Levels of polybrominated diphenyl ethers in the Korean metropolitan population are declining: A trend from 2001 to 2013

The role of iron materials in the abiotic transformation and biotransformation of polybrominated diphenyl ethers (PBDEs): A review

Polybrominated diphenyl ethers (PBDEs), widely used as flame retardants, easily enter the environment, thus posing environmental and health risks. Iron materials play a key role during the migration and transformation of PBDEs. This article reviews the processes and mechanisms of adsorption, degradation, and biological uptake and transformation of PBDEs affected by iron materials in the environment. Iron materials can effectively adsorb PBDEs through hydrophobic interactions, π-π interactions, hydrogen/halogen bonds, electrostatic interactions, coordination interactions, and pore filling interactions. In addition, they are beneficial for the photodegradation, reduction debromination, and advanced oxidation degradation and debromination of PBDEs. The iron material-microorganism coupling technology affects the uptake and transformation of PBDEs. In addition, iron materials can reduce the uptake of PBDEs in plants, affecting their bioavailability. The species, concentration, and size of iron materials affect plant physiology. Overall, iron materials play a bidirectional role in the biological uptake and transformation of PBDEs. It is necessary to strengthen the positive role of iron materials in reducing the environmental and health risks caused by PBDEs. This article provides innovative ideas for the rational use of iron materials in controlling the migration and transformation of PBDEs in the environment.

Typical organic contaminants in hair of adult residents between inland and coastal capital cities in China: Differences in levels and composition profiles, and potential impact factors

The growing of urbanization, industrialization, and agricultural production have resulted in the increasing contamination of typical organic contaminants (OCs) in China. However, data on differences in exposure characteristics of typical OCs between the coastal and inland cities among residents in China are limited. In this study, hair samples were collected from adult residents in 10 and 17 provincial capital cities in coastal and inland China, respectively, to investigate the differences in the levels and composition profiles of typical OCs. The potential factors impacting the human exposure to OCs were also examined based on the relationship among the hair OC levels and the population characteristics and statistical indicators. The median concentrations of dichlorodiphenyltrichloroethane's (DDTs), polybrominated diphenyl ethers (PBDEs), and organophosphorus flame retardants (PFRs) in hair of coastal urban residents were 3.64, 5.58, and 268 ng/g, respectively, while their concentrations in samples from inland urban residents were 1.84, 3.85, and 202 ng/g, respectively. Coastal residents showed significantly higher hair OC concentrations than inland residents (p < 0.05). BDE209 and p,p'-DDE were the predominant chemicals for PBDEs and DDTs, respectively, in both coastal and inland cities. Tris(2-chloroisopropyl) phosphate (TCIPP) was the dominant PFR in coastal residents' hair, while triphenyl phosphate (TPHP) was the major PFR in inland residents' hair, possibly owing to the different usages of the PFRs. Significant gender differences were observed in the levels and composition profiles of OCs (p < 0.05). The levels of p,p'-DDE and TCIPP were significantly related to the gross domestic product (GDP), gross secondary industry product, and the per capita consumption of aquatic products (p < 0.05). This study provides scientific data for evaluating human exposure to OCs in urban residents at a large scale and its associations with statistical indicators including urbanization, industrialization, agricultural production, and diet in China.

Serum polybrominated diphenyl ether exposure and influence factors in blood donors of Wuxi adults from 2013 to 2016

Polybrominated diphenyl ethers (PBDEs) have been used as brominated flame retardants worldwide and are correlated with extensive environmental pollution and human health concerns. This study is aimed at analyzing the concentrations of PBDEs and at evaluating their temporal trends among a population of blood donors (n = 33) over a 4-year period. A total of 132 serum samples were used for PBDE detection. Nine PBDE congeners were quantified in serum samples by gas chromatography with mass spectrometry (GC-MS). The median concentrations of Σ₉PBDEs in each year were 33.46, 29.75, 30.85, and 35.02 ng/g lipid, respectively. Most of the PBDE congeners showed a downward trend from 2013 to 2014 and then increased after 2014. No correlations between age and PBDE congener concentrations were observed, while concentrations of each congener and Σ₉PBDE were nearly always lower in females than in males, especially in BDE-66, BDE-153, BDE-183, BDE-190, and Σ₉PBDE. We also found that the intake of fish, fruit, and eggs in the daily diet was related to the exposure level of PBDEs. Our results suggest that, as deca-BDE is still produced and used in China, diet is an important exposure pathway for PBDEs, and follow-up studies will be required to improve our understanding of the behaviors of PBDE isomers in humans and the exposure levels.

Critical review of analytical methods for the determination of flame retardants in human matrices

Human biomonitoring is a powerful approach in assessing exposure to environmental pollutants. Flame retardants (FRs) are of particular concern due to their wide distribution in the environment and adverse health effects. This article reviews studies published in 2009-2020 on the chemical analysis of FRs in a variety of human samples and discusses the characteristics of the analytical methods applied to different FR biomarkers of exposure, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), novel halogenated flame retardants (NHFRs), bromophenols, incl. tetrabromobisphenol A (TBBPA), and organophosphorous flame retardants (PFRs). Among the extraction techniques, liquid-liquid extraction (LLE) and solid phase extraction (SPE) were used most frequently due to the good efficiencies in the isolation of the majority of the FR biomarkers, but with challenges for highly lipophilic FRs. Gas chromatography-mass spectrometry (GC-MS) is mainly applied in the instrumental analysis of PBDEs and most NHFRs, with recent inclusions of GC-MS/MS and high resolution MS techniques. Liquid chromatography-MS/MS is mainly applied to HBCD, bromophenols, incl. TBBPA, and PFRs (including metabolites), however, GC-based analysis following derivatization has also been used for phenolic compounds and PFR metabolites. Developments are noticed towards more universal analytical methods, which enable widening method scopes in the human biomonitoring of FRs. Challenges exist with regard to sensitivity required for the low concentrations of FRs in the general population and limited sample material for some human matrices. A strong focus on quality assurance/quality control (QA/QC) measures is required in the analysis of FR biomarkers in human samples, related to their variety of physical-chemical properties, low levels in most human samples and the risk of contamination.

Assessing microbial degradation degree and bioavailability of BDE-153 in natural wetland soils: Implication by compound-specific stable isotope analysis

Microbial degradation is an important pathway for the attenuation of polybrominated diphenyl ethers (PBDEs) in natural soils. In this study, the compound-specific stable isotope analysis (CSIA) was applied to characterize microbial degradation of BDE-153, one of the prevailing and toxic PBDE congeners, in natural wetland soils. During the 45-day incubation, the residual percentages of BDE-153 decreased to 67.9% and 73.6% in non-sterilized soils spiked with 1.0 and 5.0 μg/g, respectively, which were both much lower than those in sterilized soils (96.0% and 97.2%). This result indicated that microbial degradation could accelerate BDE-153 elimination in wetland soils. Meanwhile, the significant carbon isotope fractionation was observed in non-sterilized soils, with δ¹³C of BDE-153 shifting from -29.4‰ to -26.7‰ for 1.0 μg/g and to -27.2‰ for 5.0 μg/g, respectively, whilst not in sterilized soils. This phenomenon indicated microbial degradation could induce stable carbon isotope fractionation of BDE-153. The carbon isotope enrichment factor (ε_c) for BDE-153 microbial degradation was first determined as -7.58‰, which could be used to assess the microbial degradation and bioavailability of BDE-153 in wetland soils. Based on δ¹³C and ε_c, the new methods were developed to dynamically and quantitatively estimate degradation degree and bioavailability of BDE-153 during degradation process, respectively, which could exclude interference of physical processes. This work revealed that CSIA was a promising method to investigate in situ microbial degradation of PBDEs in field studies.

Exposure to Polybrominated Diphenyl Ethers and a Polybrominated Biphenyl and Risk of Thyroid Cancer in Women: Single and Multi-Pollutant Approaches

BACKGROUND

Thyroid cancer incidence is the most rapidly increasing malignancy; rates are three times higher in women than men. Thyroid hormone-disrupting flame-retardant chemicals, including polybrominated diphenyl ethers (PBDE) and polybrominated biphenyls (PBB), may contribute to this trend.

METHODS

We investigated the relationship between PBDE/PBB exposure and papillary thyroid cancer (PTC) in 250 incident female papillary thyroid cancer cases and 250 female controls frequency-matched on age. Interviews and postdiagnostic serum samples were collected from 2010 to 2013. Serum samples were analyzed for 11 congeners. We calculated ORs and 95% confidence intervals (95% CI) using single-pollutant logistic regression models for continuous and categorical lipid-adjusted serum concentrations of PBDE/PBB, adjusted for age, alcohol consumption, and education. We applied three multi-pollutant approaches [standard multipollutant regression models, hierarchical Bayesian logistic regression modeling (HBLR), principal components analysis (PCA)] to investigate associations with PBDE/PBB mixtures.

RESULTS

In single-pollutant models, a decreased risk was observed at the highest (>90th percentile) versus lowest (

CONCLUSIONS

Our results using single- and multi-pollutant modeling do not generally support a positive association with PBDE/PBB and PTC risk.

IMPACT

Prospective studies with more advanced statistical approaches to analyze mixtures and populations with higher exposures could reveal new insights.

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Key Words Collapse

MESH Headings

• Adult
• Aged
• Case-Control Studies
• Connecticut/epidemiology
• Environmental Exposure/adverse effects
• Environmental Exposure/statistics & numerical data
• Environmental Pollutants/blood
• Female
• Flame Retardants/pharmacokinetics
• Halogenated Diphenyl Ethers/blood
• Humans
• Middle Aged
• Polybrominated Biphenyls/blood
• Prognosis
• Thyroid Cancer, Papillary/blood
• Thyroid Cancer, Papillary/chemically induced
• Thyroid Cancer, Papillary/epidemiology
• Thyroid Cancer, Papillary/pathology
• Thyroid Neoplasms/blood
• Thyroid Neoplasms/chemically induced
• Thyroid Neoplasms/epidemiology
• Thyroid Neoplasms/pathology

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Grants

• R01 ES020361 NIEHS NIH HHS
• UL1 TR001863 NCATS NIH HHS

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Affiliation(s)

Nicole C Deziel Department of Environmental Health Sciences, Yale School of Public Health, New Haven, Connecticut.
Javier Alfonso-Garrido Department of Environmental Health Sciences, Yale School of Public Health, New Haven, Connecticut
Joshua L Warren Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut
Huang Huang Department of Surgery, Yale School of Medicine, New Haven, Connecticut
Andreas Sjodin Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia
Yawei Zhang Department of Environmental Health Sciences, Yale School of Public Health, New Haven, Connecticut Department of Surgery, Yale School of Medicine, New Haven, Connecticut

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Assessment of selected chlorinated and brominated flame retardants in human plasma samples among co-residing family members

Three hexachloronorbornene-based flame retardants and five polybrominated diphenyl ethers (PBDEs) were measured in 414 human plasma samples, (169 from children, 167 from mothers, and 78 from fathers), collected from 200 families between 2014 and 2016. The median concentration of ∑PBDEs (sum of BDE-47, -99, -100, -153 and -183) was 13.2 ng/g lipid for child, 9.03 ng/g lipid for mother and 12.7 ng/g lipid for father, respectively. Among the hexachloronorbornene-based flame retardants, Dec 602 was the most frequently detected chemical. Significant and positive correlations between the concentrations of PBDE congeners as well as between Dec 602 and Dec 603 were observed. Concentrations of PBDE congeners also showed significant and positive correlations in paired samples from family members (child-mother-father), while Dec 602 was the only hexachloronorbornene-based flame retardant whose concentrations correlated between family members, and only in mother-father paired samples. This is the largest study to date focusing on measuring and correlating HRFs in children and their parents living in the same household. The results convey important information on human exposure to measured HFRs, which can help researchers and regulators more clearly understand the influence of diet and the home environment.

Temporal trends in serum polybrominated diphenyl ether concentrations in the Australian population, 2002-2013

In Australia, systematic biomonitoring of persistent organic pollutants (POPs) in pooled serum samples stratified by age and sex has occurred every two years between 2002/03 and 2012/13. Multiple regression modeling on log10-transformed serum pool concentrations of BDEs 47, 99, 100 and 153 and on the sum of these (Σ₄PBDE) was conducted to examine trends by sex and time since baseline, stratified by age group. Temporal trends were age- and congener-specific, with the largest changes per year of observation in the 0-4 year old group, with β (SE) = -0.098 (0.013) for log₁₀BDE47; -0.119 (0.012) for log₁₀BDE99; -0.084 (0.014) for log₁₀BDE100, and -0.053 (0.013) for log₁₀BDE153, all p < 0.001. Adults over age 16 showed much smaller decreasing temporal trends for BDE47 and BDE99, no significant changes in BDE100, and, for the oldest age groups, slight increases in BDE153. As a result, Σ₄PBDE concentrations were stable over the entire time period in adults older than 16. Concentrations of each BDE in pools from females aged 31-60 were significantly lower compared to males. Relative proportions of BDE47 declined, while BDE153 accounted for a greater share of Σ₄PBDE over time. Whereas previously we saw a large elevation in the youngest age groups compared to older children and adults, this is no longer the case. This may be due to a decline in infant and toddler exposures in the indoor environment as use of PBDEs in consumer products has been phased out, suggesting temporal changes in the relative sources of exposure for young children in Australia.