Effects and Trends of POPs on Polar Bears

Updated 2000-06-14

LONG TERM: Determine the effects, at the individual and population level, of persistent organic pollutants (POPs) and their metabolites in the polar bear; determine trend of POPs in the Arctic marine environment using polar bear tissues as a biomonitor. SHORT TERM: a. Determine 10-year temporal trends of POPs in the Hudson Bay Sub-Arctic Ecosystem from 1990-1989 by analysis of archived polar bear biopsy samples, including changes in enantiomeric composition of -HCH and chlordane compounds and ratio of -HCH/-HCH (cross-referenced to separate proposal on HCHs). b. Determine if there is selective tissue distribution of the enantiomers of chiral contaminants in polar bears, which may influence target organ toxicity, by analysis of archived polar bear samples. c. Determine the endocrine disrupting effect of POPs on testosterone and PCB metabolite profiles by in vitro metabolism studies using polar bear liver microsomes. d. In collaboration with CWS P&N Region, the Norwegian Polar Institute and the Norwegian Veterinary Institute, determine the immunotoxic effects of PCBs and other organochlorines in polar bears throughout a gradient of exposure (Hudson Bay, low; Svalbard, high). e. Determine the effects of hydroxy-PCBs on circulating thyroid hormone and vitamin A concentrations.

This is not a National Implementation Plan (NIP) project

Time frame

Project time span
1984 -
Data collection
1984 - 2000
Data processing
1984 - 1999
Data reporting
1984 - 1999

Contact information

Contact person
Ross J. Norstrom
Environment Canada National Wildlife Research Centre 100 Gamelin Boulevard Hull, QC K1A 0H3 Canada
+1 819 997-1411
+1 819 954-6612

Parameters and Media

Parameter groups measured/observed/modelled
Biological effects
Persistent organic pollutants (POPs)
Media sampled/studied/modelled
Marine mammals
Terrestrial mammals
Additional information or further specification of types of data / information collected, species / tissues / organs sampled, etc.

Polar bear fat, blood. Recent emphasis on phenolic metabolites of PCBs and other POPs on thyroid hormone and vitamin A homeostasis, immunotoxic effects of PCBs


Regions studied
Arctic, Circumpolar
Stations or areas where observations are made

Recent research focussed on SW Hudson Bay (Cape Churchill), Barrow Strait (Resolute Bay) and Svalbard (in collaboration with Norway).

Data availability

Are data archived or planned to be archived at an AMAP Thematic Data Centre?
If no (or only part of data are reported to a TDC), where and how are (other) data stored?
Data are largely stored as Excel files at the National Wildlife Research Centre, and the primary method of reporting is to the Northern Contaminants Program, Dept. of Indian Affairs and Northern Development, in the primary scientific literature and as Ph.D. theses. The data are available to AMAP.
References to key publications (or planned publications) and data reports
REPORTS AMAP Assessment Report, 1998 CACAR Report Norstrom, R.J. 1999a. Trends and effects of contaminants in polar bears. In: Synopsis of Research Conducted Under the 1998/99 Northern Contaminants Program, S. Kalhok, ed., Northern Affairs Program, Department of Indian Affairs and Northern Development, Ottawa, Canada, pp. 175-188. Norstrom, R.J. 1999b. Trends and effects of contaminants in polar bears. In: Synopsis of Research Conducted Under the 1997/98 Northern Contaminants Program, J. Jensen, ed., Environmental Studies No. 75, Northern Affairs Program, Public Works and Government Services Canada, Ottawa, Canada, pp. 175-188. THESES Letcher, R.J. 1996. The ecological and analytical chemistry of chlorinated hydrocarbon contaminants and methyl sufonyl-containing metabolites in the polar bear (Ursus maritimus) food chain. Ph.D. Thesis, Dept. of Chemistry, Carleton University, Ottawa, ON 169 pp. Polischuk, S.C. 1999. Organochlorine dynamics in free-ranging polar bears and their cubs. Ph.D. Thesis, Dept. of Biol. U. of Saskatchewan, Saskatoon, SK, 200 pp. PUBLICATIONS Bandiera, S.M. Torok, M.A. Ramsay and R.J. Norstrom. 1995. Catalytic and immunological characterization of hepatic and lung cytochromes P450 in the polar bear. Biochem. Pharmacol. 49:1135-1146. Letcher, R.J., R.J. Norstrom and D.C.G. Muir. 1998. Biotransformation versus bioaccumulation: Sources of methyl sulfone PCB and 4,4'-DDE metabolites in the polar bear food chain. Environ. Sci. Technol. 32:1656-1661. Letcher, R.J., R.J. Norstrom, S. Lin, M.A. Ramsay and S.M. Bandiera. 1996. Immunoquantitation and microsomal monooxygenase activities of hepatic cytochromes P450 1A and P450 2B and chlorinated hydrocarbon contaminant levels in polar bear (Ursus maritimus). Toxicol. Appl. Pharmacol. 137:127-140. Letcher, R.J., R.J. Norstrom and C. Bergman. 1995. Geographical distribution of MeSO2-PCB and -DDE metabolites in pooled polar bear (Ursus maritimus) adipose tissue from western hemisphere arctic and subarctic regions. Sci. Total Environ. 160,161:409-420. Muir, D., B. Braune, B. DeMarch, R. Norstrom, R. Wagemann, L. Lockhart,B. Hargrave, D. Bright, R. Addisson, J. Payne and K. Reimer. 1999. Spatial and temporal trends in the Canadian Arctic marine ecosystem. Sci. Total Environ. 230:83-144. Muir, D.C.G. and R.J. Norstrom. 2000. Geographical Differences and time trends of persistent organic pollutants in the Arctic. Toxicol. Lett. 112:93-101. Muir, D.C.G., R.J. Norstrom and M. Simon. 1988. Organochlorine contaminants in Arctic marine food chains: accumulation of specific PCB congeners and chlordane-related compounds. Environ. Sci. Technol. 22:1071-1079. Norstrom, R.J., S.E. Belikov, E.W. Born, G.W. Garner, B. Malone, S. Olpinski, M. A. Ramsay, S. Schliebe, I. Stirling, M.S. Stishov, M.K. Taylor and q. Wiig. 1998. Chlorinated hydrocarbon contaminants in polar bears from eastern Russia, North America, Greenland and Svalbard: biomonitoring of Arctic pollution. Arch. Environ. Contam. Toxicol. 35:354-367. Norstrom, R.J. and D.C.G. Muir. 1994. Chlorinated Hydrocarbon Contaminants in Arctic Marine Mammals. Sci. Total Environ. 154:107-128 Norstrom, R.J., M. Simon and D.C.G. Muir. 1990. Polychlorinated dibenzo-p-dioxins and dibenzofurans in marine mammals in the Canadian north. Environ. Pollut. 66:1-19. Norstrom, R.J., M. Simon, D.C.G. Muir and R. Schweinsburg. 1988. Organochlorine contaminants in Arctic marine food chains: identification, geographical distribution and temporal trends in polar bears. Environ. Sci. Technol. 22:1063-1071. Polischuk, S.C., R.J. Letcher, R.J. Norstrom and M.A. Ramsay. 1995. Preliminary results on the kinetics of organochlorines in western Hudson Bay polar bear (Ursus maritimus) Sci. Total Environ. 160,161:465-472. Sandau, C.D., I.T.M. Meerts, R.J. Letcher, A.J. McAlees, B. Chittim, A. Brouwer and R.J. Norstrom. 2000. Identification of 4-hydroxy-heptachlorostyrene in polar bear plasma and its binding affinity to transthyretin: a metabolite of octachlorostyrene? Environ. Sci. Technol. (in press). Sandau, C.D., Ayotte, P., Dewailly, É., Duffe, J., Norstrom, R.J. 2000a. Analysis of hydroxylated metabolites of PCBs and other chlorinated phenolic compounds in whole blood from Canadian Inuit. Environmental Health Perspectives, Vol. 108 (in press). Sandau, C.D. and R.J. Norstrom. 1998. Analysis of hydroxylated metabolites of PCBs (OH-PCBs) in polar bear plasma and human whole blood. Proc. 2nd Biennial Intl. Conf. Chem. Measure. and Monitor. Environ., R. Clement and B. Burk, eds., Chemistry Dept., Carleton University, Ottawa, Canada, pp. 405-410. Wiberg, K.A., R. Letcher, C. Sandau, J. Duffe, R. Norstrom, P. Haglund and T. Bidleman. 1998. Enantioselecive gas chromatography/mass spectrometry of methysulfonyl PCBs with application to Arctic marine mammals. Anal. Chem. 70:3840-3844. Wiberg, K.A., R. Letcher, C. Sandau, R. Norstrom, M. Tysklind and T. Bidleman. 2000. Chiral Chlordane and -HCH Contaminants in the Polar Bear Food Chain: Enantiomer Ratios and Biomagnification Factors in Relation to Organochlorine Concentrations and Biological Data. Environ. Sci. Technol. (in press). Zhu, J., R.J. Norstrom, D.C.G. Muir, L. A. Ferron, J.-P. Weber and E. Dewailly. 1995. Persistent chlorinated cyclodiene compounds in Ringed seal, polar bear and human plasma from Northern Quebec, Canada: Identification and concentrations of photoheptachlor. Environ. Sci. Technol. 28:267-271. Zhu, J.P and R.J. Norstrom. 1994. Identification of polychlorocamphenes (PCCs) in the polar bear (Ursus maritimus) food chain. Chemosphere 27:1923-1935. PROJECTED PUBLICATIONS Duffe, J.A. and R.J. Norstrom. 1999. Multi-variate analysis of PCB congener and chlordane components in polar bears: Geographical trends. In prep. Duffe, J.A. and R.J. Norstrom. 1999. Organochlorines in polar bears: Influence of season, sex and age. In prep. Polischuk, S.C., R.J. Norstrom, and M.A. Ramsay. 1999. Influence of seasonal fasting on whole body burdens and tissue concentrations of organochlorines in polar bears. In prep. Polischuk, S.C., R.J. Norstrom, and M.A. Ramsay. 1999. Tissue distribution of organochlorines in polar bear adipose tissue, plasma, and milk. In prep. Polischuk, S.C., R.J. Norstrom, and M.A. Ramsay. 1999. Geographic and tissue variaiton of chlorobenzenes and hexachlorocyclohexanes in polar bears. In prep. Polischuk, S.C., R.J. Norstrom, and M.A. Ramsay. 1999. Inter- and intra- annual changes in organochlorine concentrations from sequentially-handled polar bears. In prep. Polischuk, S.C., R.J. Norstrom, and M.A. Ramsay. 1999. Organochlorine body burdens in female polar bears decline during pregnancy and early lactation. In prep. Polischuk, S.C., R.J. Norstrom, and M.A. Ramsay. 1999. Transfer of organochlorines from female polar bears to their cubs. In prep. Pagliarulo, O.M., D. Flipo, A. Lacroix, J. Duffe, M.A. Ramsay, R.J. Norstrom and M. Fournier. Effects of in vitro exposure on polar bear (Ursus maritimus) lymphocyte proliferation. (in prep.) Sandau, C.D., Ramsay, M., Wiig, O., Derocher, A., Norstrom, R.J. Analytical determination and methodology of halogenated phenolic compounds in polar bear plasma. In prep. Sandau, C.D., Ramsay, M., Wiig, O., Derocher, A., Norstrom, R.J. Circulating concentrations and patterns of PCB metabolites (OH-PCBs) in polar bear plasma from Resolute Bay, Nunavut and Svalbard, Norway. In prep. Sandau, C.D., Brown, S.A., Ramsay, M., Wiig, O., Derocher, A., Duffe, J. Norstrom, R.J. Implications of hydroxylated metabolites of PCBs (OH-PCBs) and other organochlorine compounds as endocrine disruptors in polar bears. In prep. Sandau, C.D., Bandiera, S., Norstrom, R.J. The optimization and Vmax and Kmax parameters in the metabolism of CB47, CB 52 and CB77 using polar bear liver microsomes. In prep.
Samples/specimens archived in specimen banks?
Specimen banking information

Polar bear fat, fat biopsies, blood plasma. Stored at -40 deg. in CWS Specimen Bank, NWRC, Hull, QC for an indeterminate period.

Methods & Procedures

Procedures and methodology used for, e.g., sampling and sample storage, sample pretreatment, extraction and analysis, including which laboratories are involved, references to methods employed, etc.

Methodology is complex for a variety of different substrates and analytes and analyte classes, and has evolved considerably over the past 16 years. Refer to publications for specific methods

QA/QC Information (what QA/QC procedures are implemented, laboratories involvment in QA/QC activities, model verification/validation routines, etc.)

Participated in Northern Contaminants QA/QC program, interlaboratory calibration.

Additional Information

Is this a bi- AND multi-lateral project (i.e. a project involving cooperation between different countries)?
Other institutes involved in the project

University of British Columbia University of Saskatchewan Carleton University University of Montreal University of Stockholm Freshwater Institute, Dept. Fish. Ocean Norwegian Polar Institute Norwegian School of Veterinary Science

Is this project reporting to other organizations/programmes?

Northern Contaminants Program, Canada

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