Body burdens and tissue concentrations of organochlorines in polar bears (Ursus maritimus) vary during seasonal fasts

Polischuk, Susan C.; Norstrom, Ross J.; Ramsay, Malcolm A.

doi:10.1016/s0269-7491(01)00278-0

Cited by 137 publications

(118 citation statements)

References 32 publications

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“…Age contributed significantly to the variation of AOC (sum of all OC compounds and by-products), A 42 PCB, and AMeSO 2 -PCB concentrations in a multivariate analysis of variance for samples where all analytes were analyzed (GLM; F 3,80 = 7.9, p b 0.001). It has been shown that concentrations of some lipophilic CHCs, notably CHLs and PCBs, are higher in sub-adult polar bears compared to adults, particularly in cubs of the year, because of inheritance from lactational transfer from mother to cub (Polischuk et al, 2002). The significant number of sub-adult polar bears b 5 years of age in the present dataset probably accounts for most of the age effect.…”

Section: Data Analysesmentioning

confidence: 57%

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Verreault

Muir

Norstrom

et al. 2005

Science of The Total Environment

125

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A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO 2 ) PCB and p,pV-dichlorodiphenyldichloroethylene ( p,pV-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The East Greenland and Svalbard populations of polar bears were distinguished by higher proportions of dichlorodiphenyldichloroethane (DDT)-related compounds, nonachlors, oxychlordane, and higher-chlorinated and persistent PCB congeners (hepta-to nona-chlorinated). Conversely, Alaska, the westernmost population of the North American Arctic, was characterized by higher proportions of relatively volatile compounds such as hexachlorocyclohexanes (HCHs) and pentachlorobenzene (PnCBz), lower-chlorinated PCB congeners (tri-to penta-chlorinated), and lower proportions of oxychlordane. Geometric mean (GM) with 95% confidence limits (CL) AHCH concentrations were highest in Alaska male polar bear fat samples (GM 593; CL 363À909 ng g À 1 lipid weight), ADDT concentration were highest in East Greenland female samples (GM 309; CL 249À490 ng g À 1 l.w.), and A 42 PCB (GM 5972; CL 4637À9129 ng g À 1 l.w.) and AMeSO 2 -PCB (GM 198; CL 162À279 ng g À 1 l.w.) concentrations were highest in female samples collected from Svalbard. The distribution of A-chlordanerelated compounds (ACHL), ACBz, mirex, and dieldrin was relatively uniform among the populations of polar bears investigated. The present 1996À2002 data of female polar bear fat samples was compared to spatial assessments of female polar bear fat samples collected between 1989 and 1993 from comparable populations. The two-point temporal comparisons showed a general decrease for age-adjusted mean concentrations of ACHL, p,pV-DDE, A 42 PCB, AMeSO 2 -PCB and 3-MeSO 2 -p,pV-DDE over a period of approximately 10 years. However, concentrations of dieldrin were comparatively unchanged. Comparisons of present 2001À2002 concentrations in fat of female polar bears from Western Hudson Bay showed great consistency with temporal trends (1991À1999) previously reported for the same region, i.e. the apparent non-decreasing trend of ACHL, h-HCH, AHCH and dieldrin, and the apparent declining trend for APCB. However, present concentrations of a-HCH and ACBz were elevated, and ADDT was notably lower in Western Hudson Bay samples compared to the last measurements in fat samples collected in 1999, which was not in accord with reported temporal trends for this region. As a result of their relatively high degree of contamination, East Greenland and Svalbard polar bears are at higher health risk of contaminant exposure among Arctic and Subarctic populations. In addition to continued biomonitoring, further research on health and population status is needed to evaluate the impact from chronic exposure of polar bear pop...

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Section: Data Analysesmentioning

confidence: 57%

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Verreault

Muir

Norstrom

et al. 2005

Science of The Total Environment

125

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“…Climate warming causes earlier break-up of sea-ice and thus prolongs this fasting period in polar bears, resulting in increased mortality rates due to emaciation and starvation (Gagnon and Gough, 2005;Molnar et al, , 2014Stirling and Derocher, 2012). Because many lipid-soluble POPs are not excreted, fasting and especially emaciation will cause large increases of the concentrations of these compounds in blood and target tissues (Polischuk et al, 2002;Christensen et al, 2007;Helgason et al, 2013). Thus, prolonged fasting due to climate induced ice-loss and resultant lowered prey availability increases the likelihood for POPs levels to exceed threshold levels for effects.…”

Section: Combined Effects On Energetic Processesmentioning

confidence: 99%

Anthropogenic flank attack on polar bears: interacting consequences of climate warming and pollutant exposure

et al. 2015

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Polar bears (Ursus maritimus) are subjected to several anthropogenic threats, climate warming and exposure to pollutants being two of these. For polar bears, one of the main effects of climate warming is limited access to prey, due to loss of their sea ice habitat. This will result in prolonged fasting periods and emaciation and condition related negative effects on survival and reproduction success. Prolonged fasting will result in increases of the tissue concentrations of persistent organic pollutants (POPs) in polar bears, and thus increase the probability for POP levels to exceed threshold levels for effects on health, and thus on reproductive success and survival. There are clear potentials for interactions between impacts of climate warming and impacts of pollutant exposure on polar bears. It is likely that that fasting-induced increases of POPs will add to mortality rates and decrease reproductive success beyond effects caused by loss of habitat alone. However, there is a lack of studies that have addressed this. Thus, there is a need to focus on population effects of POP exposure in polar bears, and to consider such effects in relation to the effects of climate induced habitat loss.

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“…As the most nutritionally stressed group of bears in spring, female polar bears with small cubs will likely be particularly vulnerable to the loss of this potential prey (Watts & Hansen 1987;Atkinson & Ramsay 1995). Since fat-soluble contaminants are released into blood circulation when stored fat is metabolized, high levels of contaminants are carried to the mothers' vital organs during the period when the pregnant female is fasting in the den and during the first months of lactation, which causes transfer of pollutants first to the foetuses in utero and after birth to the cubs through the milk (Polischuk et al 2002). The negative effects of pollution and less sea-ice in the Barents Sea will act on polar bears synergistically if the combined effect is greater than one would expect by adding up the effects of the individual stressors (Derocher 2005;Jenssen 2006).…”

Section: Stressors and Cumulative Effectsmentioning

confidence: 99%

Barents Sea polar bears (Ursus maritimus): population biology and anthropogenic threats

Andersen

Aars²

2016

Polar Research

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Body burdens and tissue concentrations of organochlorines in polar bears (Ursus maritimus) vary during seasonal fasts

Cited by 137 publications

References 32 publications

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Anthropogenic flank attack on polar bears: interacting consequences of climate warming and pollutant exposure

Barents Sea polar bears (Ursus maritimus): population biology and anthropogenic threats

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