Polybrominated Biphenyls Research Articles

Levels of brominated flame retardants and methoxylated polybrominated diphenyl ethers in eggs of white-tailed sea eagles breeding in different regions of Sweden

Forty-four unhatched eggs from white-tailed sea eagle ( Haliaeetus albicilla), collected in four regions in Sweden in 1992–2005, were analysed for contents of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyl (PBB), hexabromocyclododecane (HBCD) and naturally occurring methoxylated polybrominated diphenyl ethers (MeO-PBDEs). Two freshwater areas—Lapland in the arctic zone (LAP) and inland lakes in central and southern Sweden (INL), and two brackish marine areas in the Baltic Sea—the south Bothnian Sea (SB) and the Baltic Proper (BP)—were chosen for comparison of the concentrations and congener distributions in white-tailed sea eagles with different diet and migratory patterns. The geometric mean (GM) concentrations (ng/g lipid weight (l.w.)) of ∑ 5PBDE (BDE-47, -99, -100, -153, and -154) were 720 (LAP), 1500 (INL), 4 100 (SB) and 4 300 (BP), whereas BDE-209 was not detectable in any of the samples. The GM concentrations for HBCD content in LAP, INL, SB and BP were 60, 90, 150 and 140 ng/g l.w., respectively, whereas the corresponding values for BB-153 were 20, 30, 100 and 120 ng/g l.w. In general, the eggs from all four regions demonstrated similar patterns of PBDE congeners, with concentrations in descending order of BDE-47, -100, -99, -153 and -154. The ∑ 3-MeO-BDEs (6-MeO-BDE47, 2′-MeO-BDE68, 5-Cl-6-MeO-BDE47) for these same regions (as above) were 80, 40, 340 and 240 ng/g l.w., respectively. ∑ 3-MeO-BDEs for LAP and INL (freshwaters) were significantly different, whereas those for SB and BP were not. The presence of MeO-PBDEs in all of the inland samples indicates that there is an as-yet-unidentified source of these compounds in the freshwater ecosystem. Between the two more contaminated subpopulations from the Baltic Sea coast, SB showed significantly lower productivity than BP, but no correlation was found between productivity and PBDE, PBB and HBCD at the concentrations found in this study.

Method Evaluation Computer Program for Quantitative Analysis of PBBs and PBDEs in Plastics

Polybrominated biphenyls (PBBs) and polybrominated biphenyl ethers (PBDEs) are substances used in electrical and electronic products. They are restricted substances due to their potential risk to human health and the environment. In this research work, a test method was evaluated for the quantitative analysis of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) in acrylonitrile-butadiene–styrene (ABS) plastic and polyethylene materials, based on solvent extraction of a plastic sample with soxhlet extraction techniques and detection by gas chromatography/mass spectrometry. We have also developed a computer program for checking the suitability of the analytical method by evaluating validation characteristics, including accuracy, precision, specificity/selectivity, limit of detection (LOD), limit of quantification (LOQ), linearity, range and sensitivity. The computer program was successfully applied for evaluation of the analytical method for prohibited PBBs and PBDEs in plastics. Graphical charts for the evaluation of the analytical method are presented along with their values, and researchers can get insight into evaluating several parameters together. It was found that the analytical method was able to quantify monobrominated - decabrominated biphenyl and monobrominated diphenyl ether–nonabrominated diphenyl ether between 100-1750 mg/kg and decabrominated diphenyl ether between 100–8,000 mg/kg. In addition, ERM-EC590 Polyethylene certified reference material from the Institute for Reference Materials and Measurements (IRMM) was used to validate the analytical method for PBBs and PBDEs in plastics. The obtained accuracy and precision indicate that the method successfully meets the required accuracy expressed as % recovery (70-130%) and the required precision expressed as percentage relative standard deviation (less than 20% RSD) of the IEC 62321:2008 international standard method.

PHAHs in large reservoir sediments from Hebei and Hubei provinces, China

This study was undertaken to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from large reservoirs located in Hebei and Hubei provinces in China. The concentrations of 21 polybrominated biphenyl (PBB) congeners, seven polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediments were measured using the GC-MS/MS technique. Low-brominated PBBs (including 1, 3, 4, 10, 30, 31 and 53) were the most abundant PBB congeners and PBDEs 28, 47 and 99 were the most prevalent PBDE congeners in these samples. Among the three subfamilies of PHAHs, PCBs were the most predominant pollutants detected. The measured levels of PHAHs were compared with recent results reported in the literature and their respective sediment quality guidelines recommended by USEPA. The levels of PHAHs in the present study were generally lower than their respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwaters from other regions. This suggests that, in these reservoirs, toxic biological effects on aquatic biota—due to PHAH contamination of sediments—can be expected to be negligible. Thus, in terms of PHAHs, the sediments in the selected reservoirs are relatively uncontaminated.

Scientific Opinion on Polybrominated Biphenyls (PBBs) in Food

Scientific Opinion on Polybrominated Biphenyls (PBBs) in Food

The role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western Hudson Bay polar bears, 1991–2007

Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-(∑-)contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, ∑ DDT (and p,p′-DDE, p,p′-DDD, p,p′-DDT) decreased (−8.4%/year); α-hexachlorocyclohexane (α-HCH) decreased (−11%/year); β-HCH increased (+ 8.3%/year); and ∑ PCB and ∑ chlordane (CHL), both contaminants at highest concentrations in all years (> 1 ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (−1.6%/year to −6.3%/year), whereas CB153 levels tended to increase (+ 3.3%/year). Parent CHLs ( c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). ∑ chlorobenzene, octachlorostyrene, ∑ mirex, ∑ MeSO 2-PCB and dieldrin did not significantly change. Increasing ∑ PBDE levels (+ 13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(α)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or “weathering” of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year. DDT patterns were not associated with any explanatory variables, possibly related to local DDT sources. Contaminant pattern trends may be useful in distinguishing the possible role of ecological/diet changes on contaminant burdens from expected dynamics due to atmospheric sources and weathering.

PKa values of the monohydroxylated polychlorinated biphenyls (OH-PCBs), polybrominated biphenyls (OH-PBBs), polychlorinated diphenyl ethers (OH-PCDEs), and polybrominated diphenyl ethers (OH-PBDEs)

The SPARC software program aqueous pKa prediction module was validated against corresponding experimental acidity constants for chlorinated and brominated phenols and the limited experimental aqueous pKa data sets for monohydroxylated polychlorinated biphenyls (OH-PCBs), polychlorinated diphenyl ethers (OH-PCDEs), and polybrominated diphenyl ethers (OH-PBDEs). pKa values were then estimated for all 837 monohydroxylated mono- through nona-halogenated congeners in each of the OH-PCB, OH-PCDE, and OH-PBDE classes, as well as for the monohydroxylated polybrominated biphenyls (OH-PBBs), giving a total of 3348 compounds. Large intrahomolog pKa variation by up to six units is expected within each contaminant class, with pKa values ranging from about 4 to 11 dependent on the degree and pattern of halogenation. Increasing halogenation generally decreased the average pKa within each homolog group. Significant intrahomolog differences in pKa values exist between OH-PCB, OH-PBB, OH-PCDE, and OH-PBDE congeners, including large acidity constant variation between isomers with equivalent halogenation patterns but varying location of the hydroxy moiety. Congener specific pH dependent investigations into the partitioning and degradation behaviors of these compounds are necessary, including greater consideration of analyte ionization effects during their extraction and analysis.

Contribution of Synthetic and Naturally Occurring Organobromine Compounds to Bromine Mass in Marine Organisms

An extraction, separation, and purification method was developed for the identification and quantification of total bromine (TBr), extractable organobromine (EOBr), and five classes of identified EOBrs. Instrumental neutron activation analysis (INAA) was utilized to quantify EOBr and TBr. The method was then applied to liver samples of tuna, albatross, and polar bear collected from remote marine locations. Polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), bromophenols (BRPs), hydroxylated (OH-) and methoxylated (MeO-) PBDEs were analyzed as identified EOBr. The majority of the bromine in these marine organisms was nonextractable or inorganic, with EOBr accounting for 10-28% of the TBr. Of the identified EOBr, in tuna and albatross, naturally occurring compounds, including MeO-PBDEs, OH-PBDEs, and BPRs, were prevalent. However, the identifiable EOBr in polar bears consisted primarily of synthetic compounds, including PBDEs and PBBs. Overall, 0.08-0.11% and 0.008-0.012% of EOBr and TBr, respectively, were identified. The proportion of EOBr that was identified in marine organisms was relatively small compared to the proportions for organofluorine and organochlorine compounds. This could be related to the great diversity of naturally occurring organobromine compounds in the environment. Naturally occurring brominated fatty acids were estimated to be the predominant compounds in the EOBr fraction.

Likelihood‐based methods for estimating the association between a health outcome and left‐ or interval‐censored longitudinal exposure data

The Michigan Female Health Study (MFHS) conducted research focusing on reproductive health outcomes among women exposed to polybrominated biphenyls (PBBs). In the work presented here, the available longitudinal serum PBB exposure measurements are used to obtain predictions of PBB exposure for specific time points of interest via random effects models. In a two-stage approach, a prediction of the PBB exposure is obtained and then used in a second-stage health outcome model. This paper illustrates how a unified approach, which links the exposure and outcome in a joint model, provides an efficient adjustment for covariate measurement error. We compare the use of empirical Bayes predictions in the two-stage approach with results from a joint modeling approach, with and without an adjustment for left- and interval-censored data. The unified approach with the adjustment for left- and interval-censored data resulted in little bias and near-nominal confidence interval coverage in both the logistic and linear model setting.

Determination of Selected Polybrominated Diphenylethers and Polybrominated Biphenyl in Polymers by Ultrasonic-Assisted Extraction and High-Performance Liquid Chromatography−Inductively Coupled Plasma Mass Spectrometry

A new method has been developed for the determination of selected polybrominated diphenylethers (PBDEs) and polybrominated biphenyl (PBB) in four polymers: high-density polyethylene (HDPE), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), and polypropylene (PP). PBDEs and PBB in the polymers were extracted with toluene, using ultrasonic-assisted extraction (UAE). The extracts were then determined by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), using external calibration (single-point). Extraction parameters of UAE and several ICP-MS parameters were optimized. Extraction efficiencies almost reached 100%. The relative standard deviations (RSDs) were in the range of 0.7%-5.4%. The results demonstrate that the method possesses advantages of good precision, as well as high extraction efficiency and accuracy. The method especially overcomes the problem of the thermal degradation of highly brominated PBDEs, such as PBDE-209.

High concentrations of persistent organic pollutants including PCBs, DDT, PBDEs and PFOS in little brown bats with white-nose syndrome in New York, USA

White-nose syndrome (WNS) is a condition associated with white fungal growth on ears, wings, and nose of hibernating bats; this condition has recently resulted in high bat mortality in the northeastern United States. Nevertheless, the pathogenesis of morbidity and mortality are still unknown. Elevated exposure to toxic contaminants could be a contributing factor via the consequent immunosuppression and endocrine disruption. In this study, diseased little brown bats ( Myotis lucifugus) were collected from several hibernacula in eastern New York State in 2008. Fat tissues of bats were analyzed for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and organochlorine pesticides (OCPs; DDT, chlordanes, HCB, and HCH), and liver was analyzed for perfluorinated compounds (PFCs). A reference population of little brown bats, not affected by WNS, was also collected from a cave in Kentucky for the analysis of trace organic contaminants. Concentration of PCBs in fat tissues of bats from New York ranged from 1900 ng g −1 to 35 000 ng g −1, lipid wt, with the highest concentrations found in bats collected from caves in Albany County. High concentrations of PCBs were also found in bats from Kentucky (17 100–18 400 ng g −1, lipid wt). Total PBDE concentrations in fat tissues ranged from 520 ng g −1 to 10 900 ng g −1, lipid wt, in bats from New York and from 4300 ng g −1 to 13 000 ng g −1, lipid wt, in bats from Kentucky. High concentrations of DDT (26 900 ng g −1, lipid wt), chlordanes (6350 ng g −1, lipid wt), and HCB (260 ng g −1, lipid wt) were found in bats from New York. Concentrations of hexabromobiphenyl congener 153 (PBB 153) in bats from New York ranged from 8.6 ng g −1 to 12 4000 ng g −1, lipid wt. Concentrations of PFCs were on the order of a few tens to a few hundreds of nanograms per gram liver, on a wet weight basis. Overall, high concentrations of PCBs, PBDEs, DDT, and chlordanes were found in fat tissues of diseased bats from New York, although the concentrations in bats from non-diseased, reference population, from Kentucky were also high.

Environmental and human exposure to persistent halogenated compounds derived from e‐waste in China

Various classes of persistent halogenated compounds (PHCs) can be released into the environment due to improper handling and disposal of electronic waste (e-waste), which creates severe environmental problems and poses hazards to human health as well. In this review, polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), tetrabromobisphenol A (TBBPA), polybrominated phenols (PBPs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are the main target contaminants for examination. As the world's largest importer and recycler of e-waste, China has been under tremendous pressure to deal with this huge e-waste situation. This review assesses the magnitude of the e-waste problems in China based on data obtained from the last several years, during which many significant investigations have been conducted. Comparative analyses of the concentrations of several classes of toxic compounds, in which e-waste recycling sites are compared with reference sites in China, have indicated that improper e-waste handling affects the environment of dismantling sites more than that of control sites. An assessment of the annual mass loadings of PBDEs, PBBs, TBBPA, PBPs, PCDD/Fs, and ClPAHs from e-waste in China has shown that PBDEs are the dominant components of PHCs in e-waste, followed by ClPAHs and PCDD/Fs. The annual loadings of PBDEs, ClPAHs, and PCDD/Fs emission were estimated to range from 76,200 to 182,000, 900 to 2,000 and 3 to 8 kg/year, respectively. However, PCDD/Fs and ClPAHs should not be neglected because they are also primarily released from e-waste recycling processes. Overall, the magnitude of human exposure to these toxics in e-waste sites in China is at the high end of the global range.

Low Dose of Some Persistent Organic Pollutants Predicts Type 2 Diabetes: A Nested Case–Control Study

BackgroundLow doses of some persistent organic pollutants (POPs) associate cross-sectionally with type 2 diabetes, whereas associations with high POP exposures are inconsistent.ObjectivesWe investigated whether several POPs prospectively predict type 2 diabetes within the Coronary Artery Risk Development in Young Adults (CARDIA) cohort.MethodsParticipants in this nested case–control study were diabetes free in 1987–1988. By 2005–2006, the 90 controls remained free of diabetes, whereas the 90 cases developed diabetes. Using serum collected in 1987–1988, we measured 8 organochlorine pesticides, 22 polychlorinated biphenyl congeners (PCBs), and 1 polybrominated biphenyl (PBB). We compared POP concentrations from CARDIA and the National Health and Nutrition Examination Survey (NHANES) in 2003–2004. We computed odds ratios (ORs) for incident diabetes using logistic regression analysis.ResultsChlorinated POPs in CARDIA in 1987–1988 were much higher than corresponding NHANES 2003-2004 concentrations. POPs showed nonlinear associations with diabetes risk. The highest risk was observed in the second quartiles of trans-nonachlor, oxychlordane, mirex, highly chlorinated PCBs, and PBB153—a finding that suggests low-dose effects. We concentrated risk by summing these POPs and isolated very low concentrations of multiple POPs in the lowest sextile of the sum. The adjusted OR in the second sextile vs. the lowest sextile was 5.3 overall and 20.1 for body mass index ≥ 30 kg/m2.ConclusionsSeveral POPs at low doses similar to current exposure levels may increase diabetes risk, possibly through endocrine disruption. Certain POPs may a play a role in the current epidemic of diabetes, which has been attributed to obesity.

탁상형 및 휴대형 X-선 형광 분석기를 이용한 폴리에틸렌 및 폴리프로필렌 시료 중 RoHS 규제 물질의 비교 분석

As a basic research for development of the domestic portable XRF spectrometer, we discussed the analytical results of bench-top and portable XRF methods for RoHS materials of the Cd, Pb, Hg, Cr(IV), polybrominated biphenyls(PBB) and polybrominated diphenyl ehters(PBDE). The instrumental parameters such as measurement time of bench-top and portable XRF were optimized using certified reference materials of polyethylene and polypropylene with 5 hazardous materials of 0~1,200 mg/kg. The quantitative analysis of total-Cr, total-Br, Cd, Hg and Pb in certified reference materials and plastic samples were compared by empirical method, fundamental parameter method of bench-top XRF and portable XRF.

PBB levels in fish from the Baltic and North seas and in selected food products from Poland

Recently, a significant amount of attention has been devoted to the determination of polybrominated biphenyls in food and the environment. In this study, PBB contamination of fish from the North and Baltic Seas, with a special focus on samples from Poland and France, was investigated. North Sea fish like salmon, herring, scarp, gilthead seabream and grey gurnard were collected from a French fish market. Baltic Sea fish like salmon, tunny, trout, herring, and freshwater fish such as carp were purchased from a Polish fish market. Cod livers in oil were also analyzed in this study. As additional food samples, butter, pork fat and beef fat were tested. Concentrations of PBBs in North Sea fish (except herring) were higher than in fish from the Baltic Sea. The highest total PBB concentration was measured in scarp muscle tissue (635 ± 107 pg g −1 wet weight), and the lowest was in carp samples (0.567 ± 0.245 pg g −1 wet weight). The PBB content in tunny oil samples was below the detection limits (0.45–1.05 pg g −1 fat). Our study also demonstrated that PBBs may bioaccumulate in the liver, where PBB concentrations were 2116 ± 351 pg g −1 wet weight and 841 ± 147 pg g −1 wet weight. In fish species from Poland, the most dominant congeners were tetrabromobiphenyls, followed by pentabromobiphenyls and hexabromobiphenyls. In some species of fish from the North Sea, the most dominant groups were hexabromobiphenyls and tetrabromobiphenyls. Although the relative abundances of structurally known and unknown isomers varied from species to species, all fish (except tunny) were contaminated with PBBs.

Evaluation of the state-of-the-art measurement capabilities for selected PBDEs and decaBB in plastic by the international intercomparison CCQM-P114

An international intercomparison involving eight national metrology institutes (NMIs) was conducted to establish their current measurement capabilities for determining five selected congeners from the brominated flame retardant classes polybrominated diphenyl ethers and polybrominated biphenyls. A candidate reference material consisting of polypropylene fortified with technical mixtures of penta-, octa- and decabromo diphenyl ether and decabromo biphenyl, which was thoroughly assessed for material homogeneity and stability, was used as study material. The analytical procedures applied by the participants differed with regard to sample pre-treatment, extraction, clean-up, employed calibrants and type of calibration procedure as well as regarding analytical methods used for separation, identification and quantification of the flame retardant congeners (gas chromatography coupled to an electron capture detector (GC-ECD), gas chromatography-mass spectrometry in the electron ionisation mode (GC-EI-MS), gas chromatography-mass spectrometry in the electron capture negative ionisation mode (GC-ECNI-MS), and liquid chromatography-inductive coupled plasma-mass spectrometry (LC-ICP-MS)). The laboratory means agreed well with relative standard deviations of the mean of means of 1.9%, 4.8%, 5.5% and 5.4% for brominated diphenyl ether (BDE) 47, 183 and 209 and for the brominated biphenyl (BB) congener 209, respectively. For BDE 206, a relative standard deviation of 28.5% was obtained. For all five congeners, within-laboratory relative standard deviations of six measurements obtained under intermediate precision conditions were between 1% and 10%, and reported expanded measurements uncertainties typically ranged from 4% to 10% (8% to 14% for BDE 206). Furthermore, the results are in good agreement with those obtained in the characterization exercise for determining certified values for the flame retardant congeners in the same material. The results demonstrate the state-of-the-art measurement capabilities of NMIs for quantifying representative BDE congeners and BB 209 in a polymer. The outcome of this intercomparison (pilot study) in conjunction with possible improvements for employing exclusively calibrants with thoroughly assessed purity suggests that a key comparison aiming at underpinning calibration and measurement capability (CMC) claims of NMIs can be conducted.

Gas chromatography coupled to electron capture negative ion mass spectrometry with nitrogen as the reagent gas – an alternative method for the determination of polybrominated compounds

Gas chromatography in combination with electron capture negative ion mass spectrometry (GC/ECNI-MS) is a sensitive method for the determination of polybrominated compounds in environmental and food samples via detection of the bromide ion isotopes m/z 79 and 81. The standard reagent gas for inducing chemical ionization in GC/ECNI-MS is methane. However, the use of methane has some drawbacks as it promotes carbonization of the filament and ion source. In this study, we explored the suitability of nitrogen as reagent gas for the determination of brominated flame retardants (polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), allyl-2,4,6-tribromophenyl ether (ATE) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE)) and halogenated natural products (for instance, methoxylated tetrabrominated diphenylethers and polybrominated hexahydroxanthene derivatives). An ion source temperature of 250 degrees C and a nitrogen pressure of 7 Torr in the ion source gave the highest response for m/z 79 and 81 of virtually all investigated polybrominated compounds. Using these conditions, nitrogen-mediated GC/ECNI-MS usually gave higher sensitivity than the method with methane previously used in our lab. In addition, the ion source was not contaminated to the same degree and the lifetime of the filament was significantly increased. Moreover, the response factors of the different polybrominated compounds with the exception of 2,4,6-tribromophenol were more uniform than with methane. Nitrogen is available at very high purity at relatively low price.

Brominated flame retardants in the Arctic environment — trends and new candidates

Polybrominated diphenyl ethers (PBDEs) containing two to 10 bromines are ubiquitous in the Arctic, in both abiotic and biotic samples. Hexabromocyclododecane (HBCD) is also ubiquitous in the Arctic, with the γ-HBCD isomer predominating in air, the α-HBCD isomer predominating in biota and similar concentrations of α-, β- and γ-HBCD found in marine sediments. Other brominated flame retardants (BFRs) found in some Arctic samples are polybrominated biphenyls (PBBs), tetrabromobisphenol A (TBBPA), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), hexabromobenzene (HxBBz), pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH). Temporal trends of tetra- to heptaBDEs and HBCD show increasing concentrations or a tendency to levelling off depending on the matrix (air, sediment, biota) and location, but no uniform picture for the Arctic emerges. BDE-209 concentrations are increasing in air. PBDEs and HBCD spatial trends in seabirds and marine mammals are similar to those seen previously for polychlorinated biphenyls (PCBs), with highest concentrations found in organisms from East Greenland and Svalbard. These trends indicate western Europe and eastern North America as important source regions of these compounds via long range atmospheric transport and ocean currents. Latitudinal trends showed lower concentrations and fluxes of PBDEs at higher latitudes. The tetra-hexaBDEs and α-HBCD biomagnify in Arctic food webs. Results for BDE-209 are more conflicting, showing either only low or no biomagnification potential. PBDE and HBCD concentrations are lower in terrestrial organisms and higher in marine top predators such as some killer whale populations in Alaska and glaucous gulls from the Barents Sea area. Higher concentrations are seen near populated areas indicating local sources. Findings of BTBPE, HxBBz, PBEB, PBT and TBECH in seabirds and/or marine mammals indicate that these compounds reach the Arctic, most probably by long range atmospheric transport and accumulate in higher trophic level organisms and that increasing use as PBDE replacements will lead to increasing concentrations.

A cohort study of the association between secondary sex ratio and parental exposure to polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB)

BackgroundPolybrominated biphenyl (PBB), a brominated flame retardant, was accidently mixed into animal feed in Michigan (1973–1974) resulting in human exposure through consumption of contaminated meat, milk and eggs. Beginning in 1976 individuals who consumed contaminated products were enrolled in the Michigan Long-Term PBB Study. This cohort presents a unique opportunity to study the association between parental exposures to PBB and offspring sex ratio.MethodsWe identified offspring of female PBB cohort participants (born 1975–1988) and obtained electronic birth records for those born in the state of Michigan. We linked this information to parental serum PBB and PCB concentrations collected at enrollment into the cohort. We modeled the odds of a male birth with generalized estimating equations accounting for the non-independence of siblings born to the same parents. We explored potential confounders: parental age and education at offspring's birth, parental body mass index at cohort enrollment, birth order, gestational age and year of offspring's birth.ResultsThe overall proportion of male offspring among 865 live births to cohort mothers was 0.542. This was higher than the national male proportion of 0.514 (binomial test: p = 0.10). When both parents were in the cohort (n = 300), we found increased odds of a male birth with combined parents' enrollment PBB exposure ≥ the median concentrations (3 μg/L for mothers; 6 μg/L for fathers) compared to combined parents' PBB exposure < the median concentrations (AOR = 1.43, 95% CI: 0.89–2.29), although this did not reach statistical significance. In addition, there was a suggestion of increased odds of a male birth for combined parents' enrollment PCB exposure ≥ the median concentrations (6 μg/L for mothers; 8 μg/L for fathers) compared to combined parents' enrollment PCB exposure < the median concentrations (AOR = 1.53, 95% CI: 0.93–2.52).ConclusionThis study adds to the body of literature on secondary sex ratio and exposure to environmental contaminants. In this population, combined parental exposure to PBBs or PCBs increased the odds of a male birth. Further research is needed to corroborate these findings and shed light on the biological mechanisms by which these types of chemicals may influence the secondary sex ratio.

Bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals ( Pusa hispida) and polar bears ( Ursus maritimus) from East Greenland

We report on the comparative bioaccumulation, biotransformation and/or biomagnification from East Greenland ringed seal ( Pusa hispida) blubber to polar bear ( Ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (PCBs), chlordanes (CHLs), hydroxyl (OH-) and methylsulfonyl (MeSO 2-) PCBs, polybrominated biphenyls (PBBs), OH-PBBs, polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants and OH- and methoxyl (MeO-) PBDEs, 2,2-dichloro-bis(4-chlorophenyl)ethene ( p, p′-DDE), 3-MeSO 2- p, p′-DDE, pentachlorophenol (PCP) and 4-OH-heptachlorostyrene (4-OH-HpCS). We detected all of the investigated contaminants in ringed seal blubber with high frequency, the main diet of East Greenland bears, with the exception of OH-PCBs and 4-OH-HpCS, which indicated that these phenolic contaminants were likely of metabolic origin and formed in the bears from accumulated PCBs and octachlorostyrene (OCS), respectively, rather than being bioaccumulated from a seal blubber diet. For all of the detectable sum of classes or individual organohalogens, in general, the ringed seal to polar bear mean BMFs for ΣPCBs, p, p′-DDE, ΣCHLs, ΣMeSO 2-PCBs, 3-MeSO 2- p, p′-DDE, PCP, ΣPBDEs, total-(α)-HBCD, ΣOH-PBDEs, ΣMeO-PBDEs and ΣOH-PBBs indicated that these organohalogens bioaccumulate, and in some cases there was tissue-specific biomagnification, e.g., BMFs for bear adipose and liver ranged from 2 to 570. The blood-brain barrier appeared to be effective in minimizing brain accumulation as BMFs were ≤ 1 in the brain, with the exception of ΣOH-PBBs (mean BMF = 93 ± 54). Unlike OH-PCB metabolites, OH-PBDEs in the bear tissues appeared to be mainly accumulated from the seal blubber rather than being metabolic formed from PBDEs in the bears. In vitro PBDE depletion assays using polar bear hepatic microsomes, wherein the rate of oxidative metabolism of PBDE congeners was very slow, supported the probability that accumulation from seals is the main source of OH-PBDEs in the bear tissues. Our findings demonstrated from ringed seal to polar bears that organohalogen biotransformation, bioaccumulation and/or biomagnification varied widely and depended on the contaminant in question. Our results show the increasing complexity of bioaccumulated and in some cases biomagnified, chlorinated and brominated contaminants and/or metabolites from the diet may be a contributing stress factor in the health of East Greenland polar bears.

Effect of brominated diphenyl ethers-209 on superoxide dismutase,malondialdehyde and glutathione reductase in primary cultured hippocampal neurons of fetal rats

Objective To determine the effect of brominated diphenyl ethers-209 (BDE-209) on superoxide dismutase (SOD) activity,malondialdehyde (MDA) and glutathione reductase (GSH) concentrations in the hippocampal neurons of fetal rats.Methods The activities of SOD,concentrations of MDA and GSH were measured respectively after the rat hippocampal neurons were exposed to 2.5 (group A),5.0(group B),10.0(group C),20.0(group D),40.0 μg/ml(group E) BDE-209 for 24 h in vitro.Those rats without BDE-209 exposure were served as control.Results The SOD activity in the hippocampus was decreased with the increased exposure to BDE-209,and the experimental groups showed significant difference from the control group(29.809±3.269,28.424±1.953,26.912±1.439,25.533±2.259,15.678±2.607 vs 38.056±4.210,P<0.01);The MDA contents in the five experimental groups also increased with increase of BDE-209 exposure,and that in group C(1.421±0.531),D(1.997±0.499),and E(2.233±0.865) was higher than in the control group (0.544±0.236),respectively (P<0.01).However,the GSH contents was decreased with the increased exposure to BDE-209,and that in each experiment group was significantly lower than in the control (288.576±77.514,257.929±70.959,126.349±40.649,76.350±13.850,59.634±17.533 vs 347.228±38.162,P<0.05).Conclusions BDE-209 exposure can induce damage of nervous system during fetal development through accelerating lipid peroxidation of cerebral tissues. Key words: Phenyl ethers; Polybrominated biphenyls; Hippocampus; Neurons; Superoxide dismutase; Malondialdehyde; Glutathione