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Ma Y, Stubbings WA, Abdallah MAE, Cline-Cole R, Harrad S. Temporal trends in concentrations of brominated flame retardants in UK foodstuffs suggest active impacts of global phase-out of PBDEs and HBCDD. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 863:160956. [PMID: 36528953 DOI: 10.1016/j.scitotenv.2022.160956] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/29/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Global restrictions on use of legacy brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) have generated demand for novel BFRs (NBFRs) as substitutes. Our research group has previously reported decreased concentrations of PBDEs and HBCDD and increased concentrations of NBFRs in UK indoor environments, suggesting that restrictions on PBDEs and HBCDD are exerting an impact. In this study, we analysed UK foodstuffs collected in 2020-21 and compared the BFR concentrations found with those found in similar samples collected in 2015 to investigate whether similar trends in BFR concentrations would be observed. Concentrations of PBDEs and HBCDD isomers detected in our samples had declined by 78-92 % and 59-97 % since the 2015 study, respectively. Moreover, concentrations of NBFRs (dominated by 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE or TBE), and bis(2-ethyl hexyl) tetrabromophthalate (BEH-TEBP or TBPH)) in UK foodstuffs increased significantly (28-1400 %) between 2015 and 2020-21. Combined, these findings suggest that restrictions on use of PBDEs and HBCDD have had a discernible impact on concentrations of these legacy BFRs and their NBFR replacements in UK foodstuffs. Interestingly, given recent reports of a significant increase in concentrations of decabromodiphenyl ethane (DBDPE) in UK house dust between 2014 and 2019, a significant decline (70-84 %) in concentrations of DBDPE was observed in UK foodstuffs.
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Affiliation(s)
- Yulong Ma
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - William A Stubbings
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | | | - Reginald Cline-Cole
- Department of African Studies & Anthropology, School of History and Cultures, University of Birmingham, Birmingham B15 2TT, UK
| | - Stuart Harrad
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
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Nephrotoxicity of Flame Retardants: An Understudied but Critical Toxic Endpoint. CURRENT OPINION IN TOXICOLOGY 2022. [DOI: 10.1016/j.cotox.2022.100359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Smythe TA, Su G, Bergman Å, Letcher RJ. Metabolic transformation of environmentally-relevant brominated flame retardants in Fauna: A review. ENVIRONMENT INTERNATIONAL 2022; 161:107097. [PMID: 35134713 DOI: 10.1016/j.envint.2022.107097] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
Over the past few decades, production trends of the flame retardant (FR) industry, and specifically for brominated FRs (BFRs), is for the replacement of banned and regulated compounds with more highly brominated, higher molecular weight compounds including oligomeric and polymeric compounds. Chemical, biological, and environmental stability of BFRs has received some attention over the years but knowledge is currently lacking in the transformation potential and metabolism of replacement emerging or novel BFRs (E/NBFRs). For articles published since 2015, a systematic search strategy reviewed the existing literature on the direct (e.g., in vitro or in vivo) non-human BFR metabolism in fauna (animals). Of the 51 papers reviewed, and of the 75 known environmental BFRs, PBDEs were by far the most widely studied, followed by HBCDDs and TBBPA. Experimental protocols between studies showed large disparities in exposure or incubation times, age, sex, depuration periods, and of the absence of active controls used in in vitro experiments. Species selection emphasized non-standard test animals and/or field-collected animals making comparisons difficult. For in vitro studies, confounding variables were generally not taken into consideration (e.g., season and time of day of collection, pollution point-sources or human settlements). As of 2021 there remains essentially no information on the fate and metabolic pathways or kinetics for 30 of the 75 environmentally relevant E/BFRs. Regardless, there are clear species-specific and BFR-specific differences in metabolism and metabolite formation (e.g. BDE congeners and HBCDD isomers). Future in vitro and in vivo metabolism/biotransformation research on E/NBFRs is required to better understand their bioaccumulation and fate in exposed organisms. Also, studies should be conducted on well characterized lab (e.g., laboratory rodents, zebrafish) and commonly collected wildlife species used as captive models (crucian carp, Japanese quail, zebra finches and polar bears).
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Affiliation(s)
- Tristan A Smythe
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada; Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6, Canada.
| | - Guanyong Su
- School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Åke Bergman
- Department of Analytical Chemistry and Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada; Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6, Canada.
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Young AS, Herkert N, Stapleton HM, Cedeño Laurent JG, Jones ER, MacNaughton P, Coull BA, James-Todd T, Hauser R, Luna ML, Chung YS, Allen JG. Chemical contaminant exposures assessed using silicone wristbands among occupants in office buildings in the USA, UK, China, and India. ENVIRONMENT INTERNATIONAL 2021; 156:106727. [PMID: 34425641 PMCID: PMC8409466 DOI: 10.1016/j.envint.2021.106727] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/14/2021] [Accepted: 06/16/2021] [Indexed: 05/11/2023]
Abstract
Little is known about chemical contaminant exposures of office workers in buildings globally. Complex mixtures of harmful chemicals accumulate indoors from building materials, building maintenance, personal products, and outdoor pollution. We evaluated exposures to 99 chemicals in urban office buildings in the USA, UK, China, and India using silicone wristbands worn by 251 participants while they were at work. Here, we report concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other brominated flame retardants (BFRs), organophosphate esters (OPEs), phthalates and phthalate alternatives, pesticides, and polycyclic aromatic hydrocarbons (PAHs). First, we found major differences in office worker chemical exposures by country, some of which can be explained by regulations and use patterns. For example, exposures to several pesticides were substantially higher in India where there were fewer restrictions and unique malaria challenges, and exposures to flame retardants tended to be higher in the USA and UK where there were historic, stringent furniture flammability standards. Higher exposures to PAHs in China and India could be due to high levels of outdoor air pollution that penetrates indoors. Second, some office workers were still exposed to legacy PCBs, PBDEs, and pesticides, even decades after bans or phase-outs. Third, we identified exposure to a contemporary PCB that is not covered under legacy PCB bans due to its presence as an unintentional byproduct in materials. Fourth, exposures to novel BFRs, OPEs, and other chemicals commonly used as substitutes to previously phased-out chemicals were ubiquitous. Fifth, some exposures were influenced by individual factors, not just countries and buildings. Phthalate exposures, for example, were related to personal care product use, country restrictions, and building materials. Overall, we found substantial country differences in chemical exposures and continued exposures to legacy phased-out chemicals and their substitutes in buildings. These findings warrant further research on the role of chemicals in office buildings on worker health.
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Affiliation(s)
- Anna S Young
- Harvard T.H. Chan School of Public Health, Boston, MA, USA; Harvard Graduate School of Arts and Sciences, Cambridge, MA, USA.
| | | | | | | | - Emily R Jones
- Harvard T.H. Chan School of Public Health, Boston, MA, USA; Harvard Graduate School of Arts and Sciences, Cambridge, MA, USA
| | | | - Brent A Coull
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Russ Hauser
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Marianne Lahaie Luna
- Harvard T.H. Chan School of Public Health, Boston, MA, USA; University of Toronto Dalla Lana School of Public Health, Toronto, Canada
| | - Yu Shan Chung
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Joseph G Allen
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
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Xiong P, Yan X, Zhu Q, Qu G, Shi J, Liao C, Jiang G. A Review of Environmental Occurrence, Fate, and Toxicity of Novel Brominated Flame Retardants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13551-13569. [PMID: 31682424 DOI: 10.1021/acs.est.9b03159] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Use of legacy brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), has been reduced due to adverse effects of these chemicals. Several novel brominated flame retardants (NBFRs), such decabromodiphenyl ethane (DBDPE) and bis(2,4,6-tribromophenoxy) ethane (BTBPE), have been developed as replacements for PBDEs. NBFRs are used in various industrial and consumer products, which leads to their ubiquitous occurrence in the environment. This article reviews occurrence and fate of a select group of NBFRs in the environment, as well as their human exposure and toxicity. Occurrence of NBFRs in both abiotic, including air, water, dust, soil, sediment and sludge, and biotic matrices, including bird, fish, and human serum, have been documented. Evidence regarding the degradation, including photodegradation, thermal degradation and biodegradation, and bioaccumulation and biomagnification of NBFRs is summarized. The toxicity data of NBFRs show that several NBFRs can cause adverse effects through different modes of action, such as hormone disruption, endocrine disruption, genotoxicity, and behavioral modification. The primary ecological risk assessment shows that most NBFRs exert no significant environmental risk, but it is worth noting that the result should be carefully used owing to the limited toxicity data.
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Affiliation(s)
- Ping Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xueting Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Qingqing Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Guangbo Qu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
- Institute of Environment and Health , Jianghan University , Wuhan , Hubei 430056 , China
| | - Jianbo Shi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
- Institute of Environment and Health , Jianghan University , Wuhan , Hubei 430056 , China
| | - Chunyang Liao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
- Institute of Environment and Health , Jianghan University , Wuhan , Hubei 430056 , China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
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Briels N, Torgersen LN, Castaño-Ortiz JM, Løseth ME, Herzke D, Nygård T, Bustnes JO, Ciesielski TM, Poma G, Malarvannan G, Covaci A, Jaspers VLB. Integrated exposure assessment of northern goshawk (Accipiter gentilis) nestlings to legacy and emerging organic pollutants using non-destructive samples. ENVIRONMENTAL RESEARCH 2019; 178:108678. [PMID: 31520824 DOI: 10.1016/j.envres.2019.108678] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/08/2019] [Accepted: 08/16/2019] [Indexed: 06/10/2023]
Abstract
In the present study, concentrations of legacy and emerging contaminants were determined in three non-destructive matrices (plasma, preen oil and body feathers) of northern goshawk (Accipiter gentilis) nestlings. Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs), together with emerging pollutants, including per- and polyfluorinated alkyl substances (PFASs), novel brominated flame retardants (NBFRs), phosphorus flame retardants (PFRs) and Dechlorane Plus isomers (DPs) were targeted. Plasma, preen oil and feather samples were collected from 61 goshawk nestlings in Norway (Trøndelag and Troms) in 2015 and 2016, and pollutant concentrations were compared between the three matrices. In plasma, PFASs were detected in the highest concentrations, ranging between 1.37 and 36.0 ng/mL, which suggests that the nestlings were recently and continuously exposed to these emerging contaminants, likely through dietary input. In preen oil, OCPs (169-3560 ng/g) showed the highest concentrations among the investigated compounds, consistent with their high lipophilicity. PFRs (2.60-314 ng/g) were the dominant compounds in feathers and are thought to originate mainly from external deposition, as they were not detected in the other two matrices. NBFRs and DPs were generally not detected in the nestlings, suggesting low presence of these emerging contaminants in their environment and/or low absorption. Strong and significant correlations between matrices were found for all POPs (rs = 0.46-0.95, p < 0.001), except for hexachlorobenzene (HCB, rs = 0.20, p = 0.13). Correlations for PFASs were less conclusive: linear perfluorooctane sulfonate (PFOS), perfluoroundecanoate (PFUnA), perfluorododecanoate (PFDoA) and perfluorotetradecanoate (PFTeA) showed strong and significant correlations between plasma and feathers (rs = 0.42-0.72, p < 0.02), however no correlation was found for perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA) and perfluorotridecanoate (PFTriA) (rs = 0.05-0.33, p = 0.09-0.85). A lack of consistency between the PFAS compounds (contrary to POPs), and between studies, prevents concluding on the suitability of the investigated matrices for PFAS biomonitoring.
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Affiliation(s)
- Nathalie Briels
- Norwegian University of Science and Technology (NTNU), Department of Biology, Høgskoleringen 5, 7491, Trondheim, Norway.
| | - Lene Norstrand Torgersen
- Norwegian University of Science and Technology (NTNU), Department of Biology, Høgskoleringen 5, 7491, Trondheim, Norway
| | - Jose Maria Castaño-Ortiz
- Norwegian University of Science and Technology (NTNU), Department of Biology, Høgskoleringen 5, 7491, Trondheim, Norway
| | - Mari Engvig Løseth
- Norwegian University of Science and Technology (NTNU), Department of Biology, Høgskoleringen 5, 7491, Trondheim, Norway
| | - Dorte Herzke
- Norwegian Institute for Air Research (NILU), FRAM Centre, 9007, Tromsø, Norway
| | - Torgeir Nygård
- Norwegian Institute for Nature Research (NINA), Høgskoleringen 9, 7034, Trondheim, Norway
| | - Jan Ove Bustnes
- Norwegian Institute for Nature Research (NINA), FRAM Centre, 9007, Tromsø, Norway
| | - Tomasz Maciej Ciesielski
- Norwegian University of Science and Technology (NTNU), Department of Biology, Høgskoleringen 5, 7491, Trondheim, Norway
| | - Giulia Poma
- University of Antwerp, Toxicological Centre, Department of Pharmaceutical Sciences, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Govindan Malarvannan
- University of Antwerp, Toxicological Centre, Department of Pharmaceutical Sciences, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Adrian Covaci
- University of Antwerp, Toxicological Centre, Department of Pharmaceutical Sciences, Universiteitsplein 1, 2610, Wilrijk, Belgium
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Tao F, Abou-Elwafa Abdallah M, Ashworth DC, Douglas P, Toledano MB, Harrad S. Emerging and legacy flame retardants in UK human milk and food suggest slow response to restrictions on use of PBDEs and HBCDD. ENVIRONMENT INTERNATIONAL 2017; 105:95-104. [PMID: 28525835 DOI: 10.1016/j.envint.2017.05.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 05/06/2023]
Abstract
The legacy flame retardants (LFRs) polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD), together with six emerging flame retardants (EFRs) were measured in United Kingdom (UK) human milk collected in 2010 (n=25) and 2014-15 (n=10). These data are the first report of the presence of EFRs in UK human milk. The most abundant EFR was β-tetrabromoethylcyclohexane (DBE-DBCH) (average=2.5ng/g lw; geometric mean=1.5ng/g lw), which is comparable to the concentrations of the most abundant LFRs i.e. BDE 47 and α-HBCDD at 2.8 and 2.1ng/g lw, respectively (geometric mean=2.1 and 1.7). The estimated median dietary intake of ΣEFRs by UK nursing infants was 18ng/kg bw/day. EFRs were also measured in UK foodstuffs with β-DBE-DBCH again the predominant compound detected, accounting - on average - for 64.5±23.4% of ΣEFRs. Average estimated dietary intakes of ∑EFRs in the UK were 89 and 26ng/day (1.3 and 2.6ng/body weight/day) for adults and toddlers, respectively. Concentrations of Σtri-hexa BDEs in our UK food samples exceeded those reported in UK samples from the same food categories collected in 2003-04 and 2006. Despite this and our recent report elsewhere of significant temporal declines in concentrations of BDE 209 in UK indoor dust (p<0.05) and HBCDDs in UK indoor dust and air (p<0.001), no significant temporal differences (p>0.05) were observed between concentrations of Σtri-hexa BDEs, BDE 209 and HBCDDs in human milk sampled in 2010 and those obtained in 2014-15. UK adult body burdens for EFRs were predicted via inhalation, diet and dust ingestion using a simple pharmacokinetic model. The predicted EFR body burdens compared well with observed concentrations in human milk.
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Affiliation(s)
- Fang Tao
- Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Mohamed Abou-Elwafa Abdallah
- Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK; Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt.
| | - Danielle C Ashworth
- MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College London, W2 1PG, UK; National Institute for Health Research Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London, a Partnership with Public Health England, and collaboration with Imperial College London, W2 1PG, UK
| | - Philippa Douglas
- MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College London, W2 1PG, UK; National Institute for Health Research Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London, a Partnership with Public Health England, and collaboration with Imperial College London, W2 1PG, UK
| | - Mireille B Toledano
- MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College London, W2 1PG, UK; National Institute for Health Research Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London, a Partnership with Public Health England, and collaboration with Imperial College London, W2 1PG, UK
| | - Stuart Harrad
- Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
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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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