Enantiomer fractions of polychlorinated biphenyls in three selected Standard Reference Materials

The enantiomer composition of six chiral polychlorinated biphenyls (PCBs) were measured in three different certified Standard Reference Materials (SRMs) from the US National Institute of Standards and Technology (NIST): SRM 1946 (Lake Superior fish tissue), SRM 1939a (PCB Congeners in Hudson River Sediment), and SRM 2978 (organic contaminants in mussel tissue--Raritan Bay, New Jersey) to aid in quality assurance/quality control methodologies in the study of chiral pollutants in sediments and biota. Enantiomer fractions (EFs) of PCBs 91, 95, 136, 149, 174, and 183 were measured using a suite of chiral columns by gas chromatography/mass spectrometry. Concentrations of target analytes were in agreement with certified values. Target analyte EFs in reference materials were measured precisely (<2% relative standard deviation), indicating the utility of SRM in quality assurance/control methodologies for analyses of chiral compounds in environmental samples. Measured EFs were also in agreement with previously published analyses of similar samples, indicating that similar enantioselective processes were taking place in these environmental matrices.     

Profile of persistent chlorinated contaminants,including selected chiral compounds,in wolverine (Gulo gulo) livers from the Canadian Arctic

Wolverines (Gulo gulo) are circumpolar omnivores that live throughout the alpine and arctic tundra ecosystem. Wolverine livers were collected at Kugluktuk (Coppermine), NU (n=12) in the western Canadian Arctic to report, for the first time, the residue patterns of persistent organochlorine contaminants (OCs) in this species. The enantiomer fractions (EFs) of several chiral OCs, including PCB atropisomers, in wolverines were also determined. Results were compared to OC concentrations and EFs of chiral contaminants in arctic fox (Alopex lagopus) from Ulukhaqtuuq (Holman), NT (n=20); a closely related species that scavenges the marine and terrestrial arctic environment. The rank order of hepatic concentrations for sum ( summation operator ) OC groups in wolverines were polychlorinated biphenyls ( summation operator PCB)>chlordane-related components ( summation operator CHLOR)>DDT-related compounds ( summation operator DDT)>hexachlorocyclohexane isomers ( summation operator HCHs). The most abundant OC analytes detected in wolverine liver were PCB-153, PCB-180, and oxychlordane (OXY). Wolverine age and gender did not influence OC concentrations, which were comparable to lipid-normalized values in arctic fox. The EFs of several chiral OCs (alpha-HCH, cis- and trans-chlordane, OXY, heptachlor exo-epoxide) and PCB atropisomers (PCB-136, 149) were nonracemic in arctic fox and wolverine liver and similar to those previously calculated in arctic fox and polar bears from Iceland and the Canadian Arctic. Results suggest that these species have similar ability to biotransform OCs. As well, contaminant profiles suggest that terrestrial mammals do not represent the major source of OC exposure to wolverines and that wolverines are scavenging more contaminated prey items, such as marine mammals. While summation operator PCB did not exceed the concentrations associated with mammalian reproductive impairment, future research is required to properly evaluate the potential affect of other OCs on the overall health of wolverines.     

Polybrominated diphenyl ethers and traditional organochlorine pollutants in fulmars (Fulmarus glacialis) from the Faroe Islands

The observed high-level burdens of organohalogens among the residents of the Faroe Islands, needs to be explained. Long-finned pilot whale (Globicephala melas) blubber and meat are known sources of environmental exposure. The present study focus on the organohalogen contamination of the fulmar (Fulmarus glacialis). The compounds quantified in fulmar muscle, fat, and egg are PCBs, DDTs, hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The dominating pollutants are the 4,4'-DDT metabolite 4,4'-DDE and the two PCB congeners, CB-153 and CB-180, which are present in geometric mean concentrations of 7100, 4700 and 2500 ng/g lipid weight (l.w.), respectively, in adult fulmar muscle. 4,4'-DDT and HCB concentrations are approximately 250 ng/gl.w., each. Concentrations in the eggs are about 50% of the fulmar muscle levels, due to differences in lipid amounts, 4% in muscle and 10% in the eggs, the exposure contribution on a fresh weight basis is almost the same. As a result, both the egg and the adult fulmar muscle may lead to a significant exposure risk, if consumed by humans. BDE-153, the most abundant PBDE congener in fulmar muscle, with a geometric mean concentration of 6.5 ng/gl.w., is much lower than the individual PCB congeners and 4,4'-DDE concentrations. In the adult fulmar muscle, the relative PBDE congener pattern is different from that previously observed in biota, with BDE-153 and BDE-154 as the dominating congeners, rather than BDE-47. In contrast, BDE-47 is the most abundant congener in juvenile muscle and subcutaneous fat. The summation operatorPBDE concentrations are almost the same in egg, muscle (adult and juvenile) and subcutaneous fat (juvenile). For the polybrominated biphenyl (BB-153) the concentrations are considerably higher in the adult bird and egg than in the juvenile bird; this is also seen for the PCB and 4,4'-DDE concentrations. PCB concentrations found in fulmar egg and muscle are in the same range as seen in the pilot whale, i.e. 590-5700 ng/gl.w. for CB-153. Hence humans are also exposed to PCBs at a reasonable degree via intake of fulmar and/or fulmar egg and not only via pilot whale blubber.     

Organochlorine-induced histopathology in kidney and liver tissue from Arctic fox (Vulpes lagopus)

The effects of persistent organic pollutants on renal and liver morphology in farmed arctic fox (Vulpes lagopus) were studied under experimental conditions. Control animals received a diet containing pork (Sus scrofa) fat with low amounts of persistent organic pollutants, while the diet of the exposed animals contained whale blubber, 'naturally' contaminated with persistent organic pollutants. Polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) concentrations in the whale blubber were 488 and 395 ng/g wet weight, respectively. Animals were sacrificed and sampled when they were at their fattest (winter) as well as their lowest body weight (summer). The results show that PCB and OCP exposure causes renal (and probably also liver) lesions in arctic foxes. The prevalence of glomerular, tubular and interstitial lesions was significantly highest in the exposed group (chi-square: all p<0.05). The frequency of liver lesions (steatosis, intravascular granulocyte accumulations, interstitial cell infiltrations, lipid granulomas, portal fibrosis and bile duct hyperplasia) were also highest in the exposed group, although not significantly (chi-square: all p>0.05). The prevalence of lesions was not significantly different between lean (winter) and fat (summer) foxes for any of the lesions (chi-square: all p>0.05). We suggest that wild arctic foxes exposed to an environmental cocktail of persistent organic pollutants, such as PCBs and OCPs, in their natural diet are at risk for developing chronic kidney and liver damage. Whether such lesions may have an impact on age and health of the animals remains uncertain.     

Review on persistent organic pollutants in the environment of Greenland and Faroe Islands

The literature concerning persistent organic pollutants (POPs) in the environment of Greenland and the Faroe Islands covering the period up to 1995 has been revisited. It is difficult to compare data from earlier studies with those from more recent investigations. Thus as the former quantified the content of CBs by comparison to a technical mixture of CBs (e.g. Aroclor 1254), the latter analyses typically are quantified on a single congener level. Single CB congeners have in some cases been determined, but the results were subsequently expressed as total PCB related to an Aroclor standard. For studies based on single CB congener determinations, the highest levels are reported for porpoise blubber from Greenland (700-4500 micrograms/kg wet weight), the conclusion, however being based on two determinations only. In Greenlandic seal blubber and peregrine falcon plasma equal levels of CBs (130-750 micrograms/kg ww) and of DDTs (150-860 micrograms/kg ww) were found. Levels of CBs and DDTs in fish liver were found to be around 40-75 micrograms/kg ww. In sediment samples the CBs were almost all below the detection limit (< 0.02-0.1 microgram/kg dry weight), and thereby being the matrix with the lowest CBs concentration levels. Earlier data based on Aroclor standards showed DDT levels in Greenlandic whale blubber in the range of 2700-4100 micrograms/kg ww and PCB levels of 3700 micrograms/kg-5400 micrograms/kg ww. DDT levels for seal blubber were at the same level (2700-4500 micrograms/kg ww) whereas the PCB level was lower (900-3900 micrograms/kg ww). The PCB level corresponds to the level found in human adipose tissue determined with a similar quantification technique. The lowest levels reported for mammals correspond to walrus blubber, the sum of PCBs and DDTs being in the ranges of 180-360 micrograms/kg ww and 50-90 micrograms/kg ww, respectively. The content of PCBs in scallops was found to be 3 micrograms/kg ww near the Thule Air base.     

Development and calibration of epiphytic lichens as saltfall biomonitors--dry-deposition modelling

Blubber collected from beluga whales and ringed seals during subsistence hunts in the southern Baffin Island region of the Canadian Arctic were analysed for polychlorinated naphthalenes and eight planar PCB congeners (mono-ortho PCBs: 105, 114, 118 and 156; non-ortho PCBs: 77, 81, 126, 169). SigmaPCN (3-7 Cl) concentrations in blubber ranged from 35.9-383 pg/g (lipid weight; lw) in beluga and 35.4-71.3 pg/g (lw) in ringed seal. These represent the first measurements of PCNs in marine mammals in the Canadian Arctic, mammals which are an important part of the traditional diet of the indigenous population. SigmaCoplPCB concentrations were much higher, ranging from 15.5-317 ng/g (lw) in beluga whale blubber and 16.5-40.9 ng/g (lw) in ringed seal blubber. PCNs and coplanar PCBs both exhibit dioxin-like toxicity. Although average sigmaPCN concentrations were less than 1% of sigmaCoplPCBs, PCNs contribute up to 11% of TEQ relative to the coplanar PCBs based on TEFs determined by H4IIE enzyme assays.     

PCBQ: Computerized quantification of total PCB and congeners in environmental samples

Computerized methodologies for the quantification of total PCBs, PCB in Aroclor mixtures and individual PCB congeners in environmental samples are presented. The method for total PCBs is based on a multiple-linear regression analysis using data from capillary gas chromatography of Arocolor standards. PCB congeners were identified and their weight percentages determined in Aroclor mixtures by GC/MS. PCB congeners and total PCBs were accurately quantified in predetermined test data and environmental samples.     

Organochlorine pesticides and polychlorinated biphenyls in California sea lions

Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few microg/g to several hundreds of microg/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several microg/g on a lipid weight basis.     

Organochlorine levels in subcutaneous blubber biopsies of fin whales (Balaenoptera physalus) and striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea

Polychlorinated biphenyls (PCBs) and DDT compounds were determined in subcutaneous blubber of fin whales (Balaenoptera physalus) and striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea. From 1990 to 1993, 68 fin whale and 89 dolphin blubber biopsies were analysed. The whales were sampled while passing through the Ligurian Sea, whereas the dolphins were collected in different areas of the Mediterranean: the Ligurian, Tyrrhenian and Ionian Seas. Total PCBs and DDTs were 5.5-7.1 ppm and 4.2-9.5 ppm, respectively, in the whales and 15.5-86.0 ppm and 15.6-63.5 ppm, respectively, in the dolphins. Thirty PCB congeners were identified for each sample, IUPAC numbers 153, 138, 187, 180 and 170 being the most abundant, totalling an average of 55% of total PCBs in the whale and 60% in the dolphin. The large differences in accumulation are related to position in the food chain. In striped dolphins significant differences were found in relation to sampling site, and in fin whales in relation to sex.     

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional seafood items from western Greenland

In this study, contamination levels were determined for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional Greenland seafood items, such as raw and smoked fish fillet (salmon and halibut), whale and seal meat and narwhal mattak (skin and blubber). The daily intake of PCBs, PBDEs and PFASs through traditional seafood items in Greenland was assessed. Based on the presented levels of contaminants, in combination with earlier food intake studies, suggests that the daily exposure was below the tolerable daily intake threshold for all compounds. BDE-47 was the only PBDE-congener detected in all food items, except in smoked halibut. The levels of BDE-47 varied from < LOD in smoked halibut up to 18 ng/g lw in narwhal mattak and 21 ng/g lw in whale beef. ∑PCB were lowest in smoked halibut (37 ng/g lw) and highest in narwhal mattak with 1,146 ng/g lw. Perfluorooctane sulfonate (PFOS) was the most common of the PFASs. However, ΣPFASs were below detection limits in most fish fillet samples, and varied from 2.9 ng/g ww in whale beef to 13.5 ng/g ww in seal beef. The present study shows that the exclusion from the diet of local food items such as intestines and blubber have a strong positive effect for the reduction of POPs levels in food, without a reducing the health benefits of traditional food intake considerably.     

Temporal and biogeographic comparisons of PCBs and persistent organochlorine pollutants in the blubber of fin whales from eastern Canada in 1971-1991

Concentrations of PCB congeners and organochlorine (OC) pesticides were studied in archived fin whale (Balaenoptera physalus) blubber samples collected in 1971-1972 from Newfoundland (Nfld) and Nova Scotia (NS) with the objective of obtaining a historical perspective on contaminant levels and proportions at a time when many persistent OCs were still in use. Concentrations of sigmaPCBs and sigmaDDTs in the blubber of 17 fin whales from historical whaling stations in 1971-1972 were generally in agreement with previously reported values for fin whales from Atlantic Canada. Although some differences in sex and body length (age) distribution of samples occurred, significant differences were detected in the concentrations and patterns of PCBs, DDTs and chlordanes in whales from Nfld and NS, supporting ecological evidence that whales from these regions represent relatively separate stocks. Temporal and geographical variations were examined by comparing data to those reported for fin whales from the St Lawrence Estuary (StL) in 1991 by Gauthier et al. (1997a). Significantly higher levels of sigmaDDT, sigmaCHL and HCB were found in the NS (1971-1972) stock compared with the StL (1991) animals, and in HCB between the Nfld stock (1971-1972) and the StL (1991) animals, as well as higher p,p'-DDE/sigmaDDT and lower p,p'-DDT/sigmaDDT ratios in the 1991 whales suggesting that temporal trends in these whales between the 1970s and 1990s were consistent with those in other marine mammals in Atlantic Canada. Evidence also suggests that geographical variations in patterns may occur for individuals from two relatively distinct stocks of fin whales in Atlantic Canada (NS, Nfld) and perhaps for one population (StL) related to, but recognisably different from the NS stock.     

Enantioselective determination of persistent and partly degradable toxaphene congeners in high trophic level biota

Enantiomer separation of chiral toxaphene components in biological samples was studied by application of different chiral stationary phases based on modified cyclodextrins. Several pairs of enantiomers were resolved on permethylated beta-cyclodextrin (beta-PMCD), among them 2-endo,3-exo,5-endo,6-exo,8,8,9,10-octachlorobornane (B8-1412), which was not enantiomerically resolved on tert-butyldimethylsilylated beta-cyclodextrin (beta-BSCD). The latter column was applied to determine the enantiomer ratios (ERs) of 2-endo,3-exo,5-endo,6-exo,8,8,10,10-octachlorobornane (B8-1413 or P-26) in brain tissue of three seal species. The ER of B8-1413 (P-26) in brain was virtually racemic as well as those of the two persistent and chiral components of technical chlordane, 1-exo,2,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-metha noindane (trans-nonachlor III or MC 6) and 1-exo,2-endo,3-exo,4,5,6,8,8-octachloro-3a,7,7a-tetrahydro-4,7- methanoindane (U82). In contrast, B8-1412 and 2-exo,5,5,8,9,9,10,10-octachlorobornane (B8-2229 or P-44) were significantly enantiomerically enriched in several samples of high trophic level biota. 2,2,5,5,8,9,9,10,10-Nonachlorobornane (B9-1025 or P-62), a chlorobornane metabolisable by seals and the presumable precursor of B8-2229 (P-44), was also enantiomerically enriched in seal blubber. These results confirm the assumption that some less persistent toxaphene components may be significantly degraded in biological samples. Enantioselective gas chromatography provides the information that such a degradation is happening by the characteristic change of the ratio of the two enantiomers in the respective tissues.     

Serum concentrations of indicator PCB congeners in the Czech adult population

In 2006, levels of seven indicator polychlorinated biphenyl congeners (PCB28, 52, 101, 118, 138, 153, and 180) in blood serum of 202 blood donors residing for more than 2 years in five urban areas included in the Czech Human Biomonitoring project were measured by GC/MS/MS method. PCB congeners 138, 153 and 180 accounted for about 97% of the sum of the indicator congeners analyzed. Overall, the median and 95th percentile of the most abundant congener PCB 153 were 438 ng/g lipid and 1079 ng/g lipid, respectively. The highest median levels were found in Uherské Hradiste (669 ng/g lipid) and Ostrava (672 ng/g lipid in males compared to 341 ng/g lipid in females). Serum PCB concentrations were significantly associated with age, gender, place of residence and smoking habit, but not with body mass index and education. The results suggest the importance of PCB body burden in the Czech general population and the existence of hot spots.     

Polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in a cod liver oil reference material

A cod liver oil reference material, Standard Reference Material (SRM) 1588, which was issued by the National Institute of Standards and Technology (NIST) in 1989, has certified concentrations for five polychlorinated biphenyl (PCB) congeners and ten chlorinated pesticides. Recently, this SRM has been extensively characterized by additional analyses at NIST and by analyses at the Canadian Wildlife Service (CWS) where the SRM was used as a control sample during routine analyses of wildlife tissue specimens. In this paper the results from NIST and CWS are compared and the concentrations for over 40 PCB congeners and 20 chlorinated hydrocarbons are reported.     

Extraction of organic contaminants from marine sediments and tissues using microwave energy.

In this study, we compared microwave solvent extraction (MSE) to conventional methods for extracting organic contaminants from marine sediments and tissues with high and varying moisture content. The organic contaminants measured were polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polycyclic aromatic hydrocarbons (PAHs). Initial experiments were conducted on dry standard reference materials (SRMs) and field collected marine sediments. Moisture content in samples greatly influenced the recovery of the analytes of interest. When wet sediments were included in a sample batch, low recoveries were often encountered in other samples in the batch, including the dry SRM. Experiments were conducted to test the effect of standardizing the moisture content in all samples in a batch prior to extraction. SRM1941a (marine sediment). SRM1974a (mussel tissue), as well as QA96SED6 (marine sediment), and QA96TIS7 (marine tissue), both from 1996 NIST Intercalibration Exercise were extracted using microwave and conventional methods. Moisture levels were adjusted in SRMs to match those of marine sediment and tissue samples before microwave extraction. The results demonstrated that it is crucial to standardize the moisture content in all samples, including dry reference material to ensure good recovery of organic contaminants. MSE yielded equivalent or superior recoveries compared to conventional methods for the majority of the compounds evaluated. The advantages of MSE over conventional methods are reduced solvent usage, higher sample throughput and the elimination of halogenated solvent usage.     

Chlorohydrocarbons, PCB congeners, polychlorodioxins, furans and dibenzothiophenes in pine needles in the vicinity of a metal reclamation plant

Chlorohydrocarbons, PCB congeners, polychlorodioxins, furans and dibenzothiophenes in pine needles in the vicinity of a metal reclamation plant were analyzed by GC/ECD and GC/MS. Wax and the rest of the needles were analyzed separately. As a rule the concentrations of -HCH (0.5–13.6 ng/g), γ-HCH (0.4–7.3 ng/g), HCB (0.2–3.4 ng/g), PCB congeners (0.2–67 ng/g), PCDDs and PCDFs were higher in the older needles. The ratio of the concentration in the wax to the concentration in the rest of the needles was higher in the younger needles. The concentrations of PCB congeners, TeCDDs and TeCDFs were higher in the needles collected in the area nearest to the plant. The samples, obviously, contained tri- and tetrachlorodibenzothiophenes but these were not determined quantitatively due to interfering peaks in GC/MS.     

Concentrations and accumulation patterns of organochlorine contaminants in the blubber of harbour porpoises, Phocoena phocoena, from the coast of Newfoundland, the Gulf of St Lawrence and the Bay of Fundy/Gulf of Maine

Concentrations of 99 organochlorine compounds were measured in the blubber of 196 harbour porpoises, Phocoena phocoena, killed in commercial gill net fisheries in the western North Atlantic. PCBs and chlorinated bornanes (CHB) were the dominant contaminants in all porpoises. Mean concentrations (with standard deviations) of PCBs and CHBs from the three regions were as follows: Bay of Fundy/Gulf of Maine, PCB males 17.3 +/- 11.2 microg/g, PCB females 11.4 +/- 4.8 microg/g, CHB males 11.5 +/- 6.6 microg/g, CHB females 8.4 +/- 5.3 microg/g; Gulf of St Lawrence, PCB males 10.6 +/- 5.4 microg/g, PCB females 7.2 +/- 3.9 microg/g, CHB males 14.1 +/- 8.8 microg/g, CHB females 9.0 +/- 6.3 microg/g; southeast Newfoundland, PCB males 5.2 +/- 2.5 microg/g, PCB females 5.5 +/- 4.4 microg/g, CHB males 7.0 +/- 2.2 microg/g, CHB females 5.5 +/- 3.0 microg/g. The relative composition of the major contaminant groups found in male and female harbour porpoise blubber from the three locations varied. In order of decreasing concentration, porpoises from Fundy/Maine had PCBs > CHB > DDT > chlordanes (CHL), whereas Gulf of St Lawrence and Newfoundland porpoises had CHB > PCB > DDT > CHL. Significant increases with age were observed for most contaminants in male harbour porpoises, and significant decreases were observed in females. Females lose about 15% of their contaminant burden per birth. PCB and DDT levels in porpoises from the Bay of Fundy are significantly lower than those recorded in the 1970s.     

Serum polychlorinated biphenyl and organochlorine insecticide concentrations in a Faroese birth cohort

A prospective birth cohort of 1022 participants was established in the Faroe Islands over a 21-month period during 1986-1987. We collected questionnaire data on potential persistent organic pollutant (POP) concentration predictors, such as duration of breastfeeding and blubber consumption. To assess the participants' exposure from in utero to 14 years of age to polychlorinated biphenyls (PCBs) and the insecticide p,p'-DDT and its primary degradate p,p'-DDE, we measured 37 PCB congeners and pesticides in 316 umbilical cord samples taken from participants at birth, in 124 serum samples collected from participants at approximately 7 years of age, and in 795 serum samples collected from participants at 14 years of age. Measurements of higher chlorination PCB congeners made on individuals' serum samples collected at 7 years and 14 years were highly correlated (typically r > 0.5, p > 0.01), although their concentrations at 7 years were generally two to three times higher than at 14 years. Similarly, umbilical cord PCB concentrations were correlated with PCB concentrations in both 7- and 14-year serum samples. Sex-specific differences in higher chlorination PCB and p,p'-DDE concentrations were found at 14 years but not at 7 years, although a sex interaction with blubber consumption and nursing duration was observed at both ages. Both duration of breastfeeding and consumption of blubber were significant predictors of serum summationPCB concentrations at 7 and 14 years. Multivariate analyses showed that breastfeeding duration was the primary contributor to serum summationPCB concentrations at 7 years, and blubber consumption was the primary contributor at 14 years. These data suggest that infant exposures from breastfeeding were sufficiently large so that continued exposures to PCBs, p,p'-DDT, and p,p'-DDE through the diet have not fully diluted their contribution to the summationPCB and p,p'-DDE body burden of the children.     

Methylsulfonyl PCB and DDE metabolites and their enantioselective gas chromatographic separation in human adipose tissues, seal blubber and pelican muscle

In the present investigation, eleven human adipose tissue samples, two seal blubber samples and two pelican muscles samples were analyzed with regard to their concentrations of PCB parent compounds as well as to the respective chiral methylsulfonyl metabolites 3-MeSO2-CB 91, 4-MeSO2-CB 91, 3-MeSO2-CB 95, 4-MeSO2-CB 95, 3-MeSO2-CB 149, 4-MeSO2-CB 149, 3-MeSO2-CB 132, 4-MeSO2-CB 132, 3-MeSO2-CB 174, and 4-MeSO2-CB 174 and the achiral metabolites 3-MeSO2-CB 49, 4-MeSO2-CB 49, 3-MeSO2-CB 101, 4-MeSO2-CB 101, 3-MeSO2-CB 110, 4-MeSO2-CB 110 and 3-MeSO2-DDE. In order to verify enantioselective transformation processes and to compare the different enzymatic transformation pathways in birds and mammals, the enantioselective excesses of the chiral PCB-metabolites were determined by enantioselective gas chromatography with electron capture and mass spectrometric detection using modified cyclodextrin phases, including heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl-)-beta-cyclodextrin/OV1701 (1:1) for the parent PCBs and heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl-)-beta-cyclodextrin/SE52 (1:4) for the metabolites, respectively.     

Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 1. Accumulation patterns in harbour seals and harbour porpoises

Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are two representative top predator species of the North Sea ecosystem. The median values of sum of 21 polychlorinated biphenyl (PCB) congeners and sum of 10 polybrominated diphenyl ether (PBDE) congeners were 23.1 μg/g lipid weight (lw) and 0.33 μg/g lw in blubber of harbour seals (n = 28) and 12.4 μg/g lw and 0.76 μg/g lw in blubber of harbour porpoises (n = 35), respectively. For both species, the highest PCB concentrations were observed in adult males indicating bioaccumulation. On the contrary, the highest PBDE concentrations were measured in juveniles, likely due to better-developed metabolic capacities with age in adults. A higher contribution of lower chlorinated and non-persistent congeners, such as CB 52, CB 95, CB 101, and CB 149, together with higher contributions of other PBDE congeners than BDE 47, indicated that harbour porpoises are unable to metabolize these compounds. Harbour seals showed a higher ability to metabolize PCBs and PBDEs.