151
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Rauert C, Harrad S, Stranger M, Lazarov B. Test chamber investigation of the volatilization from source materials of brominated flame retardants and their subsequent deposition to indoor dust. INDOOR AIR 2015; 25:393-404. [PMID: 25142809 DOI: 10.1111/ina.12151] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 08/14/2014] [Indexed: 06/03/2023]
Abstract
UNLABELLED Numerous studies have reported elevated concentrations of brominated flame retardants (BFRs) in dust from indoor micro-environments. Limited information is available, however, on the pathways via which BFRs in source materials transfer to indoor dust. The most likely hypothesized pathways are (a) volatilization from the source with subsequent partitioning to dust, (b) abrasion of the treated product, transferring microscopic fibers or particles to the dust (c) direct uptake to dust via contact between source and dust. This study reports the development and application of an in-house test chamber for investigating BFR volatilization from source materials and subsequent partitioning to dust. The performance of the chamber was evaluated against that of a commercially available chamber, and inherent issues with such chambers were investigated, such as loss due to sorption of BFRs to chamber surfaces (so-called sink effects). The partitioning of polybrominated diphenyl ethers to dust, post-volatilization from an artificial source was demonstrated, while analysis in the test chamber of a fabric curtain treated with the hexabromocyclododecane formulation, resulted in dust concentrations exceeding substantially those detected in the dust pre-experiment. These results provide the first experimental evidence of BFR volatilization followed by deposition to dust. PRACTICAL IMPLICATIONS Brominated flame retardants (BFRs) are ubiquitous in indoor air and dust, leading to human exposure and resultant concerns about their adverse impact on health. Indoor dust has been demonstrated to constitute an important vector of human exposure to BFRs, especially for toddlers. Despite the greater importance of dust contamination in the context of human exposure to BFRs, the mechanisms via which BFRs transfer from source materials to dust have hitherto been subject to only limited research. In this study, a test chamber is utilized to simulate the migration of BFRs to dust via volatilization from source materials and subsequent deposition to dust.
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Affiliation(s)
- C Rauert
- School of Geography Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - S Harrad
- School of Geography Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - M Stranger
- Environmental Risk and Health Unit, VITO, Mol, Belgium
| | - B Lazarov
- Environmental Risk and Health Unit, VITO, Mol, Belgium
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152
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Yu L, Han Z, Liu C. A review on the effects of PBDEs on thyroid and reproduction systems in fish. Gen Comp Endocrinol 2015; 219:64-73. [PMID: 25585150 DOI: 10.1016/j.ygcen.2014.12.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 12/05/2014] [Accepted: 12/19/2014] [Indexed: 02/07/2023]
Abstract
The objective of this review was to summarize and discuss the effects of Polybrominated diphenyl ethers (PBDEs) on thyroid and reproduction systems in fish. We reviewed the evidences and mechanisms for PBDEs-induced thyroid and reproduction disruption, as well as the cross-talk between the two systems in fish. In thyroid disruption, we mainly paid attention to the effects of PBDEs on hypothalamic-pituitary-thyroid (HPT) axis, thyroid hormones (THs) transport and metabolism, thyroid receptors (TRs) and thyroid follicle histology. In reproduction disruption, we focused on the effects of PBDEs on steroid hormone production, expression of genes involved in steroidogenesis, and gonadal development. Despite that there is an interaction between thyroid and reproductive systems in fish, it is still remains unclear that PBDE-induced reproductive impairments are caused by direct effects on hypothalamic-pituitary-gonadal (HPG) functioning or by indirect action through cross-talk between the two systems. Future studies are needed to explore the relationships between reproductive toxicity and thyroid system disruption after PBDEs exposure.
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Affiliation(s)
- Liqin Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Zhihua Han
- Nanjing Institute of Environmental Sciences, MEP, Nanjing, Jiangsu 210042, China.
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
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153
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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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154
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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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155
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La Guardia MJ, Hale RC. Halogenated flame-retardant concentrations in settled dust, respirable and inhalable particulates and polyurethane foam at gymnastic training facilities and residences. ENVIRONMENT INTERNATIONAL 2015; 79:106-14. [PMID: 25812808 DOI: 10.1016/j.envint.2015.02.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 02/24/2015] [Accepted: 02/26/2015] [Indexed: 05/22/2023]
Abstract
Halogenated flame-retardants (FRs) are used in a wide array of polymer-containing products. Animal studies and structure-activity modeling exercises suggest that FR exposure may result in detrimental toxicological effects. Workers with extended contact with such polymers (e.g., electronic dismantlers, carpet installers and aircraft personnel) have previously been observed to exhibit elevated body burdens of FRs, e.g., polybrominated diphenyl ethers (PBDEs). Recently, elevated PBDE blood levels were also reported in a non-occupational exposure group, gymnasts. These levels were hypothesized to be related to the large volumes of FR-treated polyurethane foam in gymnastics facilities. To further our understanding of workers' potential exposure, we analyzed FR concentrations in indoor dust and size-fractionated air particulates (respirable (<4 μm) and inhalable (>4 μm)) from gymnastic studios. Values were compared to samples from the homes of coaches employed at these facilities. Polyurethane foam blocks (i.e., pit foam) were also analyzed to characterize potential FR sources. FRs examined included those used to flame-retard polyurethane foam: 8 PBDE congeners, two brominated components of Firemaster 550 (2-ethylhexyl 2, 3, 4, 5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 3, 4, 5, 6-tetrabromophthalate (TBPH)) and three chlorinated organophosphates (tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP) and tris(1,3-dichloro-2-propyl) phosphate (TDCPP)). Several additional FRs not used in polyurethane were also evaluated. These have also been detected in indoor dust and air and may also lead to adverse health effects. These include: BDE-183 and its replacement product (1, 2-bis(2, 4, 6-tribromophenoxy) ethane (BTBPE), two congeners of the deca-BDE formulation (BDE-206, -209) and their replacement decabromodiphenyl ethane (DBDPE) and hexabromocyclododecane (α-, β-, γ-HBCD), and tetrabromobisphenol-A (TBBPA)). Pit foam contained multiple FRs at cumulative concentrations of 12,100 to 25,800 μg g(-1), or 1.2% to 2.6% by weight. TBB and TBPH were the most abundant FRs detected, followed by TDCPP and several PBDEs. The mean total FR burden detected at the gyms was 8.6-fold higher (574 μg g(-1)) than that observed in the house dust samples (66.8 μg g(-1)). However, the polyurethane additives TBB and TDCPP were the only FRs that exhibited significantly greater levels (P<0.05) in gym than house dust. Mean levels of five FRs (BDE-99, -100, -153, -209 and TDCPP) were also higher in respirable particulates from the gyms than the homes and four FRs (BDE-47, TBB, TBPH and DBDPE) were higher at the homes than the gyms; these differences were not significant (P>0.05). Several additional FRs were detected in inhalable particulates; mean levels of BDE-66, -206 and TCPP were higher in the homes and BDE-47, -85, -99, -100, -153, -209, TBB, TBPH, and TDCPP were higher at the gyms. But, only the polyurethane additives i.e., BDE-100, TBB and TDCPP were significantly greater (P<0.05) in inhalable particulates from the gyms than at the homes. In conclusion, polyurethane foam collected from gymnastic studios exhibited a variety of FR compositional signatures; likely reflective of changes in FR usage over time and by different manufacturers. FR concentrations and compositional signatures also differed between settled dust, respirable and inhalable particulates between the gyms and homes. Concentrations of FRs used in polyurethane foam were higher in gym air and dust compared to homes, particularly TBB and TDCPP - which were also the primary FRs detected in the pit foam samples. Although these results should be interpreted with caution, as the sample size was small, these findings do suggest that FR concentrations observed in dust and air particulates from the gymnastic studios are further evidence that individuals frequenting these environments are at greater risk for exposure to these polymer additives.
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Affiliation(s)
- Mark J La Guardia
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA, United States.
| | - Robert C Hale
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA, United States
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156
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Sahlström LM, Sellström U, de Wit CA, Lignell S, Darnerud PO. Estimated intakes of brominated flame retardants via diet and dust compared to internal concentrations in a Swedish mother–toddler cohort. Int J Hyg Environ Health 2015; 218:422-32. [DOI: 10.1016/j.ijheh.2015.03.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/17/2015] [Accepted: 03/21/2015] [Indexed: 11/15/2022]
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157
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Macaulay LJ, Bailey JM, Levin ED, Stapleton HM. Persisting effects of a PBDE metabolite, 6-OH-BDE-47, on larval and juvenile zebrafish swimming behavior. Neurotoxicol Teratol 2015; 52:119-26. [PMID: 25979796 DOI: 10.1016/j.ntt.2015.05.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 12/09/2022]
Abstract
Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants that are widely detected in the environment, biota, and humans. In mammals, PBDEs can be oxidatively metabolized to form hydroxylated polybrominated diphenyl ethers (OH-BDEs). While studies have examined behavioral deficits or alterations induced by exposure to PBDEs in both rodents and fish, no study to date has explored behavioral effects from exposure to OH-BDEs, which have been shown to have greater endocrine disrupting potential compared to PBDEs. In the present study, zebrafish (Danio rerio) were exposed during embryonic and larval development (0-6 days post fertilization, dpf) to a PBDE metabolite, 6-hydroxy, 2,2',4,4' tetrabromodiphenyl ether (10-50 nM) and then examined for short and long-term behavioral effects. Exposed zebrafish tested as larvae (6 dpf) showed an altered swimming response to light-dark transitions, exhibiting hypoactivity in light periods compared to control fish. When fish exposed from 0-6 dpf were tested as juveniles (45 dpf), they showed an increased fear response and hyperactivity in response to tests of novel environment exploration and habituation learning. These results demonstrate that early life exposure to a PBDE metabolite can have immediate or later life (more than a month after exposure) effects on activity levels, habituation, and fear/anxiety.
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Affiliation(s)
- Laura J Macaulay
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Jordan M Bailey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA
| | - Edward D Levin
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA; Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA
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158
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Collins CD, Craggs M, Garcia-Alcega S, Kademoglou K, Lowe S. 'Towards a unified approach for the determination of the bioaccessibility of organic pollutants'. ENVIRONMENT INTERNATIONAL 2015; 78:24-31. [PMID: 25728561 DOI: 10.1016/j.envint.2015.02.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/02/2015] [Accepted: 02/03/2015] [Indexed: 06/04/2023]
Abstract
Bioaccessibility studies have been widely used as a research tool to determine the potential human exposure to ingested contaminants. More recently they have been practically applied for soil borne toxic elements. This paper reviews the application of bioaccessibility tests across a range of organic pollutants and contaminated matrices. Important factors are reported to be: the physiological relevance of the test, the components in the gut media, the size fraction chosen for the test and whether it contains a sorptive sink. The bioaccessibility is also a function of the composition of the matrix (e.g. organic carbon content of soils) and the physico-chemical characteristics of the pollutant under test. Despite the widespread use of these tests, there are a large number of formats used and very few validation studies with animal models. We propose a unified format for a bioaccessibility test for organic pollutants. The robustness of this test should first be confirmed through inter laboratory comparison, then tested in-vivo.
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Affiliation(s)
| | - Mark Craggs
- Soil Research Centre, University of Reading, Reading, UK
| | | | | | - Stephen Lowe
- Soil Research Centre, University of Reading, Reading, UK
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159
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Shen B, Whitehead TP, McNeel S, Brown FR, Dhaliwal J, Das R, Israel L, Park JS, Petreas M. High levels of polybrominated diphenyl ethers in vacuum cleaner dust from California fire stations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4988-94. [PMID: 25798547 DOI: 10.1021/es505463g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Firefighters are exposed to chemicals during fire events and may also experience chemical exposure in their fire stations. Dust samples from used vacuum cleaner bags were collected from 20 fire stations in California and analyzed for polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) using gas chromatography-mass spectrometry. Median dust concentrations were higher for PBDEs (e.g., 47 000 ng/g for BDE-209) than for PAHs (e.g., 220 ng/g for benzo[a]pyrene) or PCBs (e.g., 9.3 ng/g for PCB-180). BDE-209 concentrations in dust from California fire stations were among the highest of any previously documented homes or occupational settings in the world. We examined factors such as the frequency of emergency responses, the number of fire vehicles on site, and building age, but we could not account for the high levels of BDE-209 observed in fire station dust. Based on the findings of our pilot study, we hypothesize that possible sources of BDE-209 in fire stations include contaminated ash tracked back from fire events via boots, clothing, and other equipment as well as specialized equipment treated with BDE-209, including turnout gear and fire vehicles. We suggest possible follow-up studies to confirm these hypotheses.
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Affiliation(s)
- Beverly Shen
- †School of Public Health, University of California, 50 University Hall, Berkeley, California 94720, United States
| | - Todd P Whitehead
- †School of Public Health, University of California, 50 University Hall, Berkeley, California 94720, United States
| | - Sandra McNeel
- ‡Environmental Health Investigations Branch, California Department of Public Health, 850 Marina Bay Parkway, Richmond, California 94804, United States
| | - F Reber Brown
- §Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Avenue, Berkeley, California 94710, United States
| | - Joginder Dhaliwal
- §Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Avenue, Berkeley, California 94710, United States
| | - Rupali Das
- ‡Environmental Health Investigations Branch, California Department of Public Health, 850 Marina Bay Parkway, Richmond, California 94804, United States
| | - Leslie Israel
- ∥Center for Occupational and Environmental Health, University of California, 5201 California Avenue, Irvine, California 92617, United States
| | - June-Soo Park
- §Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Avenue, Berkeley, California 94710, United States
| | - Myrto Petreas
- §Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Avenue, Berkeley, California 94710, United States
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160
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Wu XM, Bennett DH, Moran RE, Sjödin A, Jones RS, Tancredi DJ, Tulve NS, Clifton MS, Colón M, Weathers W, Hertz-Picciotto I. Polybrominated diphenyl ether serum concentrations in a Californian population of children, their parents, and older adults: an exposure assessment study. Environ Health 2015; 14:23. [PMID: 25884939 PMCID: PMC4381357 DOI: 10.1186/s12940-015-0002-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 02/04/2015] [Indexed: 05/04/2023]
Abstract
BACKGROUND Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many household items. Given concerns over their potential adverse health effects, we identified predictors and evaluated temporal changes of PBDE serum concentrations. METHODS PBDE serum concentrations were measured in young children (2-8 years old; N = 67), parents of young children (<55 years old; N = 90), and older adults (≥55 years old; N = 59) in California, with concurrent floor wipe samples collected in participants' homes in 2008-2009. We also measured serum concentrations one year later in a subset of children (N = 19) and parents (N = 42). RESULTS PBDE serum concentrations in children were significantly higher than in adults. Floor wipe concentration is a significant predictor of serum BDE-47, 99, 100 and 154. Positive associations were observed between the intake frequency of canned meat and serum concentrations of BDE-47, 99 and 154, between canned meat entrees and BDE-154 and 209, as well as between tuna and white fish and BDE-153. The model with the floor wipe concentration and food intake frequencies explained up to 40% of the mean square prediction error of some congeners. Lower home values and renting (vs. owning) a home were associated with higher serum concentrations of BDE-47, 99 and 100. Serum concentrations measured one year apart were strongly correlated as expected (r = 0.70-0.97) with a slight decreasing trend. CONCLUSIONS Floor wipe concentration, food intake frequency, and housing characteristics can explain 12-40% of the prediction error of PBDE serum concentrations. Decreasing temporal trends should be considered when characterizing long-term exposure.
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Affiliation(s)
- Xiangmei May Wu
- Department of Public Health Sciences, University of California, One Shields Avenue, MS1C, 95616, Davis, CA, USA.
| | - Deborah H Bennett
- Department of Public Health Sciences, University of California, One Shields Avenue, MS1C, 95616, Davis, CA, USA.
| | - Rebecca E Moran
- Department of Public Health Sciences, University of California, One Shields Avenue, MS1C, 95616, Davis, CA, USA.
| | - Andreas Sjödin
- Centers for Disease Control and Prevention, National Center for Environment Health, Atlanta, GA, USA.
| | - Richard S Jones
- Centers for Disease Control and Prevention, National Center for Environment Health, Atlanta, GA, USA.
| | | | - Nicolle S Tulve
- U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Human Exposure and Atmospheric Sciences Division, Research Triangle Park, NC, USA.
| | - Matthew Scott Clifton
- U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Human Exposure and Atmospheric Sciences Division, Research Triangle Park, NC, USA.
| | - Maribel Colón
- U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Human Exposure and Atmospheric Sciences Division, Research Triangle Park, NC, USA.
| | - Walter Weathers
- U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Human Exposure and Atmospheric Sciences Division, Research Triangle Park, NC, USA.
| | - Irva Hertz-Picciotto
- Department of Public Health Sciences, University of California, One Shields Avenue, MS1C, 95616, Davis, CA, USA.
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161
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Betts KS. Hand-me-down hazard: flame retardants in discarded foam products. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:A56-63. [PMID: 25730841 PMCID: PMC4348733 DOI: 10.1289/ehp.123-a56] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
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162
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Noyes PD, Haggard DE, Gonnerman GD, Tanguay RL. Advanced morphological - behavioral test platform reveals neurodevelopmental defects in embryonic zebrafish exposed to comprehensive suite of halogenated and organophosphate flame retardants. Toxicol Sci 2015; 145:177-95. [PMID: 25711236 DOI: 10.1093/toxsci/kfv044] [Citation(s) in RCA: 182] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The increased use of flammable plastics and electronic devices along with stricter fire safety standards has led to the heavy use of flame retardant chemicals in many consumer, commercial, and industrial products. Although flame retardant use has increased, a great deal of uncertainty surrounds their safety with some evidence showing toxicity and risk to human and environmental health. Recent efforts have focused on designing high-throughput biological platforms with nonmammalian models to evaluate and prioritize chemicals with limited hazard information. To complement these efforts, this study used a new morphological and behavioral testing platform with embryonic zebrafish to characterize the developmental toxicity of 44 halogenated and organophosphate flame retardants, including several of their known metabolites. Zebrafish were exposed to flame retardants from 6 to 120 h post fertilization (hpf) across concentrations spanning 4 orders of magnitude (eg, 6.4 nM to 64 µM). Flame retardant effects on survival and development were evaluated at 24 and 120 hpf, and neurobehavioral changes were measured using 2 photomotor response (PMR) assays. Compared to controls, 93% (41/44) of flame retardants studied elicited adverse effects among one or more of the bioassays and concentrations tested with the aryl phosphate ester (APE)-based mono-isopropylated triaryl phosphate and the brominated-bisphenol-A analog tetrabromobisphenol-A producing the greatest array of malformations. Hierarchical clustering showed that APE flame retardants with isopropyl, butyl, and cresyl substituents on phenyl rings clustered tightly and were particularly potent. Both PMR assays were highly predictive of morphological defects supporting their use as nonlethal means of evaluating teratogenicity that could allow for additional evaluations of long-term or delayed effects in older animals. Taken together, evidence presented here indicates that zebrafish neurodevelopment is highly sensitive to many flame retardants currently in use and can be used to understand potential vulnerabilities to human health.
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Affiliation(s)
- Pamela D Noyes
- Department of Environmental & Molecular Toxicology, Environmental Health Sciences Center, and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Derik E Haggard
- Department of Environmental & Molecular Toxicology, Environmental Health Sciences Center, and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Greg D Gonnerman
- Department of Environmental & Molecular Toxicology, Environmental Health Sciences Center, and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Robert L Tanguay
- Department of Environmental & Molecular Toxicology, Environmental Health Sciences Center, and the Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
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163
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Gross MS, Butryn DM, McGarrigle BP, Aga DS, Olson JR. Primary role of cytochrome P450 2B6 in the oxidative metabolism of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100) to hydroxylated BDEs. Chem Res Toxicol 2015; 28:672-81. [PMID: 25629761 DOI: 10.1021/tx500446c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human exposure to polybrominated diphenyl ethers (PBDEs) through various routes poses deleterious health effects. PBDEs are biotransformed into hydroxylated metabolites (OH-BDEs) via cytochrome P450s (P450s), which may add to their neurotoxic effects. This study characterizes the in vitro metabolism of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100), one of the most abundant PBDE congeners found in humans, by recombinant human P450s and pooled human liver microsomes (HLMs). Ten recombinant P450s were individually incubated with BDE-100 to monitor P450-specific metabolism. P450 2B6 was found to be the predominant enzyme responsible for nearly all formation of six mono-OH-pentaBDE and two di-OH-pentaBDE metabolites. Four metabolites were identified as 3-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (3-OH-BDE-100), 5'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (5'-OH-BDE-100), 6'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (6'-OH-BDE-100), and 4'-hydroxy-2,2',4,5',6-pentabromodiphenyl ether (4'-OH-BDE-103) through use of reference standards. The two remaining mono-OH-pentaBDE metabolites were hypothesized using mass spectral fragmentation characteristics of derivatized OH-BDEs, which allowed prediction of an ortho-OH-pentaBDE and a para-OH-pentaBDE positional isomer. Additional information based on theoretical boiling point calculations using COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) and experimental chromatographic retention times were used to identify the hypothesized metabolites as 2'-hydroxy-2,3',4,4',6-pentabromodiphenyl ether (2'-OH-BDE-119) and 4-hydroxy-2,2',4',5,6-pentabromodiphenyl ether (4-OH-BDE-91), respectively. Kinetic studies of BDE-100 metabolism using P450 2B6 and HLMs revealed Km values ranging from 4.9 to 7.0 μM and 6-10 μM, respectively, suggesting a high affinity toward the formation of OH-BDEs. Compared to the metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) reported in previous studies, BDE-100 appears to be more slowly metabolized by P450s due to the presence of a third ortho-substituted bromine atom.
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Affiliation(s)
- Michael S Gross
- †Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Deena M Butryn
- †Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Barbara P McGarrigle
- ‡Department of Pharmacology and Toxicology and Department of Epidemiology and Environmental Health, University at Buffalo, The State University of New York, Buffalo, New York 14214, United States
| | - Diana S Aga
- †Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - James R Olson
- ‡Department of Pharmacology and Toxicology and Department of Epidemiology and Environmental Health, University at Buffalo, The State University of New York, Buffalo, New York 14214, United States
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164
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Yeh A, Kruse SE, Marcinek DJ, Gallagher EP. Effect of omega-3 fatty acid oxidation products on the cellular and mitochondrial toxicity of BDE 47. Toxicol In Vitro 2015; 29:672-80. [PMID: 25659769 DOI: 10.1016/j.tiv.2015.01.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 12/08/2014] [Accepted: 01/25/2015] [Indexed: 01/01/2023]
Abstract
High levels of the flame retardant 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) have been detected in Pacific salmon sampled near urban areas, raising concern over the safety of salmon consumption. However, salmon fillets also contain the antioxidants eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), whose oxidation products induce cellular antioxidant responses. Because oxidative stress is a mechanism of BDE 47 toxicity, we hypothesized that oxidized EPA and DHA can ameliorate the cellular and mitochondrial toxicity of BDE 47. HepG2 cells were treated with a mixture of oxidized EPA and DHA (oxEPA/oxDHA) at a ratio relevant to salmon consumption (1.5/1 oxEPA/oxDHA) followed by exposure to 100 μM BDE 47. Pretreatment with oxEPA/oxDHA for 12 h prior to BDE 47 exposure prevented BDE 47-mediated depletion of glutathione, and increased expression of antioxidant response genes. oxEPA/oxDHA also reduced the level of reactive oxygen species production by BDE 47. The oxEPA/oxDHA antioxidant responses were associated with partial protection against BDE 47-induced loss of viability and also mitochondrial membrane potential. Mitochondrial electron transport system functional analysis revealed extensive inhibition of State 3 respiration and maximum respiratory capacity by BDE 47 were partially reversed by oxEPA/oxDHA. Our findings indicate that the antioxidant effects of oxEPA/oxDHA protect against short exposures to BDE 47, including a protective role of these compounds on maintaining cellular and mitochondrial function.
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Affiliation(s)
- Andrew Yeh
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105-6099, United States
| | - Shane E Kruse
- Department of Radiology, University of Washington Medical School, Seattle, WA 98195, United States
| | - David J Marcinek
- Department of Radiology, University of Washington Medical School, Seattle, WA 98195, United States
| | - Evan P Gallagher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105-6099, United States.
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165
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McIntyre RL, Kenerson HL, Subramanian S, Wang SA, Kazami M, Stapleton HM, Yeung RS. Polybrominated diphenyl ether congener, BDE-47, impairs insulin sensitivity in mice with liver-specific Pten deficiency. BMC OBESITY 2015. [PMID: 26217518 PMCID: PMC4510911 DOI: 10.1186/s40608-014-0031-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background The potential health effects of polybrominated diphenyl ethers (PBDEs) that are widely used as flame-retardants in consumer products have been attributed, in part, to their endocrine disrupting properties. The purpose of this study is to examine the in vivo effects of an early exposure to PBDEs on the development of insulin resistance in mice. Results The metabolic consequences of BDE-47 in mice with varying insulin sensitivities secondary to liver-specific activation of Akt (Ptenfl/fl;AlbCre) and mTORC1 (Tsc1fl/fl;AlbCre) as well as wild-type littermates, were studied. BDE-47, a dominant congener of PBDE, was given daily (1 mg/kg/day) for six weeks by oral gavage in young mice following weaning. At the end of the exposure, there were no significant differences in total body, liver, or white adipose tissue weights between the BDE-47-treated vs. DMSO-treated mice for each respective genotype. Metabolic studies revealed significant impairment in insulin sensitivity in the BDE-47-treated Ptenfl/fl;AlbCre mice, but not in wild-type or Tsc1fl/fl;AlbCre mice. This was not accompanied by significant alterations in plasma insulin levels or hepatic triglyceride accumulation in the Ptenfl/fl;AlbCre mice. The mean plasma BDE-47 level in the wild-type mice was 11.7 ± 2.9 ng/g (wet weight). Conclusions Our findings indicate that BDE-47 exposure during the early post-natal period induces a mild disturbance in glucose metabolism in susceptible mice with increased baseline insulin sensitivity. These results suggest an interaction between BDE-47 and genetic factors that regulate insulin signaling, which may result in long-term consequences.
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Affiliation(s)
- Rebecca L McIntyre
- Department of Surgery, University of Washington, 1959 NE Pacific, Seattle, WA 98195 USA
| | - Heidi L Kenerson
- Department of Surgery, University of Washington, 1959 NE Pacific, Seattle, WA 98195 USA
| | | | - Shari A Wang
- Department of Medicine, University of Washington, Seattle, WA USA
| | - Machiko Kazami
- Department of Surgery, University of Washington, 1959 NE Pacific, Seattle, WA 98195 USA
| | | | - Raymond S Yeung
- Department of Surgery, University of Washington, 1959 NE Pacific, Seattle, WA 98195 USA
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166
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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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167
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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: 241] [Impact Index Per Article: 26.8] [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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168
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Wang BL, Pang ST, Zhang XL, Li XL, Sun YG, Lu XM, Zhang Q. Levels of polybrominated diphenyl ethers in settled house dust from urban dwellings with resident preschool-aged children in Nanjing, China. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 68:9-19. [PMID: 25034333 DOI: 10.1007/s00244-014-0065-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/19/2014] [Indexed: 05/21/2023]
Abstract
We investigated the levels and possible determinants of polybrominated diphenyl ethers (PBDEs) in the settled house-dust (SHD) of urban dwellings with resident preschool-aged children in Nanjing, China. The possible neurodevelopmental effects of house-dust PBDEs were also explored. SHD was collected from 216 urban houses. Levels of 8 PBDEs were measured by gas chromatography-negative chemical ionization mass spectrometry. The Child Behavior Checklist and the Gesell Development Inventory were used to evaluate the child's development. BDE47, BDE99, BDE153, BDE18, and BDE209 were detected in the SHD of >90 % of houses, of which BDE209 predominated. Most PBDEs were found at significantly greater levels in indoor than in outdoor dust (P < 0.05). Levels of BDE28 and BDE154 in houses with solid-wood floors were significantly greater than those in houses with plywood floors (P < 0.05). BDE154 levels in houses with wallpaper were significantly greater than those without wallpaper (P < 0.05). Greater BDE47 concentrations were found in houses with less natural ventilation time (linear trend P < 0.05). After dichotomization at the geometric mean concentration, BDE209 and total BDEs showed significant risks for depressed behavior problems and lower personal social developmental quotients (DQs); BDE99 and BDE153 indicated a risk for lower personal social DQs. In conclusion, PBDEs (especially BDE209) are ubiquitous in urban SHD in Nanjing residences. Natural ventilation and floor materials potentially influence PBDE levels in SHD. The potential adverse effect of postnatal exposure to PBDEs on the behavior and neurodevelopment of preschool-age children requires follow-up in larger studies.
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Affiliation(s)
- Bing-Ling Wang
- Qingdao Centers for Disease Control and Prevention, No. 175 Shandong Rd, Qingdao, 266033, China,
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169
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Zhu NZ, Liu LY, Ma WL, Li WL, Song WW, Qi H, Li YF. Polybrominated diphenyl ethers (PBDEs) in the indoor dust in China: levels, spatial distribution and human exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2015; 111:1-8. [PMID: 25450909 DOI: 10.1016/j.ecoenv.2014.09.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/17/2014] [Accepted: 09/18/2014] [Indexed: 05/21/2023]
Abstract
Indoor environment is an important source of human exposure to several toxicants, such as brominated flame retardants. Indoor dust samples were collected in winter season in 2010, which covered 23 provinces across China, for the analysis of polybrominated diphenyl ethers (PBDEs). Concentrations of PBDEs (Σ14PBDEs) ranged from 8.92 to 37,500 ng/g, with the mean of 3520 ng/g. BDE-209 was the most dominate congener, followed by BDE-183, BDE-47 and BDE-99. PBDE concentrations and the longitude were significantly correlated (p<0.05), which was consistent with the status of social-economic development and human activities. The results of exposure to PBDEs through dust ingestion and dermal absorption indicated that the toddlers had the highest exposure dose, with the median value of 6.0 ng/kg-bw/day. According to the hazard quotients, health risk of PBDEs via dust ingestion in China is currently acceptable. Monte Carlo simulation was implemented to quantify the uncertainty and sensitivity of exposure models for determining the most influential variables. The results suggested that more specific and accurate parameters should be used for dust ingestion and dermal absorption exposure models in future.
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Affiliation(s)
- Ning-Zheng Zhu
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China
| | - Li-Yan Liu
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China
| | - Wan-Li Ma
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China
| | - Wen-Long Li
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China
| | - Wei-Wei Song
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China
| | - Hong Qi
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China.
| | - Yi-Fan Li
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, Heilongjiang, China.
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170
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Whitehead TP, Crispo Smith S, Park JS, Petreas MX, Rappaport SM, Metayer C. Concentrations of persistent organic pollutants in California women's serum and residential dust. ENVIRONMENTAL RESEARCH 2015; 136:57-66. [PMID: 25460621 PMCID: PMC4262624 DOI: 10.1016/j.envres.2014.10.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/20/2014] [Accepted: 10/14/2014] [Indexed: 05/17/2023]
Abstract
BACKGROUND Humans are exposed to persistent organic pollutants (POPs) through various routes, including consumption of contaminated food and accidental ingestion of settled dust. OBJECTIVES We aimed to identify key routes of exposure to organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in California women of reproductive age. METHODS Blood was collected from 48 mothers participating in the California Childhood Leukemia Study from 2006 to 2007 and analyzed for POPs using gas chromatography-mass spectrometry. Multivariable linear regression models of natural-log transformed serum concentrations were used to identify determinants of exposure from available questionnaire information on dietary habits, reproductive history, and demographic characteristics, as well as vacuum cleaner dust-POP levels. RESULTS After adjusting for blood lipid levels, age, body mass index, cumulative lactation, and sampling date, serum concentrations of multiple major PCBs were positively associated with fish consumption, but not dust-PCB levels. After adjusting for blood lipid levels, Hispanic ethnicity, country of origin, and household annual income, serum concentrations of multiple major PBDEs were positively associated with dust-PBDE levels. CONCLUSIONS Our findings suggest that the relative contribution of specific exposure routes to total POP intake varies by chemical class, with dust being a relatively important source of PBDEs and diet being a relatively important source of PCBs.
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Affiliation(s)
- Todd P Whitehead
- School of Public Health, University of California Berkeley, 50 University Hall, Berkeley, CA 94720, USA.
| | - Sabrina Crispo Smith
- Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Ave, Berkeley, CA 94710, USA; Sequoia Foundation, 2166 Avenida De La Playa, La Jolla, CA 92037, USA.
| | - June-Soo Park
- Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Ave, Berkeley, CA 94710, USA.
| | - Myrto X Petreas
- Environmental Chemistry Laboratory, California Department of Toxic Substances Control, 700 Heinz Ave, Berkeley, CA 94710, USA.
| | - Stephen M Rappaport
- School of Public Health, University of California Berkeley, 50 University Hall, Berkeley, CA 94720, USA.
| | - Catherine Metayer
- School of Public Health, University of California Berkeley, 50 University Hall, Berkeley, CA 94720, USA.
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171
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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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172
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Cequier E, Marcé RM, Becher G, Thomsen C. Comparing human exposure to emerging and legacy flame retardants from the indoor environment and diet with concentrations measured in serum. ENVIRONMENT INTERNATIONAL 2015; 74:54-59. [PMID: 25454220 DOI: 10.1016/j.envint.2014.10.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/29/2014] [Accepted: 10/01/2014] [Indexed: 06/04/2023]
Abstract
This study investigates associations between serum concentrations of emerging and legacy halogenated flame retardants (HFRs) in 46 Norwegian women and measured indoor air and dust concentrations of the HFRs as well as detailed information on diet and household factors. Hexabromobenzene (median 0.03ng/g lipid) and Dechlorane 602 (median 0.18ng/g lipid) were detected in about 50% of the samples and Dechlorane Plus syn (median 0.45ng/g lipid) and anti (median 0.85ng/g lipid) in more than 78%. The most abundant polybrominated diphenyl ethers were 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153; median 0.82ng/g lipid) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47; median 0.49ng/g lipid) detected in more than 70% of the samples. In the bivariate analysis, no consistent associations were observed between the biomonitoring data and measured concentrations in indoor air and dust. On the other hand, consumption of specific food items (mainly lamb/mutton and margarine) correlated significantly with more than two HFR serum concentrations, while this was not the case for household factors (electronic appliances). Only the significant bivariate associations with diet were confirmed by multivariate linear regression analyses, which might indicate a higher contribution from food compared to the indoor environment to the variation of the body burden of these HFRs.
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Affiliation(s)
- Enrique Cequier
- Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, Oslo, Norway; Department of Analytical Chemistry and Organic Chemistry, Universitat Rovira i Virgili, Tarragona, Spain.
| | - Rosa Maria Marcé
- Department of Analytical Chemistry and Organic Chemistry, Universitat Rovira i Virgili, Tarragona, Spain
| | - Georg Becher
- Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, Oslo, Norway; Department of Chemistry, University of Oslo, Norway
| | - Cathrine Thomsen
- Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, Oslo, Norway
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173
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Makey CM, McClean M, Sjödin A, Weinberg J, Carignan CC, Webster TF. Temporal variability of polybrominated diphenyl ether (PBDE) serum concentrations over one year. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:14642-9. [PMID: 25383963 PMCID: PMC4270390 DOI: 10.1021/es5026118] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 10/07/2014] [Accepted: 11/10/2014] [Indexed: 05/22/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals used in consumer products. They are common contaminants in human serum and associated with adverse health effects. Our objectives were to characterize PBDE serum concentrations in a New England cohort and assess temporal variability of this exposure biomarker over a one-year period. We collected three repeated measurements at six-month intervals from 52 office workers from the greater Boston (MA, United States) area from 2010 to 2011. The intraclass correlation coefficient for BDEs 28, 47, 99, 100, and 153 ranged from 0.87 to 0.99, indicating that a single serum measurement can reliably estimate exposure over a one-year period. This was true for both lipid adjusted and nonlipid adjusted concentrations. The kappa statistics, quantifying the level of agreement of categorical exposure classification, based on medians, tertiles, or quartiles ranged from 0.67 to 0.90. Some congeners showed nonsignificant increases from sampling round 1 (winter) to round 2 (summer) and significant decreases from round 2 to round 3 (winter). This study highlights the high reliability of a single serum PBDE measurement for use in human epidemiologic studies.
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Affiliation(s)
- Colleen M. Makey
- Department
of Environmental Health, Boston University
School of Public Health, 715 Albany Street, Boston, Massachusetts 02118, United States
- Phone: (617) 638-4620; fax: 617 638-4857; e-mail:
| | - Michael
D. McClean
- Department
of Environmental Health, Boston University
School of Public Health, 715 Albany Street, Boston, Massachusetts 02118, United States
| | - Andreas Sjödin
- Centers
for Disease Control and Prevention, 1600 Clifton Road, Atlanta, Georgia 30329, United
States
| | - Janice Weinberg
- Department
of Biostatistics, Boston University School
of Public Health, 1010
Massachusetts Avenue, Boston, Massachusetts 02118, United States
| | - Courtney C. Carignan
- Department
of Environmental Health, Boston University
School of Public Health, 715 Albany Street, Boston, Massachusetts 02118, United States
- Department
of Biostatistics, Boston University School
of Public Health, 1010
Massachusetts Avenue, Boston, Massachusetts 02118, United States
- Department
of Biological Sciences, Dartmouth College, 79 College Street, Hanover, New Hampshire 03755, United States
| | - Thomas F. Webster
- Department
of Environmental Health, Boston University
School of Public Health, 715 Albany Street, Boston, Massachusetts 02118, United States
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174
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Bradman A, Castorina R, Gaspar F, Nishioka M, Colón M, Weathers W, Egeghy PP, Maddalena R, Williams J, Jenkins PL, McKone TE. Flame retardant exposures in California early childhood education environments. CHEMOSPHERE 2014; 116:61-66. [PMID: 24835158 DOI: 10.1016/j.chemosphere.2014.02.072] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 02/25/2014] [Accepted: 02/28/2014] [Indexed: 05/28/2023]
Abstract
Infants and young children spend as much as 50h per week in child care and preschool. Although approximately 13 million children, or 65% of all U.S. children, spend some time each day in early childhood education (ECE) facilities, little information is available about environmental exposures in these environments. We measured flame retardants in air and dust collected from 40 California ECE facilities between May 2010 and May 2011. Low levels of six polybrominated diphenyl ether (PBDE) congeners and four non-PBDE flame retardants were present in air, including two constituents of Firemaster 550 and two tris phosphate compounds [tris (2-chloroethyl) phosphate (TCEP) and tris (1,3-dichloroisopropyl) phosphate (TDCIPP)]. Tris phosphate, Firemaster 550 and PBDE compounds were detected in 100% of the dust samples. BDE47, BDE99, and BDE209 comprised the majority of the PBDE mass measured in dust. The median concentrations of TCEP (319 ng g(-1)) and TDCIPP (2265 ng g(-1)) were similar to or higher than any PBDE congener. Levels of TCEP and TDCIPP in dust were significantly higher in facilities with napping equipment made out of foam (Mann-Whitney p-values<0.05). Child BDE99 dose estimates exceeded the RfD in one facility for children<3 years old. In 51% of facilities, TDCIPP dose estimates for children<6 years old exceeded age-specific "No Significant Risk Levels (NSRLs)" based on California Proposition 65 guidelines for carcinogens. Given the overriding interest in providing safe and healthy environments for young children, additional research is needed to identify strategies to reduce indoor sources of flame retardant chemicals.
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Affiliation(s)
- Asa Bradman
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA.
| | - Rosemary Castorina
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | - Fraser Gaspar
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | | | - Maribel Colón
- United States Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Walter Weathers
- United States Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Peter P Egeghy
- United States Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Randy Maddalena
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, USA
| | | | | | - Thomas E McKone
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA; Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, USA
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175
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Stapleton HM, Misenheimer J, Hoffman K, Webster TF. Flame retardant associations between children's handwipes and house dust. CHEMOSPHERE 2014; 116:54-60. [PMID: 24485814 PMCID: PMC4116470 DOI: 10.1016/j.chemosphere.2013.12.100] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 12/18/2013] [Accepted: 12/21/2013] [Indexed: 05/20/2023]
Abstract
Polybrominated diphenyl ether (PBDE), flame retardants (FRs) have been ubiquitously detected at high concentrations in indoor environments; however, with their recent phase-out, more attention is being focused on measurements of exposure to alternative FRs such as organophosphate FRs (OPFRs). In our previous research, we found that PBDE residues measured on children's handwipes were a strong predictor of serum PBDE levels. Here we build upon this research to examine longitudinal changes in PBDEs in indoor dust and children's handwipes, and explore the associations between handwipes and dust for alternative FRs. Children from our previous study were re-contacted after approximately two years and new samples of indoor dust and handwipes were collected. PBDE dust-levels were significantly correlated between two different sampling rounds separated by two years; however, PBDE levels in handwipes were not correlated, perhaps suggesting that the sources of PBDEs remained relatively constant in the home, but that behavioral differences in children are changing with age and influencing handwipe levels. OPFRs [i.e. tris(1,3-dichloroisopropyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP)], 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB, also known as TBB), di(2-ethylhexyl) tetrabromophthalate (BEH-TEBP, also known as TBPH), and 1,2,5,6,9,10-hexabromocyclododecane (HBCD) were also ubiquitously detected in house dust samples and geometric mean levels were similar to PBDE levels, or higher in the case of the OPFRs. Significant associations between handwipes and house dust were observed for these alternative FRs, particularly for EH-TBB (rs=0.54; p<0.001). Increasing house dust levels and age were associated with higher levels of FRs in handwipes, and high hand washing frequency (>5 times d(-1)) was associated with lower FR levels in handwipes. Overall these data suggest that exposure to these alternative FRs will be similar to PBDE exposure, and the influence of hand-to-mouth behavior in children's exposure needs to be further examined to better estimate exposure potential.
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Affiliation(s)
| | - John Misenheimer
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Thomas F Webster
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
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176
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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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177
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Brown FR, Whitehead TP, Park JS, Metayer C, Petreas MX. Levels of non-polybrominated diphenyl ether brominated flame retardants in residential house dust samples and fire station dust samples in California. ENVIRONMENTAL RESEARCH 2014; 135:9-14. [PMID: 25261858 PMCID: PMC4262617 DOI: 10.1016/j.envres.2014.08.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 07/28/2014] [Accepted: 08/21/2014] [Indexed: 05/19/2023]
Abstract
Eleven novel brominated flame retardants (NBFRs) were analyzed in dust samples from California homes as a part of the Northern California Childhood Leukemia Study (NCCLS) and from the living quarters of California fire stations as a part of the Firefighter Occupational Exposure (FOX) study using high resolution gas chromatography/mass spectrometry. The eleven NBFRs were α- and β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (α- and β-DBE-DBCH), 2-bromoallyl 2,3,6-tribromophenylether (BATE), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (TBP-DBPE), hexabromobenzene (HBB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), and decabromodiphenylethane (DBDPE). Six of the seven NBFRs that are produced in relatively small quantities (i.e., α-, β-DBE-DBCH, BATE, PBEB, PBT, TBP-DBPE) were measured close to or below the limit of quantitation (0.64 ng/g) in both the NCCLS and FOX samples, and the seventh, HBB, was measured at median concentrations of 1.85 ng/g and 9.40 ng/g in the NCCLS and FOX samples, respectively. The remaining four NBFRs, EH-TBB, BEH-TEBP, BTBPE, and DBDPE, are produced in higher quantities, and were detected at median concentrations of 337 ng/g, 186 ng/g, 22.3 ng/g, and 82.8 ng/g, respectively in the NCCLS samples, and at median concentrations of 2687 ng/g, 2076 ng/g, 28.4 ng/g, and 161 ng/g, respectively, in the FOX samples. Concentrations of NBFRs in the NCCLS and FOX dust samples were several times lower than concentrations of PBDEs previously measured in the same samples. Concentrations of NBFRs in the NCCLS and FOX dust samples were generally comparable to concentrations of NBFRs in other studies of house dust from the US and Canada.
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Affiliation(s)
- F Reber Brown
- Environmental Chemistry Laboratory, Department of Toxic Substances Control, 700 Heinz Avenue Suite 100, Berkeley, CA 94710, USA.
| | - Todd P Whitehead
- School of Public Health, University of California Berkeley, Berkeley, CA, USA
| | - June-Soo Park
- Environmental Chemistry Laboratory, Department of Toxic Substances Control, 700 Heinz Avenue Suite 100, Berkeley, CA 94710, USA
| | - Catherine Metayer
- School of Public Health, University of California Berkeley, Berkeley, CA, USA
| | - Myrto X Petreas
- Environmental Chemistry Laboratory, Department of Toxic Substances Control, 700 Heinz Avenue Suite 100, Berkeley, CA 94710, USA
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178
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Meeker JD, Cooper EM, Stapleton HM, Hauser R. Exploratory analysis of urinary metabolites of phosphorus-containing flame retardants in relation to markers of male reproductive health. ACTA ACUST UNITED AC 2014; 1:e26306. [PMID: 24795899 DOI: 10.4161/endo.26306] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The use of phosphorus-containing flame retardants (PFRs) has increased over the past decade. Widespread human exposure has been reported, but information on the safety or potential health risks of PFRs is lacking. We assessed the relationship between urinary concentrations of two PFR metabolites [bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPHP)] and semen quality, sperm motion parameters, and serum hormone levels in 33 men. BDCPP and DPHP concentrations were significantly greater in urine samples collected in the afternoon compared to those collected in the morning (p <0.05). In multivariable models, a number of statistically significant or suggestive associations were observed between the reproductive health measures and both PFR metabolites. While the study was limited by a small sample size, these results warrant further investigation in a larger study population. Additional studies on sources, pathways, and routes of PFR exposure, along with research on toxicokinetics and exposure measure utility, are also needed.
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Affiliation(s)
- John D Meeker
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Ellen M Cooper
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | | | - Russ Hauser
- Department of Environmental Health, Harvard School of Public Health, Boston, MA ; Vincent Memorial Obstetrics and Gynecology Service, Massachusetts General Hospital, Boston, MA
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179
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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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180
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Ward MH, Colt JS, Deziel NC, Whitehead TP, Reynolds P, Gunier RB, Nishioka M, Dahl GV, Rappaport SM, Buffler PA, Metayer C. Residential levels of polybrominated diphenyl ethers and risk of childhood acute lymphoblastic leukemia in California. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:1110-6. [PMID: 24911217 PMCID: PMC4181922 DOI: 10.1289/ehp.1307602] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 05/30/2014] [Indexed: 05/04/2023]
Abstract
BACKGROUND House dust is a major source of exposure to polybrominated diphenyl ethers (PBDEs), which are found at high levels in U.S. homes. METHODS We studied 167 acute lymphoblastic leukemia (ALL) cases 0-7 years of age and 214 birth certificate controls matched on date of birth, sex, and race/ethnicity from the Northern California Childhood Leukemia Study. In 2001-2007, we sampled carpets in the room where the child spent the most time while awake; we used a high-volume small-surface sampler or we took dust from the home vacuum. We measured concentrations of 14 PBDE congeners including penta (28, 47, 99, 100, 153, 154), octa (183, 196, 197, 203), and decaBDEs (206-209). Odds ratios (ORs) were calculated using logistic regression, adjusting for demographics, income, year of dust collection, and sampling method. RESULTS BDE-47, BDE-99, and BDE-209 were found at the highest concentrations (medians, 1,173, 1,579, and 938 ng/g, respectively). Comparing the highest to lowest quartile, we found no association with ALL for summed pentaBDEs (OR = 0.7; 95% CI: 0.4, 1.3), octaBDEs (OR = 1.3; 95% CI: 0.7, 2.3), or decaBDEs (OR = 1.0; 95% CI: 0.6, 1.8). Comparing homes in the highest concentration (nanograms per gram) tertile to those with no detections, we observed significantly increased ALL risk for BDE-196 (OR = 2.1; 95% CI: 1.1, 3.8), BDE-203 (OR = 2.0; 95% CI: 1.1, 3.6), BDE-206 (OR = 2.1; 95% CI: 1.1, 3.9), and BDE-207 (OR = 2.0; 95% CI: 1.03, 3.8). CONCLUSION We found no association with ALL for common PBDEs, but we observed positive associations for specific octa and nonaBDEs. Additional studies with repeated sampling and biological measures would be informative.
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Affiliation(s)
- Mary H Ward
- Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
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181
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Butt CM, Congleton J, Hoffman K, Fang M, Stapleton HM. Metabolites of organophosphate flame retardants and 2-ethylhexyl tetrabromobenzoate in urine from paired mothers and toddlers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:10432-8. [PMID: 25090580 DOI: 10.1021/es5025299] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
As a result of the polybrominated diphenyl ether (PBDE) ban in the mid-2000s, the chemical flame retardant market has moved toward alterative compounds including chlorinated alkyl and nonchlorinated aryl organophosphate flame retardants (OPFRs) as well as aromatic brominated compounds such as Firemaster 550 (FM550). Recent studies have shown that the OPFRs and Firemaster 550 components are frequently detected in polyurethane foams and in indoor dust. Some OPFRs are considered carcinogenic and/or neurodevelopmental toxicants, and children's exposure to these compounds is a concern. OPFRs are readily metabolized and excreted in the urine as their dialkyl and diaryl compounds which function as biomarkers for OPFR exposure. Limited research has shown that adults are broadly exposed to OPFRs, but nothing is known about children's exposure. Similarly, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), a FM550 component, is metabolized to tetrabromobenzoic acid (TBBA). The current study measured levels of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(1-chloro-2-propyl) phosphate (BCIPP), diphenyl phosphate (DPHP), 2 alkylated DPHPs, and TBBA in urine collected in 2013 from 21 US mother-toddler pairs. BDCIPP, DPHP, and ip-DPHP were detected in 100%, 98%, and 96% of all individuals, whereas BCIPP and tert-butyl-DPHP (tb-DPHP) were only detected in 8% and 13%. Further, TBBA was detected in 27% of adults but 70% of children. Overall, children had higher urinary levels of BDCIPP, DPHP, ip-DPHP, and TBBA as compared to their mothers, suggesting higher exposure. For example, on average, BDCIPP levels in children were 4.9 times those of mothers. BDCIPP and DPHP levels in mother's urine were also significantly correlated with levels in children's urine, suggesting similar exposure routes, likely in the home environment. Various potential predictors of OPFR exposure were assessed using a questionnaire. In children some predictors of hand-mouth exposure were associated with elevated BDCIPP and DPHP levels (e.g., less frequent hand washing for BDCIPP). Overall, these trends are consistent with higher flame retardant levels in children as a result of increased hand-mouth behavior and elevated dust exposure.
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Affiliation(s)
- Craig M Butt
- Nicholas School of the Environment, Duke University , Box 90328, Levine Science Research Center, Room A220, Durham, North Carolina 27708, United States
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182
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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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183
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Gong M, Zhang Y, Weschler CJ. Measurement of phthalates in skin wipes: estimating exposure from dermal absorption. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:7428-7435. [PMID: 24911978 DOI: 10.1021/es501700u] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study has determined the levels of six phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), di(isobutyl) phthalate (DiBP), di(n-butyl) phthalate (DnBP), butyl benzyl phthalate (BBzP), and di(2-ethylhexyl) phthalate (DEHP)) in skin wipes; examined factors that might influence the levels, including body location, time of sampling, and hand-washing; and estimated dermal absorption based on the measured levels. Skin wipes were collected from the forehead, forearm, back-of-hand, and palm of 20 participants using gauze pads moistened with isopropanol. DiBP, DnBP, and DEHP were most frequently detected; DEHP levels were substantially higher than DnBP and DiBP levels, and DnBP levels were somewhat lower than DiBP levels. The levels differed at different body locations, with palm > back-of-hand > forearm ≥ forehead. Repeated wipe sampling from six participants over a 1 month period indicated that levels at the same body location did not vary significantly. The estimated median total dermal absorption from skin surface lipids on the palm, back-of-hand, arm, and head are 0.48, 0.68, and 0.66 (μg/kg)/day for DiBP, DnBP, and DEHP, respectively. These estimates are roughly 10-20% of the total uptake reported for Chinese adults and suggest that dermal absorption contributes significantly to the uptake of these phthalates. Washing with soap and water removed more than 50% of the phthalates on the hands and may be a useful tool in decreasing aggregate phthalate exposure.
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Affiliation(s)
- Mengyan Gong
- Department of Building Science, Tsinghua University , Beijing 10084, China
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184
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Sahlström LMO, Sellström U, de Wit CA, Lignell S, Darnerud PO. Brominated flame retardants in matched serum samples from Swedish first-time mothers and their toddlers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:7584-7592. [PMID: 24927135 DOI: 10.1021/es501139d] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Tri-decabrominated diphenyl ethers and 21 other flame retardants were determined in matched serum samples from 24 Swedish mothers (Uppsala county) and their toddlers (11-15 months of age). The median concentrations of individual polybrominated diphenyl ethers (PBDEs) ranged from 0.036 to 0.95 ng/g lipid in mothers and from 0.057 to 1.5 ng/g lipid in toddlers. BDE-209 was detected in all but one sample. BDE-153 was the predominant congener in the mothers while in toddlers, BDE-209 was found in the highest concentrations. The levels of BDE-47, -100, -207, -208, and -209 in toddlers were significantly higher (p < 0.05) than those in their mothers. Dechlorane Plus (anti- and syn-) and α- and β-tetrabromoethylcyclohexane were detected in a few (2-4) serum samples from both mothers and toddlers. This study also reports concentrations of α-HBCD and eight emerging brominated flame retardants (EBFRs) in the standard reference material serum (SRM 1958, NIST). Lack of correlations between the matched serum samples indicate different exposure routes for octa-decaBDEs in mothers versus toddlers. Congener-to-congener correlations within the mother or toddler cohorts suggest diet as an important exposure pathway for tetra-nonaBDEs for mothers, breastfeeding as a predominant exposure pathway for tetra-hexaBDEs, and dust for octa-decaBDEs for toddlers.
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Affiliation(s)
- Leena M O Sahlström
- Department of Applied Environmental Science (ITM), Stockholm University , SE-106 91 Stockholm, Sweden
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185
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186
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Exposure to an environmentally relevant mixture of brominated flame retardants affects fetal development in Sprague-Dawley rats. Toxicology 2014; 320:56-66. [DOI: 10.1016/j.tox.2014.03.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 03/12/2014] [Accepted: 03/14/2014] [Indexed: 02/05/2023]
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187
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Human biomonitoring of emerging pollutants through non-invasive matrices: state of the art and future potential. Anal Bioanal Chem 2014; 406:4063-88. [DOI: 10.1007/s00216-014-7748-1] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/24/2014] [Accepted: 03/04/2014] [Indexed: 12/14/2022]
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188
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De Filippis SP, Brambilla G, Dellatte E, Corrado F, Esposito M. Exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) through the consumption of prepared meals in Italy. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014; 31:1114-26. [DOI: 10.1080/19440049.2014.905876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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189
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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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190
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Law RJ, Covaci A, Harrad S, Herzke D, Abdallah MAE, Fernie K, Toms LML, Takigami H. Levels and trends of PBDEs and HBCDs in the global environment: status at the end of 2012. ENVIRONMENT INTERNATIONAL 2014; 65:147-58. [PMID: 24486972 DOI: 10.1016/j.envint.2014.01.006] [Citation(s) in RCA: 293] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 01/03/2014] [Accepted: 01/04/2014] [Indexed: 05/03/2023]
Abstract
In this paper, we have compiled and reviewed the most recent literature, published in print or online from January 2010 to December 2012, relating to the human exposure, environmental distribution, behaviour, fate and concentration time trends of polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants, in order to establish their current trends and priorities for future study. More data are now becoming available for remote areas not previously studied, Indian Ocean islands, for example. Decreasing time trends for penta-mix PBDE congeners were seen for soils in northern Europe, sewage sludge in Sweden and the USA, carp from a US river, trout from three of the Great Lakes and in Arctic and UK marine mammals and many birds, but increasing time trends continue in polar bears and some birds at high trophic levels in northern Europe. This may be partially a result of the time delay inherent in long-range atmospheric transport processes. In general, concentrations of BDE209 (the major component of the deca-mix PBDE product) are continuing to increase. Of major concern is the possible/likely debromination of the large reservoir of BDE209 in soils and sediments worldwide, to yield lower brominated congeners which are both more mobile and more toxic, and we have compiled the most recent evidence for the occurrence of this degradation process. Numerous studies reported here reinforce the importance of this future concern. Time trends for HBCDs are mixed, with both increases and decreases evident in different matrices and locations and, notably, with increasing occurrence in birds of prey. Temporal trends for both PBDEs and HBCD in Asia are unclear currently. A knowledge gap has been noted in relation to metabolism and/or debromination of BDE209 and HBCD in birds. Further monitoring of human exposure and environmental contamination in areas of e-waste recycling, particularly in Asia and Africa, is warranted. More data on temporal trends of BDE and HBCD concentrations in a variety of matrices and locations are needed before the current status of these compounds can be fully assessed, and the impact of regulation and changing usage patterns among different flame retardants determined.
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Affiliation(s)
- Robin J Law
- The Centre for Environment, Fisheries and Aquaculture Science, Cefas Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK.
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
| | - Stuart Harrad
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Dorte Herzke
- Norwegian Institute for Air Research, FRAM - High North Research Centre for Climate and the Environment, H. Johansens gate 14, 9296 Tromsø, Norway
| | - Mohamed A-E Abdallah
- Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt
| | - Kim Fernie
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, 867 Lakeshore Road, Burlington L7R 4A6, Ontario, Canada
| | - Leisa-Maree L Toms
- School of Clinical Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Hidetaka Takigami
- Centre for Material Cycles and Waste Management Research, National institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, 305-8506 Ibaraki, Japan
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191
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Tracking contributions to human body burden of environmental chemicals by correlating environmental measurements with biomarkers. PLoS One 2014; 9:e93678. [PMID: 24681626 PMCID: PMC3969314 DOI: 10.1371/journal.pone.0093678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 03/05/2014] [Indexed: 11/23/2022] Open
Abstract
The work addresses current knowledge gaps regarding causes for correlations between environmental and biomarker measurements and explores the underappreciated role of variability in disaggregating exposure attributes that contribute to biomarker levels. Our simulation-based study considers variability in environmental and food measurements, the relative contribution of various exposure sources (indoors and food), and the biological half-life of a compound, on the resulting correlations between biomarker and environmental measurements. For two hypothetical compounds whose half-lives are on the order of days for one and years for the other, we generate synthetic daily environmental concentrations and food exposures with different day-to-day and population variability as well as different amounts of home- and food-based exposure. Assuming that the total intake results only from home-based exposure and food ingestion, we estimate time-dependent biomarker concentrations using a one-compartment pharmacokinetic model. Box plots of modeled R2 values indicate that although the R2 correlation between wipe and biological (e.g., serum) measurements is within the same range for the two compounds, the relative contribution of the home exposure to the total exposure could differ by up to 20%, thus providing the relative indication of their contribution to body burden. The novel method introduced in this paper provides insights for evaluating scenarios or experiments where sample, exposure, and compound variability must be weighed in order to interpret associations between exposure data.
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192
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Keller A, Raju NP, Webster TF, Stapleton HM. Flame Retardant Applications in Camping Tents and Potential Exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2014; 1:152-155. [PMID: 24804279 PMCID: PMC3958138 DOI: 10.1021/ez400185y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/07/2014] [Accepted: 01/07/2014] [Indexed: 05/02/2023]
Abstract
Concern has mounted over health effects caused by exposure to flame retardant additives used in consumer products. Significant research efforts have focused particularly on exposure to polybrominated diphenyl ethers (PBDEs) used in furniture and electronic applications. However, little attention has focused on applications in textiles, particularly textiles meeting a flammability standard known as CPAI-84. In this study, we investigated flame retardant applications in camping tents that met CPAI-84 standards by analyzing 11 samples of tent fabrics for chemical flame retardant additives. Furthermore, we investigated potential exposure by collecting paired samples of tent wipes and hand wipes from 27 individuals after tent setup. Of the 11 fabric samples analyzed, 10 contained flame retardant additives, which included tris(1,3-dichloroisopropyl) phosphate (TDCPP), decabromodiphenyl ether (BDE-209), triphenyl phosphate, and tetrabromobisphenol-A. Flame retardant concentrations were discovered to be as high as 37.5 mg/g (3.8% by weight) in the tent fabric samples, and TDCPP and BDE-209 were the most frequently detected in these samples. We also observed a significant association between TDCPP levels in tent wipes and those in paired hand wipes, suggesting that human contact with the tent fabric material leads to the transfer of the flame retardant to the skin surface and human exposure. These results suggest that direct contact with flame retardant-treated textiles may be a source of exposure. Future studies will be needed to better characterize exposure, including via inhalation and dermal sorption from air.
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Affiliation(s)
- Alexander
S. Keller
- Nicholas
School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Nikhilesh P. Raju
- 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
- E-mail: . Phone: (919) 613-8717. Fax: (919) 684-8741
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193
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Hoffman K, Daniels JL, Stapleton HM. Urinary metabolites of organophosphate flame retardants and their variability in pregnant women. ENVIRONMENT INTERNATIONAL 2014; 63:169-72. [PMID: 24316320 PMCID: PMC3932676 DOI: 10.1016/j.envint.2013.11.013] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/17/2013] [Accepted: 11/15/2013] [Indexed: 05/19/2023]
Abstract
Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.
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Affiliation(s)
- Kate Hoffman
- Nicholas School of the Environment, Duke University, LSRC, Box 90328, Durham, NC 27708, USA; Gillings School of Global Public Health, University of North Carolina, 135 Dauer Drive, Campus Box 7435, Chapel Hill, NC 27599, USA.
| | - Julie L Daniels
- Gillings School of Global Public Health, University of North Carolina, 135 Dauer Drive, Campus Box 7435, Chapel Hill, NC 27599, USA.
| | - Heather M Stapleton
- Nicholas School of the Environment, Duke University, LSRC, Box 90328, Durham, NC 27708, USA.
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194
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Lim YW, Kim HH, Lee CS, Shin DC, Chang YS, Yang JY. Exposure assessment and health risk of poly-brominated diphenyl ether (PBDE) flame retardants in the indoor environment of elementary school students in Korea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 470-471:1376-1389. [PMID: 24094588 DOI: 10.1016/j.scitotenv.2013.09.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 09/01/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
This study assessed the health risks of elementary school students' exposure to PBDEs via different possible pathways in children's facilities. After PBDE contamination was measured, exposure was demonstrated to occur through multiple routes, including inhalation of indoor dust, dermal contact with products' surfaces and children's hands, and incidental dust ingestion. Samples were collected from various children's facilities (30 elementary schools, 31 private academies, 12 living rooms and bedrooms in houses, 5 public libraries of children's literature, and 3 large hypermalls) in summer (Jul-Sep, 2008) and winter (Jan-Feb, 2009). The hazard index (HI) was estimated for non-carcinogens and PBDEs, such as TeBDE, PeBDE, HxBDE, OcBDE, and DeBDE. PBDEs were detected in all floor dust samples, 99% of indoor air samples, 94% of product-wipe samples, and 86% of hand wipe samples. The average levels of PBDEs ranged from 0.19 to 1.06 ng/m(3) in indoor air, 4623 to 6,650 ng/g-dust in floor dust, 0.012 to 0.103 ng/cm(2) on product surfaces, and 7.89 to 25.38 ng/hand on the surface of children's hands. The HI for school children via multimedia and multipathway exposure to PBDEs did not exceed 1.0. The exposure to PBDEs at home (approximately 80%) was dominant. The contribution rates of PBDE risk were 77% and 15% via dust ingestion at home and at elementary school, respectively; thus, intake of floor dust was determined to be the primary route of exposure.
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Affiliation(s)
- Young-Wook Lim
- The Institute for Environmental Research, College of Medicine, Yonsei University, 250 Seongsan-no, Seoul, Republic of Korea
| | - Ho-Hyun Kim
- The Institute for Environmental Research, College of Medicine, Yonsei University, 250 Seongsan-no, Seoul, Republic of Korea
| | - Chung-Soo Lee
- The Institute for Environmental Research, College of Medicine, Yonsei University, 250 Seongsan-no, Seoul, Republic of Korea
| | - Dong-Chun Shin
- The Institute for Environmental Research, College of Medicine, Yonsei University, 250 Seongsan-no, Seoul, Republic of Korea; Dept. of Preventive Medicine, College of Medicine, Yonsei University, 250 Seongsan-no, Seoul, Republic of Korea
| | - Yoon-Seok Chang
- Dept. of Environmental Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Ji-Yeon Yang
- The Institute for Environmental Research, College of Medicine, Yonsei University, 250 Seongsan-no, Seoul, Republic of Korea.
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195
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Cao Z, Xu F, Covaci A, Wu M, Wang H, Yu G, Wang B, Deng S, Huang J, Wang X. Distribution patterns of brominated, chlorinated, and phosphorus flame retardants with particle size in indoor and outdoor dust and implications for human exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:8839-46. [PMID: 25010345 DOI: 10.1021/es501224b] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dust samples were collected in Beijing, China, from four different indoor microenvironments (office, hotel, kindergarten, and student dormitory) and one outdoor (road dust) microenvironment. These five composite samples were fractionated into 13 sequential size fractions and an individual fraction of <50 μm for further analysis. In the fractions of <50 μm, nine phosphorus flame retardants (∑PFRs), four novel brominated flame retardants (∑NBFRs), and two Dechlorane Plus isomers (DPs) showed the highest concentrations in hotel dust (124,000 ng g(-1)), dormitory dust (14,200 ng g(-1)), and kindergarten dust (231 ng g(-1)), respectively. Nevertheless, nine polybrominated diphenyl ethers (∑PBDEs) were the dominant flame retardants (FRs) (96% of total FRs) in road dust, with the maximum concentration of 23,700 ng g(-1), higher than in any indoor dust. The FR contamination varied strongly among different types of microenvironments, leading to high human exposure to various FRs. Concentrations of FRs did not increase constantly with a particle size decrease. Fractions with a particle size around 900, 100, and 10 μm could represent peak values, while valley values were commonly detected around fractions with a particle size around 40 μm. Large differences were found between indoor dust and road dust. In road dust, FRs were mainly enriched in fractions of <50 μm. The organic content of dust, FR application, and consequent abrasion processes of FR-containing materials might be the determinants of the FR concentrations. Volatilization and abrasion were considered to be important migration pathways for FRs. DPs and BDE-209 were sought to be mainly applied in abrasion-proof materials, while most phosphorus flame retardants (PFRs) were probably added in a large proportion in materials easy to wear.
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Affiliation(s)
- Zhiguo Cao
- POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University , Beijing 100084, People's Republic of China
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196
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Sjödin A, Jones RS, Caudill SP, Wong LY, Turner WE, Calafat AM. Polybrominated Diphenyl Ethers and Other Persistent Organic Pollutants in Serum Pools from the National Health and Nutrition Examination Survey: 2001-2002. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2014; 1:92-96. [PMID: 27933302 PMCID: PMC5139909 DOI: 10.1021/ez400050w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and persistent pesticides have been measured in serum pools from participants 3-5, 6-11, 12-19, 20-39, 40-59, and ≥60 years of age from the 2001-2002 National Health and Nutrition Examination Survey. For 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47), the unweighted (not adjusted for sampling weights) arithmetic mean concentration (±95% confidence interval) was 3.4 times higher in 3-5-year-olds (216 ± 30 ng/g of lipid) than in 12-19-year-olds (64 ± 11 ng/g of lipid), with no apparent change with increasing age for adults ≥20 years of age. By contrast, unweighted arithmetic mean concentrations of traditional persistent organic pollutants (POPs) such as hexachlorobenzene (HCB) and 2,2',3,3',4,4',5,5'-octachlorobiphenyl (PCB194) were 2- and 20-fold higher, respectively, in persons ≥60 years than in 12-19-year-old adolescents. Findings suggest higher exposures to PBDEs but lower exposures to traditional POPs in 3-5-year-old children than in adults.
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197
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Carignan CC, Heiger-Bernays W, McClean MD, Roberts SC, Stapleton HM, Sjödin A, Webster TF. Flame retardant exposure among collegiate United States gymnasts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:13848-56. [PMID: 24195753 PMCID: PMC3885979 DOI: 10.1021/es4037868] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Gymnastics training facilities contain large volumes of polyurethane foam, a material that often contains additive flame retardants such as PentaBDE. While investigations of human exposure to flame retardants have focused on the general population, potentially higher than background exposures may occur in gymnasts and certain occupational groups. Our objectives were to compare PentaBDE body burden among gymnasts to the general United States population and characterize flame retardants levels in gym equipment, air, and dust. We recruited 11 collegiate female gymnasts (ages 18-22) from one gym in the eastern United States. The geometric mean (GM) concentration of BDE-153 in gymnast sera (32.5 ng/g lipid) was 4-6.5 times higher than in the general United States population groups. Median concentrations of PentaBDE, TBB, and TBPH in paired handwipe samples were 2-3 times higher after practice compared to before, indicating the gymnasts contacted these flame retardants during practice. GM concentrations of PentaBDE, TBB, and TBPH were 1-3 orders of magnitude higher in gym air and dust than in residences. Our findings suggest that these collegiate gymnasts experienced higher exposures to PentaBDE flame retardants compared to the general United States population and that gymnasts may also have increased exposure to other additive flame retardants used in polyurethane foam such as TBB and TBPH.
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Affiliation(s)
- Courtney C. Carignan
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, USA
- ; Dartmouth College, 78 College St. HB6044, Hanover, New Hampshire 03755 USA
| | - Wendy Heiger-Bernays
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Michael D. McClean
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Simon C. Roberts
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Andreas Sjödin
- Division for Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Thomas F. Webster
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, USA
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198
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Sueyoshi T, Li L, Wang H, Moore R, Kodavanti PRS, Lehmler HJ, Negishi M, Birnbaum LS. Flame retardant BDE-47 effectively activates nuclear receptor CAR in human primary hepatocytes. Toxicol Sci 2013; 137:292-302. [PMID: 24218150 DOI: 10.1093/toxsci/kft243] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Polybrominated diphenyl ether BDE-47 (2,2',4,4'-tetrabromodiphenyl ether) is a thyroid hormone disruptor in mice; hepatic induction of various metabolic enzymes and transporters has been suggested as the mechanism for this disruption. Utilizing Car (-/-) and Pxr (-/-) mice as well as human primary hepatocytes, here we have demonstrated that BDE-47 activated both mouse and human nuclear receptor constitutive activated/androstane receptor (CAR). In mouse livers, CAR, not PXR, was responsible for Cyp2b10 mRNA induction by BDE-47. In human primary hepatocytes, BDE-47 was able to induce translocation of YFP-tagged human CAR from the cytoplasm to the nucleus andCYP2B6 and CYP3A4 mRNAs expressions. BDE-47 activated human CAR in a manner akin to the human CAR ligand CITCO (6-(4-Chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde-O-(3,4-dichlorobenzyl)oxime) in luciferase-reporter assays using Huh-7 cells. In contrast, mouse CAR was not potently activated by BDE-47 in the same reporter assays. Furthermore, human pregnane X receptor (PXR) was effectively activated by BDE-47 while mouse PXR was weakly activated in luciferase-reporter assays. Our results indicate that BDE-47 induces CYP genes through activation of human CAR in addition to the previously identified pathway through human PXR.
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Affiliation(s)
- Tatsuya Sueyoshi
- Pharmacogenetics Section, Laboratory of Reproductive and Developmental Toxicology and
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199
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Zota AR, Linderholm L, Park JS, Petreas M, Guo T, Privalsky ML, Zoeller RT, Woodruff TJ. Temporal comparison of PBDEs, OH-PBDEs, PCBs, and OH-PCBs in the serum of second trimester pregnant women recruited from San Francisco General Hospital, California. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:11776-84. [PMID: 24066858 PMCID: PMC4086273 DOI: 10.1021/es402204y] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Prenatal exposures to polybrominated diphenyl ethers (PBDEs) can harm neurodevelopment in humans and animals. In 2003-2004, PentaBDE and OctaBDE were banned in California and phased-out of US production; resulting impacts on human exposures are unknown. We previously reported that median serum concentrations of PBDEs and their metabolites (OH-PBDEs) among second trimester pregnant women recruited from San Francisco General Hospital (2008-2009; n = 25) were the highest among pregnant women worldwide. We recruited another cohort from the same clinic in 2011-2012 (n = 36) and now compare serum concentrations of PBDEs, OH-PBDEs, polychlorinated biphenyl ethers (PCBs) (structurally similar compounds banned in 1979), and OH-PCBs between two demographically similar cohorts. Between 2008-2009 and 2011-2012, adjusted least-squares geometric mean (LSGM) concentrations of ∑PBDEs decreased 65% (95% CI: 18, 130) from 90.0 ng/g lipid (95% CI: 64.7, 125.2) to 54.6 ng/g lipid (95% CI: 39.2, 76.2) (p = 0.004); ∑OH-PBDEs decreased 6-fold (p < 0.0001); and BDE-47, -99, and -100 declined more than BDE-153. There was a modest, nonsignificant (p = 0.13) decline in LSGM concentrations of ∑PCBs and minimal differences in ∑OH-PCBs between 2008-2009 and 2011-2012. PBDE exposures are likely declining due to regulatory action, but the relative stability in PCB exposures suggests PBDE exposures may eventually plateau and persist for decades.
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Affiliation(s)
- Ami R. Zota
- Department of Environmental and Occupational Health, School of Public Health and Health Services, George Washington University, Washington DC, USA
- Program on Reproductive Health and the Environment, University of California, San Francisco, Oakland, California, USA
- Corresponding author: Ami R. Zota, Sc.D., M.S., Department of Environmental and Occupational Health, George Washington University School of Public Health and Health Services, 2100 M Street NW, Suite 203A, Washington DC 20037, ; Phone: 202.994.9289
| | - Linda Linderholm
- Environmental Chemistry Lab, California Department of Toxic Substances Control, Berkeley, California, USA
- Swedish Environmental Protection Agency, Stockholm, Sweden
| | - June-Soo Park
- Environmental Chemistry Lab, California Department of Toxic Substances Control, Berkeley, California, USA
| | - Myrto Petreas
- Environmental Chemistry Lab, California Department of Toxic Substances Control, Berkeley, California, USA
| | - Tan Guo
- Environmental Chemistry Lab, California Department of Toxic Substances Control, Berkeley, California, USA
- Sequoia Foundation, La Jolla, CA, USA
| | - Martin L. Privalsky
- Department of Microbiology, University of California, Davis, Davis, California, USA
| | - R. Thomas Zoeller
- Biology Department, Morrill Science Center, University of Massachusetts at Amherst, Amherst, Massachusetts, USA
| | - Tracey J. Woodruff
- Program on Reproductive Health and the Environment, University of California, San Francisco, Oakland, California, USA
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200
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Gosavi RA, Knudsen GA, Birnbaum LS, Pedersen LC. Mimicking of estradiol binding by flame retardants and their metabolites: a crystallographic analysis. ENVIRONMENTAL HEALTH PERSPECTIVES 2013; 121:1194-9. [PMID: 23959441 PMCID: PMC3801471 DOI: 10.1289/ehp.1306902] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 08/13/2013] [Indexed: 05/18/2023]
Abstract
BACKGROUND Brominated flame retardants (BFRs), used in many types of consumer goods, are being studied because of concerns about possible health effects related to endocrine disruption, immunotoxicity, reproductive toxicity, and neurotoxicity. Tetrabromobisphenol A (TBBPA), the most widely used BFR, and human metabolites of certain congeners of polybrominated diphenyl ether (e.g., 3-OH-BDE-47) have been suggested to inhibit estrogen sulfotransferase, potentially affecting estrogen metabolism. OBJECTIVES Our primary goal was to understand the structural mechanism for inhibition of the hormone-metabolizing enzyme estrogen sulfotransferase by certain BFRs. We also sought to understand various factors that facilitate the binding of flame retardants in the enzyme binding pocket. METHODS We used X-ray crystallography to obtain atomic detail of the binding modes of TBBPA and 3-OH-BDE-47 to estrogen sulfotransferase for comparison with binding of the endogenous substrate estradiol. RESULTS The crystal structures reveal how BFRs mimic estradiol binding as well as the various interactions between the compounds and protein residues that facilitate its binding. In addition, the structures provide insights into the ability of the sulfotransferase substrate binding pocket to accommodate a range of halogenated compounds that satisfy minimal structural criteria. CONCLUSIONS Our results show how BFRs or their metabolites can bind to and inhibit a key hormone-metabolizing enzyme, potentially causing endocrine disruption.
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Affiliation(s)
- Rajendrakumar A Gosavi
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, North Carolina, USA
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