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Biomedical subjects

J U Skaare

Publications and source records attributed to J U Skaare.

At least 19 recordsLinked to original sources
PubMed2006

Selective bioaccumulation of chlorinated pesticides and metabolites in Arctic seabirds.

Chlorinated pesticides and metabolites (CPs) were quantified in the seabird species: little auk (Alle alle), Brünnich's guillemot (Uria lomvia), black guillemot (Cepphus grylle) and black-legged kittiwake (Rissa tridactyla). The purpose was to evaluate avian accumulation of selected CPs based on their concentrations and relative patterns, their relation to dietary descriptors (stable isotopes of carbon and nitrogen), to enzymes involved in biotransformation, as well as CPs' accumulation potential relative to the recalcitrant polychlorinated biphenyl PCB-153. In all species, the CP pattern was dominated by p,p'-dichlorodiphenyltrichloroethane (DDE) and hexachlorbenzene (HCB). Except for HCB, concentrations were not related to trophic position. Most CPs were quantified in black guillemot, indicating a slower elimination compared to other seabird species. Brünnich's guillemot showed efficient elimination of chlordanes, whereas the opposite was found for little auk. Kittiwake showed higher accumulation of persistent CP and metabolites than auks, whereas accumulation of less recalcitrant CPs was low.

Animals↗
PubMed2005

Levels of toxaphene congeners in white whales (Delphinapterus leucas) from Svalbard, Norway.

This study reports concentrations of three pesticide toxaphene congeners (CHBs; CHB-26, -50 and -62) from the blubber of ten adult, male white whales (Delphinapterus leucas) from Svalbard, Norway. The CHB congeners that occurred at the highest levels in the blubber of the white whales were, as expected, CHB-26 (4636+/-1992 (SD) ng/g l.w.) and CHB-50 (6579+/-2214 ng/g l.w.); CHB-62 (232+/-231 ng/g l.w.) was also present, but at much lower concentrations. The mean level of the sum of the three CHBs (SigmaCHBs = 11,447+/-4208 ng/g l.w.) in this study is more than twice the mean concentrations of the well-known organochlorine (OC) pollutants SigmaDDTs (sum of pp'-DDT, pp'-DDE, pp'-DDD) and SigmaPCBs (sum of 27 PCB congeners) previously reported from the same individual white whales. The concentrations of CHBs in white whales from Svalbard are at the high end of the range for concentrations of these compounds compared to other Arctic white whale populations. Additionally, the contribution of CHBs to the overall OC burden is larger in white whales from Svalbard compared with their counterparts from other areas in the Arctic. Male white whales from Svalbard have several orders of magnitude higher concentrations of SigmaCHBs compared to seals and polar bears (Ursus maritimus) from the same area. The high levels of CHBs in these whales, and their dominance in the OC pattern, suggests that white whales in Svalbard are exposed to high levels of this group of contaminants. Further studies are needed to investigate possible effects of CHBs and other OC contaminants on the white whale population in Svalbard.

Adipose Tissue↗
PubMed2004

Total blubber burden of organochlorine pollutants in phocid seals; methods and suggested standardization.

The purpose of the present paper was to investigate methods for calculating the total blubber burden of organochlorine pollutants (OCs) in phocid seals. Harp seals (Phoca groenlandica) were used as the model species. A sample of fat pre-breeding adult females (N = 9) and a sample of thin moulting adult females (N = 7) were collected. From each animal blubber samples from five different body sites (complete blubber columns and samples from different blubber layers), in addition to a sample from a homogenate derived from the entire blubber mass, were analyzed for selected OCs. Significant differences in the concentrations of major OC contaminants were found between inner and outer blubber layer. Within each seal group, no significant difference in OC concentrations was found between homogenates from whole blubber columns from the five different sites of the animals or when comparing these with the OC concentrations found in the blubber sample deriving from a homogenate of the entire blubber mass. When comparing the two seal groups, the mean OC concentrations were significantly higher in the thin seals. However, blubber burden of OCs measured directly and calculated indirectly were not significantly different, and did not vary between the two groups of seals. Since these seals are of the same age and sex group and from the same population, this is not an unexpected result. The present results suggest that comparison of blubber concentrations of OCs in phocid seals should be avoided, especially when comparing differences between geographical areas or for time-trend analyses. For this type of study, we suggest that the blubber burden of OCs is applied as standard in the future. Furthermore, since blubber depth at a specific sampling site is required when using the estimator for calculation of the percent blubber content in phocid seals (the LMD-index), we suggest that this sampling site (central dorsally) is introduced as a standard when sampling blubber for OC analyses in phocid seals.

Adipose Tissue↗
PubMed2004

Immune function and organochlorine pollutants in Arctic breeding glaucous gulls.

Organochlorine contaminants (OCs) are known to affect the immune systems of wildlife, and in this study we assessed the relationship between blood concentration of different OCs and measurements relevant to immune status and function in arctic breeding glaucous gulls (Larus hyperboreus). In 1997 and 2001, we counted white blood cells (heterophils and lymphocytes) from blood smears, and in 2000 and 2001 we injected two novel nonpathogenic antigens (diphtheria and tetanus toxoids) into the pectoral muscle of gulls and measured the primary antibody responses. We then related these measurements to the blood concentrations of three pesticides (hexachlorobenzene [HCB], oxychlordane, and p,p'-dichlorodiphenyldichloroethylene) and seven different polychlorinated biphenyl congeners (PCB 101, 99, 118, 153, 138, 180, and 170). There were significant or near significant positive relationships (0.1 > p > 0.001) between most persistent OCs and the levels of heterophils in the blood for both sexes in 1997 and for male gulls in 2001. Similarly, levels of all persistent OCs and lymphocytes were positively related (0.1 > p > 0.001) in both sexes in 1997. This suggests that OCs are causing alterations to immune systems, which may decrease their efficiency and make the birds more susceptible to parasites and diseases. In female gulls, the antibody response to the diphtheria toxoid was significant and negative for HCB (p < 0.01) and weaker, but significant, for oxychlordane (p < 0.05), suggesting that OCs were causing an impairment of the humoral immunity. Various OCs have been linked to negative effects in our study population, including decreased survival and reproduction, and this study suggests that such compounds also affect immune status and function.

Animals↗
PubMed2003

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.

Animals↗
PubMed2003

Geographic variation of chlorinated pesticides, toxaphenes and PCBs in human milk from sub-arctic and arctic locations in Russia.

The concentrations of HCB, alpha-, beta- and gamma-HCH, 3 chlordanes (CHLs), p,p'-DDE, p,p'-DDD, p,p'-DDT, and 30 PCBs (polychlorinated biphenyls) were determined in 140 human milk samples from Kargopol (n=19), Severodvinsk (n=50), Arkhangelsk (n=51) and Naryan-Mar (n=20). Pooled samples were used for determination of three toxaphenes (chlorobornanes, CHBs). The concentrations of HCB, beta-HCH and p,p'-DDE in Russian human milk were 2, 10 and 3 times higher than corresponding levels in Norway, respectively, while concentrations of sum-PCBs and sum-TEQs (toxic equivalent quantities) of the mono-ortho substituted PCBs were in the same range as corresponding levels in Norway. The PCB-156 contributed most to the sum-TEQs. Highest mean concentrations of HCB (129 microg/kg milk fat) and sum-PCBs (458 microg/kg milk fat) were detected in Naryan-Mar, while highest mean concentrations of sum-HCHs (408 microg/kg milk fat), sum-CHLs (48 microg/kg milk fat), sum-DDTs (1392 microg/kg milk fat) and sum-toxaphenes (13 microg/kg milk fat) were detected in Arkhangelsk. An eastward geographic trend of increasing ratios of alpha/beta-HCH, gamma/beta-HCH, p,p'-DDT/p,p'-DDE and PCB-180/28 was observed. In all areas the levels of sum-HCHs decreased with parity (number of children born). Considerable variation in levels of the analysed organochlorines (OCs) was found in all the studied areas. Breast milk from mothers nursing their second or third child (multiparas) in Naryan-Mar showed a significant different PCB profile compared to mothers giving birth to their first child (primiparas) from the same area and to primi- and multiparas in the other areas. Both p,p'-DDE and p,p'-DDT showed a significant, but weak, negative correlation with the infants birth weight.

Adult↗
PubMed2003

Partitioning of persistent organic pollutants in grey seal (Halichoerus grypus) mother-pup pairs.

Phocid seals have lipid rich milk, which is known to serve as a transfer medium through which persistent organic pollutants (POPs) move from mother to offspring during lactation. However, knowledge on this generational transfer of different POPs and the partitioning of these compounds in maternal and offspring tissues over the course of the lactation are limited. In this study we examined the qualitative and quantitative partitioning of a range of chlorinated POPs in maternal blubber, blood and milk as well as in pup blubber, collected early in the lactation period and late in the lactation period. In the lactating female, the high-chlorinated and hydrophobic compounds were passed less efficiently into the milk than the low-chlorinated compounds and more water-soluble compounds. Significantly, lower maternal blood concentrations than in maternal blubber biopsies suggest a stratification of POP concentrations in the blubber column of lactating female and lower concentrations in the metabolic active inner layers. Over the course of lactation, there was a significant increase in maternal blood and milk concentrations of POPs as opposed to no change in maternal blubber biopsy concentrations. This was most apparent for the hydrophobic and high-chlorinated compounds. The most likely explanation for this is that the metabolic active inner blubber layer, from which the milk lipids are derived from, is in steady state with the circulatory system, while the outer layers are more static and only slowly respond to changes in concentrations elsewhere in the body. The concentrations of the high-chlorinated and hydrophobic compounds were substantially lower in pup blubber than in maternal blubber. This probably relates the combined effect of these compounds stratification in maternal blubber and their slow transfer into the milk. The present study shows that the more hydrophobic and high-chlorinated compounds come to steady state less quickly in the different tissues than the more water-soluble and low-chlorinated compounds in the lactating female and her offspring. This has implications for which matrices to choose when sampling for assessing the toxicological risk of POPs in seals.

Adipose Tissue↗
PubMed2002

Effects of DDT on paracetamol half-life in highly exposed mothers in Zimbabwe.

After assessment of the levels of DDT residues in the milk samples, 1 g paracetamol was administered p.o. to 28 breastfeeding mothers selected from a population of 116, according to DDT residues in their milk (the 14 with the highest values and the 14 least exposed). Post dose blood samples were taken from the basilic veins of the mothers at time intervals up to 4 h, post dose. The paracetamol blood concentrations were determined. A significantly shorter paracetamol half-life was found in mothers with higher DDT body burden, who also exhibited lower paracetamol concentrations in blood. The results highlighted concern for the highly exposed mothers taking paracetamol (NSAID) as an analgesic, or as an antipyretic.

Acetaminophen↗
PubMed2002

Influence of diet and sea ice drift on organochlorine bioaccumulation in Arctic ice-associated amphipods.

The drifting sea ice has been suggested as important in the transport and concentration of organic matter and pollutants in the Arctic. We collected sea ice-associated amphipods in the marginal ice zone north of Svalbard and in the Fram Strait in September 1998 and 1999 to assess contaminant accumulation in ice-associated organisms. Organochlorine concentrations increased from the more herbivorous Apherusa glacialis to the more carnivorous Gammarus wilkitzkii and the more necrophagous Onisimus spp. The relative contribution of compound classes to the sum of organochlorines differed between the amphipod families, with a higher relative contribution of hexachlorocyclohexanes (HCHs) in A. glacialis. The composition of the compound classes HCHs. chlordanes and dichlorodiphenyltrichloroethanes (DDTs) was similar between the amphipod families, whereas the profiles of polychlorinated biphenyls (PCBs) differed. The occurrence of organochlorines differed spatially, with higher alpha-HCH concentrations in amphipods from the Fram Strait in comparison with amphipods collected north of Svalbard. This could be related to the sea ice drift route, since sea ice in the Fram Strait had a drift route across the central Arctic Ocean, while the sea ice north of Svalbard had a western drift route to the sampling stations. Even though marine invertebrates have direct uptake by passive diffusion of contaminants across their gills. our results imply that the species' ecology such as diet is important in the bioaccumulation process of organic pollutants. In addition, the results show that sea ice drift route influences the concentrations of organochlorine pollutants in ice-associated organisms.

Animals↗
PubMed2001

Accumulation of the lipophilic environmental contaminant lindane in metacercariae of Bucephaloides gracilescens (Trematoda, Bucephalidae) in the central nervous system of bullrout Myoxocephalus scorpius.

Bucephaloides gracilescens is a common parasite in the intestine of the angler fish Lophiuspiscatorius, and the metacercariae have been recorded from a number of gadoid intermediate hosts. In a toxicokinetic study of lindane (gamma-hexachlorocyclohexane) in bullrout Myoxocephalus scorpius, metacercariae of B. gracilescens were found in the central nervous system (CNS). Furthermore, the metacercariae accumulated concentrations of lindane that were higher than in the surrounding CNS tissue. This is the first report of metacercariae of B. gracilescens in bullrout. In addition the present results contribute knowledge of the disposition of an important environmental contaminant in the metacercarial stage of a trematode that has been pointed out as a promising sentinel species of pollution in the marine environment.

Animals↗
PubMed2001

Relationships between plasma levels of organochlorines, retinol and thyroid hormones from polar bears (Ursus maritimus) at Svalbard.

Associations were determined between retinol and the thyroid hormones thyroxine (T4) and triiodothyronine (T3), respectively, and the organochlorine contaminants (OCs) polychlorinated biphenyls (PCBs), 1, 1-dichloro-2,2-bis-(4-chlorophenyl)ethylene (DDE), hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs) in blood plasma from polar bears (Ursus maritimus) caught at Svalbard. The blood samples were collected from free-ranging polar bears of different age and sex in 1991-1994. The retinol concentration and the ratio of total T4 (TT4) to free T4(FT4) (TT4/FT4 ratio) decreased linearly with increasing concentrations of PCBs and HCB. Retinol was also negatively associated with HCHs, while the TT4/FT4 ratio was positively associated with DDE. The concentrations of retinol and thyroid hormones were significantly higher in females than in males. However, the TT4/FT4 and TT3/FT3 ratios were significantly higher in males than in females. The concentrations of thyroid hormones were negatively correlated with age in male bears, while in females, thyroid hormones did not change with age. The OCs were found to explain 12, 30, and 7% of the variation of retinol concentrations and the TT4/FT4 and TT3/FT3 ratios, respectively, after correcting for age and sex. The potential consequence of these associations for the individual and the population is unknown.

Animals↗
PubMed2001

Concentrations and patterns of organochlorine contaminants in white whales (Delphinapterus leucas) from Svalbard, Norway.

Blubber was collected from live-captured, adult male white whales (Delphinapterus leucas) from Svalbard, Norway, and analysed for levels and patterns of organochlorine (OC) contaminants. The OC compounds analysed were HCB, dieldrin, sigmaHCH (alpha-HCH, beta-HCH and gamma-HCH), sigmaChl (heptachlor epoxide, oxychlordane, cis-chlordane, trans-nonachlor, and cis-nonachlor), sigmaDDT (pp'-DDT, pp'-DDE and pp'-DDD) and sigmaPCB (27 PCB congeners). The major OC compounds detected in the blubber were sigmaPCB (5103+/-1874 ng/g l.w.) and sigmaDDT (5108+/-1089 ng/g l.w.), which made up 70% of the sigmaOC. These compounds were followed in prevalence by sigmaChl (2872+/-1177 ng/g l.w.), which contributed 20% of the sigmaOC burden. SigmaHCH, HCB and dieldrin were present, but at low concentrations. This OC pattern is typical of top predators in Arctic marine food chains. OC levels in white whales from Svalbard are lower than white whales from the St Lawrence River in Canada and are generally similar to values reported previously for other Arctic white whale stocks. Some geographic patterns in relative prevalence of various OC compounds appear to be quite consistent among various marine mammal species in the Arctic. PCB and DDT concentrations in Svalbard's white whales are below the levels that are thought to have negative effects on reproduction or the immune system.

Adipose Tissue↗
PubMed2001

Organochlorine burdens in blood of ringed and bearded seals from north-western Svalbard.

Ringed seal (Phoca hispida) and bearded seal (Erignathus barbatus) are the main prey of polar bears (Ursus maritimus), and information on organochlorines (OCs) in these pinniped species is important to understand the transport, fate and effects of persistent organic pollutants in the Arctic ecosystem. Thus, OCs were analysed in blood samples of bearded and ringed seals from the coastal ecosystem of the north-western Svalbard archipelago (Kongsfjorden, 78.55degrees N). The relative contribution of OCs could be ranked as follows: Ringed seal females: sigmaPCB > sigma DDT > sigma CHL > sigma HCH > HCB > Mirex. Ringed seal males: sigma PCB > or = sigma DDT > sigma CHL > sigma HCH > or = HCB > Mirex. Bearded seal females: sigma PCB > sigma HCH > or = sigma CHL > sigma DDT > Mirex > HCB. Bearded seal males: sigma PCB > sigma DDT > or = sigma CHL > sigma HCH > Mirex > or = HCB. The concentrations of sigmaPCB and sigma DDT were higher in ringed seals than in bearded seals, whereas sigma HCH was higher in bearded than in ringed seals. In ringed seal females and males sigma PCB was 337 +/- 95 ng/g (n= 6) and 625 +/- 443 ng/g (n=6), whereas sigma DDT was 165 +/- 47 ng/g (n=6) and 621 +/- 559 ng/g (n = 6), respectively. In bearded seal females and males, sigmaPCB was 159 +/- 132 ng/g (n = 6) and 248 +/- 93 ng/g (n = 5), whereas sigmaDDT was 46 +/- 41 ng/g (n = 6) and 161 +/- 71 ng/g (n = 5), respectively. The inter-species differences are caused by a higher trophic position of ringed seals in the Svalbard ecosystem compared to bearded seals. OC levels in ringed seals at Svalbard are similar to those reported from the North-American Arctic and in the lower range compared to previously reported data from Svalbard.

Animals↗
PubMed2001

PCBs, TEQs and plasma retinol in grey heron (Ardea cinerea) hatchlings from two rookeries in Norway.

Fish-eating birds are particularly subject to accumulation of persistent organic pollutants, and polychlorinated biphenyls (PCBs) have been shown to constitute a major hazard for this group of birds. Grey heron (Ardea cinerea) hatchlings from two rookeries were applied as sentinel species to study PCB burdens in coastal ecosystems in mid Norway and north Norway, and plasma retinol and dioxin-equivalencies (sigmaTEQ) were applied to assess toxic effects of the PCB-burdens. The results show that grey herons appear to be amongst the fish-eating birds in Norway that are accumulating PCBs to the largest extent. There were no differences in sigmaPCB or sigmaTEQ in the yolk of grey heron hatchlings from the two rookeries and, accordingly, none in plasma retinol concentrations either. Furthermore, plasma retinol concentrations could not be related to sigmaPCB or sigmaTEQ. Thus, it seems that exposure levels are below the threshold for gross retinoid-related effects in grey heron hatchlings. There are also indications that the grey heron could be relatively insensitive to retinoid-related effects of PCBs. In the hatchlings with the highest pollutant levels, sigmaTEQs were in the lower range of levels that have been associated with reduced hatching success in other fish-eating bird species.

Animals↗
PubMed2001

Biomagnification of organochlorines along a Barents Sea food chain.

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.

Animals↗
PubMed2001

Monitoring PCBs in polar bears: lessons learned from Svalbard.

Monitoring pollutants in the biota of the Arctic is a high priority activity of the circumpolar Arctic nations. Polar bears (Ursus maritimus) are one species that have been selected for monitoring, owing to their high trophic position in the Arctic marine ecosystem and high contaminant levels. Considerable research has been directed at understanding the effects of pollutants, and ultimately these effects are tied to temporal trends in pollutant levels. This paper reports on the state of contaminant monitoring of polar bears in the Norwegian Arctic and provides recommendations for future monitoring programmes. PCB-153 decreased significantly in plasma collected from polar bears sampled at Svalbard during the 1990s. Future monitoring efforts should sample annually at the same location, at the same time of year and analyse 10-25 samples per year.

Animals↗
PubMed2001

Disposition and depuration of lindane (gamma-HCH) and polychlorinated biphenyl-110 (2,3,3'4'6-pentachlorobiphenyl) in cod (Gadus morhua) and bullrout (Myoxocephalus scorpius) after single oral exposures.

The disposition and depuration of lindane (gamma-hexachlorocyclohexane [HCH]) and polychlorinated biphenyl (PCB)-110 (2,3,3',4',6-pentachlorobiphenyl), orally administered to cod (Gadus morhua) and bullrout (Myoxocephalus scorpius), were investigated using whole-body autoradiography, liquid scintillation counting, and gas chromatography with electron-capture detection. Both gamma-HCH and PCB-110 were distributed mainly to lipid-rich organs after absorption from the gastrointestinal tract of cod and bullrout. Compared to bullrout liver, the cod liver contained higher concentrations of both compounds, reflecting the distribution of fat in the two species. In both species, the depuration time for gamma-HCH was shorter than for PCB-110. Both substances were excreted via bile and urine, largely as water-soluble metabolites. The water-soluble bile metabolites, together with PCB-110 metabolites associated to endogenous macromolecules, strongly indicate that this compound is metabolized in both species.

Administration, Oral↗