Temporal trends and future predictions of mercury concentrations in Northwest Greenland polar bear (Ursus maritimus) hair.

Hair samples from 117 Northwest Greenland polar bears (Ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafter Hg). The sample represented 28 independent years and the aim of the study was to analyze for temporal Hg trends. Mercury concentrations showed yearly significant increases of 1.6-1.7% (p < 0.0001) from 1892 to 2008 and the two most recent median concentrations from 2006 and 2008 were 23- to 27-fold higher respectively than baseline level from 1300 A.D. in the same region (Nuullit). This indicates that the present (2006-2008) Northwest Greenland polar bear Hg exposure is 95.6-96.2% anthropogenic in its origin. Assuming a continued anthropogenic increase, this model estimated concentrations in 2050 and 2100 will be 40- and 92-fold the baseline concentration, respectively, which is equivalent to a 97.5 and 98.9% man-made contribution. None of the 2001-2008 concentrations of Hg in Northwest Greenland polar bear hair exceeded the general guideline values of 20-30 µg/g dry weight for terrestrial wildlife, whereas the neurochemical effect level of 5.4 µg Hg/g dry weight proposed for East Greenland polar bears was exceeded in 93.5% of the cases. These results call for detailed effect studies in main target organs such as brain, liver, kidney, and sexual organs in the Northwest Greenland polar bears.

Mercury and neurochemical biomarkers in multiple brain regions of five Arctic marine mammals.

Mercury is a neurotoxic chemical that represents one of the greatest pollution threats to Arctic ecosystem health. Evaluating the direct neurotoxic effects of mercury in free ranging wildlife is challenging, necessitating the use of neurochemical biomarkers to assess potential sub-clinical neurological changes. The objective of this study was to characterize the distribution and speciation of mercury, as well as exposure-associated changes in neurochemistry, across multiple brain regions (n = 10) and marine mammal species (n = 5) that each occupy a trophic niche in the Arctic ecosystem. We found consistent species differences in mean brain and brain region-specific concentrations of total mercury (THg) and methyl mercury (MeHg), with higher concentrations in toothed whales (narwhal, pilot whales and harbour porpoise) compared to fur-bearing mammals (polar bear and ringed seal). Mean THg (µg/g dw) in decreasing rank order was: pilot whale (11.9) > narwhal (7.7) > harbour porpoise (3.6) > polar bear (0.6) > ringed seal (0.2). The higher THg concentrations in toothed whales was associated with a marked reduction in the percentage of MeHg (<40 %) compared to polar bears (>70 %) that had lower brain THg concentrations. This pattern in mercury concentration and speciation corresponded broadly to an overall higher number of mercury-associated neurochemical biomarker correlations in toothed whales. Of the 226 correlations between mercury and neurochemical biomarkers across brain regions, we found 60 (27 %) meaningful relationships (r>0.60 or p < 0.10). We add to the growing weight of evidence that wildlife accumulate mercury in their brains and demonstrate that there is variance in accumulation across species as well as across distinct brain regions, and that some of these exposures may be associated with sub-clinical changes in neurochemistry.

Temporal and Geographical Variation of Intestinal Ulcers in Grey Seals (Halichoerus grypus) and Environmental Contaminants in Baltic Biota during Four Decades.

The prevalence of intestinal ulcers and parasites was investigated in 2172 grey seals (Halichoerus grypus) collected in the Baltic Sea and 49 grey seals collected outside the Baltic Sea (i.e., the Atlantic). An increase in frequency of ileocaeco-colonic ulcers was observed in the early 1980s, followed by a decrease in the mid-1990s. At the same time, there was an increase followed by a decrease in brominated flame retardants, Perfluorooctanesulfonic acid (PFOS) and cadmium levels in herring (Clupea harengus), the most common prey item in Baltic grey seal diet, as well as in another top predator in the Baltic, the common guillemot (Uria aalge). The frequency of intestinal ulcers was significantly related to the intensity of acanthocephalan parasites, the age of the seal and the region of the Baltic Sea. Perforation of the intestinal wall was the cause of death in 26 of the investigated Baltic grey seals. In contrast, none of the investigated Atlantic grey seals had intestinal ulcers. They showed a thin colonic wall and very few acanthocephalan parasites. The high prevalence of intestinal ulcers and the high parasite intensity appear to be unique to the Baltic population of grey seals.

Twenty years of monitoring of persistent organic pollutants in Greenland biota. A review.

The Arctic Monitoring and Assessment Programme (AMAP) is a working group under the Arctic Council with the aim to monitor and assess temporal trends of contaminants in Arctic ecosystems. The Greenland AMAP Core programme was established to contribute to this effort. The Core programme includes three main components; routine monitoring, retrospective studies and new POP screening studies. The programme is based on an adaptive approach, which has led to changes throughout the years. An overview of the temporal trends during the last two to three decades is presently given together with selected examples of different characteristic trends of POPs. The results show how tissue banked samples and retrospective studies has helped in establishing time-series of compounds of emerging concern. Lastly, the statistical power of the Greenlandic time-series is discussed. The lesson learned is that trend monitoring improves with samples over time, and only pays off after decades of data are generated.

Trends in fluctuating asymmetry in East Greenland polar bears (Ursus maritimus) from 1892 to 2002 in relation to organohalogen pollution.

Fluctuating asymmetry (FA) was studied in skulls of 283 polar bears (Ursus maritimus) sampled in East Greenland from 1892 to 2002. Fourteen metric bilateral traits in skull and lower jaw were measured and compared between polar bears born until 1960 (n = 94) and from 1961 (n = 189). The period 1892-1960 was chosen to represent a period prior to appearance of organohalogens (polychlorinatedbiphenyls [PCBs], dichlorodiphenyltrichloroethanes [DDTs], hexacyclohexanes [HCHs], chlordanes [CHLs], hexachlorobenzene [HCB], polybrominateddiphenylethers [PBDEs] and dieldrin) originating from long-range transport to East Greenland from southern latitudes. The period 1961-2002 represents the period when polar bears have been exposed to organohalogens. During this latter period, the level of organochlorines is believed to have increased from 1960 to the late 1980s followed by a likely decrease from 1990 to 2002. Within this later period, other compounds such as, e.g., polybrominated flame retardants are believed to have increased throughout the period. Two different analysis showed, that the degree of fluctuating asymmetry did not differ statistically between the two periods in ten of thirteen traits (one trait excluded due to high measurement error). In fact, when significant differences were found in four of the traits, the fluctuating asymmetry was lower in skulls sampled after 1960. The degree of fluctuating asymmetry was higher in adults than in subadults for 6 of the 14 traits, whereas a higher degree of fluctuating asymmetry was found for only one trait in one of the analyses for subadults relative to adults. Females had a higher degree of fluctuating asymmetry than males in one trait. A time trend analysis did find fluctuations over time for five traits but the relationship was weak as the trend appeared to occur by chance due to the high number of regressions analysed (n = 42). A correlation analysis of FA versus the sum concentrations of various classes of organohalogens in adipose tissue from a subsample of 94 recently collected polar bears (1999-2002) did not show a trend either. Hence, the present study could not document a relationship between skull asymmetry in polar bears and periods with different exposure to organohalogens. These findings are possibly influenced by nutritional status, genetic factors, a subeffect exposure of organohalogens or confounded by other environmental factors (e.g. temperature) within the two investigated periods.

Enlarged clitoris in wild polar bears (Ursus maritimus) can be misdiagnosed as pseudohermaphroditism.

A 23-year-old female polar bear (Ursus maritimus) killed in an Inuit hunt in East Greenland on July 9, 1999 had a significantly enlarged clitoris resembling, in size, form and colour, those of previously reported 'pseudohermaphroditic' polar bears from Svalbard. It has been suggested that an enzyme defect (21-hydroxylase deficiency), androgen producing tumour or high exposure to organochlorines during the foetal stage or early development could be the reason for the supposed pseudohermaphroditism observed for Svalbard bears. Except for the enlarged clitoris, all dimensions of the external and internal reproductive organs of the present were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999-2002. The aberrant bear was a female genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively functional. A histological examination of the clitoral enlargement in the present East Greenland specimen allows a first-time histological evaluation of the earlier macroscopic field diagnosis from Svalbard. This examination revealed intense chronic ulcerative and perivascular clitoriditis similar to "acral lick dermatitis" frequently seen in domestic dogs (i.e., we did not find any signs of pseudohermaphroditic hyperplasia of clitoral tissue due to androgenic or antiestrogenic endocrine disruption). The levels of organohalogens and TEQ values were lower than concentration thresholds of toxicological risk. It is hence possible that the previously reported adult female polar bear pseudohermaphrodites from Svalbard are in fact misdiagnoses. Therefore, future studies examining pseudohermaphroditism in wildlife should consider that certain occurrences are natural events, e.g., enlarged clitoris in the present East Greenland polar bear. Furthermore, caution should be exercised in suggesting linkages of such inflammatory abnormalities with correlations to anthropogenic pollutant exposures.

Temporal trends of cadmium and mercury in Greenland marine biota.

Data for cadmium and mercury in Greenland marine biota (blue mussels, polar cod, shorthorn sculpin, glaucous gull and ringed seals) over a period of 20 years has been analysed in order to assess temporal changes. Most of the comparisons were conducted between tissue samples collected in the mid-1980s and mid-1990s. Cadmium data from a few time series obtained at reference sites during monitoring of mining activities were also included. No overall temporal trends in cadmium or mercury concentrations were found within the 20-year period assessed. However, cadmium concentrations in ringed seals tended to increase in the period from late-1970s to the mid-1980s. From the mid-1980s to the mid-1990s cadmium concentrations in ringed seals decreased again, whilst mercury concentrations showed a tendency to increase in the same period. The observed changes may reflect natural fluctuations caused by factors such as a shift in feeding behaviour, rather than changes in anthropogenic exposure.

High human exposure to lead through consumption of birds hunted with lead shot.

We assess lead contamination of Greenland seabirds killed with lead shot having studied thick-billed murre and common eider, the two most important species in the diet. The lead concentration is very high in meat of eiders killed with lead shot (mean 6.1 microg/g-wet wt, 95% CL 2.1-12). This level is about 44 times higher than in drowned eiders and eight times higher than in shot murres. Analyzing whole breasts instead of sub-samples reveals about seven times higher lead levels in birds' meat. We conclude that in some cases the lead intake by Greenland bird eaters will largely exceed the FAO/WHO tolerable lead intake guideline and that lead shot is a more important source of lead in the diet than previously estimated.

Lead, cadmium, mercury and selenium in Greenland marine animals.

Baseline concentrations of lead, cadmium, mercury and selenium are reported from different tissues in marine organisms from Greenland. Overall, lead levels in marine organisms from Greenland are low, whereas cadmium, mercury and selenium levels are high. Tissue differences are not very distinct for lead, whereas the opposite is the case for cadmium and mercury. Selenium shows an intermediate behaviour in this respect. In general, lead concentrations do not correlate with the age/size of animals, whereas cadmium, mercury and selenium increase with age/size of most species and tissues analysed. No clear conclusions can be drawn in relation to geographical differences in lead, mercury and selenium concentration in Greenland. In general, cadmium levels are higher in Northwest Greenland compared to southern areas. Local differences with increasing cadmium levels from inner fjords to the open sea in stationary species may be of the same order of magnitude as those observed over long distances in Greenland. There is no indication that lead and selenium levels increase in higher trophic levels, although this is clearly the case for cadmium and mercury. In almost all cases lead levels in marine organisms from Greenland are well below the Danish food standard limits, however, a substantial proportion of marine mammals and seabirds in Greenland have cadmium and mercury levels exceeding the Danish standard limits. No food standard limits are given for selenium in food, but in some cases human intake of selenium is estimated to be high.

Lead contamination of seabirds harvested with lead shot--implications to human diet in Greenland.

Lead contamination of seabirds from the use of lead shot in Greenland was studied in thick-billed murre hunted at Nuuk in November 1998. In each bird shot pellets were located and counted using X-ray. The birds were skinned and viscera, head, wings and legs removed, after which the carcass was cooked. The soup and breast meat were then analyzed for lead after removal of visible shot pellets. In the soup the lead concentration was quite low, mean 6.3 micrograms/l (95% confidence interval between 4.4 and 8.2 micrograms/l), whereas breast meat lead values have a mean of 0.22 microgram/g (wet weight basis; 95% confidence interval between 0.10 and 0.36 microgram/g). This is more than 10 times higher than in birds not killed with lead shot. We found no correlation between lead concentration measured and number of pellets recorded in the whole bird or in the soup or in meat. The study indicates that lead in the meat exists as small lead fragments, left during the passage of pellets through the breast. Because of inhomogeneous lead distribution in samples, the uncertainty of estimated lead concentration in breast meat is high. Based on this study, it is concluded that birds killed with lead shot are a significant source of lead, probably the most important single source, of the diet of many people in Greenland. We estimate an intake of 50 micrograms lead from eating one boiled murre with soup. In addition people will occasionally eat whole lead shot pellets which have documented health effects. An intake of 50 micrograms lead is about twice as much as the daily average lead intake from all dietary sources in Denmark, about 25 times the daily lead intake from other marine food items in Greenland, and about one-fourth of the accepted tolerable daily intake.

The use of lichen (Cetraria nivalis) and moss (Rhacomitrium lanuginosum) as monitors for atmospheric deposition in Greenland.

Concentrations of Pb, Cd, Hg, Zn, Cu, Cr, Ni, As, V, Al and Fe are reported from soil, humus, moss (Rhacomitrium lanuginosum) and lichen (Cetraria nivalis) sampled at four locations in Greenland. For Al, Fe, Cr and V the levels in soil were highest followed by humus and R. lanuginosum and with the lowest levels in C. nivalis. The same was true for Pb, Cu and Ni but without as great a difference between medias. For Cd and Hg, the lowest levels were found in soil. For Zn and As, the media with highest levels differed between locality. Data were examined by a principal component analysis. Three principal components explained 87% of the total variation. The dominant elements in the first component were Fe, Al, V, Ni, Cr, Cu and Pb. This component is interpreted as a soil dust factor. The concentrations in R. lanuginosum and C. nivalis of these elements are believed to be highly influenced by soil dust. Pb concentrations in moss and lichen may also be influenced by other sources as Pb also had some correlation's with the third component. Zn and Cd and to a lesser extent. As were the dominant elements in the second component. The third component was highly dominated by Hg with a lesser influence of Pb and As, Zn, Cd and Hg concentrations in R. lanuginosum and C. nivalis are believed to be influenced by other sources than soil dust which may be long-range atmospheric transport. In general, both the within locality and the between locality variability in the values of the three components decreased in the order soil, humus, R. lanuginosum and C. nivalis. The lichen C. nivalis is looked at as an indicator with greater potential for monitoring atmospheric deposition of elements than the moss R. lanuginosum.

Mercury in Arctic char (Salvelinus alpinus) populations from Greenland.

Mercury concentrations were determined in muscle tissue of lake resident and anadromous populations of Arctic char in Greenland. Mercury in lake sediment, and in soil and humus from the surrounding area were also determined in the main localities. Fish length and dry weight were shown to be important covariables, which have to be taken into account when comparing mercury levels between populations. Variations in fat content did not contribute further to the differing mercury concentrations. Mercury concentrations in lake sediments, humus from around the lakes and resident populations of Arctic char from west Greenland and south-west Greenland were higher than for populations from east Greenland and north-west Greenland. The mercury level in anadromous populations was found to be 10-15-fold lower than that found in lake resident populations, and similar to that found in marine fish species. Methyl mercury was determined in two of the populations investigated, and constituted 72-92% of the total mercury.

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.

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.

An assessment of selenium to mercury in Greenland marine animals.

Information on mercury and selenium molar relation in muscle, liver and kidney tissue of Greenland marine animals is presented. In the majority of the samples selenium was present in a molar surplus to mercury. This was most clear in molluscs, crustaceans, fish and seabirds. A 1:1 molar ratio was found in tissues of marine mammals with high mercury concentrations (above approx. 10 nmol/g). This was most clearly demonstrated for liver and kidney tissue of polar bear and for ringed seal with high mercury concentration in the liver. These findings support previous results found in liver tissue of marine mammals, suggesting that methyl mercury is detoxified by a chemical mechanism involving selenium. If the anthropogenic release of mercury to the environment increases in the future due to increasing energy demands, species such as polar bears and seals with high tissue mercury concentrations should be monitored to elucidate whether this protective mechanism can be maintained in target organs.

Geographical differences of zinc, cadmium, mercury and selenium in polar bears (Ursus maritimus) from Greenland.

Muscle, liver, and kidney tissues from 100 polar bears (Ursus maritimus), caught in the Avanersuaq area, north-west Greenland, and Ittoqqortoormiit area, central-east Greenland, were analysed for zinc, cadmium, mercury and selenium. The zinc concentrations in muscle and liver were higher than in kidney. Mean zinc concentrations ranged from 19.7 to 76.0 micrograms/g (all data are presented as geometric means on a wet wt. basis). The presented cadmium concentrations by area and age groups were all low in muscle and in many cases below the detection limit (range: < 0.015-0.048 microgram/g). Cadmium concentrations were intermediate in liver (range: 0.120-1.98 micrograms/g) and highest in kidney tissue (range: 2.16-28.9 micrograms/g). Mercury was likewise lowest in muscle tissue (range: 0.034-0.191 microgram/g). Mercury concentration ranged quite similarly in liver and kidney tissue (liver range: 2.13-22.0 micrograms/g; kidney range: 2.87-32.0 micrograms/g). The selenium concentration increased from muscle (range: < 0.2-0.452 microgram/g) over liver (range: 1.20-9.80 micrograms/g) to kidney (range: 2.34-13.9 micrograms/g). No age accumulation was found for zinc. A weak increase was found for selenium, whereas cadmium and mercury clearly accumulated with age. An exception was mercury concentrations in muscle tissue, where no clear pattern was observed. Polar bears had significantly lower cadmium concentrations than ringed seals from the same area in all three tissues. Likewise mercury was significantly lower in the muscle tissue of polar bears than in ringed seals, whereas liver and kidney concentrations were higher. Biomagnification factors are provided for different tissues and age groups. Tissue ratios are given for different age groups and metals to enable a rough extrapolation from one tissue to another. Tissue ratios for cadmium, selenium and for mercury vary up to a factor of 6 with age. No significant differences could be detected between the elements analysed in bears from two management zones in north-west Greenland. This finding is in agreement with the genetic pattern in the two areas. In central-east Greenland, however, cadmium, selenium, and some of the mercury concentrations in polar bears from the southern area were higher than from the northern area, indicating that the east Greenland area represents two different ecological regions with different polar bear populations. Geographical differences between polar bears from north-west and east Greenland were only found for mercury and cadmium in liver tissue, where the concentrations were highest in bears from north-west Greenland. The geographical trend of increasing cadmium concentrations in polar bear liver tissue from west to east, which has been found previously in Canada, could be extended to cover north-west Greenland as well. East of this region a decrease was found. Mercury concentrations in polar bear liver tissue showed an increase from Svalbard over east and north-west Greenland, peaking in bears from south-west Melville Island. A marked decrease was found west of Melville Island, and the lowest concentrations were found in the Chukchi Sea.

Lead, zinc, cadmium, mercury, selenium and copper in Greenland caribou and reindeer (Rangifer tarandus).

Samples of caribou and reindeer muscle (127 samples) and liver (126 samples) were collected from four locations during two seasons plus 3 years in Greenland. The levels of lead, zinc, cadmium, mercury, selenium, and copper were determined, and analyzed in relation to location, two seasons, age and year of sampling. The lead concentrations (geometric mean) ranged from below the detection limit to 0.007 microgram/g wet weight (wet wt.) in muscle and from 0.027 to 0.926 microgram/g wet wt. in liver. Zinc geometric mean concentrations ranged from 17.5 to 39.6 micrograms/g wet wt. in muscle and from 23.2 to 31.7 micrograms/g wet wt. in liver. For cadmium, the geometric mean concentrations were at, or below the detection limit in muscle, while concentrations in liver ranged from 0.121 to 0.695 microgram/g wet wt. Mercury levels ranged from 0.003 to 0.043 microgram/g wet wt. in muscle and from 0.040 to 0.618 microgram/g wet wt. in liver. Selenium concentration levels in muscle ranged from 0.030 to 0.252 microgram/g wet wt., and from 0.085 to 0.984 microgram/g wet wt. in liver. Copper levels in muscle ranged from 2.09 to 3.60 micrograms/g wet wt., and from 21.8 to 71.0 micrograms/g wet wt. in liver. Mercury concentrations were higher than those found at lower latitudes in Norway and Canada, especially in Isortoq in southern Greenland. Selenium levels were also high compared to other Arctic regions. Concentrations of lead, zinc, cadmium and copper are similar to those reported in caribou from Canada and Norway. Concentrations of elements generally decreased in the following order: Isortoq > Akia > Itinnera > Kangerlussuaq, and there was only found minor variation in the annual levels during 3 years in Itinnera. Late winter levels were generally significantly higher than early winter levels especially in the lichen-rich localities, and it is suggested that the availability of lichens as winter forage is the key determining the level of elements. Accordingly, when using caribou and reindeer as monitoring organism, knowledge of winter forage is very important for interpretation of results.

Levels and spatial and temporal trends of contaminants in Greenland biota: an updated review.

Knowledge of contaminant levels in Greenland biota has increased substantially in recent years, particularly for persistent organic pollutants. This paper reviews and updates knowledge of spatial and temporal trends of Cd, Hg and organochlorines (PCBs, DDTs, HCHs, HCB and chlordane-related compounds) in Greenland terrestrial, freshwater and marine biota. The most comprehensive studies of spatial trends of Cd and Hg in the terrestrial ecosystem concern lichens, with relatively complete coverage, and caribou (Rangifer tarandus), with coverage mainly in different regions of central West Greenland and Southwest Greenland. The Arctic char (Salvelinus alpinus) is the only freshwater organism for which studies of spatial trends of Hg levels have been completed. Information on spatial trends of Cd and Hg in the marine environment is available from studies of fish, seabirds, ringed seals (Phoca hispida) and polar bears (Ursus maritimus). Geographical patterns of Cd and Hg in Greenland biota were not always consistent among different species or different studies. In landlocked Arctic char the concentrations of Hg decreased from south to north. In marine animals levels of Hg tended to be higher in East Greenland than in West Greenland and Cd levels were highest in biota from Disko Island in central West Greenland. The observed regional differences are difficult to explain but in most cases the causes appear to be natural rather than anthropogenic. Only a few time series covering the last 20 years exist for Cd and Hg. The one time series indicating a temporal change is for ringed seals in Northwest Greenland, which shows an increasing trend of Hg and a decreasing trend of Cd since 1984. Whether the changes reflect anthropogenic inputs, seal behaviour or other environmental factors is unknown. The most significant new insights have concerned organochlorines. In general, levels of these compounds were very low in terrestrial biota compared to marine species. Concentrations in landlocked Arctic char were highest in Southeast Greenland and lowest in Northwest and Northeast Greenland. Marine species from East Greenland had consistently higher levels of SigmaPCB, SigmaDDT and SigmaHCH than marine species from West Greenland. Very few data exist to evaluate temporal changes of organochlorine levels in Greenland biota, and this is the most significant knowledge gap at present. The most pronounced change observed was a decrease of 78% in SigmaPCB levels in polar bears from East Greenland from 1990 to 2000. Levels of SigmaHCH in shorthorn sculpins (Myoxocephalus scorpius) and seals from both central West Greenland and central East Greenland appear to have decreased since 1994. Increasing trends of SigmaDDT from 1994 until now were found in both sexes of seals as well as in male sculpins from central West Greenland.

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.

Organochlorines in Greenland glaucous gulls (Larus hyperboreus) and Icelandic gulls (Larus glaucoides).

Glaucous gulls (Larus hyperboreus) and Icelandic gulls (Larus glaucoides) were sampled in 1994 from four different areas in Greenland, three on the west coast and one on the east coast. Livers of 93 glaucous gulls and seven Icelandic gulls 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 (TNC). The overall geometric means of the concentrations found in glaucous gull liver were for sigma PCBs 388 (range 20-5557), for sigma DDTs 363 (17-8604), sigma HCHs 7.4 (1-53), HCB 47 (4-594) and trans-nonachlor 19 (3-187) micrograms kg-1 wet wt., respectively. The geometric means of concentrations in Icelandic gull liver were for sigma PCBs 112 (24-435), for sigma DDTs 95 (25-298), sigma HCHs 2.9 (1.4-5.2), HCB 22 (8-58) and trans-nonachlor 5.1 (2.4-8.6) micrograms kg-1 wet wt., respectively. Significantly (P = 0.05) higher concentrations of PCBs, DDTs and HCHs were found in glaucous gulls at Ittoqqortoormiit at the east coast than in gulls from Qeqertarsuaq at the west coast of Greenland. This tendency was also seen for HCB and trans-nonachlor, but the differences were not statistically significant (P = 0.05). A decreasing trend in organochlorine concentrations followed the East Greenland Current, flowing from north to south down the east coast and to the north on the west coast. Gulls taken from the most northerly sampling area of the west coast, however, showed slightly higher concentrations than those from the central west coast. There appeared to be a tendency for higher concentrations to be found in males than females, and in adults compared to young glaucous gulls, but the differences were not statistically significant (P = 0.05). The concentration ranges found in gulls from Greenland were similar to those reported previously for gulls from northern Norway and Russia. A principal component analysis revealed no obvious link between the presence of higher chlorinated PCBs and higher PCB concentrations in glaucous gulls. Significantly higher proportions of higher chlorinated PCBs were found in glaucous gulls than in Icelandic gulls, and in adult glaucous gulls compared to young gulls of 1-2 calendar years. As no such difference was found between female and male gulls it seems that PCBs of all degrees of chlorination may be passed equally well from mother to offspring.