Origin of Hydroxylated Brominated Diphenyl Ethers: Natural Compounds or Man-Made Flame Retardants (original) (raw)
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Science of The Total Environment, 2012
Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were determined in 36 human milk samples collected in 2010 from healthy mothers living in Bizerte region from Tunisia. Gas chromatography coupled to mass spectrometry working with negative ion chemical ionization (GC-NCI-MS) was used to identify and quantify residue levels on a lipid basis of organo-brominated compounds. Among the 8 examined MeO-PBDE congeners 6-MeO-BDE-47, 2′-MeO-BDE-68, 4′-MeO-BDE-49 and 5′-MeO-BDE-100 were detected in human milk at different levels and frequencies. This is the first study reporting 5′-MeO-BDE-100 and 4′-MeO-BDE-49 levels in human milk samples. Levels of ∑MeO-PBDEs ranged from 0.23 to 4.70 ng g À 1 lipid weight (lw) in the samples, with a mean and median value of 1.52 and 1.11 ng g À 1 lw respectively. Concentrations of ∑MeO-PBDEs in human milk were negatively correlated with age of primapara mothers (po 0.05) and no age-dependency was observed for multipara mothers. Primapara mothers had higher levels of MeO-PBDEs than multipara mothers however no statistical significance was observed. A weak correlation between ∑PBDEs and ∑MeO-PBDEs was found but not between BDE-47 and its methoxylated analog 6-MeO-BDE-47, suggesting differences in exposure pathways for these contaminants in humans and further supporting the hypothesis that MeO-PBDEs were likely not only originated from PBDE precursors.
Polybrominated diphenyl ethers (PBDEs) are important chemical flame retardants, but also environmental pollutants. Their behaviour in the environment is a function of their inherent molecular properties, largely governed by the number and character of the bromine atoms substituted, and the microenvironment where they reside. In this thesis different aspects of importance for the understanding of the behaviour of lower brominated and higher brominated PBDEs in the environment are addressed. The contamination of a Swedish freshwater system with lower brominated BDEs was assessed by a retrospective study of pike from Lake Bolmen covering the time period 1967 to 2000. The concentrations of tetra-to hexaBDEs increased exponentially up to the mid-1980s and then leveled off/decreased slowly, possibly reflecting the voluntary reduction in production and usage of lower brominated BDEs in Europe. Methoxylated PBDEs were found to be present in similar concentrations to the PBDEs. However, there was no correlation between the levels of the two substance groups, and it was therefore concluded that they originated from different sources. To understand the low abundance of higher brominated BDEs in wildlife despite their extensive use and high levels in e.g. sediment, the dietary uptake of the fully brominated BDE, BDE209, was studied in fish. Although it was not expected to be taken up due to its large size and hydrophobicity, it was absorbed to a small extent via the diet. Once absorbed, BDE209 was reductively debrominated to nona-to hexa-brominated BDE congeners. Reductive debromination in vivo was also demonstrated in dairy cows exposed to higher brominated BDEs in their natural diet. The transfer of BDE209 to milk was low (< 0.2 %). In contrast to PCBs and lower brominated BDEs, there was no equilibrium between adipose tissues and milk fat, and for congeners with a log K ow > 7 a progressively smaller fraction of the ingested PBDEs was transferred to the milk. The results indicate that while lower brominated BDEs are excreted in the milk of dairy cows exposed to PBDEs, the higher brominated BDEs are accumulated in the meat. At the same time that PBDEs were receiving increasing regulatory attention, the next generation of brominated flame retardants was introduced. In this thesis decabromodiphenyl ethane, a replacement for the technical BDE209 formulation, was identified for the first time in the environment. This thesis identified differences in uptake, metabolism and excretion for brominated compounds compared to the previously thoroughly characterized organochlorines. This knowledge will be useful for future risk assessments given the ongoing use of these brominated aromatic compounds. "To dare is to lose one's footing momentarily. Not to dare is to lose oneself." Sören Kierkegaard v List of papers This thesis is based upon the following papers which are referred to in the text by their Roman numerals. I Polybrominated diphenyl ethers (PBDEs) and their methoxylated derivatives in fish from Swedish waters with emphasis on temporal trends, 1967-2000.
Marine environmental research, 2016
This study investigated the accumulation of polybrominated diphenyl ethers (PBDEs) and their hydroxylated and methoxylated analogues (OH-PBDEs and MeO-PBDEs) in the blood of harbor porpoises, Dall's porpoises, and finless porpoises stranded or bycaught in Japanese coastal waters and in the North Pacific Ocean. Moreover, we suggested the origins of these contaminants and the factors affecting their pattern of accumulation. Levels of PBDEs in Dall's porpoises were one order of magnitude greater than those in the other species. OH-PBDE and MeO-PBDE levels were comparable to those of PBDEs. However, no correlation was found between the levels of OH-PBDEs and PBDEs, whereas a strong correlation was found between that of OH-PBDEs and MeO-PBDEs (p < 0.001). 6OH-BDE47, reported compound biosynthesized by marine low-trophic level organisms, was the dominant congener. These results suggest that PBDEs found in these porpoise species derive from flame retardants, but OH-PBDEs and MeO...
Environmental Toxicology and Chemistry, 2011
The present study assessed and compared the oxidative and reductive biotransformation of brominated flame retardants, including established polybrominated diphenyl ethers (PBDEs) and emerging decabromodiphenyl ethane (DBDPE) using an in vitro system based on liver microsomes from various arctic marine‐feeding mammals: polar bear (Ursus maritimus), beluga whale (Delphinapterus leucas), and ringed seal (Pusa hispida), and in laboratory rat as a mammalian model species. Greater depletion of fully brominated BDE209 (14–25% of 30 pmol) and DBDPE (44–74% of 90 pmol) occurred in individuals from all species relative to depletion of lower brominated PBDEs (BDEs 99, 100, and 154; 0–3% of 30 pmol). No evidence of simply debrominated metabolites was observed. Investigation of phenolic metabolites in rat and polar bear revealed formation of two phenolic, likely multiply debrominated, DBDPE metabolites in polar bear and one phenolic BDE154 metabolite in polar bear and rat microsomes. For BDE209 ...
Environmental …, 2011
The present study assessed and compared the oxidative and reductive biotransformation of brominated flame retardants, including established polybrominated diphenyl ethers (PBDEs) and emerging decabromodiphenyl ethane (DBDPE) using an in vitro system based on liver microsomes from various arctic marine-feeding mammals: polar bear (Ursus maritimus), beluga whale (Delphinapterus leucas), and ringed seal (Pusa hispida), and in laboratory rat as a mammalian model species. Greater depletion of fully brominated BDE209 (14-25% of 30 pmol) and DBDPE (44-74% of 90 pmol) occurred in individuals from all species relative to depletion of lower brominated PBDEs (BDEs 99, 100, and 154; 0-3% of 30 pmol). No evidence of simply debrominated metabolites was observed. Investigation of phenolic metabolites in rat and polar bear revealed formation of two phenolic, likely multiply debrominated, DBDPE metabolites in polar bear and one phenolic BDE154 metabolite in polar bear and rat microsomes. For BDE209 and DBDPE, observed metabolite concentrations were low to nondetectable, despite substantial parent depletion. These findings suggested possible underestimation of the ecosystem burden of total-BDE209, as well as its transformation products, and a need for research to identify and characterize the persistence and toxicity of major BDE209 metabolites. Similar cause for concern may exist regarding DBDPE, given similarities of physicochemical and environmental behavior to BDE209, current evidence of biotransformation, and increasing use of DBDPE as a replacement for BDE209. Environ. Toxicol. Chem. 2011;30:150630: -151430: . # 2011
Polybrominated diphenyl ethers (PBDEs) in marine fish and blue mussels from southern Greenland
Chemosphere, 2002
A selection of PBDE congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years . The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography, and the analysis was performed on a GC-MS system operating in the NCI mode. The highest PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, and the lowest levels in fin whales and ringed seals. One-sided analyses of variance (ANOVA) followed by Tukey comparisons of means were applied to test for differences between years and sampling areas. Due to inter-year sampling variability, only general comparisons of PBDE concentrations between different sampling areas could be made. Differences in PBDE concentrations between three sampling periods, from 1986 to 2007, were evaluated in samples of pilot whales, ringed seals, white-sided dolphins and hooded seals. The highest PBDE levels were found in samples from the late 1990s or beginning of 2000, possibly reflecting the increase in the global production of technical PBDE mixtures in the 1990s. The levels of BDE #153 and #154 increased relative to the total PBDE concentration in some of the species in recent years, which may indicate an increased relative exposure to higher brominated congeners. In order to assess the effect of measures taken in legally binding international agreements, it is important to continuously monitor POPs such as PBDEs in sub-Arctic and Arctic environments.
Environment International, 2012
A selection of PBDE congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years . The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography, and the analysis was performed on a GC-MS system operating in the NCI mode. The highest PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, and the lowest levels in fin whales and ringed seals. One-sided analyses of variance (ANOVA) followed by Tukey comparisons of means were applied to test for differences between years and sampling areas. Due to inter-year sampling variability, only general comparisons of PBDE concentrations between different sampling areas could be made. Differences in PBDE concentrations between three sampling periods, from 1986 to 2007, were evaluated in samples of pilot whales, ringed seals, white-sided dolphins and hooded seals. The highest PBDE levels were found in samples from the late 1990s or beginning of 2000, possibly reflecting the increase in the global production of technical PBDE mixtures in the 1990s. The levels of BDE #153 and #154 increased relative to the total PBDE concentration in some of the species in recent years, which may indicate an increased relative exposure to higher brominated congeners. In order to assess the effect of measures taken in legally binding international agreements, it is important to continuously monitor POPs such as PBDEs in sub-Arctic and Arctic environments.
Reviews on environmental health, 2009
Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta-and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.