Organochlorines in Greenland ringed seals (Phoca hispida)

Twenty-five ringed seals (Phoca hispida) were sampled in 1994 at each of four areas in Greenland, three on the west coast and one on the east coast. Seal blubber samples were analysed for polychlorinated biphenyls (PCBs, IUPAC Nos. 28, 31, 52, 101, 105, 118, 138, 153, 156 and 180), DDTs (p,p'-DDE, p,p'-DDD, p,p'-DDT), hexachlorocyclohexanes (alpha-, beta- and gamma-HCH), hexachlorobenzene (HCB) and trans-nonachlor. A number of the seals (n = 56) were also analysed for toxaphene (total toxaphene and single congeners: CHB Nos. 26, 32, 50 and 62). The overall geometric means (and ranges) found in seals were in microgram kg-1 wet wt. for sigma PCBs: 452 (85-4200), sigma DDTs: 607 (97-6040), sigma HCHs: 123 (51-382), HCB: 13 (3-27), trans-nonachlor: 83 (21-1236) and total toxaphene: 263 (71-950). The geometric means for HCB, trans-nonachlor, toxaphenes and the sums of PCBs and DDTs were higher for the east coast samples than for those from the west coast, and a decreasing trend in concentrations followed the east Greenland current. No geographical trend was apparent for HCHs. Differences in concentrations between females and males were only significant for HCB and HCH within certain age classes and sampling areas. A tendency for concentrations to increase with age was observed, but was not statistically significant. Principal component analyses for PCB congeners revealed that the proportion of higher chlorinated PCBs (Cl atoms > or = 6) decreased with decreasing concentrations of PCBs found for the four sampling areas. No differences between the higher and lower chlorinated PCBs were seen in females and males, but a higher proportion of CB-105 and CB-118 compared to CB-52 and CB-101 was seen in male seals compared to female seals.     

Organochlorines in Greenland lake sediments and landlocked Arctic char (Salvelinus alpinus)

Lake sediments and landlocked Arctic char (Salvelinus alpinus) were sampled in 1994 and 1995 at four different locations in Greenland, three at the west coast and one at the east coast. Sediments, char muscle and char liver were analysed for PCBs (10 congeners), DDTs (pp'), HCHs (alpha, beta, gamma), dieldrin, HCB and chlordanes (5) and char in addition to toxaphene (total and 4 congeners). All organochlorines in the sediment samples were below the detection limit of 0.1 microgram kg-1 dry wt., while the overall geometric means in Arctic char muscle were, in microgram kg-1 wet wt., for PCBs 11 (range 1-140), for DDTs 4.0 (1-35), for HCHs 0.4 (0.06-1.5), for dieldrin 0.7 (< 0.1-4.2), for HCB 0.7 (0.09-3.8), for chlordanes 4.8 (1-57) and for total toxaphene 13 (1-180). The sums of PCBs, DDTs, chlordanes and total toxaphene disclosed higher concentrations in muscle of char from the east coast compared to char from the west coast. Dieldrin and HCB showed the same tendency, but less pronounced, while the sum of HCHs were found in highest concentrations at the west coast. PCB, DDT, chlordane and toxaphene concentrations showed a decreasing trend following the East Greenland Current. Principal component analysis on PCB congeners showed that the proportion of higher chlorinated PCBs (Cl > 5) were higher in Qaqortoq in south Greenland compared to the three other sampling areas in Greenland. However, no correlation was seen either between degree of chlorination and latitude or between degree of chlorination and PCB concentrations.     

Organochlorines in Greenland marine fish, mussels and sediments

Shorthorn sculpin (Myoxocephalus scorpius), polar cod (Boreogadus saida), blue mussels (Mytilus edulis) and sediments were sampled in Greenland 1994-1995 at three locations at the west coast and one at the east coast. Fish liver, mussel soft tissue and sediments were analysed for PCBs (10 congeners), DDTs (pp,'), HCHs (alpha, beta, gamma), HCB and trans-nonachlor. The overall geometric mean concentrations found for PCBs were 17 micrograms kg-1 wet wt. in shorthorn sculpin liver, 33 micrograms kg-1 wet wt. in polar cod liver, and 0.86 microgram kg-1 wet wt. in blue mussels. For the three species, the geometric mean concentrations for DDTs were 11, 36, and 0.39 micrograms kg-1 wet wt., respectively; for HCHs: 8.7, 32 and 0.56 micrograms kg-1 wet wt., respectively; for HCB: 4.2, 11 and 0.06 micrograms kg-1 wet wt., respectively; and for trans-nonachlor: 6.3, 19 and 0.16 microgram kg-1 wet wt., respectively. All organochlorines in the sediment samples were below the detection limit of 0.1 microgram kg-1 dry weight. For sculpins and mussels, most organochlorine compounds were found to increase with increasing lipid content. The weight of mussels did not influence organochlorine concentrations, whereas organochlorine content in general increased with fish length of sculpins. The concentrations were found to be comparable to levels in other Arctic regions, but orders of magnitude lower than levels found in the southern part of the North Sea. Organochlorine concentrations in sculpins showed a decreasing trend following the ocean current flowing from north to south at the east coast and from south towards north at the west coast of Greenland. The proportion of higher chlorinated PCBs (Cl atoms > or = 6) in sculpin liver followed the decreasing trend of PCB concentrations.     

Persistent organic pollutants and mercury in dead and dying glaucous gulls (Larus hyperboreus) at Bjørnøya (Svalbard)

Dead and dying glaucous gulls (Larus hyperboreus) were collected on Bjørnøya in the Barents Sea in 2003, 2004 and 2005. Autopsies of the seabirds only explained a clear cause of death for three (14%) of the 21 birds. A total of 71% of the birds were emaciated. Liver and brain samples were analysed for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ether (PBDEs), hexabromocyclododecanes (HBCDs) and mercury (Hg). High levels of ΣOCPs, ΣPCBs, ΣPBDEs and α-HBCD were found in liver and brain. Compared to the dead and dying glaucous gulls found 1989, the congeners' composition tended to change toward more persistent compounds in the 2003–2005 samples. The brain levels of OCPs and PCBs did not differ between 1989 and 2003–2005, while the liver levels were significantly lower. The brain/liver ratio for PCB and PBDE significantly decreased with halogenations of the molecule, indicating a clear discrimination of highly halogenated PCBs and PBDEs entering the brain. There was further a clear negative correlation between contaminant concentrations and body condition. The brain levels were not as high as earlier published lethal levels of p,p′-DDE or PCB. However, more recent studies reported a range of sub-lethal OCP- and PCB-related effects in randomly sampled glaucous gulls. An additional elevation of pollutants due to emaciation may increase the stress of the already affected birds. The high brain levels of OCP, PCB and PBDE of present study might therefore have contributed to the death of weakened individuals of glaucous gull.     

Lead, cadmium, mercury and selenium in Greenland marine biota and sediments during AMAP phase 1

Lead, cadmium, mercury and selenium levels in the Greenland marine environment from the first phase of the AMAP are presented. Samples were collected in 1994-1995 covering four widely separated regions in Greenland. Samples included sediments, soft tissue of blue mussel; and liver of polar cod, shorthorn sculpin, glaucous gull, Iceland gull and ringed seal. Concentrations of lead were found to increase with the size of blue mussel, but not with the age of gulls or ringed seal. Both cadmium and mercury concentrations were found to increase with the size/age of all species. Selenium concentrations decreased with increasing size of blue mussel, but increased with the age of gulls and ringed seal. Element levels found are within the range of those found in previous studies in Greenland. Relative to global background levels, lead levels must be considered low, whereas levels of cadmium, mercury and selenium in Greenland marine biota are high. Significant differences in element levels in sediments and biota among regions in Greenland were seen in several cases. There was a tendency for the highest lead and mercury concentrations to be found in east Greenland, whereas the highest cadmium concentrations were found in central west Greenland. However, the geographical differences among the media did not show a consistent pattern.     

Selected persistent organochlorine pollutants in Romania

Selected persistent organochlorine pollutants, including PCBs, DDT and its metabolites (DDTs) and hexachlorocyclohexane isomers (HCHs) were determined in soil, animal fat and human serum samples from Romania. All methods were rigorously tested and adequate quality control was ensured. Soil samples from Iassy County showed a lower contamination with organochlorines than samples from other Romanian regions. While DDTs concentrations in soil were significantly higher at rural sites, only few samples (three out of 47) exceeded the official Romanian norms for DDTs. PCBs concentrations were low in rural sites (<8 ng/g soil), but rather high (up to 134 ng/g soil) in urban soils collected mostly from parks (Bucharest, Arad, Baia Mare, Pitesti and Ploiesti). Animal fat samples from Iassy showed high concentrations of organochlorine pesticides (HCHs concentrations up to 12370 ng/g fat), but similar PCB concentrations when compared with Arad samples. Two samples (from 24) exceeded the EU norms (1000 ng/g fat) for HCHs and DDTs in animal fat. Organochlorines were found in higher concentrations in some samples of human serum from Timisoara due to a broader age range. Samples of human serum from Iassy mothers showed higher HCHs and DDTs concentrations than samples from a similar group from Antwerp, Belgium. HCB and PCBs were higher in Antwerp cohort. Romanian samples showed a higher ratio DDT/ΣDDTs, but similar ratios PCB 153/ΣPCBs.     

Temporal and spatial trends of persistent organochlorines in Greenland walrus (Odobenus rosmarus rosmarus)

Persistent organochlorines [PCBs, DDT and chlordane related compounds, dieldrin, toxaphene, hexachlorocyclohexane (HCH), chlorobenzenes] were determined in blubber of Atlantic walrus (Odobenus rosmarus rosmarus) in 1978 and 1988 from the Avanersuaq (Thule) region of north-west Greenland and in 1989 from Ittoqqortoormiit (Scoresbysund) in east Greenland. Lowest concentrations of organochlorines (OCs) were found in the samples from the Avanersuaq region while much higher levels of all compounds, except HCH isomers and mono/dichlorobiphenyls (CB5/8), were observed in samples (all males) from Ittoqqortoormiit. Total PCBs (sigma PCB) averaged 246 ng/g (wet wt.) male walrus from Avanersuaq and 2860 ng/g in samples from Ittoqqortoormiit. DDT isomers showed the greatest difference between the two locations, 50 x for p,p'-DDE and 69 x higher for p,p'-DDT. Ittoqqortoormiit walrus showed the pattern of OCs characteristic of seal-eating animals although the consumption of other organisms cannot be ruled out. The higher levels of OCs in east Greenland compared to north-west Greenland animals were consistent with results for polar bears, seals and gulls from the same regions. Principal components analysis showed that the pattern of OCs in Ittoqqortoormiit walrus was very similar to that in walrus from Inukjuaq in east Hudson Bay, which have previously been reported to be seal eaters, and quite distinct from the Avanersuaq walrus. No significant differences in mean concentrations of any OCs were found between male walrus from 1978 and 1988. For females, there were significantly higher levels of CB5/8, trichlorobiphenyls, dieldrin, toxaphene and alpha HCH as well as sigma HCH but not for sigma PCBs or DDT compounds. The data for Greenland walrus from the 1970s and late 1980s provide a baseline for future trend monitoring in walrus.     

Chlorinated pesticides and polychlorinated biphenyls in marine tucuxi dolphins (Sotalia fluviatilis) from the Cananéia estuary,southeastern Brazil

The Cananéia estuary is an important biological area on the southeast coast of Brazil. In the past, it was impacted by both chlorinated pesticides and polychlorinated biphenyls (PCBs) due to its natural location. The marine tucuxi dolphin (Sotalia fluviatilis) is a top predator in this ecosystem and can be found year round in Cananéia estuarine waters that represent an important nursing area for the species. This work investigated chlorinated compounds in the blubber of nine individuals from the Cananéia estuary. Residue levels of DDTs (0.541-125 microg g(-1) lipid wt.) were the highest, followed by PCBs (0.2-9.22 microg g(-1) lipid wt.), mirex (0.014-0.312 microg g(-1) lipid wt.), chlordanes (0.001-0.047 microg g(-1) lipid wt.), HCHs (<0.003-0.044 microg g(-1) lipid wt.), and HCB (n.d.-0.024 microg g(-1) lipid wt.). The mean p,p'-DDE/Sigma DDT ratio was approximately 0.8 and is indicative of the former DDT application in the study area. PCB contamination is suggested to be associated with atmospheric transport and relative proximity to the Cubat?o industrial complex-the most important along the Brazilian coast. Low levels of HCHs and HCB can be attributed to their high volatility in tropical environments. Concentrations of organochlorines in the blubber of marine tucuxis from the Cananéia estuary were lower than levels found in small cetacean species from developed countries, where the input of these compounds was considerably greater than in Brazil. At extremes, male dolphins can present DDT burden several orders of magnitude higher than females. Despite the high levels of total DDT found in males, the major detected compound was p,p'-DDE which is considered to be of low toxicity.     

Evaluation of the Greenland AMAP programme 1994-1995, by use of power analysis (illustrated by selected heavy metals and POPs)

The levels of PCBs, HCB, HCHs, DDTs, Cd, Pb, Hg and Se, and especially the variability in biota obtained during Phase 1 of the Greenland AMAP-programme have been used to illustrate the ability of the programme to detect differences in contaminant levels over time. The statistical power of t-tests of contaminant levels are illustrated according to various scenarios of magnitude of change, significance level and sample size. The statistical power of various time series of contaminant levels to detect linear trends in mean log-concentrations, including a random between-year variation component, is illustrated. We conclude that the ability to detect differences is rather poor for many combinations of contaminants and media, and that long time series are needed before temporal trends are likely to be detected.     

Concentrations and patterns of organochlorine pesticides and PCBs in Mediterranean monk seals (Monachus monachus) from Western Sahara and Greece

Blubber from Mediterranean monk seals (Monachus monachus) from the Western Sahara coast (Atlantic), sampled during 1996-1999, and from the Greek coast (Mediterranean), sampled during 1995-1999, was analyzed for organochlorine pollutants (OCs). In both populations, no significant difference was found between sexes. In the Atlantic population, mature females presented greater percentages of higher chlorinated PCB (polychlorinated biphenyl) congeners in relation to total PCBs (sum of 25 congeners) than pups, indicating a differential transfer of PCB congeners through lactation. In the Mediterranean, the reduced sample size of adult individuals precluded proper statistical investigation of age-related variation. Significant differences in concentrations and pollutant patterns were found between populations. Thus, Mediterranean individuals presented significantly higher levels of HCB (hexachlorobenzene), tPCB, and DDTs (dichlorodiphenyltrichloroethane) concentrations and DDE/tDDT and tDDT/tPCB ratios than their counterparts from the Atlantic. Moreover, the relative proportion of different congeners in relation to the total PCB load (congener/tPCB) was also different between the two areas. The 100*tDDT/tPCB ratio in Atlantic seals was 38.46, which indicates a predominance of industrial inputs over those associated with agriculture. Conversely, in the Mediterranean seal population, the 100*tDDT/tPCB ratio was 177.1, denoting a proportionally higher contribution of pollutants of agricultural origin.     

Persistent organic pollutants in ringed seals from the Russian Arctic

Organochlorine compounds total DDT (ΣDDT), total HCH isomers (ΣHCH), toxaphenes (sum of Parlar 26, 50, 62), mirex, endrin, methoxychlor, total chlorinated benzenes (ΣCBz), total chlordane compounds (ΣCHL), polychlorinated biphenyls (total of 56 congeners; ΣPCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and polybrominated diphenyl ethers (sum of 7 tri- to hepta congeners; ΣPBDEs) were analysed in the blubber of adult ringed seals from the four areas of the Russian Arctic (White Sea, Barents Sea, Kara Sea and Chukchi Sea) collected in 2001-2005. Ringed seals from the south-western part of the Kara Sea (Dikson Island — Yenisei estuary) were the most contaminated with ΣDDTs, ΣPCBs, ΣCHL, and mirex as compared with those found in the other three areas of Russian Arctic, while the highest mean concentrations of ΣHCHs and PCDD/Fs were found in the blubber of ringed seals from the Chukchi Sea and the White Sea, respectively. Among all organochlorine compounds measured in ringed seals from the European part of the Russian Arctic, concentrations of ΣDDT and ΣPCBs only were higher as compared with the other Arctic regions. Levels of all other organochlorine compounds were similar or lower than in seals from Svalbard, Alaska, the Canadian Arctic and Greenland. ΣPBDEs were found in all ringed seal samples analysed. There were no significant differences between ΣPBDE concentrations found in the blubber of ringed seals from the three studied areas of the European part of the Russian Arctic, while PBDE contamination level in ringed seals from the Chukchi Sea was 30-50 times lower. ΣPBDE levels in the blubber of seals from the European part of the Russian Arctic are slightly higher than in ringed seals from the Canadian Arctic, Alaska, and western Greenland but lower compared to ringed seals from Svalbard and eastern Greenland.     

Geography and stage of development affect persistent organic pollutants in stranded and wild-caught harbor seal pups from central California

Persistent organic pollutants have been associated with disease susceptibility and decreased immunity in marine mammals. Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), chlordanes (CHLDs), and hexachlorocyclohexane isomers (HCHs) were evaluated in terms of stage of development and likely exposure routes (in utero, suckling, fasting) in the blubber of 202 stranded and wild-caught, primarily young of the year (n = 177), harbor seals (Phoca vitulina) in the central California coast. This is the first report of HCH concentrations in the blubber of California seals. Lipid normalized concentrations ranged from 200 to 330,000 ng/g for sum PCBs, 320-1,500,000 ng/g for sum DDTs, 23-63,000 ng/g for sum PBDEs, 29-29,000 ng/g for sum CHLDs, and 2-780 ng/g for sum HCHs. The highest concentrations were observed in harbor seal pups that suckled in the wild and then lost mass during the post-weaning fast. Among the pups sampled in the wild and those released from rehabilitation, there were no differences in mass, blubber depth, or percent lipid although contaminant concentrations were significantly higher in the pups which nursed in the wild. When geographic differences were evaluated in a subset of newborn animals collected near their birth locations, the ratio of sum DDTs to sum PCBs was significantly greater in samples from an area with agricultural inputs (Monterey), than one with industrial inputs (San Francisco Bay). A principal components analysis distinguished between seals from San Francisco Bay and Monterey Bay based on specific PCB and PBDE congeners and DDT metabolites. These data illustrate the important influence of life stage, nutritional status, and location on blubber contaminant levels, and thus the need to consider these factors when interpreting single sample measurements in marine mammals.     

Levels and patterns of Persistent Organic Pollutants (POPS) in selected food items from Northwest Russia (1998-2002) and implications for dietary exposure

Residues of persistent organic pollutants (POPs) were analysed in 70 selected food items from Northwest Russia in 1998-2002. Levels of PCBs ranged from 0.2 to 16 ng/g wet weight (ww) in dairy products and fats, 0.2 to 23 ng/g ww in meat products, 0.5 to 16 ng/g ww in eggs and 0.3 to 30 ng/g ww in fish. High levels of DDT (16 ng/g ww) were found in locally produced butter from Kola Peninsula, in pork fat from Arkhangels region (10 to 130 ng/g ww) and in some fish samples from White Sea and Kargopol region (17 and 30 ng/g ww). Findings of low DDE/DDT ratios in many of the studied food items indicated recent contamination to DDTs. Mean levels of sum TEQs_WHO1998 of dioxin-like mono-ortho PCBs: PCBs 105, 118, 156 and 157 (∑ mo-PCBs-TEQs_WHO1998) were highest in dairy products, chicken eggs and fish, with levels of 0.292, 0.245 and 0.254 pg/g ww, respectively. The estimated daily intake (EDI) for ∑ mo-PCBs-TEQs_WHO1998 was 0.74 pg/kgbw/day and in the same range as in Sweden and Denmark. Fish, dairy products, eggs and meat were the main contributors to the EDI of ∑ mo-PCBs-TEQs_WHO1998. The EDIs of DDTs, HCHs and HCB were several times higher than in Sweden and Denmark. Consumption of meat and poultry were important sources for intake of DDTs and HCHs, respectively. Contamination of animal feed and agricultural practice were assumed the most important causes for the results in the present study. However, increased control on maximum residue levels in food and feed may have resulted in large changes on levels and patterns of POPs in food in the studied areas.     

Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of POP/OHC exposure and mediated effects are East Greenland, Svalbard and (West and South) Hudson Bay polar bears, Alaskan and Northern Norway killer whales, several species of gulls and other seabirds from the Svalbard area, Northern Norway, East Greenland, the Kara Sea and/or the Canadian central high Arctic, East Greenland ringed seal and a few populations of Arctic charr and Greenland shark.     

The status of soil contamination by semivolatile organic chemicals (SVOCs) in China: a review

This paper summarizes the published scientific data on the soil contamination by semivolatile organic chemicals (SVOCs) in China. Data has been found for more than 150 organic compounds which were grouped into six classes, namely, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and phthalic acid esters (PAEs). An overview of data collected from the literature is presented in this paper. The Chinese regulation and/or other maximum acceptable values for SVOCs were used for the characterization of soils. In general, the compounds that are mostly studied in Chinese soils are OCPs, PAHs and PCBs. According to the studies reviewed here, the most abundant compounds were PAEs and PAHs (up to 46 and 28 mg kg(-1) dry weight, respectively); PCBs and OCPs occurred generally at concentrations lower than 100 microg kg(-1) dry weight. Nevertheless, quite high concentrations of PCDD/Fs, PCBs and PBDEs were observed in contaminated sites (e.g., the sites affected by electronic waste activities). The average concentrations of PAHs and OCPs in soils of North China were higher than those in South China. The principal component analysis demonstrated different distribution patterns for PAH, PCB and PCDD/F congeners and for the various sites/regions examined. The isomer ratios of DDTs and hexachlorocyclohexanes (HCHs) indicated different sources and residue levels in soils. Finally, this review has highlighted several areas where further research is considered necessary.     

Persistent organic pollutants in edible marine species from the Gulf of Naples, Southern Italy

Edible tissues from 10 marine species, collected from the Gulf of Naples in the Southern Tyrrhenian Sea (Italy) between February and July 2003, were analysed for the presence of organochlorine pesticides hexachlorobenzene (HCB) and DDTs (p,p'-DDT, p,p'-DDE, and p,p'-DDD), and 20 polychlorinated biphenyls (PCBs). The PCB levels (calculated as the sum of all the determined congeners) were found to be the highest (from 56.8 to 47909.5 ng/g on lipid basis), followed by the DDTs (sum of p,p'-DDT and its metabolites; 相似文献   

Geographical distribution of organochlorine pesticides (OCPs) in polar bears (Ursus maritimus) in the Norwegian and Russian Arctic

Geographical variation of organochlorine pesticides (OCPs) was studied in blood samples from 90 adult female polar bear (Ursus maritimus) from Svalbard, Franz Josef Land, Kara Sea, East-Siberian Sea and Chukchi Sea. In all regions, oxychlordane was the dominant OCP. Regional differences in mean levels of HCB, oxychlordane, trans-nonachlor, alpha-HCH, beta-HCH and p,p'-DDE were found. The highest levels of oxychlordane, trans-nonachlor and DDE were found in polar bears from Franz Josef Land and Kara Sea. HCB level was lowest in polar bears from Svalbard. Polar bears from Chukchi Sea had the highest level of alpha- and beta-HCH. The lowest alpha-HCH concentration was found in bears from Kara Sea. In all the bears, summation operator HCHs was dominated by beta-HCH. The geographical variation in OCP levels and pattern may suggest regional differences in pollution sources and different feeding habits in the different regions. Polar bears from the Western Russian Arctic were exposed to higher levels of chlordanes and p,p'-DDE than polar bears from locations westwards and eastwards from this region. This may imply the presence of a significant pollution source in the Russian Arctic area. The study suggests that the western Russian Arctic is the most contaminated region of the Arctic and warrants further research.     

Halogenated environmental contaminants in perch (Perca fluviatilis) from Latvian coastal areas

The environmental contamination situation in coastal areas of the former Soviet Union has up to now been more or less unknown. This study on perch (Perca fluviatilis), collected at three locations along the coast of Latvia during 1994 and 1995, provides concentrations of several ubiquitous environmental contaminants (PCBs, HCB, HCHs, 4,4'-DDT, 4,4'-DDE, 4,4'-DDD, trans-Nonachlor, 2,2',4,4'-tetrabromodiphenyl ether). The concentrations of total PCB were similar at all study locations [0.7-1.4 ppm on a lipid weight (l.w.) basis], although a site close to the City of Riga indicated the presence of a local PCB contamination source. The contamination source was identified mainly by a higher relative content of lower chlorinated PCB congeners in the samples. Local pollution sources were also indicated for HCH and DDT. A large variation in the HCH isomer composition between 1994 and 1995 at one location demonstrates short half-lives of HCHs in the environment. The brominated flame retardant compound 2,2',4,4'-tetrabromdiphenyl ether was present in the range of 6.4-10 ng/g l.w. in the perch. The clean-up method applied in this study allowed for quantification of two semi-polar contaminants frequently overlooked in Baltic biota, namely Dieldrin and bis(4-chlorophenyl) sulfone (BCPS). Concentrations of BCPS were remarkably high, i.e. in the same magnitude as the most abundant PCB congeners. The results presented shows that the contamination of, e.g. PCB in an area of the former Soviet Union, the Gulf of Riga, is similar to that observed in other parts of the Baltic area.     

Levels and trends of organochlorines and brominated flame retardants in ivory gull eggs from the Canadian Arctic, 1976 to 2004

The ivory gull (Pagophila eburnea) is a circumpolar marine bird which has recently been listed as an endangered species in Canada. To determine whether contaminants may be playing a role in the population decline of this species, ivory gull eggs collected in 1976, 1987 and 2004 from Seymour Island in the Canadian Arctic were analyzed for organochlorines, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs. This study also provides the first account of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and polybrominated biphenyls (PBBs) in ivory gulls. The most quantitatively abundant legacy organochlorines found in the ivory gull eggs were p,p'-DDE, SigmaPCB and oxychlordane. Concentrations of the organochlorines analyzed either decreased or showed little change between 1976 and 2004. Concentrations of SigmaPCDD in ivory gull eggs were greater than SigmaPCDF, and the non-ortho PCBs (primarily PCB-126) contributed the largest fraction to the total TEQ value in all years sampled. Concentrations of PCDDs, PCDFs and SigmaTEQ decreased from 1976 to 2004. In contrast, concentrations of the PBDEs steadily increased between 1976 and 2004 driven primarily by increases in BDE-47. Although concentrations of the persistent chlorinated compounds (i.e. organochlorine pesticides, PCBs, PCDDs, PCDFs) reported in this study were below published toxicological threshold values for eggs of wild birds, we cannot rule out the possibility of synergistic/additive, sublethal effects. Very few studies have been carried out to evaluate the exposure-effect relationship of the persistent brominated compounds in avian species. Given the scarcity of information on toxicity threshold levels for PBBs and PBDEs in avian species, coupled with the trend toward increasing concentrations in ivory gulls, continued monitoring and further toxicological studies of these compounds are warranted.     

Comparison of contaminants from different trophic levels and ecosystems

The present paper provides an overview of the priority contaminants and media from the Greenland part of the Arctic Monitoring and Assessment Program. Levels and accumulation patterns of heavy metals, POPs and a radionuclide (137Cs) are compared from the terrestrial, freshwater and marine ecosystems. Of the nine compounds presented, seven (Cd, Hg, Se, sigma PCB, sigma DDT, sigma HCH, HCB) increased in concentration towards higher trophic levels. For these contaminants the concentrations in soil and aquatic sediment were in the same order of magnitude, whereas the concentrations in marine biota were higher than found in the freshwater and terrestrial ecosystems probably due to the presence of longer food chains. Pb and 137Cs showed the reverse pattern compared with the other compounds. The concentrations in soil and aquatic sediments decreased in the order terrestrial, freshwater and marine ecosystems, which was reflected in the biota as well. Reindeer had similar or lower levels of Pb and 137Cs than lichens. Levels of Pb and 137Cs in marine biota did not show the same clear increase towards higher trophic as found for the other analysed compounds. Greenland Inuit contains considerably less mercury but higher levels of sigma PCB, sigma DDT and HCB than other Arctic marine top consumers.