exposure to polybrominated diphenyl ethers (PBDEs) through mouthing toys. ENVIRONMENT INTERNATIONAL 2016; 87:101-7. [PMID: 26655676 DOI: 10.1016/j.envint.2015.11.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/04/2015] [Accepted: 11/26/2015] [Indexed: 05/20/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) have previously been detected in children toys, yet the risk of child exposure to these chemicals through the mouthing of toys or other items is still unknown. We aimed to expand on the current knowledge by investigating the impact of infants' mouthing activities on exposure to PBDEs present in toys. This was established by a leaching model for determining the amount PBDEs that can leach from toys into saliva in simulated conditions. The PBDE migration rate was at its highest for the 15 min low-exposure scenario incubations (198 pg/cm(2) × min) with the ERM EC-591 certified reference material (CRM) (0.17% w/w PBDEs). The leaching process was congener-dependent, since the percentage of lower brominated PBDE congeners that leached out was up to 4.5 times higher than for the heavier PBDEs. To study the scenario in which a child would mouth on a toy flame retarded with BDE 209 alone, a plastic item containing 7% BDE 209 (w/w) was also tested. The BDE 209 amounts leached out in only 15 min were higher than the amounts leached from the CRM after the 16 h incubation. For the Belgian population, the exposure scenario from mouthing on toys containing PBDEs in amounts similar to the REACH threshold was found to be lower than the exposure from mother's milk, but higher than the exposure through diet or even dust.
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Affiliation(s)
- Alin C Ionas
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Institute for Environmental Studies, VU University, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - Jocelyn Ulevicus
- Health and Life Sciences Department, VU University, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Ana Ballesteros Gómez
- Institute for Environmental Studies, VU University, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Sicco H Brandsma
- Institute for Environmental Studies, VU University, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Pim E G Leonards
- Institute for Environmental Studies, VU University, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Margot van de Bor
- Health and Life Sciences Department, VU University, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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171
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Miller GZ, Tighe ME, Peaslee GF, Peña K, Gearhart J. Toys, Décor, and More: Evidence of Hazardous Electronic Waste Recycled into New Consumer Products. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/jep.2016.73030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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172
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Use of alternative assays to identify and prioritize organophosphorus flame retardants for potential developmental and neurotoxicity. Neurotoxicol Teratol 2015; 52:181-93. [DOI: 10.1016/j.ntt.2015.09.003] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/02/2015] [Accepted: 09/02/2015] [Indexed: 12/26/2022]
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173
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Knudsen GA, Hughes MF, McIntosh KL, Sanders JM, Birnbaum LS. Estimation of tetrabromobisphenol A (TBBPA) percutaneous uptake in humans using the parallelogram method. Toxicol Appl Pharmacol 2015; 289:323-9. [PMID: 26387765 DOI: 10.1016/j.taap.2015.09.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/08/2015] [Accepted: 09/15/2015] [Indexed: 11/19/2022]
Abstract
Tetrabromobisphenol A (TBBPA) is currently the world's highest production volume brominated flame retardant. Humans are frequently exposed to TBBPA by the dermal route. In the present study, a parallelogram approach was used to make predictions of internal dose in exposed humans. Human and rat skin samples received 100 nmol of TBBPA/cm(2) skin and absorption and penetrance were determined using a flow-through in vitro system. TBBPA-derived [(14)C]-radioactivity was determined at 6h intervals in the media and at 24h post-dosing in the skin. The human skin and media contained an average of 3.4% and 0.2% of the total dose at the terminal time point, respectively, while the rat skin and media contained 9.3% and 3.5%, respectively. In the intact rat, 14% of a dermally-administered dose of ~100 nmol/cm(2) remained in the skin at the dosing site, with an additional 8% reaching systemic circulation by 24h post-dosing. Relative absorption and penetrance were less (10% total) at 24h following dermal administration of a ten-fold higher dose (~1000 nmol/cm(2)) to rats. However, by 72 h, 70% of this dose was either absorbed into the dosing-site skin or had reached systemic circulation. It is clear from these results that TBBPA can be absorbed by the skin and dermal contact with TBBPA may represent a small but important route of exposure. Together, these in vitro data in human and rat skin and in vivo data from rats may be used to predict TBBPA absorption in humans following dermal exposure. Based on this parallelogram calculation, up to 6% of dermally applied TBBPA may be bioavailable to humans exposed to TBBPA.
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Affiliation(s)
- Gabriel A Knudsen
- NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC, USA.
| | - Michael F Hughes
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | | | - J Michael Sanders
- NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC, USA
| | - Linda S Birnbaum
- NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC, USA
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174
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Cao Z, Xu F, Li W, Sun J, Shen M, Su X, Feng J, Yu G, Covaci A. Seasonal and Particle Size-Dependent Variations of Hexabromocyclododecanes in Settled Dust: Implications for Sampling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11151-11157. [PMID: 26301772 DOI: 10.1021/acs.est.5b01717] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Particle size is a significant parameter which determines the environmental fate and the behavior of dust particles and, implicitly, the exposure risk of humans to particle-bound contaminants. Currently, the influence of dust particle size on the occurrence and seasonal variation of hexabromocyclododecanes (HBCDs) remains unclear. While HBCDs are now restricted by the Stockholm Convention, information regarding HBCD contamination in indoor dust in China is still limited. We analyzed composite dust samples from offices (n = 22), hotels (n = 3), kindergartens (n = 2), dormitories (n = 40), and main roads (n = 10). Each composite dust sample (one per type of microenvironment) was fractionated into 9 fractions (F1-F9: 2000-900, 900-500, 500-400, 400-300, 300-200, 200-100, 100-74, 74-50, and <50 μm). Total HBCD concentrations ranged from 5.3 (road dust, F4) to 2580 ng g(-1) (dormitory dust, F4) in the 45 size-segregated samples. The seasonality of HBCDs in indoor dust was investigated in 40 samples from two offices. A consistent seasonal trend of HBCD levels was evident with dust collected in the winter being more contaminated with HBCDs than dust from the summer. Particle size-selection strategy for dust analysis has been found to be influential on the HBCD concentrations, while overestimation or underestimation would occur with improper strategies.
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Affiliation(s)
- Zhiguo Cao
- School of Environment, Henan Normal University , Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, China
- Toxicological Centre, University of Antwerp , 2610 Wilrijk, Belgium
- POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University , Beijing 100084, China
| | - Fuchao Xu
- Toxicological Centre, University of Antwerp , 2610 Wilrijk, Belgium
| | - Wenchao Li
- Toxicological Centre, University of Antwerp , 2610 Wilrijk, Belgium
- POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University , Beijing 100084, China
| | - Jianhui Sun
- School of Environment, Henan Normal University , Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, China
| | - Mohai Shen
- School of Environment, Henan Normal University , Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, China
| | - Xianfa Su
- School of Environment, Henan Normal University , Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, China
| | - Jinglan Feng
- School of Environment, Henan Normal University , Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, China
| | - Gang Yu
- POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University , Beijing 100084, China
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp , 2610 Wilrijk, Belgium
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175
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Developmental exposure to organophosphate flame retardants causes behavioral effects in larval and adult zebrafish. Neurotoxicol Teratol 2015; 52:220-7. [PMID: 26344674 DOI: 10.1016/j.ntt.2015.08.008] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 08/31/2015] [Accepted: 08/31/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Organophosphate flame retardants (OPFRs) have grown in usage since concerns about the health effects of the previously used polybrominated flame retardants led to their being phased out. The potential for OPFRs to cause adverse health effects of their own is still unexamined. Because of their structural similarities to organophosphate pesticides, which have themselves been heavily researched and shown to be neurobehavioral teratogens, we investigated the possibility that developmental exposure to two OPFRs, triphenyl phosphate (TPHP), and tris(1,3-dichloroisopropyl)phosphate (TDCIPP) might lead to behavioral impairment across the lifespan, as has been observed with the organophosphate pesticide chlorpyrifos. METHODS Zebrafish were exposed to 0.03 or 0.3 μM of TPHP, TDCIPP, or chlorpyrifos from 0 to 5 days post fertilization. Vehicle control consisted of 0.03% solution of DMSO. At 6 days post fertilization, larvae were tested on a locomotor assay. Separate cohorts of 6 day old larvae that were not tested on the larval assay were allowed to grow to adulthood. At 12 weeks post fertilization, these adult zebrafish were tested on a battery of behavioral assays that included tests of novel environment exploration, startle habituation, social affiliation, and predator escape. RESULTS Developmental exposure altered zebrafish behavior across the lifespan. Larval zebrafish exposed to the 0.03 μM doses of chlorpyrifos or TDCIPP exhibited significant (p<0.05) hyperactivity in the locomotor assay. Organophosphate exposure significantly (p<0.05) altered the time course of adult zebrafish behavior in the novel environment, startle habituation, and social affiliation assays. Predator escape behavior was significantly (p<0.05) reduced in fish exposed to the 0.3 μM dose of TDCIPP. Exposure also caused hyperactivity in adult fish, with fish exposed to the 0.3 μM dose of TDCIPP exhibiting significantly (p<0.05) elevated locomotor behavior in the novel environment assay. DISCUSSION Early developmental exposure to OPFRs produced behavioral impairment that persisted into adulthood. These findings support broader research investigating the role of organophosphate compounds, including the OPFRs used here, in developmental neurotoxicity.
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176
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Jarema KA, Hunter DL, Shaffer RM, Behl M, Padilla S. Acute and developmental behavioral effects of flame retardants and related chemicals in zebrafish. Neurotoxicol Teratol 2015; 52:194-209. [PMID: 26348672 DOI: 10.1016/j.ntt.2015.08.010] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/06/2015] [Accepted: 08/31/2015] [Indexed: 12/27/2022]
Abstract
As polybrominated diphenyl ethers are phased out, numerous compounds are emerging as potential replacement flame retardants for use in consumer and electronic products. Little is known, however, about the neurobehavioral toxicity of these replacements. This study evaluated the neurobehavioral effects of acute or developmental exposure to t-butylphenyl diphenyl phosphate (BPDP), 2-ethylhexyl diphenyl phosphate (EHDP), isodecyl diphenyl phosphate (IDDP), isopropylated phenyl phosphate (IPP), tricresyl phosphate (TMPP; also abbreviated TCP), triphenyl phosphate (TPHP; also abbreviated TPP), tetrabromobisphenol A (TBBPA), tris (2-chloroethyl) phosphate (TCEP), tris (1,3-dichloroisopropyl) phosphate (TDCIPP; also abbreviated TDCPP), tri-o-cresyl phosphate (TOCP), and 2,2-,4,4'-tetrabromodiphenyl ether (BDE-47) in zebrafish (Danio rerio) larvae. Larvae (n≈24 per dose per compound) were exposed to test compounds (0.4-120 μM) at sub-teratogenic concentrations either developmentally or acutely, and locomotor activity was assessed at 6 days post fertilization. When given developmentally, all chemicals except BPDP, IDDP and TBBPA produced behavioral effects. When given acutely, all chemicals produced behavioral effects, with TPHP, TBBPA, EHDP, IPP, and BPDP eliciting the most effects at the most concentrations. The results indicate that these replacement flame retardants may have developmental or pharmacological effects on the vertebrate nervous system.
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Affiliation(s)
- Kimberly A Jarema
- Toxicology Assessment Division NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Deborah L Hunter
- Integrated Systems Toxicology Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Rachel M Shaffer
- Integrated Systems Toxicology Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA; Curriculum in Toxicology, University of North Carolina, School of Medicine, Chapel Hill, NC, USA
| | - Mamta Behl
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Stephanie Padilla
- Integrated Systems Toxicology Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
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177
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Moser VC, Phillips PM, Hedge JM, McDaniel KL. Neurotoxicological and thyroid evaluations of rats developmentally exposed to tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tris(2-chloro-2-ethyl)phosphate (TCEP). Neurotoxicol Teratol 2015; 52:236-47. [PMID: 26300399 DOI: 10.1016/j.ntt.2015.08.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/10/2015] [Accepted: 08/17/2015] [Indexed: 02/03/2023]
Abstract
Tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tris(2-chloro-2-ethyl)phosphate (TCEP) are organophosphorous flame retardants with widespread usage and human exposures through food, inhalation, and dust ingestion. They have been detected in human tissues including urine and breast milk. Reports of disrupted neural growth in vitro, abnormal development in larval zebrafish, and altered thyroid hormones in several species have raised concern for neurodevelopmental toxicity. This is especially the case for TDCIPP, which is more potent and has more activity in those assays than does TCEP. We evaluated the potential for developmental neurotoxicity of TDCIPP and TCEP in a mammalian model. Pregnant Long-Evans rats were administered TDCIPP (15, 50, or 150 mg/kg/day) or TCEP (12, 40, 90 mg/kg/day) via oral gavage from gestational day 10 to weaning. Corn oil was the vehicle control in both studies. Body weight and righting reflex development were monitored in all pups. A subset of offspring at culling and weaning, and dams at weaning, were sacrificed for serum and organ collection for measurement of brain, liver, and thyroid weights, serum thyroid levels, and serum and brain acetylcholinesterase activities. Brain weights were also measured in a group of adult TDCIPP-treated offspring. One male and one female from each litter were allocated for behavioral testing at several ages: standard locomotor activity (preweaning, postweaning, adults), locomotor activity including a lighting change mid-way (postweaning, adults), elevated zero maze (postweaning, adults), functional observational battery (FOB; postweaning, adults), and Morris water maze (place learning, reference and working memory; adults). Neither chemical produced changes in maternal body weight or serum thyroid hormones, but relative liver weight was increased at the high doses of both TDCIPP and TCEP. In offspring, there were no effects on viability, litter size, or birth weight. With TDCIPP, absolute liver weights were lower at weaning and weight gain was lower in the high-dose offspring until about two months of age. Thyroid hormones and brain weights were not altered and acetylcholinesterase (both brain and serum) was not inhibited by either chemical. TDCIPP-treated offspring showed slight differences in floating in the water maze, hindlimb grip strength, and altered activity habituation, whereas TCEP-treated rats showed differences in quadrant time (probe) and middle-zone preference in the water maze. Regarding these few changes, the effects were minimal, mostly not related to dose, and did not appear treatment-related or biologically significant. Overall, these data do not support the potential for thyrotoxicity or developmental neurotoxicity produced by TDCIPP or TCEP.
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Affiliation(s)
- Virginia C Moser
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Pamela M Phillips
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Joan M Hedge
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Katherine L McDaniel
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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178
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Fang M, Webster TF, 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 2015; 49:10057-64. [PMID: 26172262 PMCID: PMC4786016 DOI: 10.1021/acs.est.5b01523] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
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.
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Affiliation(s)
- Mingliang Fang
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Thomas F. Webster
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts 02118, United States
| | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- Corresponding Author: Phone: 919-613-8717. Fax: 919-684-8741.
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179
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He CT, Zheng J, Qiao L, Chen SJ, Yang JZ, Yuan JG, Yang ZY, Mai BX. Occurrence of organophosphorus flame retardants in indoor dust in multiple microenvironments of southern China and implications for human exposure. CHEMOSPHERE 2015; 133:47-52. [PMID: 25898308 DOI: 10.1016/j.chemosphere.2015.03.043] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/18/2015] [Accepted: 03/20/2015] [Indexed: 06/04/2023]
Abstract
Organophosphorus flame retardants (OPFRs) are important alternatives to brominated flame retardants (BFRs), but information on their contamination of the environment in China is rare. We examined the occurrence of 12 OPFRs in indoor dust in four microenvironments of southern China, including a rural electronic waste (e-waste) recycling area, a rural non-e-waste area, urban homes, and urban college dormitory rooms. The OPFR concentrations (with a median of 25.0 μg g(-1)) were highest in the e-waste area, and the concentrations in other three areas were lower and comparable (7.48-11.0 μg g(-1)). The levels of OPFRs in the present study were generally relatively lower than the levels of OPFRs found in Europe, Canada, and Japan because BFRs are still widely used as the major FRs in China. The composition profile of OPFRs in the e-waste area was dominated by tricresyl phosphate (TCP) (accounting for 40.7%, on average), while tris(2-chloroethyl) phosphate (TCEP) was the most abundant OPFR (64.4%) in the urban areas (homes and college dormitories). These two distribution patterns represent two OPFR sources (i.e., emissions from past e-waste and from current household products and building materials). The difference in the OPFR profiles in the rural area relative to the OPFR profiles in the urban and e-waste areas suggests that the occurrence of OPFRs is due mainly to emissions from characteristic household products in rural homes. Although human exposures to all the OPFRs were under the reference doses, the health risk for residents in the e-waste area is a concern, considering the poor sanitary conditions in this area and exposure from other sources.
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Affiliation(s)
- Chun-Tao He
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jing Zheng
- Center for Environmental Health Research, South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, China
| | - Lin Qiao
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - She-Jun Chen
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
| | - Jun-Zhi Yang
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jian-Gang Yuan
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhong-Yi Yang
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China.
| | - Bi-Xian Mai
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
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Bailey JM, Levin ED. Neurotoxicity of FireMaster 550® in zebrafish (Danio rerio): Chronic developmental and acute adolescent exposures. Neurotoxicol Teratol 2015; 52:210-9. [PMID: 26239867 DOI: 10.1016/j.ntt.2015.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/04/2015] [Accepted: 07/02/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND FireMaster® 550 (FM 550) is the second most commonly used flame retardant (FR) product in consumer goods and has been detected in household dust samples. However, neurobehavioral effects associated with exposure have not been characterized in detail. We investigated the behavioral effects of FM 550 in zebrafish to facilitate the integration of the cellular and molecular effects of FM 550 with its behavioral consequences. The effects of developmental FM 550 exposure on zebrafish larvae swimming shortly after the end of exposure as well as the persisting effects of this exposure on adolescent behavior were studied. In addition, the acute effects of FM 550 on behavior with exposure during adolescence in zebrafish were studied. METHODS Developmental exposure to 0, 0.01, 0.1 or 1 mg/L of FM 550 via immersion spanned 0-5 days post fertilization, with larval testing on day 6 and adolescent testing on days 40-45. Acute adolescent (45 dpf) exposure was to 0, 1.0 or 3.0 mg/L of FM 550 via immersion, for 24 h, with testing 2 h or 1 week later. The vehicle condition was colony tank water with .0004% (developmental) or .0012% (adolescent) DMSO. Zebrafish behavior was characterized across several domains including learning, social affiliation, sensorimotor function, predator escape, and novel environment exploration. RESULTS Persisting effects of developmental FM 550 exposure included a significant (p<0.01) reduction in social behavior among all dose groups. Acute FM 550 exposure during adolescence caused hypoactivity and reduced social behavior (p's<0.05) when the fish were tested 2 h after exposure. These effects were attenuated at the 1 week post exposure testing point DISCUSSION Taken together, these data indicate that FM 550 may cause persisting neurobehavioral alterations to social behavior in the absence of perturbations along other behavioral domains and that developmental exposure is more costly to the organism than acute adolescent exposure.
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Affiliation(s)
- J M Bailey
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC 27710, USA
| | - E D Levin
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC 27710, USA; Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
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181
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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. 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 2015; 49:7400-10. [PMID: 25985095 PMCID: PMC4835823 DOI: 10.1021/acs.est.5b00977] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
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.
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Affiliation(s)
- Leona D. Scanlan
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Alexandre V. Loguinov
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Quincy Teng
- U.S. EPA, National Exposure Research Laboratory, Athens, Georgia 30605, United States
| | - Philipp Antczak
- University of Liverpool Institute for Integrative Biology, Liverpool, L69 7ZB, United Kingdom
| | - Kathleen P. Dailey
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Daniel T. Nowinski
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Jonah Kornbluh
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Xin Xin Lin
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Erica Lachenauer
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Audrey Arai
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
| | - Nora K. Douglas
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Francesco Falciani
- University of Liverpool Institute for Integrative Biology, Liverpool, L69 7ZB, United Kingdom
| | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Chris D. Vulpe
- University of California Berkeley, Department of Nutritional Sciences and Toxicology, Berkeley, California 94720, United States
- Corresponding Author.
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182
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Roberts SC, Bianco AC, Stapleton HM. Disruption of type 2 iodothyronine deiodinase activity in cultured human glial cells by polybrominated diphenyl ethers. Chem Res Toxicol 2015; 28:1265-74. [PMID: 26004626 PMCID: PMC4827872 DOI: 10.1021/acs.chemrestox.5b00072] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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.
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Affiliation(s)
- Simon C Roberts
- Nicholas School of the Environment, Duke University, Durham, NC 27708
| | - Antonio C Bianco
- Division of Endocrinology and Metabolism, Rush University Medical Center, Chicago, IL 60612
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Development of a low-density-solvent dispersive liquid-liquid microextraction with gas chromatography and mass spectrometry method for the quantitation of tetrabromobisphenol-A from dust. J Sep Sci 2015; 38:2503-9. [DOI: 10.1002/jssc.201500205] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/30/2015] [Accepted: 04/21/2015] [Indexed: 11/07/2022]
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184
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Peng H, Saunders DMV, Sun J, Codling G, Wiseman S, Jones PD, Giesy JP. Detection, identification, and quantification of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate isomers in house dust. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2999-3006. [PMID: 25621784 DOI: 10.1021/es505743d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ultra-High Resolution LC/mass spectrometry (LC-UHRMS; Thermo Fisher Q-Exactive) was used to identify two novel isomers of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) which were unexpectedly observed in a commercial standard of TBPH. By combining ultra-high resolution (UHR) mass spectra (MS(1)), mass errors to theoretical [TBPH-Br+O](-) were 2.1 and 1.0 ppm for the two isomers, UHR-MS(2) spectra and NMR analysis; the structures of the two compounds were identified as hydroxylated TBPH with a hydroxyl group on the aromatic ring. Relatively great proportions of the two isomers of OH-TBPH were detected in two technical products, Firemaster 550 (FM-550; 0.1% and 6.2%, respectively) and Firemaster BZ 54 (BZ-54; 0.1% and 7.9%), compared to a commercial standard (0.4% and 0.9%). To simultaneously analyze OH-TBPH isomers and TBPH in samples of dust, a method based on LC-UHRMS was developed to quantify the two compounds, using negative and positive ion modes, respectively. The instrumental limit of detection for TBPH was 0.01 μg/L, which was 200-300 times better than traditional methods (2.5 μg/L) based on gas chromatography-mass spectrometry. The analytical method combined with a Florisil cleanup was successfully applied to analyze TBPH and OH-TBPH in 23 indoor dust samples from Saskatoon, Saskatchewan, Canada. Two OH-TBPH isomers, OH-TBPH1 and OH-TBPH2, were detected in 52% and 91% of dust samples, respectively. Concentrations of OH-TBPH2 (0.35 ± 1.0 ng/g) were 10-fold greater than those of OH-TBPH1 (0.04 ± 0.88 ng/g) in dust, which was similar to profiles in FM-550 and BZ-54. TBPH was also detected in 100% of dust samples with a mean concentration of 733 ± 0.87 ng/g. A significant (p < 0.001) log-linear relationship was observed between TBPH and OH-TBPH isomers, further supporting the hypothesis of a common source of emission. Relatively small proportions of OH-TBPH isomers were detected in dust (0.01% ± 0.67 OH-TBPH1 and 0.1% ± 0.60 OH-TBPH2), which were significantly less than those in technical products (p < 0.001). This result indicated different environmental behaviors of OH-TBPH and TBPH. Detection of isomers of OH-TBPH is important, since compounds with phenolic groups have often shown relatively greater toxicities than nonhydroxylated analogues. Further study is warranted to clarify the environmental behaviors and potential toxicities of OH-TBPH isomers.
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Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan, Canada , S7N 5B3
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185
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Zheng Q, Nizzetto L, Li J, Mulder MD, Sáňka O, Lammel G, Bing H, Liu X, Jiang Y, Luo C, Zhang G. Spatial distribution of old and emerging flame retardants in Chinese forest soils: sources, trends and processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2904-2911. [PMID: 25661400 DOI: 10.1021/es505876k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The levels and distribution of polybrominated diphenylethers (PBDEs), novel brominated flame retardants (NBFRs) and Dechlorane Plus (DP) in soils and their dependence on environmental and anthropological factors were investigated in 159 soil samples from 30 background forested mountain sites across China. Decabromodiphenylethane (DBDPE) was the most abundant flame retardant (25-18,000 pg g(-1) and 5-13,000 pg g(-1) in O-horizon and A-horizon, respectively), followed by BDE 209 (nd-5900 pg g(-1) and nd-2400 pg g(-1) in O-horizon and A-horizon, respectively). FRs distributions were primarily controlled by source distribution. The distributions of most phasing-out PBDEs, DP isomers and TBPH were in fact correlated to a population density-based index used as proxy of areas with elevated usage and waste of FR containing products. High concentrations of some NBFRs were however observed in industrialized regions and FR manufacturing plants. Strongly positive correlations were observed between PBDEs and their replacement products suggesting similar emission pattern and environmental behavior. Exposure of mineral subsoils depended on precipitations driving leaching of FRs into the soil core. This was especially evident for some emerging BFRs (TBE, TBPH, and TBB etc.) possibly indicating potential for diffuse groundwater contamination.
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Affiliation(s)
- Qian Zheng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China
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186
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Fang M, Webster TF, Ferguson PL, 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 2015; 123:166-72. [PMID: 25314719 PMCID: PMC4314249 DOI: 10.1289/ehp.1408522] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 10/09/2014] [Indexed: 05/18/2023]
Abstract
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-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. 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.
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Affiliation(s)
- Mingliang Fang
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
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187
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Hoffman K, Garantziotis S, Birnbaum LS, Stapleton HM. Monitoring indoor exposure to organophosphate flame retardants: hand wipes and house dust. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:160-5. [PMID: 25343780 PMCID: PMC4314253 DOI: 10.1289/ehp.1408669] [Citation(s) in RCA: 246] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 10/22/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND 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. OBJECTIVES 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). METHODS 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. RESULTS 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). CONCLUSIONS PFR exposures are widespread, and hand-to-mouth contact or dermal absorption may be important pathways of exposure.
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Affiliation(s)
- Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, North Carolina USA
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188
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Abdallah MAE, Pawar G, Harrad S. Evaluation of in vitro vs. in vivo methods for assessment of dermal absorption of organic flame retardants: a review. ENVIRONMENT INTERNATIONAL 2015; 74:13-22. [PMID: 25310507 DOI: 10.1016/j.envint.2014.09.012] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 05/08/2023]
Abstract
There is a growing interest to study human dermal exposure to a large number of chemicals, whether in the indoor or outdoor environment. Such studies are essential to predict the systemic exposure to xenobiotic chemicals for risk assessment purposes and to comply with various regulatory guidelines. However, very little is currently known about human dermal exposure to persistent organic pollutants. While recent pharmacokinetic studies have highlighted the importance of dermal contact as a pathway of human exposure to brominated flame retardants, risk assessment studies had to apply assumed values for percutaneous penetration of various flame retardants (FRs) due to complete absence of specific experimental data on their human dermal bioavailability. Therefore, this article discusses the current state-of-knowledge on the significance of dermal contact as a pathway of human exposure to FRs. The available literature on in vivo and in vitro methods for assessment of dermal absorption of FRs in human and laboratory animals is critically reviewed. Finally, a novel approach for studying human dermal absorption of FRs using in vitro three-dimensional (3D) human skin equivalent models is presented and the challenges facing future dermal absorption studies on FRs are highlighted.
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Affiliation(s)
- Mohamed Abou-Elwafa Abdallah
- Division of Environmental Health and Risk Management, College of Life and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom; Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt.
| | - Gopal Pawar
- Division of Environmental Health and Risk Management, College of Life and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Stuart Harrad
- Division of Environmental Health and Risk Management, College of Life and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
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189
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Fang M, 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 2014; 48:13323-30. [PMID: 25330458 PMCID: PMC4238594 DOI: 10.1021/es503918m] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/16/2014] [Accepted: 10/20/2014] [Indexed: 05/22/2023]
Abstract
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.
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190
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Exposures, mechanisms, and impacts of endocrine-active flame retardants. Curr Opin Pharmacol 2014; 19:125-33. [PMID: 25306433 DOI: 10.1016/j.coph.2014.09.018] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 09/19/2014] [Accepted: 09/22/2014] [Indexed: 11/23/2022]
Abstract
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.
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191
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Hoffman K, Fang M, Horman B, Patisaul HB, Garantziotis S, Birnbaum LS, Stapleton HM. Urinary tetrabromobenzoic acid (TBBA) as a biomarker of exposure to the flame retardant mixture Firemaster® 550. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:963-9. [PMID: 24823833 PMCID: PMC4154220 DOI: 10.1289/ehp.1308028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 05/09/2014] [Indexed: 05/12/2023]
Abstract
BACKGROUND 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. OBJECTIVES Our objectives were to develop methods to assess exposure to FM550 in human populations and to identify potential routes of exposure. METHODS 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. RESULTS 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. CONCLUSIONS 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.
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Affiliation(s)
- Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
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192
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Belcher SM, Cookman CJ, Patisaul HB, 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. Toxicol Lett 2014; 228:93-102. [PMID: 24786373 DOI: 10.1016/j.toxlet.2014.04.017] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/17/2014] [Accepted: 04/20/2014] [Indexed: 10/25/2022]
Abstract
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.
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Affiliation(s)
- Scott M Belcher
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0575, USA.
| | - Clifford J Cookman
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0575, USA
| | - Heather B Patisaul
- Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, USA
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