Bioaccumulation of polybrominated diphenyl ethers in harbor seals from the northwest Atlantic

Alternative and legacy flame retardants in marine mammals from three northern ocean regions

Flame retardants are globally distributed contaminants that have been linked to negative health effects in humans and wildlife. As top predators, marine mammals bioaccumulate flame retardants and other contaminants in their tissues which is one of many human-imposed factors threatening population health. While some flame retardants, such as the polybrominated diphenyl ethers (PBDE), have been banned because of known toxicity and environmental persistence, limited data exist on the presence and distribution of current-use alternative flame retardants in marine mammals from many industrialized and remote regions of the world. Therefore, this study measured 44 legacy and alternative flame retardants in nine marine mammal species from three ocean regions: the Northwest Atlantic, the Arctic, and the Baltic allowing for regional, species, age, body condition, temporal, and tissue comparisons to help understand global patterns. PBDE concentrations were 100-1000 times higher than the alternative brominated flame retardants (altBFRs) and Dechloranes. 2,2',4,5,5'-pentabromobiphenyl (BB-101) and hexabromobenzene (HBBZ) were the predominant altBFRs, while Dechlorane-602 was the predominant Dechlorane. This manuscript also reports only the second detection of hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO) in marine mammals. The NW Atlantic had the highest PBDE concentrations followed by the Baltic and Arctic which reflects greater historical use of PBDEs in North America compared to Europe and greater industrialization of North America and Baltic countries compared to the Arctic. Regional patterns for other compounds were more complicated, and there were significant interactions among species, regions, body condition and age class. Lipid-normalized PBDE concentrations in harbor seal liver and blubber were similar, but HBBZ and many Dechloranes had higher concentrations in liver, indicating factors other than lipid dynamics affect the distribution of these compounds. The health implications of contamination by this mixture of compounds are of concern and require further research.

Exposure to legacy and alternative flame retardants in two harbor seal populations and the association with blubber fatty acid profiles

Flame retardants (FRs) are ubiquitously present in various environmental compartments due to widespread application. However, there have been few reports on the alternative FRs in harbor seals, and their relationship with fatty acid (FA) profiles have largely been overlooked. Here, we investigated the levels of legacy and alternative FRs and FA profiles in the blubber of harbor seals from the coasts of South Sweden (2009-2016) and Northeastern US (NE US) (1999-2010). We observed different proportions of mono- and poly-unsaturated FAs (MUFAs and PUFAs) between the two populations, which may reflect variations in the diet. Significantly higher concentrations of ΣPBDE were also observed in harbor seals from US compared to those from Sweden, both dominated by BDE 47. By comparison, the levels of alternative FRs, noticeably HBBZ and PBEB were much lower compared to those of PBDEs. Moreover, we found a positive correlation between BDE 99 and Σn-6/Σn-3 PUFA in harbor seals from Sweden. In addition, BDE 153 and BDE 154 were positively correlated with ΣUFA/ΣSFA in seals from Sweden and US, respectively. Our results imply the influence of diet in FA profiles and FR concentrations in top predators, as well as the importance of blubber FA characteristics in indicating FR exposure. Further investigations are required to assess the risk of exposure in these harbor seals, as well as to elucidate the underlying mechanisms associating FA profiles with FR exposure.

Occurrence and tissue-specific partitioning of alternative brominated flame retardants in northwest Atlantic harbor seal pups (Phoca vitulina vitulina)

Brominated flame retardants such as polybrominated diphenyl ethers (PBDEs) have been used for decades until evidence of negative health effects led to bans in many countries. PBDEs have since been replaced by alternative legacy compounds or newly developed chemicals. In this study, eight alternative brominated flame retardants were analyzed in blubber and liver of harbor seal pups (≤6 months) from the Northwest Atlantic collected during 2001-2010 to elucidate concentrations, patterns, contamination trends, potential maternal transfer, and tissue partitioning. All compounds were detected in liver and blubber tissues with hexabromocyclododecane (HBCD) isomers and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB) predominating. Overall, α-HBCD was the dominant HBCD isomer in both tissues although the concentrations of γ-HBCD exceeded those of α-HBCD in seven pups, indicating their mothers may have had alternative dietary patterns or recent exposure to the commercial mixture. Although it was detected in less than half of the samples, to our knowledge, this is the first study to report tetrabromobisphenol A (TBBPA) concentrations in multiple tissues of a top marine predator. For the brominated components of Firemaster® flame retardants, TBB concentrations exceeded bis-(2-ethylhexyl)-tetrabromophthalate (TBPH). This pattern may result from recent exposure to commercial mixtures in which TBB exceeds TBPH 4:1 or from differences in perinatal or lactational transfer efficiency of the two compounds. Between the two tissues, lipid-normalized β-HBCD, γ-HBCD, TBB and decabromodiphenyl ethane (DBDPE) concentrations were significantly higher in liver than blubber. This indicates that the bioaccumulation of these chemicals is not simply related to lipid dynamics but may be linked to blood proteins. This study demonstrates that harbor seal pups from this region are contaminated with alternative flame retardants passed to them via placental or lactational transfer. Given the evidence for negative health effects of these chemicals, this contamination adds additional pressure on the first year survival of these young, developing animals.

Persistent organic pollutants in sediments, intertidal crabs, and the threatened Olrog's gull in a northern Patagonia salt marsh, Argentina

Persistent organic pollutants (POPs) are of great concern for the environment. In this study we (a) determine levels and distribution of OCPs, PCBs, and PBDEs in sediments and two crab species (Neohelice granulata and Cyrtograpsus altimanus), (b) assess bioaccumulation in crabs, and (c) explore the occurrence of POPs in the Near Threatened Olrog's gull (Larus atlanticus) chicks and eggs in one of the most important salt marsh environments in the South West Atlantic. Sediments, crabs, and gull chicks and eggs showed POPs presence at low levels; being α-endosulfan, PCB-153, and BDE-47 the most represented compounds. In sediments, pollutant concentrations were lower than those reported in Canadian guidelines for the protection of the aquatic life. POP bioaccumulation was recorded in crabs, suggesting a risk to upper trophic level predators. Further studies are needed to understand the trophic effects of POPs in San Blas bay, particularly on the threatened Olrog's gull.

A contemporary assessment of polybrominated diphenyl ethers (PBDE) in the ambient air and soil of Azerbaijan

PBDEs were measured in air and soil across Azerbaijan to establish contemporary concentrations at 13 urban and rural sites. Polyurethane foam passive air samplers (PUF-PAS) were deployed for a period of a month with surface soil samples collected at the same sites. Unlike organochlorine pesticides previously surveyed by our group, PBDE concentrations in both contemporary air and soil were low in comparison to recent European and Asian studies. For example, mean ∑₉PBDE concentrations in air and soil were 7.13 ± 1.66 pg m^-3 and 168 ± 57 pg g^-1, respectively. The fully brominated BDE-209 was the most abundant congener observed in soil (174.8 ± 58.5 pg g^-1), comprising ~ 96% of ∑₁₀PBDE. However, the PAS-derived air concentrations for highly brominated congeners must be viewed with caution as there is uncertainty over the uptake rates of particle-bound chemicals using these devices. Some of the highest concentrations in air were observed at sites with the highest wind speeds and at several remote locations in the north of the country and this requires further research. Levels of BDE-47 and 99 (the two most abundant congeners in the widely used penta-formulation) were lower than levels reported elsewhere suggesting limited use/import of the penta-BDE formulation in Azerbaijan.

Accumulation of PBDEs in stranded harp (Pagophilus groenlandicus) and hooded seals (Cystophora cristata) from the Northeastern United States

Polybrominated diphenyl ethers (PBDEs) are highly lipophilic components of brominated flame retardants that are environmentally persistent and bioaccumulate. PBDEs are taken up from the gastrointestinal tract and accumulate mainly in fat depots and liver tissues. Seal species inhabiting Arctic and sub-Arctic regions can have upwards of 30% of their body mass composed of blubber. When those blubber stores are mobilized for energy, stored toxicants are also released into circulation. Most studies reporting accumulation of PBDEs in seals have focused on harbor and grey seals with few examining harp and hooded seals. In this study, PBDEs concentrations were analyzed in seal blubber from 21 stranded harp and 9 stranded hooded seals sampled along the northeast coast of the U.S. (1999-2010). A PBDE congener profile was determined for each individual. The results show that both species of seals are accumulating PBDEs with BDE-47 being the dominant congener. Mean ƩPBDE concentrations in harp seals were 70.55 ± 33.59 ng/g ww and for hooded seals 94.28 ± 42.65 ng/g ww. The results of this study are consistent with previous studies reporting a decrease in bioaccumulation with an increase in bromination. For both species, BDE-47 represented the highest percentage of the ƩPBDEs, composing over 50% of the ƩPBDEs in harp seals. When compared to stranding condition code, animals found alive had overall higher PBDE concentrations than those found in a state of moderate decomposition. This difference could be due to decreased blubber levels in the decomposed animals or potential degradation of the compounds in the blubber. Almost all seals used in this study were yearlings which is the most likely age class to strand. Yearling seals are at a crucial stage of development, especially of their immune system, which can be impacted by high levels of contaminants like PBDEs and increase the susceptibility to disease.

Occurrence of polybrominated dibenzo-p-dioxins, dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) in pilot whales (Globicephala melas) caught around the Faroe Islands

Blubber from Faroese pilot whales (Globicephala melas) was analysed for brominated dioxins PBDD/Fs, with a subset also analysed for chlorinated dioxins, PCDD/Fs. The studied individuals were restricted to juvenile male whales sampled in the Faroe Islands during the period 1997-2013. Among the PBDD/Fs, the furans were predominant, although the relative abundance of various congeners differed between samples. Furans accounted for, on average, 79% of the ∑PBDD/Fs in the samples, with 1,2,3,4,6,7,8-HpBDF the most abundant congener, found in half of the analysed pilot whales. The concentration range for ∑PBDD/Fs among the samples was 0.080-71 pg/g l.w. (lipid weight), and the sum of toxic equivalents ranged from 0.0039 to 4.7 pg TEQ/g l.w. No relationship was found between PBDD/Fs and PCDD/Fs. In addition, 20 pilot whale samples from the period 2010-2013 were analysed for PBDEs. Several PBDE congeners were found in all of the sampled pilot whales, and at noticeably higher levels than PBDD/Fs and PCDD/Fs. The ∑PBDEs ranged from 140 to 1900 ng/g l.w., with BDE #47 the most abundant congener detected in the samples. Results from the present study were then compared with data from previous studies on pilot wales to investigate temporal trends between 1986 and 2013. The comparison indicated that PBDE concentrations in juvenile males have decreased from 1996 to the latest observations in 2013. No relationship between the concentration levels of PBDD/Fs and PBDEs in the sampled pilot whales could be identified, which indicates possible differences in the metabolism of, or exposure to, PBDEs and PBDD/Fs.

Quantification of polybrominated diphenyl ethers (PBDEs) in food. A review

The polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardants (BFRs), are food contaminants of animal origin. Interest in food matrices analysis is growing due to the toxicity of PBDEs and European Commission (EC) recommendation (118/2014/EU). Here we review papers concerning methods of PBDEs analysis while focusing on extraction, clean up, chromatographic separation and detection techniques. The emphasis is put on EC recommendation, the congeners and the efficiency of different detection systems. Some analytical problems caused by differences between low- and high-molecular-mass congener properties, especially the possible limitations of BDE-209 analysis, are discussed. Detection techniques and mass spectrometry (MS) ionization modes applied to PBDE level determination in food of animal origin are compared. The gas chromatography (GC) coupled to high-resolution MS is undoubtedly fit for that purpose, but ion trap MS could be used to PBDEs determination as well. ECD is the most sensitive technique; however, other halogen compounds present in sample may interfere with PBDEs congeners necessitating results confirmation. Moreover, the novel atmospheric pressure chemical ionization (APCI) method applied to GC in tandem with MS places this technique in the top category of the most sensitive techniques which may be used.

Effects of carbonaceous materials on microbial bioavailability of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in sediments

In this study, we investigated the influence of various types of carbonaceous materials (CMs) on the bioavailability of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) to polybrominated diphenyl ether (PBDE)-degrading microorganisms in CM-amended sediments. The microbial debromination ratio of BDE-47 was reduced by 92.8%-98.2% in the 5.0% CM-amended sediment compared with in sediment without CM amendment after 100 d of anaerobic incubation. The concentrations of lower brominated products also decreased when the content of CMs increased from 0.2% to 5.0%. The inhibitory effects of CMs on BDE-47 debromination were CM content- and characteristic-specific. The reciprocals of BDE-47 debromination ratios and lower brominated product concentrations showed positive linear correlations with CM contents in sediments (p<0.01), and the slopes of linear regression fitting generally correlated with specific surface areas (SSAs) of CMs. Desorption of BDE-47 from CMs indicated the declined desorbing fraction of BDE-47 was responsible for the reduction in BDE-47 bioavailability to microorganisms, thus decreasing its debromination in sediments amended with CMs. This study revealed that CM amendment could reduce the PBDE bioavailability to PBDE-degrading microorganisms in sediments, and it is expected to help deepen our understanding of the environmental behaviors and risks of PBDEs.

Microbial bioavailability of 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) in natural sediments from major rivers of China

Microbial degradation plays a crucial role in eliminating polybrominated diphenyl ethers (PBDEs) in environments. However, the microbial bioavailability of PBDEs in aquatic sediments is not well understood. In this work, the bioavailability of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a typical PBDE congener, to PBDE-degrading microorganisms in natural sediments from six Chinese rivers under anaerobic conditions was investigated. The contents of black carbon (BC) and total organic carbon (TOC) in the six sediment samples were in the range of 0.025%-0.30% and 0.03%-3.38%, respectively. BDE-47 desorption from various sediments was fitted well with the first-order three-compartment desorption model. The desorbing fraction of sediment-associated BDE-47 at each desorption time interval exhibited a significant negative correlation with the BC content (p < 0.01). In the sediments, the anaerobic debromination of BDE-47 by microorganisms underwent a stepwise debromination pathway generating mainly three lower brominated congeners (BDE-28, -17 and -4). The microbial debromination ratio of BDE-47 ranged from 4.21% to 7.89% in various sediments after 120 d incubation anaerobically, and it negatively correlated with the content of sediment BC significantly (p < 0.01). However, the desorbing fraction and microbial debromination ratio of BDE-47 only showed weak correlations with the TOC content in sediments (p > 0.05). Furthermore, there was a significant positive correlation of desorbing fraction of BDE-47 from sediments with its microbial debromination ratio (p < 0.01) as well as with the level of its three lower brominated products (p < 0.05) after the first 20 d incubation. This study suggests that the BDE-47 bioavailability to microorganisms in anaerobic river sediments is mainly influenced by the content of sediment BC which controls the desorbing fraction of sediment-associated BDE-47.

Bioaccumulation characteristics of polybrominated diphenyl ethers in the marine food web of Bohai Bay

In recent years, polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants, but its bioaccumulation and debromination in biota have remained largely unclear. In this study, we analyzed six PBDEs (BDE47, 99, 100, 153, 154, and 209) in various tissues (i.e., viscera, muscle, and gill) of 11 types of marine organisms including zooplankton, invertebrate and fish. The concentrations of six PBDE including BDE209 in marine organisms ranged from 0.75 to 7.29 ng/g dry weight, BDE209 from 0.46 to 6.78 ng/g dry weight, respectively. BDE209 was the dominant congener in all samples, followed by BDE47. The concentration ratio of BDE47, 99, 154 to ΣPBDEs in various tissues of organisms (i.e., Rapana venosa, shrimp, crab, cuttlefish, octopus, Synechogobius hasta, tonguefish and wolfish) increased, while the concentration ratio of BDE209 to ΣPBDEs decreased. Large differences of the concentration ratios between BDE99 and BDE100 in tissues of crab was found, ranging from 32:68 in crab viscera to 83:17 in crab leg muscle. Biomagnification factors for individual PBDE congeners ranged from 0.16 to 78.6. In general, the BMFs for BDE209 in muscle were higher than those in viscera within feeding relationships. The study results suggesting BDE209 can be biodegraded to BDE47 through BDE154 and BDE99 in marine organism, its metabolite importantly influenced by organism type not trophic level; higher percentage of BDE154 was found in viscera than that in other tissues in the analyzed marine organisms of Bohai Bay.

PCB and PBDE levels in a highly threatened dolphin species from the Southeastern Brazilian coast

In the Northern coast of Rio de Janeiro State is located the major urban centers of the oil and gas industry of Brazil. The intense urbanization in recent decades caused an increase in human use of the coastal areas, which is constantly impacted by agricultural, industrial and wastewater discharges. Franciscana dolphin (Pontoporia blainvillei) is a small cetacean that inhabits coastal regions down to a 30 m depth. This species is considered the most threatened cetacean in the Western South Atlantic Ocean. This study investigated the levels of 52 PCB congeners and 9 PBDE congeners in liver of nine individuals found stranded or accidentally caught between 2011 and 2012 in the Northern coast of Rio de Janeiro. PCB mean levels ranged from 208 to 5543 ng g(-1) lw and PBDEs mean concentrations varied between 13.84 and 36.94 ng g(-1) lw. Contamination patterns suggest the previous use of Aroclor 1254, 1260 and penta-BDE mixtures in Brazil. While still few studies have assessed the organic contamination in cetaceans from the Southern Hemisphere, including Brazil, the levels found in this study could represent a health risk to these endangered species.

Methoxylated PBDEs (MeO-PBDEs), hydroxylated PBDEs (HO-PBDEs) and hydroxylated PCBs (HO-PCBs) in the liver of harbor seals from the northwest Atlantic

Metabolites of PCBs and PBDEs are shown to influence the thyroid hormone homeostasis and therefore, could have an influence on the growth of newborn or young animals. We have investigated the occurrence of hydroxylated PCBs (HO-PCBs), hydroxylated PBDEs (HO-PBDEs), and methoxylated PBDEs (MeO-PBDEs) in the liver (48 pups; 6 adults) and blubber (4 pups; 1 adult) of harbor seals (Phoca vitulina concolor) from the northwest Atlantic. The sum of HO-PCBs in the liver ranged from 90 to 22,450 pg/g wet weight (ww) for pups and from 410 to 5290 pg/g ww for adults. Congener 4-HO-CB 107 was predominant in almost all samples regardless of age or gender, except in one adult male. Sum HO-PCB concentrations were highly correlated with the sum of precursor PCBs in the liver of harbor seals (r(2) = 0.79; p<0.0001). Concentrations of sum HO-PBDEs in the liver ranged from 70 to 1850 pg/g ww for pups and from 90 to 230 pg/g ww for adults. HO-PBDEs were also correlated with PBDEs (r(2) = 0.58; p<0.0001). Sum MeO-PBDE concentrations in the liver ranged from 20 to 1460 pg/g ww in pups and from 10 to 270 pg/g ww in adults. HO-PCBs and HO-PBDEs were not detected in the blubber. Levels of MeO-PBDEs in the blubber ranged from 1500 to 4400 pg/g ww. In all blubber samples, 6-MeO-BDE 47 was the predominant MeO-PBDE congener, followed by 2'-MeO-BDE 68 and 5-MeO-BDE 47, respectively. The presence of HO-metabolites in pup liver suggests that young harbor seals may have some, yet limited, metabolic capacity for PCBs and PBDEs, which can lead to an excessive accumulation of these chemicals in the body. Moreover, the presence of HO-PCB and HO-PBDE metabolites may pose an additional stress for young harbor seals due to their influence on the thyroid hormone system and could have consequences for the entire population.

Polychlorinated biphenyls still pose significant health risks to northwest Atlantic harbor seals

Polychlorinated biphenyls (PCBs) have been detected at relatively high concentrations in harbor seals, apex predators in the northwest Atlantic. As part of an ongoing assessment of the effects of PCBs on population health, we analyzed tri- to deca-PCBs in the liver of 56 harbor seals (6 adult males, 50 pups) and in 11 blubber samples (4 adult males, 7 pups) and examined tissue-specific accumulation patterns, biomagnification potential, and toxic implications of current PCB concentrations. Hepatic ∑30PCB concentrations (overall mean±standard deviation: 76,860±111,800 ng/g lipid weight, lw) were higher than blubber concentrations (48,180±69,420 ng/g lw). Regional trends were suggestive of fresh PCB inputs from the industrialized, densely populated southern coast of New England versus the rural north. The lack of temporal trends confirmed that tissue concentrations of PCBs have plateaued since the early 1990s. Tissue distribution of PCBs varied significantly by age and, surprisingly by gender among the pups. Principal Component Analysis (PCA) revealed that lighter PCBs are selectively transferred from mother to pup blubber in relation to lipid solubility (log Kow), but heavier PCBs may be efficiently transferred during late lactation from mother to pup liver. Biomagnification factors (BMFs) for ∑6PCBs from prey fish to adult male seals ranged from 90 to 547 in the liver and 88 to 532 in the blubber, and suggested that molecular structure and metabolic capacity were more important influences than log Kow on the retention of PCBs. Blubber concentrations of ∑30PCBs in 87% of the pups were an order of magnitude higher than recent toxic reference values (TRVs) calculated for ∑154PCBs in nursing harbor seals, suggesting that the pups are at risk for PCB-mediated toxicity at a vulnerable stage of development. Given the recurring pattern of epizootics in these seals, the health of the population is of concern.

An overview of time trends in organic contaminant concentrations in marine mammals: going up or down?

In this article I review recent trends reported in the literature from 2008 to date for organic contaminant concentrations in marine mammal tissues worldwide, in order to get an idea of where we stand currently in relation to the control of hazardous substances. For many contaminants which have been subject to regulation regarding their production and use (e.g. organochlorine pesticides, PBDE and HBCD flame retardants, butyltins) trends are downwards. For perfluorinated compounds, trends are more mixed. For dioxins, furans and dioxin-like CBs, there are no recent data, for either concentrations or trends. For CBs overall, earlier downward trends in concentration in UK harbour porpoises following regulation beginning in the 1980s have stalled, and remain at toxicologically significant levels. This raises concerns for killer whales and bottlenose dolphins who, because of their larger size and greater bioaccumulation potential, have higher levels still, often far above accepted toxicological threshold values.

Wastewater treatment plants as chemical observatories to forecast ecological and human health risks of manmade chemicals

Thousands of chemicals have been identified as contaminants of emerging concern (CECs), but prioritizing them concerning ecological and human health risks is challenging. We explored the use of sewage treatment plants as chemical observatories to conveniently identify persistent and bioaccumulative CECs, including toxic organohalides. Nationally representative samples of sewage sludge (biosolids) were analyzed for 231 CECs, of which 123 were detected. Ten of the top 11 most abundant CECs in biosolids were found to be high-production volume chemicals, eight of which representing priority chemicals, including three flame retardants, three surfactants and two antimicrobials. A comparison of chemicals detected in nationally representative biological specimens from humans and municipal biosolids revealed 70% overlap. This observed co-occurrence of contaminants in both matrices suggests that the analysis of sewage sludge can inform human health risk assessments by providing current information on toxic exposures in human populations and associated body burdens of harmful environmental pollutants.

Developmental exposure to decabrominated diphenyl ether (BDE-209): effects on sperm oxidative stress and chromatin DNA damage in mouse offspring

Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants and have been found in human milk in recent years. This study investigates whether prenatal exposure to decabrominated diphenyl ether (BDE-209) induces sperm dysfunction in male offspring. Pregnant CD-1 mice were gavaged once daily with corn oil (control), 10, 500, and 1500 mg kg(-1) body weight of BDE-209 from day 0 of gestation to day 17. The outcomes of male reproductive parameters were assessed on postnatal day 71. Anogenital distance, sperm-head abnormalities, and testicular histopathology were significantly affected in male offspring prenatally exposed to 1500 mg kg(-1). Significant increases in the tendency for sperm DNA denaturation (αT) induction and the DNA fragmentation index (DFI) were found in those exposed to 10, 500, and 1500 mg kg(-1) (P < 0.05). We observed a significant increase of sperm hydrogen peroxide (H(2)O(2)) generation in the 10 and 1500 mg/kg/day groups compared to the control group (P < 0.05). Although our findings suggested that the mechanisms underlying BDE-209-induced sperm DNA damage and H(2)O(2) generation might not be represented as a dose-response relationship, we found that the greater the excess production of sperm H(2)O(2), the greater the sperm αT (r = 0.65, P = 0.0155) and DFI (r = 0.53, P = 0.002). In conclusion, developmental exposure to BDE-209 induced sperm-head abnormality, oxidative stress, chromatin DNA damage, and testicular histopathological changes. These findings suggest that BDE-209-induced male reproductive effects might involve the formation of sperm H(2)O(2) which attacks nucleic acids via H(2)O(2) generation.

Polychlorinated biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) in three fish species from an estuary in the southeastern coast of Brazil

Polychlorinated biphenyls (PCBs) and Polybrominated Diphenyls Ethers (PBDEs) are two highly lipophilic classes of persistent organic pollutants able to resist degradation and with the ability to bioaccumulate through the food chain. In Brazil, there are still few studies on PCBs and PBDEs in aquatic organisms. In this study, we determined the levels of PBDEs and PCBs in three different fish species from the Ilha Grande Bay, located in the southern state of Rio de Janeiro, Brazil. PBDEs levels were very low, with values below the limit of quantification. PCBs concentrations ranged from 2.29 to 27.60 ng g(-1) ww in muscle and from 3.41 to 34.22 ng g(-1) ww in liver of the three investigated fish species. Significant positive correlations were established between PCBs concentration and fish biometric variables in mullet (length and lipid content) and a statistically significant change between seasons in croaker was observed.

Species-specific differences in the accumulation features of organohalogen contaminants and their metabolites in the blood of Japanese terrestrial mammals

Residue levels and patterns of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), their hydroxylated metabolites (OH-PCBs, OH-PBDEs), and methoxylated PBDEs (MeO-PBDEs) in the blood of various terrestrial mammals in Japan, including cats, raccoon dogs, dogs, masked palm civets, foxes, raccoons, badgers, and mongooses were determined. Tri- through penta-chlorinated OH-PCBs were predominant in cat blood, whereas hexa- through octa-chlorinated OH-PCBs were found in other species. High proportion of BDE209 was found in all species, suggesting exposure to municipal waste and soil containing higher levels of deca-BDE products. 6OH-/MeO-BDE47 and 2'OH-/MeO-BDE68 were dominant in all terrestrial mammals. This is first report on the detection of OH-/MeO-PBDEs in the blood of terrestrial mammals. High concentrations of OH-/MeO-PBDEs were found in cats, suggesting the intake of these compounds from seafood. Cats exhibited higher accumulation and specific patterns of OH-PCBs, OH-PBDEs, and MeO-PBDEs, they may be at a high risk from these metabolites.

Transfer of PBDEs from e-waste to aqueous media

Experiments and analysis were carried out by contacting e-waste with distilled water and leachate from a major urban landfill. Contacting of crushed e-waste from different eras with leachate in a custom built end-over-end contactor led to appreciable mass transfer of Polybrominated diphenyl ethers (PBDEs) to the aqueous phase. Temperature had limited influence for the limited range (10-25°C) investigated. Lower pH (in the range 4 to 9) generally resulted in higher transfer of PBDEs to the aqueous phase. Exposing e-waste to distilled water in the same contactor led to lower, but still appreciable PBDE analysed concentrations, than for leachate, probably due to dislodgement of fine dust from the surface of the e-waste particles.

Bioaccumulation and debromination of BDE-209 in Japanese medaka (Oryzias Latipes) when continuously exposed to environmental relevant concentrations

BDE-209 is the most commonly used commercial polybrominated diphenyl ether, and is of particular concern due to its accumulation and debromination to more toxic congeners in aquatic organisms. In this study, Japanese medaka were continuously exposed to BDE-209 with the exposure concentrations ranging from 1 to 1000 ng/L for 15, 30 and 60 days in a flowing-through exposure device. The results showed that BDE-209 could be accumulated in fish muscle at environmental relevant concentrations and its concentration in the muscle increased with the increase of exposure time and reached to a steady state. Toxicokinetic data showed that the dose-dependent half-life of BDE-209 in the muscle of medaka ranged from 16.5 to 19.4 days. Low brominated congeners could be detected, where tri- to hexa-BDEs were predominant congeners with up to 46% to 93% of total PBDEs and lower brominated BDEs may have slower elimination rates. Concentration level of BDE-155 ranged from several ng/g wet weight (ww) to a maximum of 178 ng/g ww. BDE-154 and BDE-153 as intermediates in fish under continuous exposure were negligible. By comparing with previous work, fish may have a different bioaccumulation capacity and metabolic pattern from other species, either because of species difference or the manner of exposures.

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 35-19,547ng/glipid weight, lw) were similar to blubber concentrations, while α-HBCD levels in seal liver (range 2-279ng/glw) 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.

Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986-2009

A selection of PBDE congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography, and the analysis was performed on a GC-MS system operating in the NCI mode. The highest PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, and the lowest levels in fin whales and ringed seals. One-sided analyses of variance (ANOVA) followed by Tukey comparisons of means were applied to test for differences between years and sampling areas. Due to inter-year sampling variability, only general comparisons of PBDE concentrations between different sampling areas could be made. Differences in PBDE concentrations between three sampling periods, from 1986 to 2007, were evaluated in samples of pilot whales, ringed seals, white-sided dolphins and hooded seals. The highest PBDE levels were found in samples from the late 1990s or beginning of 2000, possibly reflecting the increase in the global production of technical PBDE mixtures in the 1990s. The levels of BDE #153 and #154 increased relative to the total PBDE concentration in some of the species in recent years, which may indicate an increased relative exposure to higher brominated congeners. In order to assess the effect of measures taken in legally binding international agreements, it is important to continuously monitor POPs such as PBDEs in sub-Arctic and Arctic environments.

Brominated diphenyl ether (BDE) levels in liver, adipose, and milk from adult and juvenile rats exposed by gavage to the DE-71 technical mixture

Brominated diphenyl ethers (BDEs) are used as flame retardants in consumer products. Rodent studies indicate that the liver, thyroid, and nervous system of developing animals are targets of BDEs. To explore the relationship between exposure and health in developing animals, BDE accumulation in adult and juvenile rats was examined in conjunction with changes in liver weight and serum thyroxine (T4). Adult (F0) rats received the commercial BDE mixture DE-71 by gavage at doses of 0.5, 5, and 25 mg kg(-1) body weight (bw)/day for 21 weeks. F0 rats were mated and exposure continued throughout breeding, pregnancy, lactation, and postweaning until the pups (F1 generation) reached postnatal day (PND) 42. Milk was collected from lactating dams. Adipose and liver samples were collected from F0 and F1 males and females for BDE congener analysis. Congener prevalence in rat tissues mimicked congener prevalence in wildlife and humans. Tissue concentrations of all congeners except BDE-153 were lower than would be expected based on dose proportionality, confirming that BDE-153 has a high capacity for bioaccumulation. BDEs were transferred from maternal tissues to milk during lactation. Milk congener profiles differed from maternal tissue profiles indicating that degree of bromination and maternal sequestration influenced BDE transfer to milk. Female F1 rats accumulated more BDEs than F1 males, indicating that female rats were less able to metabolize and/or excrete BDEs. Significant effects on liver weight and serum T4 levels were observed in adults and juveniles in the middle and high dose groups, corresponding to BDE levels in the μg g(-1) range. Although it remains to be determined how human liver and thyroid are affected by exposure to much lower BDE levels, the present study confirmed that gender and reproductive status influence BDE accumulation in tissues and BDE transfer to the neonate via milk.

Temporal trends of hexabromocyclododecane, polybrominated diphenyl ethers and polychlorinated biphenyls in ringed seals from East greenland

Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. α-HBCD was the only diastereoisomer consistently above levels of quantification and showed a significant log-linear (exponential) increase from 2.0 to 8.7 ng/g lipid weight (median concentrations) with an annual rate of +6.1%. The concentrations were up to several orders of magnitude lower than those reported for marine mammals from industrialized areas. Previously presented time trends on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding tolerable daily intake rates for seal blubber as traditional Arctic food items.

PBDEs in serum and blubber of harbor, grey and harp seal pups from Eastern Canada

Serum and blubber of pup harbor (Phoca vitulina), grey (Halichoerus grypus) and harp (Phoca groenlandica) seals from the Estuary and the Gulf of St. Lawrence were analyzed for polybrominated diphenyl ethers (PBDEs). Concentrations of ∑PBDEs (on lipid weight basis) in tissues of harbor seal pups inhabiting the St. Lawrence Estuary were about five times higher than in those from a colony located in the northern Gulf. Harp seal pups have the lowest levels of ∑PBDEs among the seal species born in the Gulf of St. Lawrence. Lipid normalized concentrations of ∑PBDEs in serum and blubber were strongly correlated, suggesting that the blood collection as a less invasive method could be used to monitor ∑PBDEs in pups. This study shows that fluvial inputs of PBDEs are important to the St. Lawrence marine ecosystem and that inhabiting harbor seal pups have a substantial exposure to PBDEs at a critical developmental stage. In addition, the observed difference in PBDE levels between harp and grey or harbor seal pups from the Gulf of St. Lawrence is explained by the difference in diets of their mothers which is linked with their residency time in the Gulf and their seasonal migration pattern.

Persistent organic pollutants and methoxylated PBDEs in harbour porpoises from the North Sea from 1990 until 2008: Young wildlife at risk?

In the European North Sea, harbour porpoises are top predators with relatively long life spans and a limited capacity for metabolic biotransformation of contaminants compared to some other marine mammal species. As such, they are exposed to a mixture of persistent pollutants, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), DDT and metabolites (DDXs), hexachlorobenzene (HCB) and chlordanes (CHLs) that bioaccumulate in their tissues. We report here on the levels of persistent organic pollutants and of the naturally-produced methoxylated PBDEs (MeO-PBDEs) in blubber, liver and kidney of harbour porpoise neonates (n=3), calves (n=15), juveniles (n=6) and adults (n=4) of the southern North Sea. Concentrations of almost all contaminant classes decrease slightly in all age groups over the period 1990-2008. For some classes (e.g. PCBs and DDXs) however, levels seem to increase little in harbour porpoise calves. In all animals, blubber had the highest concentrations, followed by liver and kidney, whereas liver and kidney were the preferred tissues for several compounds, such as octa- and deca-PCBs. Our data suggest that harbour porpoises calves are exposed to higher or comparable concentrations of POPs and of MeO-PBDEs and somewhat different patterns of selected POPs than adults, potentially placing them, and the entire population, at a disproportionate risk for exposure-related health effects.

Halogenated flame retardants: do the fire safety benefits justify the risks?

Since the 1970s, an increasing number of regulations have expanded the use of brominated and chlorinated flame retardants. Many of these chemicals are now recognized as global contaminants and are associated with adverse health effects in animals and humans, including endocrine and thyroid disruption, immunotoxicity, reproductive toxicity, cancer, and adverse effects on fetal and child development and neurologic function. Some flame retardants such as polybrominated diphenyl ethers (PBDEs) have been banned or voluntarily phased out by manufacturers because of their environmental persistence and toxicity, only to be replaced by other organohalogens of unknown toxicity. Despite restrictions on further production in some countries, consumer products previously treated with banned retardants are still in use and continue to release toxic chemicals into the environment, and the worldwide use of organohalogen retardants continues to increase. This paper examines major uses and known toxic effects of commonly-used organohalogen flame retardants, replacements for those that have been phased out, their combustion by-products, and their effectiveness at reducing fire hazard. Policy and other solutions to maintain fire safety while reducing toxicity are suggested. The major conclusions are: (1) Flammability regulations can cause greater adverse environmental and health impacts than fire safety benefits. (2) The current options for end-of-life disposal of products treated with organohalogens retardants are problematic. (3) Life-cycle analyses evaluating benefits and risks should consider the health and environmental effects of the chemicals, as well as their fire safety impacts. (4) Most fire deaths and most fire injuries result from inhaling carbon monoxide, irritant gases, and soot. The incorporation of organohalogens can increase the yield of these toxic by-products during combustion. (5) Fire-safe cigarettes, fire-safe candles, child-resistant lighters, sprinklers, and smoke detectors can prevent fires without the potential adverse effects of flame retardant chemicals. (6) Alternatives to organohalogen flame retardant chemicals include using less flammable materials, design changes, and safer chemicals. To date, before evaluating their health and environmental impacts, many flame retardant chemicals have been produced and used, resulting in high levels of human exposure. As a growing literature continues to find adverse impacts from such chemicals, a more systematic approach to their regulation is needed. Before implementing new flammability standards, decision-makers should evaluate the potential fire safety benefit versus the health and environmental impacts of the chemicals, materials, or technologies likely to be used to meet the standard. Reducing the use of toxic or untested flame retardant chemicals in consumer products can protect human and animal health and the global environment without compromising fire safety.

Characterization of maternal transfer of decabromodiphenyl ether (BDE-209) administered to pregnant Sprague-Dawley rats

To evaluate maternal transfer of decabromodiphenyl ether (BDE-209), Sprague-Dawley rats were given daily oral doses of 5 μmol/kgb.w. BDE-209 in peanut oil from gestation day (GD) 7 to postpartum day (PD) 4. BDE-209 was increased temporally in maternal blood, placenta, fetuses and neonates. Furthermore, more BDE-209 was found in neonate whole-body samples obtained during lactational period (PD 4) than in that of fetal whole-body samples during pregnancy GD 15 and 21. Overall an increase was observed over time for nona-BDE levels in maternal blood and placenta, but these congeners were decreased in fetuses or neonates. Slight changes were observed for octa-BDEs in both maternal blood and placenta while a significant decrease was observed in the fetuses or neonates for BDE-196 and 198/203. These results demonstrated that BDE-209 and its metabolites can transport to the placenta and milk, and eventually enter the fetuses and/or the neonates.

Brominated flame retardants and organochlorine contaminants in winter flounder, harp and hooded seals, and North Atlantic right whales from the Northwest Atlantic Ocean

Various brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and current-use, non-PBDE BFRs, as well as organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were measured in winter flounder, harp and hooded seals, and North Atlantic right whales from the Eastern United States and Canada. The concentrations of PBDEs in winter flounder and right whales were similar in magnitude to the levels of PCBs, which was unlike the pattern observed in seals. In these marine mammals, the levels of PBDEs were orders of magnitude lower than the levels of OCs and PCBs detected. Evidence existed for the accumulation of methoxylated (MeO)-PBDEs of natural origin in seals and right whales. Current-use, non-PBDE BFRs (including hexabromocyclododecane, pentabromoethylbenzene, hexabromobenzene, and pentabromotoluene) were detected in winter flounder and marine mammals. Future research should focus on monitoring PBDEs, current-use, non-PBDE BFRs, and MeO-BDEs of natural origin in marine organisms from Massachusetts and Cape Cod Bays.

Levels and trends of brominated diphenyl ethers in blubber of harbor porpoises (Phocoena phocoena) from the U.K., 1992-2008

Controls were placed on the production and use of the penta-mix polybrominated diphenyl ether (PBDE) formulation within the European Union in 2004. In porpoises stranded or bycaught around the U.K., BDE congeners from this product predominate. Lipid-normalized concentrations of 9 (summed) BDE congeners in the blubber of 415 porpoises sampled during the period 1992-2008 have been investigated for possible time trends resulting from the regulatory action. Our analysis suggests that, overall, median Sigma9BDE concentrations peaked around 1998 and have since reduced by between 53.8% and 73.5% to 2008. Our best point estimate is that the reduction has been 67.6%. This decline was highly statistically significant (p < 0.001) and was not confounded by a range of other factors which were also considered (area, season, nutritional status, bycaught/stranded, and age class).

Occurrence of anthropogenic and naturally-produced organohalogenated compounds in tissues of Black Sea harbour porpoises

Harbour porpoises are one of the three cetacean species inhabiting the Black Sea. This is the first study to report on polybrominated diphenyl ethers (PBDEs) and naturally-produced compounds, methoxylated PBDEs (MeO-PBDEs) and polybrominated hexahydroxanthene derivatives (PBHDs), in tissues (kidney, brain, blubber, liver, muscle) of male harbour porpoises (11 adults, 9 juveniles) from the Black Sea. Lipid-normalized concentrations decreased from muscle>blubber>liver>kidney>brain for the sum of polychlorinated biphenyls (PCBs) and for the sum of PBDEs. Among the naturally-produced compounds, levels of PBHDs were higher than of MeO-PBDEs, with tri-BHD and 6-MeO-BDE 47 being the dominant compounds for both groups, respectively. Concentrations of naturally-produced compounds decreased from blubber to brain, similarly to the sum of DDT and metabolites (DDXs). Concentrations of DDXs were highest, followed by PCBs, HCB, PBHDs, PBDEs and MeO-PBDEs. Levels of PCBs and PBDEs in blubber were lower than concentrations reported for harbour porpoises from the North Sea, while concentrations of DDXs were higher.

Effects of individual polybrominated diphenyl ether (PBDE) congeners on harbour seal immune cells in vitro

Effects of polybrominated diphenyl ethers (PBDEs) on the immune system of marine mammals are poorly understood. One important innate immune function of granulocytes is the respiratory burst which generates reactive oxygen species (ROS) used to kill engulfed microorganisms. The present study investigates in vitro the effects of BDE-47, -99 and -153, on the formation of ROS, on intracellular level of thiols, on activity and efficiency of phagocytosis and on apoptosis in granulocytes of harbour seals. Compounds were tested at four different concentrations ranging from 1.5 to 12 microM. Results showed that ROS levels, thiol levels and phagocytosis were all affected when harbour seal cells were exposed to the highest concentration (12 microM) of PBDE congeners. Apoptosis was not affected by PBDEs. The observed effects were similar in adults, pups and in the 11B7501 cell line of harbour seals.

Occurrence of polybrominated diphenyl ethers in fish and shellfish downstream from electronic-waste recycling plants

We measured 39 polybrominated diphenyl ethers (PBDEs) in the muscle tissue of three species of fish (Sciaenops ocellatus, Sparus macrocephalus, and Lateolabraxjaponicus) and four species of shellfish (Tegillarca granosa, Cyclina sinensis, Sinonovacula constricta, and Ostrea cucullata) that were collected downstream of electronic-waste recycling plants in Taizhou, China. A total of 24 PBDE congeners (PBDE24) in the samples were detected. The sigma PBDE24 (total PBDE) ranged from 545.4 to 1688.7 ng/kg ww (wet weight). The mean sigma PBDE24 concentration was 1382.6 ng/kg ww in fish and 858.1 ng/kg ww in shellfish. The lower brominated congeners were detected at relatively high concentrations in all species. The penta-products, produced from e-waste, were found at relatively low levels. A principal component analysis suggested a significant correlation among di-, tri-, tetra-, and hepta-BDEs for the three species of fish. Similarly, we found a significant correlation between mono- and tri-BDEs in the shellfish. Our results suggested that the processes of PBDE metabolism and elimination were similar in both fish and shellfish. In addition, the primary source of PBDEs appeared to be from the debromination of high brominated PBDEs.

Debrominated and methoxylated polybrominated diphenyl ether metabolites in rainbow trout (Oncorhynchus mykiss) after exposure to decabromodiphenyl ether

Decabromodiphenyl ether (BDE209) is the primary component in a commonly used flame retardant. Previous studies had proved that BDE209 itself was not toxic, while its metabolites including debrominated diphenyl ethers (De-BDEs) and methoxylated brominated diphenyl ethers (MeO-BDEs) posed a potential threat to organisms. Many studies had indicated that BDE209 could metabolize quickly in mammals, but lacking in the basic data about the metabolism of BDE209 in fish. In the present study, two replicate treatment groups of rainbow trout (Oncorhynchus mykiss) were exposed to BDE209 via a single intraperitoneal injection approximately 100 and 500 ng/g, respectively. Muscle, liver and blood samples were collected to analyze the specific metabolites on day 1 and day 28 post injection. The highest concentration of BDE209 was detected in muscle tissues, from 796.1 ng/g wet weight (day 1) to 687.1 ng/g wet weight (day 28) in high dose group, suggesting that BDE209 could accumulate slightly in muscle tissues. However, BDE209 was not detected in the blood for all treatments. Most congeners of De-BDEs were found in muscle and liver tissues, with the highest concentration in the liver. The main De-BDEs were nona-, octa-, hepta- and penta-De-BDEs. A total of seven MeO-BDE metabolites were observed among different fish tissues. Blood had the highest contribution of the MeO-BDE metabolites. Each MeO-BDE congener increased over the 28 days. These results in contrast to other studies suggested possible species-specific differences in metabolic abilities.

Polybrominated diphenyl ethers in marine ecosystems of the American continents: foresight from current knowledge

Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta- and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.

Bioaccumulation of polybrominated diphenyl ethers and hexabromocyclododecane in the northwest Atlantic marine food web

Seven species of teleost fishes comprising major prey of northwest Atlantic harbor seals were analyzed for polybrominated diphenyl ethers (PBDEs). PBDE concentrations in whole fish samples (n=87) were compared with those measured previously in harbor seal blubber to evaluate the transfer of PBDEs from prey to predator. Hexabromocyclododecane (HBCD) concentrations were measured in three fish species to provide an initial estimation of HBCD contamination in this ecosystem. HBCD was detected in 87% of the fish samples at concentrations ranging from 2.4 to 38.1 ng/g, lw (overall mean 17.2+/-10.2 ng/g, lw). SigmaPBDE concentrations in fish ranged from 17.9 to 94 ng/g, lw (overall mean 62+/-34 ng/g, lw). SigmaPBDE concentrations in the harbor seals were two orders of magnitude higher than levels in the fish. Biomagnification factors (BMFs) from fish to seals averaged from 17 to 76, indicating that tetra- to hexa-BDEs are highly biomagnified in this marine food web. BDE-47 was the dominant congener in all samples, suggesting exposure to the penta-BDE mixture. The presence of higher brominated congeners including BDE-209 at measurable levels in fish and seal tissue, along with the very high biomagnification of BDE-153, as well as -155, and -154, suggests recent exposure to the octa- and deca-BDE formulations in this US coastal marine food web, as well as the additional contribution of BDE-209 debromination in fish to the loading of persistent PBDEs in the seals. This is the first study to report the occurrence of BDE-209 and other higher BDEs in commercially important marine fishes from the northwest Atlantic.

Specific accumulation of perfluorochemicals in harbor seals (Phoca vitulina concolor) from the northwest Atlantic

Concentrations of perfluorochemicals (PFCs) including perfluoroalkylsulfonates (PFSAs), and perfluoroalkylcarboxylates (PFCAs) were determined in liver of harbor seals (n=68) collected from the northwest Atlantic between 2000 and 2007. Of ten PFCs measured, perfluorooctane sulfonate (PFOS) concentrations were the highest in liver (8-1388 ng/g, ww), followed by perfluoroundecanoic acid (PFUnDA) (<1-30.7 ng/g, ww). An unusual accumulation profile of long-chain (C7-C12) PFCAs, and the predominance of PFUnDA, followed by PFNA in seal liver suggested that fluorotelomer alcohols (FTOHs) may be a major source of PFCAs in the northwest Atlantic. No gender-related differences in the concentrations of individual PFCs or total PFCs were found. Concentrations of PFOS and PFDS were higher in tissues of the pups than the adults, whereas concentrations of the PFCAs were similar between pups and adults. PFOS concentrations in the pups were 2.6-fold higher than those in the adult females, suggesting the importance of maternal transfer of PFCs. Hepatic PFOS concentrations were strongly, positively correlated with PFOSA, PFDS and individual PFCAs, indicating that harbor seals are exposed simultaneously to these compounds. Temporal comparisons of hepatic PFC concentrations showed a marginal increase of PFOS and PFCAs in the adult seals from 2000 to 2007. Unlike the spatial trend observed for polychlorinated biphenyls (PCBs), no south to north (urban-rural-remote) decreasing trend was observed for PFCs, suggesting the presence of diffuse sources of PFC contamination throughout the northwest Atlantic.