Trends in Mercury in Hair off Greenlandic Polar Bears (Ursus marrtimus) during 1892-2001

摘要

Mercury concentrations in hair from 397 Greenland polar bears (Ursus maritimus) sampled between 1892 and 2001 were analyzed for temporal trends.In East Greenland the concentrations showed a significant (p < 0.0001,n = 27) increase of 3.1%/year in the period 1892-1973.In Northwest Greenland,a similar (p < 0.0001,n = 69) increase of 2.1%/year was found,which continued until 1991,when the most recent samples were obtained.In East Greenland,a significant (p = 0.009,n = 322) decrease of 0.8%/year was observed after 1973.Two Northwest Greenland samples from 1300 A.D.had a mean value of 0.52 mg/kg of dry weight,which can be considered as a baseline level.The Hg concentration during 1985-1991 from Northwest Greenland (mean value of 7.45 mg/kg of dry weight) was more than 14-fold higher than the assumed baseline level from 1300 A.D.from the same region (i.e.,about 93% anthropogenic).Although a decrease was found in East Greenland after 1973,the concentration is still ca.11-fold higher than the baseline level (i.e.,about 90% anthropogenic).