Amount Of Polybrominated Diphenyl Ethers Research Articles

Substance flow analysis and environmental releases of PBDEs in life cycle of automobiles

Polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardants, have been widely used in many applications in industry such as automobiles, textiles, and electronics. This study focused on a quantitative substance flow analysis (SFA) of PBDEs in automobiles in order to identify their flow by life cycle and treatment pathways of PBDEs-containing materials in end-of-life vehicles (ELVs) in Korea. In addition, this study has estimated environmental releases of PBDEs in automobiles by life cycle in Korea. During this study, PBDEs were analyzed for the samples collected from several ELVs treatment facilities using X-ray fluorescence and gas chromatography/mass spectrometry (GC/MS) methods. The system boundary for SFA of PBDEs ranged from manufacturing/trade to disposal stage of automobiles by life cycle. Based on the result of the SFA, it was found that the amount of PBDEs in automobiles were the highest in use stage (7748ton/year), followed by production stage (1743ton/year) in 2014. In disposal stage, automobile shredded residues (ASR) and seat fabrics were the main components with relatively high levels of PBDEs in ELVs. The major treatment methods of such components included incineration (84%), energy recovery (9%), and landfilling (6%). This research indicates that PBDEs were emitted the highest amount from interior components during the use stage of automobiles, followed by recycling processes such as dismantling and shredding. This study suggests that PBDEs in ASR and seat fabrics should be properly managed to prevent the widespread dispersion in the environment.

Legacy and emerging flame retardants (FRs) in the freshwater ecosystem: A review

In this review article, we have compiled and reviewed the previously published available literature on environmental distribution, behaviour, fate and regional trends of legacy and emerging flame retardants (FRs) including brominated (BFRs), organo-phosphate (OPFRs), novel brominated flame retardants (NBFRs) and dechlorane plus (DP) in the freshwater ecosystem. Transport and fate is discussed briefly with the evidences of de-bromination, sedimentation and accumulation in biota. De-bromination of BDE-209 is considered of concern because the lower brominated congeners are more toxic and mobile thus posing increased risk to the freshwater ecosystem. The available data on temporal and spatial trends as yet, is too few to show any consistent trends, enabling only general conclusions to be drawn. There is a lack of temporal studies in Asia, while, overall the trends are mixed, with both increasing and decreasing concentrations of BFRs and OPFRs. OPFRs and NBFRs have replaced classical BFRs (polybrominated diphenyl ethers (PBDEs)) in some countries but the amount of PBDEs in the environment is still considerable. Knowledge gaps and recommendations for future research are discussed emphasizing on further monitoring, advanced analytical methodologies, and risk assessment studies to completely understand the science of flame retardants in the freshwater ecosystem.

Thermochemical Formation of Polybrominated Dibenzo-p-Dioxins and Dibenzofurans Mediated by Secondary Copper Smelter Fly Ash, and Implications for Emission Reduction.

Heterogeneous reactions mediated by fly ash are important to polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) formation. However, the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) through heterogeneous reactions is not yet well understood. Experiments were performed to investigate the thermochemical formation of PBDD/Fs at 150-450 °C through heterogeneous reactions on fly ash from a secondary copper smelter. The maximum PBDD/F concentration was 325 times higher than the initial PBDD/F concentration in the fly ash. The PBDD/F concentration after the experiment at 150 °C was five times higher than the initial concentration. PBDD/Fs have not previously been found to form at such a low temperature. Secondary-copper-smelter fly ash clearly promoted PBDD/F formation, and this conclusion was supported by the low activation energies that were found in Arrhenius's law calculations. Thermochemical formation of PBDD/Fs mediated by fly ash deposited in industrial facilities could explain "memory effects" that have been found for PCDD/Fs and similar compounds released from industrial facilities. Abundant polybrominated diphenyl ethers (PBDEs) that were formed through fly ash-mediated reactions could be important precursors for PBDD/Fs also formed through fly ash-mediated reactions. The amounts of PBDEs that formed through fly ash-mediated reactions suggested that secondary copper smelters could be important sources of reformed PBDEs.

Fate of Polybrominated Diphenyl Ethers during Cooking of Fish in a New Model Cooking Apparatus and a Household Microwave

Fish is a major source of human exposure to polybrominated diphenyl ethers (PBDEs). Because fish is mainly consumed after cooking, this measure may alter the pattern and amounts of PBDEs that are finally consumed. To investigate this issue, we developed a model cooking apparatus consisting of a small glass bowl and a beaker glass with an exhaust fitted with a polyurethane foam filter connected to a water jet pump. In this model cooking apparatus, fish (1 g) and/or sunflower oil (0.2/0.4 g) spiked with three PBDE congeners was cooked for 30 min. Small amounts of the semi-volatile PBDEs were evaporated from the fish (BDE-47 < BDE-15), while the non-volatile BDE-209 was partly transformed. Additional experiments in a household microwave provided similar results, except that no transformation was observed for BDE-209. The model cooking apparatus proved to be well-suited to study the fate of polyhalogenated compounds in fish during cooking.

Polybrominated diphenyl ethers in maternal serum, umbilical cord serum, colostrum and mature breast milk. Insights from a pilot study and the literature

Human serum and mother's milk are frequently used to assess exposure to polybrominated diphenyl ethers (PBDEs), including transplacental transfer to the foetus. However, little is known about the kinetics of PBDEs, especially the highly brominated BDE congeners.In this pilot study, maternal serum samples were collected from 10 women at delivery and five to six weeks post partum. Umbilical serum was also obtained. Milk was donated two to five days, and five to six weeks after delivery. The amount of PBDEs in these samples was determined using liquid–liquid extraction and GC/MS.Low, moderately and highly brominated diphenyl ethers were present in umbilical cord serum, indicating placental transfer. The lipid-adjusted levels of BDE-47, BDE-207 and BDE-209 were similar in maternal and umbilical cord serum, whereas the cord serum levels for the penta- to octa-BDEs quantified were lower than in maternal serum.Marked changes were seen in the congener pattern in breast milk during the first month of lactation, whereas maternal serum levels did not change significantly. The general pattern was an enrichment of low to moderately brominated congeners (i.e. from BDE-17 to BDE-154, with the exception of BDE-28) in colostrum compared with maternal serum. In contrast, more highly brominated congeners were found at similar, or lower levels in colostrum than in maternal serum. After the transition from colostrum to mature milk, the levels of BDE-153 and BDE-209 were substantially reduced, and BDE‐209 was below the limit of detection in 6 out of 9 samples.A literature review on the design and reporting of studies on the transfer of PBDEs from mother to infant revealed a lack of transparency in many cases. The use of the recently published STROBE-ME guidelines is therefore recommended.

Investigating the distribution of polybrominated diphenyl ethers through an Australian wastewater treatment plant

The aim of this study was to quantify the amount of polybrominated diphenyl ethers (PBDEs) released into the environment (biosolids, effluent) from a conventional Australian activated sludge treatment wastewater treatment plant (WWTP). The concentration of PBDE congeners was measured at various treatment stages and included four aqueous samples (raw, primary, secondary and tertiary effluents) and three sludges (primary, secondary and lime stabilized biosolids), collected at three sampling events over the course of the experiment (29 days). Semi-permeable membrane devices (SPMDs) were also installed for the duration of the experiment, the first time that SPMDs have been used to measure PBDEs in a WWTP. Over 99% of the PBDEs entering the WWTP were removed through the treatment processes, principally by sedimentation. The main congeners detected were BDE 47, 99 and 209, which are characteristic of the two major commercial formulations viz penta-BDE and deca-BDE. All the PBDE congeners measured were highly correlated with each other, suggesting a similar origin. In this case, the PBDEs are thought to be from domestic sources since domestic wastewater is the main contribution to the in-flow (∼ 95%). The mean concentration of ΣPBDEs in chemically stabilized sewage sludge (biosolids) was 300 μg kg − 1 dry weight. It is calculated that 2.3 ± 0.3 kg of PBDEs are disposed of each year with biosolids generated from the WWTP. If all Australian sewage sludge is contaminated to at least this concentration then at least 110 kg of PBDEs are associated with Australian sewage sludge annually. Less than 10 g are released annually into the environment via ocean outfall and field irrigation; this level of contamination is unlikely to pose risk to humans or the environment. The environmental release of treated effluent and biosolids is not considered a large source of PBDE environmental emissions compared to the quantities used annually in Australia.

Polybrominated Diphenyl Ethers (PBDEs) Concentration in Sediments Located in the Vicinity of Fish Plant Effluent Outfalls in the Maritimes

Since polybrominated biphenyl ethers (PBDEs) are known to be present in various species of fish, it is likely that fish processing effluent would contain significant amount of PBDEs. The purpose of this study was to determine the PBDE concentrations in sediments located near fish plant effluent outfalls. The range of concentrations of PBDEs in marine sediments in Canada published in the literature was very similar to the results obtained in this study (0.015-5.12 ng/g, dry weight). The concentrations measured in this study for all three technical mixtures (2.78 x 10(-3), 1.92 x 10(-3) and 2.02 x 10(-3) mg/kg, respectively) were all below known toxicity thresholds (0.031, 9.1 and 76 mg/kg, respectively).

Proteomic Insights into Brain Development: Neurotoxic Effects of PBDE-99 in Mice

The amounts of polybrominated diphenyl ethers (PBDEs) found in human tissues, particularly breast milk, are rising steadily. PBDEs are flame retardants that reduce fire risks when added to electronic equipment and household products. Epidemiologic studies have yet to show conclusive evidence of PBDE toxicity in humans. However, studies in animals have shown these chemicals to produce effects such as liver damage, altered thyroid hormone levels, developmental changes, and neurotoxicity. In the present study, a Swedish team uses proteomic methods to investigate the early-stage neurotoxic effects of PBDE-99 on two parts of the developing mouse brain: the striatum and the hippocampus [EHP 114:254–259]. The findings help deconstruct the mysterious mechanisms that underlie PBDE-99 neurotoxicity. The striatum and the hippocampus are both part of the cholinergic and monaminergic systems, which play roles in neurotransmitter functioning and other aspects of cognition. The authors sought specifically to uncover PBDE-induced cellular events leading from the neonatal brain growth spurt to permanent neurological problems in adult animals. PBDE-99 is among the most common PBDE congeners found in environmental and human tissue samples. This pentabrominated compound impairs spontaneous behavior and habituation among adult mice exposed neonatally to moderate doses. These effects are progressive, worsening with age. During the study, 10-day-old mice of both sexes were given a single dose of 12 milligrams PBDE-99 per kilogram body weight. After 24 hours, the mice were sacrificed, their brains dissected, and the striatum and hippocampus isolated for study. The team used 2D-DIGE to compare protein expression patterns between treatment and control groups. The analysis illuminated 40 proteins in the striatum and 56 proteins in the hippocampus whose expression was altered by PBDE-99 exposure. From this initial grouping, nine striatal proteins and ten hippocampal proteins were selected for identification using MALDI-ToF-MS. Among the striatal proteins affected by PBDE-99 were several (including Gap-43/neuromodulin and stathmin) that participate in neurode-generation and neuroplasticity. The affected hippocampal proteins (including α-enolase, γ-enolase, Atp5b, and α-synuclein) tend to participate in metabolism and energy production. Many of these proteins are linked to protein kinase C, a signaling molecule whose role in development and function, as well as in learning and memory, has been intensively studied. Based on these findings, the authors conclude they have identified potential protein biomarkers that reflect the immediate consequences of early-stage PBDE-99 toxicity, in addition to the processes that drive its neurological effects in older animals. The researchers suggest that protein kinase C signaling is a target of PBDE-99 toxicity in the developing mouse brain. Moreover, the authors propose that neonatal cell stress induced by PBDE-99 exposure, in addition to related neurodegenerative processes and aberrant neuroplasticity, may contribute to the latter-stage behavioral effects observed in adult mice. The responses within the striatum and hippocampus differ, however, reflecting the underlying heterogeneity between different brain parts and cell populations.