Biomagnification of naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in harbour seals and harbour porpoises from the Southern North Sea

Harbour seals and harbour porpoises are top predator species from the North Sea, have long life spans and hence, are known to accumulate high levels of anthropogenic contaminants. To gain knowledge about the behaviour of naturally-produced compounds in these marine mammals, the biomagnification of naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) was assessed. The biomagnification of MeO-PBDEs (2′-MeO-BDE 68 and 6-MeO-BDE 47) was lower in harbour seals (all biomagnification factors (BMFs) < 1) compared to the same age–gender groups of the harbour porpoises (all BMFs > 1). This may indicate a better metabolic breakdown of MeO-PBDEs in harbour seals, as was previously suggested for polybrominated diphenyl ethers (PBDEs). In both predators, 6-MeO-BDE 47 had the highest concentrations (range: 45–483 ng/g lw and 2–38 ng/g lw for harbour porpoises and seals, respectively) compared to 2′-MeO-BDE 68 (range: 2–28 ng/g lw and 1–6 ng/g lw for harbour porpoises and seals, respectively). In general, the highest concentrations were found in juveniles, suggesting an increased biotransformation capacity with age or the influence of dilution by growth for both species. Here we show that naturally-produced brominated organic compounds can biomagnify and accumulate in North Sea top predators, although to a lesser extent than anthropogenic lipophilic contaminants, such as polychlorinated biphenyls (PCBs) or PBDEs.     

Concentrations of polybrominated diphenyl ethers in matched samples of indoor dust and breast milk in New Zealand

Polybrominated diphenyl ethers (PBDEs) are present in many consumer goods. There is evidence that PBDEs are toxic to humans, particular young children. The purpose of this study was to assess indoor dust as an exposure source for PBDEs. Concentrations of 16 PBDEs were determined in dust samples from 33 households in New Zealand, and in breast milk samples from 33 mothers living in these households. Associations between dust and breast milk PBDE concentrations were assessed, and children's PBDE intake from breast milk and dust estimated. Influences of household and demographic factors on PBDE concentrations in dust were investigated. Indoor dust concentrations ranged from 0.1 ng/g for BDE17 to 2500 ng/g for BDE209. Breast milk concentrations were positively correlated (p < 0.05) with mattress dust concentrations for BDE47, BDE153, BDE154, and BDE209 and with floor dust for BDE47, BDE183, BDE206, and BDE209. The correlation for BDE209 between dust and breast milk is a novel finding. PBDE concentrations in floor dust were lower from households with new carpets. The estimated children's daily intake of PBDEs from dust and breast milk was below U.S. EPA Reference Dose values. The study shows that dust is an important human exposure source for common PBDE formulations in New Zealand.     

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in biota from the Pearl River Estuary, South China

Two hundred and fifty-four biota samples (four species of invertebrates and ten species of fish) were collected from the Pearl River Estuary between 2005 and 2007 and one hundred and twenty four individual or composite samples were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of PBDEs in organisms varied from 6.2 to 208 ng/g lipid weight. This PBDE level was significantly lower than those collected in 2004, showing a decreasing trend of PBDEs in biota in the study area. Trophic magnification factors (TMFs) for nine BDE congeners were calculated with values ranging from 0.78 to 3.0. TMFs of BDE47, 66, 100, 99, 154, and 153 were statistically greater than one, indicating a biomagnifcation potential for these congeners. Significant positive correlations were also found between concentrations of the total PBDEs, BDE28, 47, 66, 100, 99, 154, and153 and lipid content in biota, indicating the that bioconcentration also played an important role in the accumulation of PBDEs. No correlation between trophic level and lipid content was found, suggesting that biomagnification was not the result of lipid content effect but indeed occurred. The concentration ratios of BDE99 to BDE100 were much lower in biota than that in water implying that potential congener-specific biotransformation of PBDEs occurred and influenced the biomagnification of BDE congeners.     

Tissue-specific accumulation of polybrominated diphenyl ethers (PBDEs) including Deca-BDE and hexabromocyclododecanes (HBCDs) in harbor seals from the northwest Atlantic

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) are widely used flame retardants that enter coastal waters from multiple sources and biomagnify in marine food webs. PBDEs have been detected at relatively high concentrations in harbor seals, apex predators in the northwest Atlantic. Whereas tri- to hexa-BDEs readily biomagnified from prey fishes to seal blubber, Deca-BDE (BDE-209) did not biomagnify in blubber. To explore tissue-specific differences in the accumulation/biomagnification of BFRs, we analyzed tri- to Deca-BDES in liver of 56 harbor seals (6 adult males, 50 pups), and compared hepatic concentrations and biomagnification potential with those in blubber. HBCDs were analyzed in seal liver and blubber to enable similar comparisons. Hepatic ΣPBDE (tri- to Octa-BDE) concentrations (range 35–19,547 ng/g lipid weight, lw) were similar to blubber concentrations, while α-HBCD levels in seal liver (range 2–279 ng/g lw) were significantly higher than levels in blubber. Tissue distribution of PBDEs and α-HBCD varied significantly by age and, surprisingly, by gender among the pups. Biomagnification of α-HBCD from fish to seal liver and blubber was negligible to low, implying that harbor seals can metabolize this persistent isomer. Similar to the patterns in blubber, tri- through hexa-BDEs were highly biomagnified from fish to seal liver. In contrast, BDE-209 concentrations in liver were up to five times higher than those in blubber, which is consistent with observations that BDE-209 migrates to perfused tissues such as the liver in biota. Although detection frequency was low, BDE-209 levels in seal liver were up to ten times higher than those in their prey fish, suggesting that the accumulation/biomagnification of Deca-BDE in marine food webs is tissue-specific. As BDE-209 is the dominant PBDE found in marine sediments, its biomagnification in marine ecosystems is of concern.     

Brominated flame retardants and polychlorinated biphenyls in fish from the river Scheldt, Belgium

Levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), and polychlorinated biphenyls (PCBs) were measured in several fish species originating from the river Scheldt (Belgium). Five sampling locations were chosen in a highly industrialized area along the river, while two ponds in the vicinity of the river served as reference sites. The present study is a follow-up of a survey performed in 2000 which reported extremely high levels of PBDEs and HBCDs in eel (Anguilla anguilla) collected from the same region (Oudenaarde, Flanders). The sum of tri- to hepta-BDE congeners (2270+/-2260 ng/g lipid weight (lw), range 660-11500 ng/g lw) and total HBCDs (4500+/-3000 ng/g lw, range 390-12100 ng/g lw) were one order of magnitude higher than levels usually reported from freshwater systems, indicating the presence of point sources. In most samples, levels of total HBCDs were higher than those of PBDEs, probably due to the high density of factories using HBCD as an additive brominated flame retardant (BFR). The high values of HBCDs were confirmed by both gas- and liquid-chromatography-mass spectrometry. Although BFR levels were between the highest ever reported in freshwater ecosystems, PCBs could be detected at even higher concentrations (16000+/-14300 ng/g lw, range 3900-66600 ng/g lw), being among the highest levels recorded in Belgium. The inter-sampling site variation of PBDEs, HBCDs and PCBs was comparable. All locations presented similar PBDE congener profiles, with BDE 47 being the dominant congener, followed by BDE 100, BDE 99 and BDE 49, probably originating from the former use of the penta-BDE technical mixture. In order to estimate the impact of these point sources on human exposure, we further focussed on eels which showed a considerable decrease in the PBDE and HBCD levels between 2000 and 2006. Due to the wide span in concentrations between the different sampling locations, a variable contribution to the total human exposure through local eel consumption was estimated. The calculated daily intake ranged from 3 ng to 330 ng PBDEs/day for normal eel consumers, but was as high as 9800 ng PBDEs/day for anglers, which may be considered at risk.     

Maternal transfer of organochlorines and brominated flame retardants in blue tits (Cyanistes caeruleus)

Although eggs have frequently been used as a biomonitoring tool for contamination with organohalogenated pollutants (OHPs), few studies have investigated the processes of maternal transfer in birds. Here, maternal transfer of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) was investigated through comparison of the concentrations and profiles between whole homogenised female blue tits (Cyanistes caeruleus) and their eggs. In addition, we examined if there was an effect of laying order on the concentrations of PCBs, OCPs and PBDEs. PCBs were the most abundant contaminants in female blue tits and their eggs, followed by OCPs and PBDEs. Among the OCPs, p,p'-DDE was the most dominant compound and accounted for more than 80% of the sum OCPs. Egg concentrations decreased significantly in relation to the laying order from 1623+/-148 ng/g lipid weight (lw) to 1040+/-47 ng/g lw for the sum PCBs, from 342+/-24 ng/g lw to 235+/-17 ng/g lw for the sum OCPs and from 49+/-5 ng/g lw to 27+/-5 ng/g lw for the sum PBDEs. When reviewing all studies investigating laying order effects of OHPs in birds, no clear patterns emerged, which may be due to differences in study species and methodology among studies. Despite the fact that there were laying order effects in blue tit clutches, the variance in concentrations of PCBs and PBDEs was larger among clutches than within clutches. Variance in OCP concentrations among clutches was similar to the variance within clutches. These results suggest that one randomly collected blue tit egg from a clutch is useful as biomonitoring tool for PCBs and PBDEs, while for OCPs it is recommended to consistently use the same egg from the laying sequence as a biomonitoring tool. Lipid-normalized concentrations of sum PCBs, sum OCPs and sum PBDEs in female blue tits after clutch completion were comparable to the concentrations in the first-laid eggs. The egg/female lipid concentration ratios for sum PCBs, sum OCPs and sum PBDEs decreased significantly from 1.0+/-0.09 to 0.7+/-0.003, 1.1+/-0.1 to 0.7+/-0.02 and 1.2+/-0.14 to 0.8+/-0.05, respectively, during the course of egg laying. The profiles of the females and eggs differed significantly for the PCBs, OCPs and PBDEs. There was a higher contribution of lower chlorinated PCB congeners (CB 28, CB 52, CB 95, CB 101 and CB 110), BDE 183, p,p'-DDT and other less persistent OCPs in the females compared to their eggs. Maternal transfer in blue tits seemed to be selective for the more bioaccumulative and persistent congeners/compounds.     

Distribution of persistent organic pollutants in two different fat compartments from obese individuals

There are only few studies defining persistent organic pollutant (POP) concentrations in various fat compartments from living obese individuals. The present study has therefore determined the concentrations of various classes of organohalogenated compounds, such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in visceral fat (VF: n = 52) and subcutaneous abdominal fat (SF: n = 52) samples collected in 2010–2012 from obese individuals in Belgium. Organohalogen compounds were detected in all fat samples in the decreasing order of their concentrations: PCBs > DDTs > HCHs > CHLs > HCB > HBCDs > PBDEs, suggesting that Belgians have been widely exposed to these contaminants. The levels and the patterns of POP distribution in VF and SF tissue depots were not significantly different. Concentrations of PCBs (VF/SF; median: 285/275 ng/g lw) and DDTs (VF/SF; median: 150/155 ng/g lw) were the major POPs in all fat samples. Concerning PCBs, PCB 153 (VF/SF: 27/26%) was the most dominant congener, followed by PCB 180 (VF/SF: 17/18%), PCB 138 (VF/SF: 15/14.5%) and PCB 170 (VF/SF: 8.1/8.4%) to the sum PCBs, respectively. Levels of HBCDs (VF/SF; median: 4.0/3.7 ng/g lw) and PBDEs (VF/SF; median: 2.6/2.7 ng/g lw) were 1–2 orders of magnitude lower than those of PCBs and DDTs. Among PBDEs, BDE 153 (VF/SF: 31/34%) was the dominant congener, followed by BDE 47 (VF/SF: 26/23%), BDE 154 (VF/SF: 16/16%), BDE 100 (VF/SF: 10/11%) and BDE 99 (VF/SF: 9/9%). To our knowledge, this is the first report on HBCD concentrations in Belgian human fat tissues. Total PBDE and HBCD levels in human fat samples could not be correlated with age. In agreement with the literature, a significant correlation (p < 0.05) between age and the concentration of PCBs (r = 0.828), DDTs (r = 0.640), HCHs (r = 0.666), CHLs (r = 0.534) and HCB (r = 0.754), was observed in the present study. Levels of DDTs, HCHs, HCB and CHLs were also significantly correlated to each other, suggesting that they share similar exposure routes. Correlation with computed tomography (CT) scan data revealed that VF and VF/SF ratios are positive for most of the POPs, such as PCBs, PBDEs, p,p′DDE, CHLs, β-HCH, and HCB. To our knowledge, this study is the first to assess the relationship between POP levels in adipose tissue and markers of abdominal adiposity, determined by CT.     

Levels and trends of persistent organic pollutants in ringed seals (Phoca hispida) from Central West Greenland, with particular focus on polybrominated diphenyl ethers (PBDEs)

Polybrominated diphenyl ethers (PBDEs) and the organochlorine compounds polychlorinated biphenyls (PCBs), DDTs, HCB, chlordane-related pesticides, HCH and toxaphene were analysed in blubber of juvenile ringed seals from Central West Greenland collected between 1982 and 2006. The longest time series could be established for PBDEs, partly based on archived material, while PCBs and DDTs covered a study period from 1994-2006. All organochlorines showed decreasing trends, most pronounced for DDT and HCH with an annual change of 8%. BDE-47 had a significantly increasing trend of 5% annually. It was the only BDE congener consistently above the detection limit, with annual median concentrations between 0.78 ng/g lw to 3.54 ng/g lw, i.e. about 10 times lower than values from East Greenland observed in a similar time trend study on ringed seal blubber [Rigét F, Vorkamp K, Dietz R, Rastogi SC. Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from East Greenland. J Environ Monit 2006; 8: 1000-5]. A clear East>West difference was also found for PCBs and DDTs, but not for chlordanes, toxaphene or HCHs. Sigma 10-PCB, Sigma DDT and Sigma Chlordanes had similar annual median concentrations, typically exceeding SigmaPBDE by two orders of magnitude. The concentrations of HCH and toxaphene were in an intermediate group, with highest annual median concentrations of 135 ng/g lw and 20 ng/g lw, respectively. For most compound groups, the circumpolar trend previously established under for example the Arctic Monitoring and Assessment Programme was confirmed, but apparently, more data are needed for chlordane-related compounds and toxaphene. Statistical analyses of the compound patterns in the ringed seal samples revealed significantly greater differences between seals from East and West than between different sampling years. Higher proportions of PCBs and DDTs and lower proportions of chlordanes and HCHs were found in seals from East Greenland than in those from West Greenland. Based on principal component analysis of individual congener and compounds, seals from East Greenland were found to contain higher proportions of the higher chlorinated CB congeners. Varying patterns between sampling locations may be caused by different exposure situations related to contaminant emissions and transport, but different feeding habits may also affect the contaminant composition.     

Polybrominated diphenyl ethers in the serum and breast milk of the resident population from production area, China

Polybrominated diphenyl ethers (PBDEs) have been produced in the south coast area of Laizhou Bay, Shandong Province in China, but little is known about the PBDE exposure level of residents to these compounds. We set out to assess potential health risks of PBDEs in the south coast area of the Laizhou Bay by determining the concentrations of PBDEs in serum and breast milk. We measured concentrations of eight PBDE congeners in serum and breast milk. The arithmetic means of Σ₈PBDE in pooled serum and breast milk were 613 ng/g lipid and 81.5 ng/g lipid, respectively. The highest concentration for Σ₈PBDE in all serum pools was 1830 ng/g lipid from the 41–50 year old female group. BDE-209 was the predominant congener, with the mean concentrations of 403 ng/g lipid in serum and 45.6 ng/g lipid in breast milk, respectively. BDE-209 averagely accounted for 65.8% and 54.2% of the total PBDEs, respectively. Our results suggest that high exposures to PBDEs have led to very high PBDE concentrations in serum and breast milk from the residents living in the south coast area of Laizhou Bay. High PBDE concentrations in human serum, particularly in women, pose a potential public health threat to local residents.     

Three decades (1983–2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 2: Brominated flame retardants

Brominated flame retardants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28 years between 1983 and 2010. Significant linear increases were found for sum polybrominated diphenyl ether (ΣPBDE), BDE100, BDE153, and hexabromocyclododecane (HBCD). Average increases of 5.0% per year (range: 2.9–7.6%/year) were found for the subadult polar bears. BDE47 and BDE99 concentrations did not show a significant linear trend over time, but rather a significant non-linear trend peaking between 2000 and 2004. The average ΣPBDE concentrations increased 2.3 fold from 25.0 ng/g lw (95% C.I.: 15.3–34.7 ng/g lw) in 1983–1986 to 58.5 ng/g lw (95% C.I.: 43.6–73.4 ng/g lw) in 2006–2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Analyses of δ¹⁵N and δ¹³C stable isotopes in hair revealed no clear linear temporal trends in trophic level or carbon source, respectively, and non-linear trends differed among sex and age groups. These increasing concentrations of organobromine contaminants contribute to complex organohalogen mixture, already causing health effects to the East Greenland polar bears.     

Country specific comparison for profile of chlorinated,brominated and phosphate organic contaminants in indoor dust. Case study for Eastern Romania, 2010

We have evaluated the levels and specific profiles of several organohalogenated contaminants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and flame retardants (FRs), such as polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), novel brominated FRs (NBFRs), and organophosphate FRs (OPFRs), in 47 indoor dust samples collected in 2010 from urban locations from Iasi, Eastern Romania. The dominant contaminants found in the samples were OPFRs (median sum OPFRs 7890 ng/g). Surprisingly, OCPs were also measured at high levels (median 1300 ng/g). Except for BDE 209 (median 275 ng/g), PBDEs were present in dust samples at relatively low levels (median sum PBDEs 8 ng/g). PCBs were also measured at low levels (median sum PCBs 35 ng/g), while NBFRs were only occasionally detected, showing a low usage in goods present on the Romanian market. The results of the present study evidence the existence of a multitude of chemical formulations in indoor dust. FRs are usually associated to human exposure via ingestion of dust, but other chemicals, such as OCPs, are not commonly reported in such matrix. Although OCPs were found at comparable levels with OPFRs in Romanian dust, OCPs possess a higher risk to human health due to their considerably lower reference dose (RfD) values. Indeed, the OCP exposure calculated for various intake scenarios was only 2-fold lower than the corresponding RfD. Therefore, the inclusion of OCPs as target chemicals in the indoor environment becomes important for countries where elevated levels in other environmental compartments have been previously shown.     

Natural and man-made organobromine compounds in marine biota from Central Norway

Brominated organic pollutants were found in selected samples of mollusk tissue, fish liver, as well as in the eggs and livers of shag from three sites in Central Norway. More than 80 organobromines were identified owing to the defined isotope ratio acquired by GC/ECNI-MS. However, only a few peaks could be assigned to anthropogenic brominated flame retardants (polybrominated diphenyl ethers). Most of the organobromine compounds detected were unknown or halogenated natural products. The known halogenated natural products MHC-1 and TBA were abundant in all samples and usually between equally abundant, and up to 50 fold more concentrated than the major polybrominated diphenyl ether congener BDE 47. The halogenated natural products BC-2 (2-MeO-BDE 68) and BC-3 (6'-MeO-BDE 47), were on level with BDE 100 which was the second most abundant BDE congener in many samples. The previously identified natural polybrominated hexahydroxanthene derivatives (PBHDs) were detected for the first time in bird eggs. Being major contaminants in bird eggs, PBHDs were only present at low levels in bird liver from nestlings originating from the same clutch. Such differences were detected for several other major contaminants. One unknown tetrabromo compound particularly abundant in mussels from Munkholmen was studied by GC/MS and the molecular ion was detected at m/z 446. The abundance of the most important unknown compounds did not correlate with BDEs and they most likely represent halogenated natural products. This study supports that halogenated natural products have to be treated as serious contaminants of marine coastal waters. Our data suggest that their abundance is highest in habitats along the shoreline. Thorough examination of these compounds in environmental samples is an important task.     

Concentrations of chlorinated and brominated contaminants and their metabolites in serum of harbour seals and harbour porpoises

Harbour seals (Phoca vitulina) and harbour porpoises (Phocoena phocoena) are top predators in the North Sea and consequently accumulate a variety of pollutants in their tissues. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) were measured in serum of wild harbour seals (n = 47) and captive harbour porpoises (n = 21). Both species exhibit long life spans and do not have extreme situations, such as complete fasting during periods of lactation, in their annual cycles. For PCBs, concentrations in adult males were slightly higher than in juveniles and lowest in juvenile females. For PBDEs, juveniles have higher levels than adult males and females, probably as a consequence of lactational transfer. However, differences between these age–gender groups were not statistical significant, indicating that individual variation was limited within each species, even without knowing the feeding status of the animals. Body condition, particularly emaciation, has a major influence on the levels of chlorinated and brominated contaminants in serum. Profiles of PCBs were CB 153 > CB 138 > CB 187 > CB 180 and CB 153 > CB 138 > CB 149 > CB 187 > CB 180 for harbour seals and porpoises respectively. For PBDEs, BDE 47 was the predominant congener followed by BDE 100 and 99 in both species. In harbour seals, concentrations of sum PCBs (median: 39,200 pg/ml) were more than 200 times higher than levels of sum PBDEs (median: 130 pg/ml) and almost 10 times higher than concentrations of sum HO-PCBs (4350 pg/ml). In harbour porpoises, concentrations of sum PCBs (median: 24,300 pg/ml) were about 20 times higher than concentrations of PBDEs (median: 1300 pg/ml). HO-PCBs were detected in only 4 harbour porpoises and this at very low concentrations. Naturally-produced MeO-PBDEs were only found in harbour porpoises at concentrations ranging from 120 to 810 pg/ml. HO-PBDEs were not found in any species. In general, harbour seals accumulate less compounds and have mostly lower concentrations than harbour porpoises possibly as a result of a better developed metabolism.     

Children's exposure to polybrominated diphenyl ethers (PBDEs) through mouthing toys

Polybrominated diphenyl ethers (PBDEs) have previously been detected in children toys, yet the risk of child exposure to these chemicals through the mouthing of toys or other items is still unknown. We aimed to expand on the current knowledge by investigating the impact of infants' mouthing activities on exposure to PBDEs present in toys. This was established by a leaching model for determining the amount PBDEs that can leach from toys into saliva in simulated conditions. The PBDE migration rate was at its highest for the 15 min low-exposure scenario incubations (198 pg/cm² × min) with the ERM EC-591 certified reference material (CRM) (0.17% w/w PBDEs). The leaching process was congener-dependent, since the percentage of lower brominated PBDE congeners that leached out was up to 4.5 times higher than for the heavier PBDEs. To study the scenario in which a child would mouth on a toy flame retarded with BDE 209 alone, a plastic item containing 7% BDE 209 (w/w) was also tested. The BDE 209 amounts leached out in only 15 min were higher than the amounts leached from the CRM after the 16 h incubation. For the Belgian population, the exposure scenario from mouthing on toys containing PBDEs in amounts similar to the REACH threshold was found to be lower than the exposure from mother's milk, but higher than the exposure through diet or even dust.     

Brominated flame retardants (BFRs) in breast milk and associated health risks to nursing infants in Northern Tanzania

The main aim of this study was to assess brominated flame retardants (BFRs) in breast milk in the Northern parts of Tanzania. Ninety-five colostrum samples from healthy, primiparous mothers at Mount Meru Regional Referral Hospital (MMRRH), Arusha Tanzania, were analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), hexabromobenzene (HBB), (2,3-dibromopropyl) (2,4,6-tribromophenyl) ether (DPTE), pentabromoethylbenzene (PBEB) and 2,3,4,5,6-pentabromotoluene (PBT). The Ʃ₇PBDE (BDE 28, 47, 99, 100, 153, 154, 183) ranged from below level of detection (< LOD) to 785 ng/g lipid weight (lw). BDE 47, 99, 100 and 153 were the dominating congeners, suggesting recent and ongoing exposure to banned, commercial PentaBDE mixture. A multiple linear regression model revealed that mothers eating clay soil/Pemba during pregnancy had significantly higher levels of BDE 47, 99, 100 and 153 in their breast milk than mothers who did not eat clay soil/Pemba. Infant birth weight and birth length were significantly correlated with the levels of BDE 47, 99, 100 and 153. The estimated daily intake (ng/kg body weight/day) of BDE 47 and 99 exceeded the US EPA Reference doses (RfD) in four and eight mothers, respectively, suggesting a potential health risk to the nursing infants.     

Brominated flame retardants and organochlorines in the European environment using great tit eggs as a biomonitoring tool

Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale.     

Distribution of polybrominated diphenyl ethers (PBDEs) and other persistent organic pollutants in human serum from Greece

Human serum samples (n=61) were collected in Attika, Greece between June and October 2007 and analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Thirty samples were collected from computer clerks of a large computer company in Athens working full-time with computers, and thirty-one from a control population in the Attika region with no computer use. Σ(5)PBDE concentrations (sum of tri- to hexa-BDEs) in all samples (n=61) ranged from 0.68 to 13.3 ng g(-1) lipid, with a median of 1.07 ng g(-1) lipid. These concentrations are on the lower end of those reported from other countries, probably reflecting lower usage of PBDE-containing products or lower exposures to these chemicals. Individual and Σ(5)PBDE concentrations did not statistically differ between the two groups of computer clerks and non-computer users (p>0.05), with the exception of BDE 153 (p=0.033). The predominant congener was BDE 153, followed by BDEs 47, 100, 99, 183, 154 and 28. HBCD was also detected in 70% of the samples. BDE 209 was detected in 8 out 61 samples (13%), with concentrations ranging from 1.18 to 19.1 ng g(-1) lipid, and a median of 2.94 ng g(-1) lipid. No age dependency was found for PBDEs. Σ(11)PCB (sum of PCBs 74, 99, 118, 138, 146, 153, 156, 170, 180, 183 and 187,) in all samples (n=61) ranged from 36 to 402 ng g(-1) lipid, with a median of 110 ng g(-1) lipid. pp'-DDE concentrations ranged from 53.8 to 1649 ng g(-1) lipid, with a median of 268 ng g(-1) lipid. This is the first study to report levels of PBDEs in a possibly occupationally exposed subset of the Greek population.     

Persistent organic pollutants in the Scheldt estuary: Environmental distribution and bioaccumulation

Levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) were determined in the sediment and several species (European flounder, Platichthys flesus; common sole, Solea solea; Chinese mitten crab, Eriocheir sinensis; shore crab, Carcinus maenas; brown shrimp, Crangon crangon; blue mussel, Mytilus edulis and bristle worms, Polychaeta) from 7 locations in the Scheldt estuary (SE, the Netherlands–Belgium). Overall POP levels in the sediment were low. The average PCB and PBDE concentrations were respectively 31.5 and 115 ng/g dry weight (dw). Highest sediment loads were measured in the vicinity of Antwerp (368 ng PCBs/g dw), a location with intense harbor and industrial activities. Pollution concentrations in the tissues of biota were species-specific. Blue mussels contained the highest lipid concentrations (2.74 ± 0.55%) and reached the highest contamination levels (from 287 to 1688 ng PCBs/g ww, from 2.09 to 12.4 ng PBDEs/g ww). Lowest tissue loads were measured in brown shrimp (from 3.27 to 39.9 ng PCBs/g ww, from 0.05 to 0.47 ng PBDEs/g ww). The PCB congener profile in most of the species was similar with the pattern found in the sediment. PCB 153 was the most abundant congener (16.5–25.7% in biota, 10.4% in sediment). In the sediment, the total amount of PBDEs consisted for more than 99% of BDE 209. Congener BDE 47 had the highest concentrations in all sampled species (38.5–70.1%). Sediment POP loadings and tissue concentrations were poorly correlated, indicating that a simple linear or non-linear relationship is insufficient to describe this relationship, possible caused by the complexity of the bioaccumulation processes and the variability in exposure. Because of the high PCB levels, regular consumption of fish and seafood, especially mussels, from the Scheldt estuary should be avoided.     

Can starling eggs be useful as a biomonitoring tool to study organohalogenated contaminants on a worldwide scale?

Large-scale international monitoring studies are important to assess emission patterns and environmental distributions of organohalogenated contaminants (OHCs) on a worldwide scale. In this study, the presence of OHCs was investigated on three continents (Europe, North America and Australasia), using eggs of starlings (Sturnus vulgaris and Sturnus unicolor) to assess their suitability for large-scale monitoring studies. To the best of our knowledge, this is the first study using bird eggs of the same species as a biomonitor for OHCs on an intercontinental scale. We found significant differences in OHC concentrations of the eggs among sampling locations, except for hexachlorocyclohexanes (HCHs). Mean concentrations of sum polychlorinated biphenyls (PCBs) in eggs ranged from 78 ± 26 ng/g lipid weight (lw) in Australia to 2900 ± 1300 ng/g lw in the United States. The PCB profile was dominated by CB 153 and CB 138 in all locations, except for New Zealand, where the contribution of CB 95, CB 101 and CB 149 was also high. The highest mean sum polybrominated diphenyl ether (PBDE) concentrations were found in Canada (4400 ± 830 ng/g lw), while the lowest mean PBDE concentrations were measured in Spain (3.7 ± 0.1 ng/g lw). The PBDE profile in starling eggs was dominated by BDE 47 and BDE 99 in all countries, but in Belgium, the higher brominated PBDEs had a higher contribution compared to other countries. For the organochlorine pesticides (OCPs), dichlorodiphenyltrichloroethanes (DDTs) ranged from 110 ± 16 ng/g lw in France to 17,000 ± 3400 ng/g lw in New Zealand, while HCHs and hexachlorobenzene were generally in low concentrations in all sampling locations. Chlordanes were remarkably high in eggs from the United States (2500 ± 1300 ng/g lw). The OCP profile in all countries was largely dominated by p,p′-DDE. In general, the worldwide trends we observed in starling eggs were in accordance with the literature on human and environmental OHC data, which suggests that there is potential for using starling eggs as a biomonitoring tool on a large geographical scale.     

Interspecific differences in concentrations and congener profiles of chlorinated and brominated organic pollutants in three insectivorous bird species

We investigated the accumulation of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in eggs of three insectivorous bird species, the great tit (Parus major), the Northern lapwing (Vanellus vanellus) and the Mediterranean gull (Larus melanocephalus), near the harbour of Antwerp (Belgium). Our results show that lapwing eggs had the highest median concentrations of PCBs (4358 ng/g lw) and PBDEs (109 ng/g lw). Mediterranean gulls feed during breeding on ground-dwelling invertebrates on agricultural fields, which is reflected in higher OCP concentrations in eggs (1235 ng/g lw). Apart from differences in accumulation, also interspecific differences in contaminant profiles were investigated. Significant differences among species were found in the profile of PCBs, PBDEs and OCPs. These differences could be attributed to differences in diet, behaviour and metabolic capacity. Interestingly, the OCP profile in lapwing eggs deviated extremely from the two other species. In both great tit and Mediterranean gull eggs p,p'-DDE was by far the most important compound, whereas in lapwing eggs hexachlorobenzene, oxychlordane, trans-nonachlor and even p,p'-DDT were relatively more abundant than p,p'-DDE. The high p,p'-DDT/p,p'-DDE ratio has previously been described in lapwings, which suggests that low p,p'-DDE accumulation in eggs might be inherent for this species.