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Vojta Š, Melymuk L, Klánová J. Changes in Flame Retardant and Legacy Contaminant Concentrations in Indoor Air during Building Construction, Furnishing, and Use. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11891-11899. [PMID: 28910084 DOI: 10.1021/acs.est.7b03245] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A newly constructed university building was selected for targeted assessment of changes in the levels of flame retardants and legacy contaminants during the installation of building equipment, furniture, electronics, and first year of building use. Indoor air samples were collected during several periods of intensive equipment installation to determine a relationship between newly introduced equipment and changes in the concentrations and profiles of contaminants in indoor air. Samples were analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), and new types of flame retardants: brominated (BFRs) and organophosphate esters (OPEs). Additionally, typical outdoor contaminants such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were also analyzed for comparison. From the set of 90 compounds analyzed here, hexabromobenzene (HBB) and tris(2-chloroisopropyl)phosphate (TCIPP) showed a significant concentration increase in indoor air concentrations during computer installation and operation, suggesting emission by operating computers, while an order of magnitude concentration increase in tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tri-m-cresyl phosphate (TMTP) was observed after the furniture and carpet was introduced to the computer room, suggesting furniture or carpet as a source. However, the majority of compounds had no systematic change in concentrations during equipment installation, indicating that no sources of target compounds were introduced or, that source introduction was not reflected in indoor air concentrations. Generally, low levels of legacy flame retardants compared to their novel alternatives were observed.
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Affiliation(s)
- Šimon Vojta
- Research Centre for Toxic Compounds in the Environment (RECETOX), Kamenice 753/5, 62500 Brno, Czech Republic
| | - Lisa Melymuk
- Research Centre for Toxic Compounds in the Environment (RECETOX), Kamenice 753/5, 62500 Brno, Czech Republic
| | - Jana Klánová
- Research Centre for Toxic Compounds in the Environment (RECETOX), Kamenice 753/5, 62500 Brno, Czech Republic
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102
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Nguyen KH, Abou-Elwafa Abdallah M, Moehring T, Harrad S. Biotransformation of the Flame Retardant 1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) in Vitro by Human Liver Microsomes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10511-10518. [PMID: 28846412 DOI: 10.1021/acs.est.7b02834] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The technical mixture of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH or DBE-DBCH) and the pure β-TBECH isomer were subjected to in vitro biotransformation by human liver microsomes (HLM). After 60 min of incubation, 5 potential metabolites of TBECH were identified in microsomal assays of both the TBECH mixture and β-TBECH using ultraperformance liquid chromatography-Q-Exactive Orbitrap mass spectrometry. These include mono- and dihydroxylated TBECH and mono- and dihydroxylated TriBECH as well as an α-oxidation metabolite bromo-(1,2-dibromocyclohexyl)-acetic acid. Our results indicate potential hepatic biotransformation of TBECH via cyctochrome P450-catalyzed hydroxylation, debromination, and α-oxidation. Kinetic studies revealed that the formation of monohydroxy-TBECH, dihydroxy-TBECH, and monohydroxy-TriBECH were best fitted to a Michaelis-Menten enzyme kinetic model. Respective estimated Vmax values (maximum metabolic rate) for these metabolites were 11.8 ± 4, 0.6 ± 0.1, and 10.1 ± 0.8 pmol min-1 mg protein-1 in TBECH mixture and 4992 ± 1340, 14.1 ± 4.9, and 66.1 ± 7.3 pmol min-1 mg protein-1 in β-TBECH. This indicates monohydroxy-TBECH as the major metabolite of TBECH by in vitro HLM-based assay. The estimated in vitro intrinsic clearance (Clint) of TBECH mixture was slower (P < 0.05) than that of pure β-TBECH. While the formation of monohydroxy-TBECH may reduce the bioaccumulation potential and provide a useful biomarker for monitoring TBECH exposure, further studies are required to fully understand the levels and toxicological implications of the identified metabolites.
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Affiliation(s)
- Khanh-Hoang Nguyen
- School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham, B5 2TT United Kingdom
| | - Mohamed Abou-Elwafa Abdallah
- School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham, B5 2TT United Kingdom
- Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University , 71526 Assiut, Egypt
| | - Thomas Moehring
- Thermo Fisher Scientific (GmbH) Bremen , Hanna-Kunath-Strasse 11, 28199 Bremen, Germany
| | - Stuart Harrad
- School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham, B5 2TT United Kingdom
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103
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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: 70] [Impact Index Per Article: 10.0] [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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104
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Tay JH, Sellström U, Papadopoulou E, Padilla-Sánchez JA, Haug LS, de Wit CA. Human Exposure to Legacy and Emerging Halogenated Flame Retardants via Inhalation and Dust Ingestion in a Norwegian Cohort. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8176-8184. [PMID: 28661659 DOI: 10.1021/acs.est.7b02114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In this study, we estimated human exposure to polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), and several emerging flame retardants (EFRs) via inhalation and dust ingestion. Sixty indoor stationary air samples, 13 personal air samples, and 60 settled dust samples were collected from a Norwegian cohort during winter 2013. PBDEs showed the highest median concentration in dust (1200 ng/g), followed by EFRs (730 ng/g) and HBCDDs (190 ng/g). The PBDE concentrations in dust were mainly driven by BDE-209 and those of EFRs by bis(2-ethylhexyl) tetrabromophthalate. EFRs predominated in stationary air samples, with 2-ethylhexyl 2,3,4,5-tetrabromobenzoate and 4-(1,2-dibromoethyl)-1,2-dibromocyclohexane having the highest median concentrations (150 and 25 pg/m3 (sum of α- and β-isomers), respectively). Different profiles and concentrations were observed in personal air samples compared to the corresponding stationary air samples. In relation to inhalation exposure, dust ingestion appears to be the major exposure pathway to FRs (median total exposure 230 pg/kg bw/d, accounting for more than 65% of the total exposure) for the Norwegian cohort. The calculated exposure due to air inhalation was substantially lower when the stationary air concentrations were used rather than personal air concentrations (43 pg/kg bw/d versus 130 pg/kg bw/d). This suggests that other exposure situations (such as outdoors or in offices) contributed significantly to the overall personal exposure, which cannot be included by using only a stationary air sampling technique. The median and 95th percentile exposures for all target FRs did not exceed the reference dose.
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Affiliation(s)
- Joo Hui Tay
- Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University , SE-106 91 Stockholm, Sweden
| | - Ulla Sellström
- Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University , SE-106 91 Stockholm, Sweden
| | - Eleni Papadopoulou
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health (NIPH) , Lovisenberggata 8, N-0403 Oslo, Norway
| | - Juan Antonio Padilla-Sánchez
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health (NIPH) , Lovisenberggata 8, N-0403 Oslo, Norway
| | - Line Småstuen Haug
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health (NIPH) , Lovisenberggata 8, N-0403 Oslo, Norway
| | - Cynthia A de Wit
- Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University , SE-106 91 Stockholm, Sweden
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105
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Kademoglou K, Xu F, Padilla-Sanchez JA, Haug LS, Covaci A, Collins CD. Legacy and alternative flame retardants in Norwegian and UK indoor environment: Implications of human exposure via dust ingestion. ENVIRONMENT INTERNATIONAL 2017; 102:48-56. [PMID: 28190611 DOI: 10.1016/j.envint.2016.12.012] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 12/01/2016] [Accepted: 12/05/2016] [Indexed: 05/22/2023]
Abstract
Indoor dust has been acknowledged as a major source of flame retardants (FRs) and dust ingestion is considered a major route of exposure for humans. In the present study, we investigated the presence of PBDEs and alternative FRs such as emerging halogenated FRs (EHFRs) and organophosphate flame retardants (PFRs) in indoor dust samples from British and Norwegian houses as well as British stores and offices. BDE209 was the most abundant PBDE congener with median concentrations of 4700ngg-1 and 3400ngg-1 in UK occupational and house dust, respectively, 30 and 20 fold higher than in Norwegian house dust. Monomeric PFRs (m-PFRs), including triphenyl phosphate (TPHP), tris(chloropropyl) phosphate (TCPP) and tris(2-chloroethyl) phosphate (TCEP) dominated all the studied environments. To the best of our knowledge, this is the first report of isodecyldiphenyl phosphate (iDPP) and trixylenyl phosphate (TXP) in indoor environments. iDPP was the most abundant oligomeric PFR (o-PFR) in all dust samples, with median concentrations one order of magnitude higher than TXP and bisphenol A bis(diphenyl phosphate (BDP). iDPP and TXP worst-case scenario exposures for British workers during an 8h exposure in the occupational environment were equal to 34 and 1.4ngkgbw-1day-1, respectively. The worst-case scenario for BDE209 estimated exposure for British toddlers (820ngkgbw-1day-1) did not exceeded the proposed reference dose (RfD) (7000ngkgbw-1day-1), while exposures for sum of m-PFRs (Σm-PFRs) in British toddlers and adults (17,900 and 785ngkgbw-1day-1 respectively) were an order of magnitude higher than for Norwegian toddlers and adults (1600 and 70ngkgbw-1day-1).
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Affiliation(s)
| | - Fuchao Xu
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk-Antwerp, Belgium
| | | | - Line Småstuen Haug
- Norwegian Institute of Public Health (NIPH), P.O. Box 4404, Nydalen, 0403 Oslo, Norway
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk-Antwerp, Belgium
| | - Chris D Collins
- Soil Research Centre, University of Reading, Reading RG6 6DW, UK.
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