Levels Of Polybrominated Diphenyl Ethers Research Articles

Bioconcentration of polybrominated diphenyl ethers and organochlorine pesticides in algae is an important contaminant route to higher trophic levels.

Persistent organic pollutants (POPs) present in water may be bioconcentrated in phytoplankton and further transferred into higher trophic levels. In the present study, seawater, sediment, phytoplankton and macroalgae (Ulva lactuca L.) samples were collected from two estuarine bays in South China and analyzed for 24 polybrominated diphenyl ethers (PBDEs) and 22 organochlorine pesticides (OCPs). The concentrations of PBDE congeners except BDE-209 were low in both phytoplankton and Ulva. BDE-209 was the predominant congener in phytoplankton and Ulva, accounting for 89.5% and 86.6% of the total average concentrations of PBDEs (48.5 and 4.1ngg-1dw), respectively. The average concentrations of DDTs, HCHs and 1-chloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDMU) in phytoplankton were 398, 241 and 11.3ngg-1dw, respectively, while those of DDTs and HCHs in Ulva were 8.4 and 33.1ngg-1dw. The levels of both PBDEs and OCPs were an order of magnitude higher in phytoplankton than in Ulva, indicating that phytoplankton with larger surface areas have higher uptake efficiency for POPs than Ulva. Bioconcentration factors (BCFs) of DDT and PBDE in phytoplankton from the two bays were in the range of 105-106, suggesting that bioconcentration may be one of the key sources of POPs and algae can be an important route for POPs to move toward higher trophic levels.

An innovative ultrasound assisted extraction micro-scale cell combined with gas chromatography/mass spectrometry in negative chemical ionization to determine persistent organic pollutants in air particulate matter

New clean technologies are needed to determine concentration of organic pollutants without generating more pollution. A method to extract Persistent Organic Pollutants (POPs) from airborne particulate matter was developed using a novel technology recently patented called ultrasound assisted extraction micro-scale cell (UAE-MSC). This technology extracts, filters, collects the sample, and evaporates the solvent, on-line. No sample transfer is needed. The cell minimizes sample manipulation, solvent consumption, waste generation, time, and energy; fulfilling most of the analytical green chemistry protocol. The methodology was optimized applying a centred 23 factorial experimental design. Optimum conditions were used to validate and determine concentration of 16 organochlorine pesticides (OCls) and 6 polybrominated diphenyl ethers (PBDEs). The best conditions achieved were 2 extractions with 5mL (each) of dichloromethane over 5min (each) at 60°C and 80% ultrasound potency. POPs were determined by gas chromatography/mass spectrometry in negative chemical ionization (GC/MS-NCI). Analytical method validation was carried out on airborne particles spiked with POPs at seven concentration levels between 0.5 and 26.9pgm−3. This procedure was done by triplicate (N=21). Recovery, ranged between 65.5±2.3% and 107.5±3.0% for OCls and between 79.1±6.5% and 105.2±3.8% for PBDEs. Linearity (r2) was ≥0.94 for all compounds. Method detection limits, ranged from 0.5 to 2.7pgm−3, while limits of quantification (LOQ), ranged from 1.7 to 9.0pgm−3. A Bias from −18.6% to 9% for PBDEs was observed in the Standard Reference Material (SRM) 2787. SRM 2787 did not contain OCls. OCls recoveries were equivalent by UAE-MSC and Soxhlet methods UAE-MSC optimized extraction conditions reduced 30 times less solvent and decreased the extraction time from several hours to ten minutes, respect to Soxhlet. UAE-MSC was applied to 15 samples of particles less than 2.5μm (PM2.5) from three seasons (warm dry, rainy, and cold dry) collected in five sites around Mexico City. OCls (4,4′-DDE and endrin aldehyde) concentrations ranged from <LOQ to 12.6pgm−3, while PBDEs levels were below the quantification limit, although BDE-99 was detected in all samples. UAE-MSC is a novel technology to determine organic compounds present in trace concentrations in particulate matter. This technology can be extended to extract organic compounds in different solid matrices to minimize time extraction and solvent consumption.

Occurrence, profiles, and ecological risks of polybrominated diphenyl ethers in mangrove sediments of Shantou, China.

Surface sediments were collected from three mangrove wetlands (Yifeng Xi, Shuanghan, and Su'ai Wan) in Shantou coastal zone of South China to investigate spatial distributions of polybrominated diphenyl ethers (PBDEs). The results demonstrate that PBDEs were detected in all the samples, indicating their widespread occurrence in coastal sediments of the studied area. Σ9PBDEs (defined as the sum of nine targeted PBDE congeners except BDE-209) and BDE-209 are in the range of 2.3 to 11.5 and 16.7 to 58.2ng/g, respectively. BDE-209 is the dominant PBDE congener in all sediment samples. The sediment concentrations of ∑9PBDEs and BDE-209 among the three wetlands decrease in the order of Su'ai Wan > Shuanghan > Yifeng Xi. The concentrations of ∑9PBDEs are higher in mangrove sediments than in mudflats, but no obvious regularity can be found on the correlation between mangrove species and PBDE levels in sediments. The contents of total organic carbon are moderately correlated with BDE-209 concentrations in sediments but not with ∑9PBDE concentrations. The samples collected from different locations show slightly different composition profiles except BDE-209, with BDE-100 and BDE-47 being the pre-dominated congeners. The mudflats exhibit higher abundances of tri- to hexa-substituted congeners than the mangrove sediments. Ecological risk assessment demonstrates that the surface sediments from Shantou may pose a potential ecological risk of exposure to sediment-dwelling organisms.

Polybrominated diphenyl ethers (PBDES) and hexa-brominated biphenyls (Hexa-BBs) in fresh foods ingested in Taiwan

Polybrominated diphenyl ethers (PBDEs) and hexa-brominated biphenyls (Hexa-BBs) are bioaccumulative and aggregate in the food chain. Therefore, background monitoring and risk assessment for dietary intake are necessary. In present study, a systematic sampling method was first used to collect the high fat content foodstuff such as poultry, livestock, eggs, fish, other seafood, dairy products, and the infant foods and then foodstuff with high consumption in seven categories of 600 food samples. After integrating four years of background surveys of PBDE levels (2010–2013) and one year of that of Hexa-BBs (2013), the highest estimated daily intake (EDI) of PBDEs for Taiwanese food consumption was found in 0- to 3-year-olds (mean = 9.38 ng kg−1 bw d−1, the 95% upper limit of Monte Carlo Simulation (MCS P95) was 21.52 ng kg−1 bw d−1), and the lowest in 16- to 18-year-old girls (mean = 3.35 ng kg−1 bw d−1, MCS P95 was 6.53 ng kg−1 bw d−1). Moreover, the highest of EDI of Hexa-BBs was found in 0–3 years old (mean = 0.007 ng kg−1 bw d−1, MCS P95 = 0.019 ng kg−1 bw d−1), and lowest in 17–18 years old female (mean = 0.002 ng/kg/day, MCS P95 = 0.005 ng kg−1 bw d−1). This study suggests that the large MOEs (>2.5) for the four important congeners BDE-47, -99, −153, and −209, indicate that the dietary exposures are not probably a significant health concern for Taiwanese.

Polybrominated diphenyl ethers (PBDEs) in Great Lakes fish: Levels, patterns, trends and implications for human exposure

Levels of polybrominated diphenyl ethers (PBDEs) were measured in edible portions of Great Lakes fish, with the goal of examining patterns/trends and evaluating implications for human exposure. A total of 470 fillets of 18 fish species collected from various parts of the Canadian waters of the Great Lakes between 2006 and 2013 were analyzed for 17 (expanded to 33 in 2009) PBDEs. For a limited number of species, fillet to whole body and fillet to eggs PBDEs were compared to examine pattern and concentration among tissue types. Levels and patterns of PBDEs varied dramatically within and among the 18 fish species. Bottom dwelling Common Carp (and White Sucker) exhibited the highest ∑PBDE levels (27–71ng/g). Lake Trout and Lake Whitefish from Lake Superior had higher levels than those from the other Great Lakes; otherwise the spatial trend was Lake Ontario≫Erie~Huron~Superior. The measured levels would result in restriction on consumption of only Common Carp from the Toronto waterfront area, which is in proximity to the most urbanised region on the Canadian side of the basin. Deca-BDE was the major congener in panfish, while BDE-47 was the major congener in top predators and its contribution to ∑PBDE increased with the contamination. Although ∑PBDE was related to fish length and lipid content when all measurements were pooled, the relationships were variable for individual sampling events (species/location/year). Whole body ∑PBDE for bottom dweller Brown Bullhead and Common Carp were 2.6–4.9 times greater and egg ∑PBDE for four fatty Salmon/Trout species were same to 6.5 times greater than the corresponding fillet concentrations. Levels of major lower brominated PBDEs appear to have declined in fish fillets by 46–74% between 2006/07 and 2012. Although PBDE in existing consumer items will remain in-use for a while, it will likely not result in appreciable accumulation of PBDEs in fish. Based on an overall assessment, regular monitoring of PBDEs in Great Lake fish can be replaced with targeted surveillance and focus can be shifted to other in-use flame retardants.

Accumulation of polybrominated diphenyl ethers in breast milk of women from an e-waste recycling center in China

Polybrominated diphenyl ethers (PBDEs) can be transferred to infants through the ingestion of breast milk, resulting in potential health risk. In this study, PBDEs, hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and 2,2′,4,4′,5,6′-hexachlorobiphenyl (CB-153) in human milk from women living adjacent to e-waste recycling sites of Wenling, China, were investigated. The median level of PBDEs in samples from residents living in the e-waste recycling environment >20years (R20 group, 19.5ng/g lipid weight (lw)) was significantly higher than that for residents living in Wenling <3years (R3 group, 3.88ng/g lw) (p<0.05), likely ascribable to specific exposure to PBDEs from e-waste recycling activities. In the R20 group, most congeners (except for BDE-209) were correlated with each other (p<0.05). Moreover, CB-153 showed significant association with most PBDE congeners, rather than BDE-209. The relationship indicated that most BDE congeners other than BDE-209 shared common sources and/or pathways with CB-153, e.g., dietary ingestion. The correlations between BDE-209 and other congeners were different in the two groups, likely suggesting their different exposure sources and/or pathways for PBDEs. Although estimated dietary intake of PBDEs for infants via breast milk was lower than the minimum value affecting human health, the PBDE exposure of infants should be of great concern because of their potential effect on the development of neonates over long-term exposure. OH-PBDEs were not detected in the collected samples, which is in accordance with reports in published literature, likely indicating that they were not apt to be accumulated in human milk.

PBDEs Levels in House Dust and Human Exposure to PBDEs via Dust Ingestion in Hangzhou

In order to evaluate the pollution degree of the dust in Hangzhou City, the indoor dust samples of 19 offices, families and students' dormitories were collected from August to March in 2013 at Hangzhou for evaluating the pollution level of polybrominated diphenyl ethers (PBDEs), to analyze concentrations of 14 PBDEs congeners and congener distribution as well as the possible influencing factors, and to estimate the PBDEs exposure levels of adults and children through the dust intake. The results showed that the average ∑14PBDEs of office was 9.28×102 ng·g-1, and the median was 1.03×103 ng·g-1; the average ∑14PBDEs of family was 7.83×102 ng·g-1, and the median was 9.11×102 ng·g-1; the average ∑14PBDEs of student dormitory was 4.07×102 ng·g-1, and the median was 4.03×102 ng·g-1. The pollution level of the office was higher than that of the living environment. BDE-209 was the largest monomer, and its contribution was 75.48%, followed by BDE-190, BDE-154 and BDE-71.PBDEs exposure levels of adults and children by dust intake were 13.12-32.63 ng·d-1 and 32.40-54.54 ng·d-1, respectively. Children's PBDEs exposure in the dust was higher than that of the adults, mainly because the average dust intake of children was higher than that of adults. The analysis showed that the PBDEs from indoor dust intake was a potential health hazard, and the biggest potential harm to children.

Polybrominated Diphenyl Ethers (PBDEs) in Surface Soils across Five Asian Countries: Levels, Spatial Distribution, and Source Contribution.

A total of 23 polybrominated diphenyl ether (PBDE) congeners were measured in soil samples collected in areas with no known point source [urban/rural/background (U/R/B) sites] and in areas with known point source [brominated flame retardant (BFR)-related industrial sites (F sites) and e-waste recycling sites (E sites)] across five Asian countries. The highest PBDE concentrations were found in BFR-related industrial and e-waste recycling sites. The concentrations of PBDEs in U/R/B sites decreased in the following order: urban > rural > background sites. Total PBDE concentrations were dominated by BDE-209, while BDE-17, -85, -138, -191, -204, and -205 were the least abundant compounds. In both urban sites and rural sites, the mean concentrations of total PBDEs (∑23BDEs) in soils decreased in the following order: Japan > China > South Korea > India > Vietnam. The concentrations of PBDEs in soils were comparable with those reported in other studies. Among the three commercial PBDE mixtures, relatively large contributions of commercial penta-BDE were observed in Vietnam, whereas deca-BDE was the dominant form in mixtures contributing from 55.8 ± 2.5 to 100.0 ± 1.2% of the total PBDEs in soils collected from other four countries. Regression analysis suggested that local population density (PD) is a good indicator of PBDEs in soils of each country. Significant and positive correlation between soil organic content and PBDE level was observed in Chinese soil for most nondeca-BDE homologues with their usage stopped 10 years ago, indicating its important role in controlling the revolatilization of PBDEs from soil and changing the spatial trend of PBDE in soil from the primary distribution pattern to the secondary distribution pattern, especially when primary emission is ceased.

Polybrominated diphenyl ethers in marine sediments of Sanggou Bay in east China

Polybrominated diphenyl ethers (PBDEs) were measured in the surface sediments collected in August 2015 in Sanggou Bay, China. The total concentrations of 13 PBDEs, including BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183 and -190, and concentrations of BDE-209 were 0.223–1.259ng/g and 0.865–9.275ng/g, respectively. The PBDE levels increased from the outer bay to the inner bay. BDE-209 was the predominant congener, followed by BDE-47, BDE-71, and BDE-99. Significant positive correlations were observed for tri-BDEs with organic carbon (r=0.598, p<0.05) and with clay content (r=0.592, p<0.05). Principal component analysis revealed that PBDEs in Sanggou Bay were mainly derived from the usage, dismantling and degradation of commercial products (penta-, octa-, and deca-BDEs), which were then transported through continental runoff and atmospheric deposition. The ecological risks were mainly attributed to deca-BDE congeners with moderate risk level.

Polybrominated diphenyl ethers (PBDEs) and their hydroxylated and methoxylated analogues in the blood of harbor, Dall's and finless porpoises from the Japanese coastal waters

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-PBDEs are mainly of natural origins.

Tracking polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in sediments and soils from the southwest of Buenos Aires Province, Argentina (South eastern part of the GRULAC region)

PCBs and PBDEs (7 and 10 congeners, respectively) were analyzed in four coastal surface sediments collected from the northern shore of Bahía Blanca estuary and in nine soils from different locations of Bahía Blanca city and the surrounding region (Southwest of Buenos Aires Province, Argentina). Sediment samples showed PCBs(Σ7) concentrations ranged from 0.61 to 17.6ngg−1 (dry weight=dw) and PBDEs(Σ10) from 0.16 to 2.02ngg−1 dw, whereas in soil samples ranged from 0.04 to 1.67ngg−1 dw for PCBs(Σ7) and 0.04 to 10.7ngg−1 dw for PBDEs(Σ10). The highest concentrations of both chemicals were detected in the urban and industrial/port areas showing a dominance of the higher chlorinated PCB congeners: in sediments for PCB-180 (56±33%) and PCB-153 (11±6%); and in soils for PCB-138 (23±3%), PCB-153 (22±2%) and PCB-180 (18±7%). In contrast, lower chlorinated PCB congeners were predominant at more distant sites; in sediments for congeners PCB-28 (33±4%) and PCB-52 (14.5±0.2%); and in soils PCB-28 (56±14%) and PCB-52 (33±19%). PBDE-209 (high brominated PBDE) showed the highest relative abundance in both sample types i.e., sediment (94±7%) and soil (80±12%). These findings can be considered lower or similar when compared with other sites of the world, and are likely associated with anthropogenic activities in their surrounding area, which has experienced a fast industrial growth in the last decade. This is the first investigation of PBDEs levels in the whole study area and of PCBs in soils from the Bahía Blanca city and surrounding region. This article provides new and useful information on POP levels in the South eastern part of the GRULAC region.

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.

Accumulation of polybrominated diphenyl ethers in the brain compared with the levels in other tissues among different vertebrates from an e-waste recycling site

This study aimed to investigate the accumulation of polybrominated diphenyl ethers (PBDEs) in the brain compared with that in other tissues among different vertebrates. We collected mice, chickens, ducks, frogs, and fish from an e-waste recycling region in Taizhou, China, and measured PBDE concentrations in brain, liver and muscle tissues. The levels of PBDE in the tissues of mice, chickens, ducks, frogs and fish ranged 0.45–206, 0.06–18.8, 1.83–112, 2.75–108, and 0.02–32.0 ng/g wet weight, respectively. Preferential distribution in the liver and muscle relative to the brain was observed for PBDEs in mice, chickens, ducks and frogs. However, a high retention in the brain compared to the liver and muscle was observed in fish. Comparison of the brain/liver concentration (B/L) ratios revealed differences in PBDEs accumulation in the brain among these vertebrates. PBDEs accumulation in the brain was greatest in fish, followed by frogs, while the lowest accumulation occurred in the brains of mammals and birds. The findings apparently coincided with the evolution of the blood-brain barrier (BBB) across vertebrates, i.e. the BBB of fish might be less efficient than those of mammals, birds and amphibian. Low brominated congeners (such as BDE-28, BDE-47 and BDE-99) were predominant in the brains of investigated vertebrates, whereas BDE-209 was most abundant in liver and muscle tissues of mice, chickens and ducks. Significant differences in B/L ratios among PBDE congeners were found in both mice and chickens (p < 0.05). Particularly in mice, the B/L ratios of PBDE congeners presented a declining trend with increased bromine number. Our findings suggested that low brominated congeners might have a higher capacity to penetrate the BBB and accumulate in the brain, whereas high brominated congeners such as BDE-209 might have less potency to pass through the barrier. Further experimental studies are needed to confirm our findings.

Polybrominated diphenyl ethers in plastic products, indoor dust, sediment and fish from informal e-waste recycling sites in Vietnam: a comprehensive assessment of contamination, accumulation pattern, emissions, and human exposure

Residue concentrations of polybrominated diphenyl ethers (PBDEs) in different kinds of samples including consumer products, indoor dust, sediment and fish collected from two e-waste recycling sites, and some industrial, urban and suburban areas in Vietnam were determined to provide a comprehensive assessment of the contamination levels, accumulation pattern, emission potential and human exposure through dust ingestion and fish consumption. There was a large variation of PBDE levels in plastic parts of obsolete electronic equipment (from 1730 to 97,300ng/g), which is a common result observed in consumer plastic products reported elsewhere. PBDE levels in indoor dust samples collected from e-waste recycling sites ranged from 250 to 8740ng/g, which were markedly higher than those in industrial areas and household offices. Emission rate of PBDEs from plastic parts of disposed electronic equipment to dust was estimated to be in a range from 3.4×10-7 to 1.2×10-5 (year-1) for total PBDEs and from 2.9×10-7 to 7.2×10-6 (year-1) for BDE-209. Some fish species collected from ponds in e-waste recycling villages contained elevated levels of PBDEs, especially BDE-209, which were markedly higher than those in fish previously reported. Overall, levels and patterns of PBDE accumulation in different kinds of samples suggest significant emission from e-waste sites and that these areas are potential sources of PBDE contamination. Intakes of PBDEs via fish consumption were generally higher than those estimated through dust ingestion. Intake of BDE-99 and BDE-209 through dust ingestion contributes a large proportion due to higher concentrations in dust and fish. Body weight normalized daily intake through dust ingestion estimated for the e-waste recycling sites (0.10-3.46ng/day/kg body wt.) were in a high range as compared to those reported in other countries. Our results highlight the potential releases of PBDEs from informal recycling activities and the high degree of human exposure and suggest the need for continuous investigations on environmental pollution and toxic impacts of e-waste-related hazardous chemicals.

Prenatal levels of Polybrominated Diphenyl Ethers (PBDEs) in association with Autism Spectrum Disorder

Introduction: Increasing evidence suggests prenatal exposure to polybrominated diphenyl ethers (PBDEs) has neurodevelopmental impacts, perhaps via thyroid hormone and immune system dysfunction. This raises the hypothesis that prenatal PBDE exposure may be associated with higher risk of autism spectrum disorder (ASD), but no studies of ASD diagnosis have examined this, to our knowledge. Methods: Using data from a large population-based case-control study in southern California, we examined PBDE levels measured in 2nd trimester maternal serum samples in association with offspring ASD (n=545) or intellectual disability (ID, n=181), relative to controls from the general population (n=418). Six PBDE congeners and their sum were categorized into quartiles (Q) and adjusted odds ratios (AOR) calculated. Results: Prenatal levels of most PBDE congeners were lower for children with ASD or ID than for controls. In adjusted analyses, reduced risks for ASD were observed with higher maternal PBDE levels (Q4 vs. Q1); for BDE153, AOR=0.56 (95% CI 0.38, 0.84) and for the sum, AOR=0.54 (95% CI 0.36, 0.80), with other congeners (BDE-47, 99, 100, and 153) showing consistent patterns. When stratified by child gender, the inverse associations were limited to boys, whereas odds ratios were elevated in girls, with BDE28 and, more so BDE47, approaching statistical significance (AOR=2.6; 95% CI 0.86, 7.8, and AOR=2.6; 95% CI 0.97, 7.2, respectively). For ID risk, similar overall and sex-specific patterns were seen with some congeners, but no associations were significant. Conclusions: Contrary to expectation, our primary analyses did not suggest increased risk of ASD or ID with higher prenatal PBDE levels; however, stratifying by child gender revealed striking differences that appeared stronger for ASD than ID. These findings therefore suggest the potential for sexual dimorphism, as has been demonstrated in animal studies, in neurodevelopmental effects of prenatal exposure to PBDEs.

Predictors of polybrominated diphenyl ether (PBDE) serum levels in a cohort of U.S. children aged 1-5 years

Introduction. We investigated predictors of polybrominated diphenyl ether (PBDE) serum concentrations among young children in the southeastern United States. Methods. Serum levels of PBDE congeners (BDE-47, -99, -100, -153, -154, -209) were measured via gas chromatography-tandem mass spectrometry in a sample of 81 healthy children aged 1-5 years who were under anesthesia for ear tube surgery. Demographics and behaviors such as smoking and breastfeeding were reported by parents on a questionnaire; a research nurse recorded anthropometric measures and insurance status. In a subset of 17 children, PBDEs were measured in a house dust sample collected with a solvent-cleaned high volume small surface sampler (HVS3) vacuum, and from two hand wipes sampled from the child at a home visit. In linear and Tobit regression we modeled natural log-transformed serum PBDE levels of the most frequently detected congeners (PBDE-153 and ∑BDE-47,-99,-100) as a function of child characteristics, including median household income in the child’s residential zip code from the U.S. Census. Results. A $10,000 increase in median income in a child’s zip code was associated with a 21% (95%CI=9-32%) lower serum BDE-153 concentration and a 17% (95%CI=6–27%) lower serum concentration of ∑BDE-47,-99,-100. A similar pattern was observed for other markers of socioeconomic status. Higher BMI z-score was associated with lower serum levels of BDE-153, but not ∑BDE-47,-99,-100. Among the subset of children who participated in a home visit, serum PBDEs were positively correlated with hand wipe PDBEs, most strongly for ∑BDE-47,-99,-100 (Spearman r=0.48), but not dust PBDEs. Conclusions. Results suggest socioeconomic factors are strong predictors of serum PBDE levels among young children in the southeastern United States. This study adds to the evidence indicating PBDEs measured on hand wipes are more predictive of serum PBDE levels than vacuum-collected dust from the home.

Dust levels of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) in the Taiwanese elementary school classrooms: Assessment of the risk to school-age children

Elementary school classroom dust is an important source of exposure to polybrominated dibenzo-p-dioxins/furans and diphenyl ethers (PBDD/DF/DEs) for school-age children. Our goal is thus to investigate concentrations of PBDD/DF/DEs in elementary school classroom dust to further assess the impact on school-age children via ingestion. The dust from classrooms, including both normal (NR) and computer classrooms (CR), was collected from six urban and four rural schools. Fourteen PBDEs and twelve PBDD/Fs were measured using high-resolution gas-chromatography/high-resolution mass-spectrometry. The mean levels of Σ14PBDEs in NR and CR dust from the urban classrooms were 370 and 2510ng/g and those whose dust from the rural classrooms were 464 and 1780ng/g. The means of ΣPBDD/Fs were 0.0401ng-WHO2005-TEQ/g (concentration: 4.72ng/g) in urban NR dust, 0.0636ng-WHO2005-TEQ/g (7.51ng/g) in urban CR dust, 0.0281ng-WHO2005TEQ/g (3.60ng/g) in rural NR dust, and 0.0474ng-WHO2005TEQ/g (6.28ng/g) in rural CR dust. The PBDEs pattern in NR dust was quite different from that in CR dust, but the PBDD/Fs patterns in NR and CR dust were similar. A linearly significant correlation coefficient (n=20, r=0.862, p<0.001) was found between ΣPBDEs and ΣPBDD/Fs in NR and CR dust, indicating that the PBDEs and PBDD/Fs in the dust may be from the same sources in the elementary school classrooms. This study assessed the risks (daily intake and cancer and non-cancer risks) of PBDEs and PBDD/Fs for the children from the classroom dust, and the calculated risk values did not exceed the related thresholds. With regard to the exposure scenarios for school-age children in an indoor environment, the results suggest that they might ingest more dust PBDD/DF/DEs in their homes than in the schools. In conclusion, the exposure of Taiwanese elementary school children to PBDD/DF/DEs via indoor dust was with a safe range based on our findings.

Assessment of polybrominated diphenyl ethers in sediment of Asunle stream of the Obafemi Awolowo University, Ile-Ife, Nigeria.

Assessment of levels of polybrominated diphenyl ethers (PBDEs) from the sediment of Asunle stream, an adjourning stream of the Obafemi Awolowo University dumpsite, has been carried out. Sediment samples were collected from the stream at six locations for a period of 8months, composed of 4months each of wet (May-Aug) and dry (Nov-Feb) seasons. Soxhlet extraction was employed for the isolation of all the target compounds from the sediment samples. Extracts were further subjected to multi-layer column chromatography employing different forms of silica gel. The prepared samples were analyzed using GC-MS. The overall mean concentrations of the total PBDEs ranged from 1.80 to 9.46ng/g. The results showed that the concentrations of the PBDEs were slightly higher during the wet season than those during the dry season. In all the studied locations, BDE28, BDE47, BDE99, BDE100, BDE153, and BDE154 were detected in all the sediment samples at concentrations that ranged from 0.73 to 10.43ng/g. Results of this study indicated that BDE153 was the major pollutant of the Asunle stream sediments.

Polybrominated Diphenyl Ethers in Maternal Serum, Breast Milk, Umbilical Cord Serum, and House Dust in a South Korean Birth Panel of Mother-Neonate Pairs.

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants. Although many reports have indicated an association between exposure to PBDEs and developmental neurotoxicity, the relative contributions of different sources of dust PBDE congeners to the levels in various tissues of mother–baby pairs is not well understood. The aims of this study were thus to measure the quantitative relationship between the level of PBDEs in house dust and tissues of mother-neonate pairs, and to investigate the chemical sources of the PBDEs. Forty-one mother-neonate pairs were recruited and provided samples of maternal serum (n = 29), umbilical cord serum (n = 25), breast milk (n = 50), and house dust (n = 41), where PBDEs were determined with high-resolution gas chromatography coupled with high-resolution mass spectrometry. While deca- (e.g., BDE 209, detected 100%), nona- (BDE 206/207, 95.1%), octa- (BDE 183, 100%), penta- (BDE 99/153, 100%, 98%) and tetra-BDEs (BDE 47, 100%) were detected abundantly in dust, penta- (BDE 99, 76%, 92%) and tetra-BDEs (BDE 47, 84%, 98%) were detected abundantly in umbilical cord serum and breast milk, respectively; tetra-BDEs (BDE 47, 86%) were detected more often relative to other congeners in maternal serum. Spearman’s pairwise comparison showed that the levels of BDE 47 (ρ = 0.52, p < 0.001) and −99 (ρ = 0.64, p < 0.01) in umbilical cord serum were associated with BDE 209 levels in dust; BDE 47 in maternal serum also showed correlation with BDE 99 in cord serum (ρ = 0.48, p < 0.01) but there was no significant correlation between maternal BDE 47 and dust BDE 209. On the other hand, a comparison of the distribution among congeners suggested probable associations of BDE 47 in maternal serum, breast milk, and umbilical cord serum with BDE 209 in dust; and of BDE 99 in maternal and umbilical cord serum, breast milk, and dust with BDE 209 in dust. Although further studies are needed, a radar chart-based distributional comparison among congeners supported associations between BDE 47 or −99 in human tissues and BDE 209 in dust.

Overview on relative importance of house dust ingestion in human exposure to polybrominated diphenyl ethers (PBDEs): International comparison and Korea as a case

Human exposure studies to polybrominated diphenyl ethers (PBDEs) have reached different results about the relative importance of diet intake and house dust ingestion. In the present study, concentrations of PBDEs in Korean house dust (n=15) from geographically different cities were measured, which were in agreement with a previous result, and compared with those for 22 countries of five continents collected from the most recent scientific literature. Compared with other exposure pathways, diet intake was the most important contributor to total PBDEs exposure of Korean adults (i.e., 71% of overall intake). On global comparison, total PBDE levels in house dust differed by two to three orders of magnitude among the countries investigated, with a significant relationship with gross domestic product (GDP). Whereas, dietary daily intakes exhibited a narrow difference within one order of magnitude worldwide and no relationship with GDP. Consequently, the relative importance of major two pathways depended on the contamination extent of PBDEs in house dust, which may be associated with the amount of PBDE products in use. In most countries except for UK and USA, the contribution of house dust ingestion was less important than diet intake in the current and are expected to much more mitigate in the future. However, how fast the effect of regulation will be reflected to house dust and human exposure is necessary to be monitored steadily.