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J U Skaare

Publications and source records attributed to J U Skaare.

At least 19 recordsLinked to original sources
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↗
PubMed2001

Whole blood concentrations of organochlorines as a dose metric for studies of the glaucous gull (Larus hyperboreus).

In order to examine if whole blood concentrations of organochlorines (OCs) is an appropriate dosimetric parameter for use in ecotoxicological studies of free-living birds, a number of incubating glaucous gulls (Larus hyperboreus) were repeatedly sampled within and between subsequent breeding seasons. The wet weight concentrations of selected OCs, differing in persistence and fat solubility, were compared and it was assessed to what extent present concentrations could be predicted from concentrations previously measured in the individuals. There were only a few significant differences in the blood concentrations of the selected OCs within and between seasons. The most persistent compound, polychlorinated biphenyl (PCB)-153, showed a low interindividual variability, and between seasons, 70% of the variance could be explained by the level in the previous year, while changes in body condition and blood lipid percentage were of less importance. For PCB-101, the predictability of the present blood concentration from the previous concentration was lower than for PCB-153, and changes in body condition and blood lipid percentage explained a higher proportion of the variance. The present level of alpha-hexachlorocyclohexane (HCH) could not be predicted from the previous level. Sex did not explain any significant proportion of the variance in OC concentrations when previous level and changes in body mass and blood lipid were included in the statistical models. Thus, for the most persistent OCs, concentration in the blood of incubating glaucous gulls is representative for the interindividual differences over time and whole blood concentrations of OCs appear adequate as a dose metric in ecotoxicological studies.

Animals↗
PubMed2000

Possible immunotoxic effects of organochlorines in polar bears (Ursus maritimus) at Svalbard.

Associations between immunoglobulin G (IgG) levels and the organochlorine contaminants (OCs) polychlorinated biphenyls (PCBs), chlordanes, 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE), hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs) in blood plasma from polar bears caught at Svalbard were determined. The blood samples were collected from free-living polar bears of different age and sex between 1991 and 1994. The IgC concentration increased with age and was significantly higher in males than in females. IgG was negatively correlated with sigmaPCB level and with three individual PCB congeners, IUPAC numbers 99, 194, and 206. HCB was also negatively correlated with IgG. The significant negative OC correlation with IgG levels may indicate an immunotoxic effect.

Aging↗
PubMed2000

Organochlorines in top predators at Svalbard--occurrence, levels and effects.

Alarmingly high polychlorinated biphenyl (PCB) levels have been found in the top predators such as glaucous gull (Larus hyperboreus) and polar bear (Ursus maritimus) at Svalbard [Gabrielsen, G.W., Skaare, J.U., Polder, A., Bakken, V., 1995. Chlorinated hydrocarbons in glaucous gull (Larus hyperboreus). Sci. Total Environ. 160/161, 337-346; Bernhoft, A., Skaare, J.U., Wiig, O., 1997. Organochlorines in polar bears (Ursus maritimus) at Svalbard. Environ. Pollut. 95, 159-175; Henriksen, E.O., Gabrielsen, G.W., Trudeau, S., Wolkers, H., Sagerup, K., Skaare, J.U., 1999. Organochlorines and possible biochemical effects in glaucous gull (Larus hyperboreus) from Bear Island, the Barents Sea. Arch. Environ. Contam. Toxicol. (in press). ]. Studies of the possible toxic effects, particularly on the immune system and reproduction, of the very high PCB levels in these species are currently being investigated. Data obtained in the field (f.i. reproductive success in polar bears and intestinal nematodes in glaucous gulls), as well as levels of various biochemical and physiological parameters (f.i. thyroid hormones, retinol, EROD activity, CYP1A, IgG), have been coupled with the PCB levels [Skaare, J.U., Wiig, O., Bernhoft, A., 1994. Klorerte organiske miljogifter; Nivâer og effekter i isbjorn. Norwegian Polar Institute Reportseries no. 86, 1-23 (in Norwegian); Bernhoft, A., Skaare, J.U., Wiig, O., 1997. Organochlorines in polar bears (Ursus maritimus) at Svalbard. Environ. Pollut. 95, 159-175; Bernhoft, A., Skaare, J.U., Wiig, O., Derocher, A.E., Larsen, H.J., 2000. Possible immunotoxic effects of organochlorines in polar bears (Ursus maritimus) at Svalbard (in press); Henriksen, E.O., Gabrielsen, G.W., Skaare, J.U., Skjegstad, N., Jensen, B.M., 1998a. Relationship between PCB levels, hepatic EROD activity and plasma retinol in glaucous gull, Larus hyperboreus. Marine Environ. Res. 46, 45-49; Henriksen, E.O., Gabrielsen, G.W., Trudeau, S., Wolkers, H., Sagerup, K., Skaare, J.U. , 1999. Organochlorines and possible biochemical effects in glaucous gull (Larus hyperboreus) from Bear Island, the Barents Sea. Arch. Environ. Contam. Toxicol. (in press); Sagerup, K., Gabrielsen, G.W., Skorping, A., Skaare, J.U., 1998. Association between PCB concentrations and intestinal nematodes in glaucou gulls, Larus hyperboreus, from Bear Island. Organohalogen compounds 39, 449-451; Skaare, J.U., Wiig, O., Bernhoft, A., 1994. Klorerte organiske miljogifter; Nivâer og effekter i isbjorn. Norwegian Polar Institute Reportseries no. 86, 1-23. (in Norwegian)].

Adipose Tissue↗
PubMed2000

Organochlorines and possible biochemical effects in glaucous gulls (Larus hyperboreus) from Bjørnøya, the Barents Sea.

To study possible biochemical effects of organochlorine contaminants (OCs) in glaucous gulls (Larus hyperboreus), 40 adult individuals were collected from colonies on Bjornoya in the Barents Sea. OCs (four pesticides and nine PCB congeners), microsomal 7-ethoxyresorufin O-deethylase (EROD) activity, microsomal testosterone hydroxylation, highly carboxylated porphyrins (HCPs), retinol, and retinyl palmitate were quantified in liver samples. The hepatic vitamin A stores in glaucous gulls were larger than in herring gulls (Larus argentatus) from other studies conducted in contaminated locations in North America. No significant relationships were found between liver retinoid concentrations and OC levels. The hepatic EROD activity was low compared to other studies on fish-eating birds and only marginally associated with PCB levels. Microsomal testosterone hydroxylase activity was only observed at the 6beta-position and could not be related to OC levels. The low P450-associated enzyme activities in the glaucous gull suggests that they have a low capacity for metabolizing OCs, which may contribute to the high accumulation of OCs in this species. HCPs were only elevated (138 pmol g(-1)) in the sample with highest OC levels, whereas the remaining samples contained low levels of HCPs (<30 pmol g(-1)). The weak association between EROD activity and PCB levels and the low level of HCPs suggest that these biochemical parameters were unaffected by OCs in most of the sampled gulls. Thus, the glaucous gull seems not to be particularly sensitive toward Ah-receptor mediated effects.

Animals↗
PubMed2000

Determination of toxaphenes in fish and marine mammals.

An analytical method for the determination of toxaphene in biological materials using gas chromatography with an electron capture detector (GC-ECD) has been established and validated for three single congeners (chlorinated bornanes (CHB) 26, 50 and 62). The analytical method was based on a method for determination of PCB, DDT and other chlorinated pesticides. To include toxaphene congeners an extra step, adsorption chromatography on silica columns, was introduced to separate the pesticides from PCB. The recovery of CHB-26, 50 and 62 were 97+/-11%, 94+/-10% and 99+/-12%, respectively. Samples from cod, ringed seal and polar bear from the Norwegian arctic environment have been analysed. The levels of CHB-26 and 50 found were 13-55 ng/g fat in cod, 1.3-7.7 ng/g fat in ringed seal and 0.4-119 ng/g fat in polar bear. The levels of CHB-62 were 2.0-13, 0.8-3.4, 0.2-11 ng/g fat in cod, ringed seal and polar bear, respectively.

Animals↗
PubMed2000

Spatial distribution of persistent organochlorines in ringed seal (Phoca hispida) blubber.

Blubber samples, taken through the entire blubber column, were collected from three different anatomical locations on ringed seals (Phoca hispida). The outer and inner layers of these samples were analysed for concentrations of sigma PCBs (sum of the analysed congeners, polychlorinated biphenyls) and p,p'-DDE (4,4'-dichlorodiphenyldichloroethylene). No significant differences were found in blubber thickness or in per cent extractable lipid when comparing age- and sex-groups, or in extractable lipid content when comparing anatomical locations of the blubber or blubber depth. No significant differences were found between the three different anatomical locations with respect to the concentrations of sigma PCBs or p,p'-DDE. However, the concentrations of both sigma PCB and p,p'-DDE were significantly higher in the outer blubber layer compared to the inner. Higher levels of both sigma PCB and p,p'-DDE were found in males compared to females and juveniles in both the inner and outer parts of the blubber column. The most commonly used blubber sampling devices are biopsy tools that penetrate only the outer layer of the blubber. Analyses of such samples will not reflect the real body burden of organochlorines. Standard methods for sampling blubber of marine mammals should be developed so that comparative studies and longitudinal monitoring programs of pollutants in marine mammals can be conducted in a meaningful way.

Adipose Tissue↗
PubMed2000

Biological transport and mammal to mammal transfer of organochlorines in Arctic fauna.

Ringed seal (Phoca hispida) is assumed to be the most important and common prey of polar bears (Ursus maritimus). However, during a scientific survey in the ice area of the northern Barents Sea east of Svalbard in June 1995, an unexpectedly high number of polar bears were observed feeding on harp seal (Phoca groenlandica) carcasses. Samples of both harp and ringed seals were obtained and organochlorine (OC) occurrence and pattern in these two potential polar bear prey species were determined. Significantly higher OC concentrations were found in harp seals, as compared to the ringed seals. All animals in the northern harp seal group were lean specimens in late moult. The industrial chemicals, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB), and the OC pesticides bis-2,2,(chlorophenyl)-1,1,1-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes (CHLORs) were analysed in blubber. The concentrations of sigma PCB (sum of concentrations of 16 PCB congeners) and sigma DDT (sum of concentrations of p,p'-DDT and p,p'-DDE) in the northern harp seal group ranged from 2093 to 20,382 and 1460 to 10,381 ng g-1 lipid weight, with mean concentrations of 11,133 and 6847 ng g-1 lipid weight, respectively. The mean concentrations of the CHLORs, oxychlordane and trans-nonachlor, were 1311 and 3743 ng g-1 lipid weight, respectively, while the mean concentrations of HCB and HCH isomers (alpha-, beta- and gamma-HCH) were all < 500 ng g-1 lipid weight. No significant difference was found in the mean total blubber mass between the two seal species when collected in June. This indicates that polar bears preying on harp seals instead of ringed seals at this time of the year could accumulate significantly higher PCB concentrations. We suggest that polar bears feeding along the ice-edge east of Svalbard in May and June preferentially prey on harp seals instead of ringed seals, and that this may partly explain the variation in PCB concentrations among polar bears from the Norwegian Arctic. An hypothesis is that the harp seal may function as a transport vector of OCs into the high Arctic environment.

Adipose Tissue↗