The Inuit population of Nunavik (Canada) is exposed to immunotoxic organochlorines (OCs) mainly through the consumption of fish and marine mammal fat. We investigated the effect of perinatal exposure to polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) on the incidence of acute infections in Inuit infants. We reviewed the medical charts of a cohort of 199 Inuit infants during the first 12 months of life and evaluated the incidence rates of upper and lower respiratory tract infections (URTI and LRTIs, respectively), otitis media, and gastrointestinal (GI) infections. Maternal plasma during delivery and infant plasma at 7 months of age were sampled and assayed for PCBs and DDE. Compared to rates for infants in the first quartile of exposure to PCBs (least exposed), adjusted rate ratios for infants in higher quartiles ranged between 1.09 and 1.32 for URTIs, 0.99 and 1.39 for otitis, 1.52 and 1.89 for GI infections, and 1.16 and 1.68 for LRTIs during the first 6 months of follow-up. For all infections combined, the rate ratios ranged from 1.17 to 1.27. The effect size was similar for DDE exposure but was lower for the full 12-month follow-up. Globally, most rate ratios were > 1.0, but few were statistically significant (p
The majority of analytical results in the Greenland AMAP (Arctic Monitoring and Assessment Programme) have been produced by laboratories that participate regularly in performance studies. This makes it possible to judge the quality of the results based on objective measurements made by independent assessors. AMAP laboratories participated while analysing the AMAP samples in the QUASIMEME laboratory performance study programme, in the 'Interlaboratory Comparison Program' organised by Le Centre de Toxicologie du Québec, in a toxaphene intercomparison study organised by The Food Research Division of Health Canada, and in an International Atomic Energy Agency Intercomparison exercise. The relative errors of the trace analyses, i.e. the relative deviation of the result obtained by the AMAP laboratory from the assigned value, are in most cases less than the 25% which is regarded as acceptable by QUASIMEME. Usually the errors, especially for trace elements, are less than 12.5%, while errors for trace organics below 1 microgram kg-1 may rise to 50% or more. This study covers the period 1993 to 1998 for trace elements and one or more years from the period 1994-1996 for trace organics.
As a contribution to the FAO/WHO organochlorine monitoring programme, samples of milk, eggs, beef pork, chops, game, animal livers as well as fish-liver oils were analysed for PCB-, DDT- and toxaphene compounds, hexachlorobenzene (HCB), heptachlor and hexachlorocyclohexanes (HCH). From the annual consumption of the foodstuffs investigated average intakes of organochlorines were estimated and compared with the acceptable daily intakes (ADI) as set by FAO/WHO. Intakes from the sources studied were then compared with those from fish, butter and margarine. Total average dietary intakes were determined to be 14.4 micrograms/day for PCB, 2.9 for DDT, 2,3 for gamma-HCH, 1.7 for HCB, and 0.5 micrograms/day for heptachlor representing 0.08% of the ADI for DDT, 0.3% for HCH, 4.2% for HCB and 1.4% of the ADI for heptachlor.
Persistent organochlorines (OC) contaminants, including polychlorinated biphenyl (PCB) congeners, Dichlorophenyltrichloroethane (DDT)- and chlordane (CHL) related compounds, hexachlorocyclohexanes (HCH) isomers and chlorobenzenes (CBz) were determined in blubber of harp seals (Phoca groenlandica), ringed seals (Phoca hispida) and bearded seals (Eringnathus barbatus) as well as in fishes and invertebrates from the White Sea, in northwest Russia. Highest summation operator PCB and summation operator DDT concentrations were found in samples from two male bearded seals (means of 4150 ng/g lw and 3950 ng/g lw, respectively). Female harp seals had mean summation operator PCB and summation operator DDT concentrations of 1070+/-504 ng/g lw and 619+/-328 ng/g lw, respectively. Male and female adult ringed seals had similar mean summation operator PCB concentrations as harp seals (955+/-385 ng/g lw and 999+/-304 ng/g lw, respectively). summation operator CHL concentrations ranged from 63+/-29 ng/g lw in blubber of female adult ringed seals, to 322+/-156 ng/g lw in adult harp seals and averaged 465 ng/g lw in bearded seals. HCH isomers, mirex and chlorobenzenes were detected in all seal samples but were present at lower levels than summation operator CHL, summation operator DDT and summation operator PCB. Concentrations of summation operator CHL, summation operator DDT and summation operator PCB in ringed seals from the White Sea were within the range reported for the Barents Sea but lower than in ringed seals from the Kara Sea. Temporal trends were investigated by comparing concentrations of OCs in blubber of harp seal pups collected in 1992 with pups of the same age collected in 1998. The declines over the 6 year period ranged from approximately 33% for summation operator DDT to 60% for summation operator PCB. These declines are consistent with reports of declining concentrations summation operator DDT in seawater from the White Sea and inflowing rivers in the 1980's and early 1990s. The major OC contaminants in fishes from the White Sea were DDT-related compounds and PCBs. Navaga (Eleginus navaga) had the highest concentrations of the 5 fish species studied with mean summation operator PCB of 41+/-6 ng/g wet wt. while lowest mean concentrations were present in cod muscle (16+/-8 ng/g ww). Concentrations of hexachlorobenzene (HCB), DDT, CHL-related compounds and PCB congeners were strongly correlated with trophic level of the organisms assigned using delta(15)N values, while beta-HCH, gamma-HCH and cis-chlordane showed no relationship with trophic level. Food web magnification factors (FWMFs) for p,p'-DDE, alpha-HCH, oxychlordane and trans-nonachlor the White Sea were similar to those from marine food webs in the Barents Sea and the Canadian arctic, while FWMFs for HCB and PCBs were generally lower. Overall the results suggest that the White Sea marine food differs in terms of the availability of contaminants in comparison to studies of open ocean arctic food webs due to proximity to urban/industrial areas and greater importance of benthic food sources.
To trace the biomagnification of organochlorines in marine food chains near Svalbard, which may lead to the high organochlorine concentrations in top predators from the area, we compared concentrations and patterns of organochlorines in selected taxa. The pelagic crustaceans, Calanus spp. (copepods), Thysanoessa spp. (euphausiids), Parathemisto libellula (amphipod), and the fish species, Boreogadus saida (polar cod) and Gadus morhua (cod) were selected to represent the lower trophic levels in the food web. Four seabird species were chosen at the higher trophic levels, Uria lomvia (Brünnich's guillemot), Cepphus grylle (black guillemot), Rissa tridactyla (black-legged kittiwake) and Larus hyperboreus (glaucous gull). We found low concentrations of the organochlorines sigma hexachlorocyclohexanes (sigma HCHs), hexachlorobenzene (HCB), sigma Chlordanes, sigma DDTs and sigma polychlorinated biphenyls (sigma PCBs) in crustaceans (11-50 ng g-1 lipid wt.) and fish (15-222 ng g-1 lipid wt.). In seabirds, the organochlorine concentrations biomagnified one to three orders of magnitude dependent on species and compound class. Glaucous gulls had the highest concentrations of all organochlorines. The organochlorine levels in all taxa except glaucous gull were comparable to those recorded in similar species in the Canadian Arctic. The organochlorine pattern changed from crustaceans and fish to seabirds. Moving up the food chain, the relative contribution of sigma HCHs, HCB and sigma Chlordanes decreased, and the relative contribution of sigma DDTs, sigma PCBs, persistent compounds and metabolites increased. The results reflected trophic transfer of organochlorines along the food chain as well as different elimination potentials due to direct diffusion in crustaceans and fish, and higher contaminant metabolic activity in seabirds.
Numerous studies have examined the relationship between organochlorines and breast cancer, but the results are not consistent. In most studies, organochlorines were measured in serum, but levels in breast adipose tissue are higher and represent cumulative internal exposure at the target site for breast cancer. Therefore, a hospital-based case-control study was conducted in Ontario, Canada to evaluate the association between breast cancer risk and breast adipose tissue concentrations of several organochlorines. Women scheduled for excision biopsy of the breast were enrolled and completed a questionnaire. The biopsy tissue of 217 cases and 213 benign controls frequency matched by study site and age in 5-year groups was analyzed for 14 polychlorinated biphenyl (PCB) congeners, total PCBs, and 10 other organochlorines, including p,p'-1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene. Multiple logistic regression was used to assess the magnitude of risk. While adjusting for age, menopausal status, and other factors, odds ratios (ORs) were above 1.0 for almost all organochlorines except five pesticide residues. The ORs were above two in the highest concentration categories of PCB congeners 105 and 118, and the ORs for these PCBs increased linearly across categories (Ps for trend
The Canadian Total Diet Study is a national survey to determine the level of chemical contaminants in the Canadian food supply. Food samples were collected from Whitehorse, Yukon, supermarkets as part of the study in 1998. Whitehorse was chosen as a sampling centre, despite its small population (n = 19,000), to determine if residue levels were different in foods available in northern communities relative to levels observed in previous studies in the more populated south. Foods were prepared as for consumption before pesticide residue analysis. Residue levels observed in most foods were similar to levels observed in samples from previous surveys from southern Canadian cities. Malathion and DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene), a transformation product of DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl(ethane), were the two most frequently detected compounds (26.4 and 25.8%, respectively). The majority of pesticides, however, had a detection frequency of
The traditional northern Norwegian fish dish "mølje", consisting of boiled cod, cod liver, cod liver oil and hard roe, is still consumed frequently during the winter months January to March. The liver of the cod is rich in lipids and the levels of persistent organic pollutants (POPs) are relatively high. To better understand the short-term consequences of this traditional meal on the plasma levels of PCBs and p,p'-DDE, individual intake of liver and cod liver oil during one meal was measured. Blood samples were collected from 33 participants before the meal, and then 4 h, 12 h and 5 days after it. Lipid-weight and wet-weight levels of 10 PCB congeners and p,p'-DDE were determined in the plasma samples and the food. The plasma levels of p,p'-DDE was found to increase significantly from 0 to 4 h, both when expressed as wet-weight (35% change) and lipid-weight (20% change). The corresponding changes (0-4 h) in wet-weight levels of the most prevalent PCB congeners were non significant. By contrast, PCB congeners with low levels in the food showed a significant drop in lipid-weight levels during the first 4 h. The observed changes were independent of amount consumed. Significant differences in fasting and non-fasting samples were found for most PCBs and p,p'-DDE. For the lipid weight levels of sum PCBs there was a significant decrease of 16% from non-fasting to fasting samples. To obtain reliable data on human levels of POPs it is, on the basis of these findings, recommended that blood samples should be collected from fasting individuals and both wet-weight and lipid-weight levels should be reported.
Environmental Conservation Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, USA. email@example.com
Gray whales are coastal migratory baleen whales that are benthic feeders. Most of their feeding takes place in the northern Pacific Ocean with opportunistic feeding taking place during their migrations and residence on the breeding grounds. The concentrations of organochlorines and trace elements were determined in tissues and stomach contents of juvenile gray whales that were taken on their Arctic feeding grounds in the western Bering Sea during a Russian subsistence harvest. These concentrations were compared to previously published data for contaminants in gray whales that stranded along the west coast of the US during their northbound migration. Feeding in coastal waters during their migrations may present a risk of exposure to toxic chemicals in some regions. The mean concentration (standard error of the mean, SEM) of sigmaPCBs [1400 (130) ng/g, lipid weight] in the blubber of juvenile subsistence whales was significantly lower than the mean level [27,000 (11,000) ng/g, lipid weight] reported previously in juvenile gray whales that stranded in waters off the west coast of the US. Aluminum in stomach contents of the subsistence whales was high compared to other marine mammal species, which is consistent with the ingestion of sediment during feeding. Furthermore, the concentrations of potentially toxic chemicals in tissues were relatively low when compared to the concentrations in tissues of other marine mammals feeding at higher trophic levels. These chemical contaminant data for the subsistence gray whales substantially increase the information available for presumably healthy animals.