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Abstract
Long-range transport of persistent organic compounds by air and ocean currents from industrialized areas resulted in high levels of these pollutants in food webs in the Svalbard area. With the aim to test if organochlorine (OC) exposure in free-living polar bears from Svalbard affected their plasma steroid hormone concentrations, it was found that polychlorinated biphenyls (PCBs) were associated with increased progesterone levels in females. The sum of pesticides (∑pesticides) and ∑PCBs contributed significantly negative to the variation of the plasma testosterone in males, and the overall contribution of the OCs to the plasma cortisol variation was negative. A second objective was to study the effects of selected OCs (i.e., PCB 153 and PCB 126) on animal health as a consequence of effects on endocrine-regulated functions such as reproduction and immunity in a goat model focusing on long-term and low-level exposure during the periods of fetal development and in the neonatal period. Additionally, acute exposure was studied in adult mice. The results indicated that exposure to low doses of PCB 153 in utero and in the suckling period influenced reproductive functions and both PCB 153 and PCB 126 exerted immunomodulatory effects on the offspring, whereas acute exposure of adult mice had minor effects on male reproductive function.
The authors thank the Norwegian Research Council for contributing to this study (NFR no. 125693/720, 110750/720, 127534/720). The Norwegian National Animal Research Authority approved experimental studies as well as capture and sampling methods for polar bears.
Notes
a Not log transformed.
aSignificant difference.
AMAP II. 2003. Persistent organic pollutants in the Arctic. Arctic Monitoring and Assessment Programme. XVI 310 pp. Oslo, Norway. January 31.
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Oskam, I. C., Lyche, J. L., Krogenaes, A., Thomassen, R., Skaare, J. U., Wiger, R, Dahl, E., Sweeney, T., Stien, A., and Ropstad, E. 2004b. Effects of long-term maternal exposure to low doses of PCB126 and PCB153 on the endocrine and reproductive systems in young male goats. In Effects of organochlorine contaminants on mammalian reproductive and endocrine systems, Studies on functional changes in steroid hormones and reproductive parameters in mice, goats and polar bears, ed. I. C. Oskam. Oslo, Norway: Thesis for the degree of PhD, Norwegian School of Veterinary Science.
