Levels of heavy metals in seals of Lake Ladoga and the White Sea.

Between 1990 and 1993 samples of hair, liver, kidney and muscle were collected from 28 ringed seals from Lake Ladoga, Phoca hispida ladogensis, 20 ringed seals, Phoca hispida hispida, and three bearded seals, Erignathus barbatus, from the White Sea for heavy-metal residue analyses in tissues. The concentration of Hg, Cd, Pb, Cu, Ni and Zn were determined by atomic absorption spectrometry (AAS). The samples of hair and liver contained the highest mean levels of the elements analysed and the muscle contained the lowest mean heavy-metal concentrations. Age and sex differences in the accumulation of pollutants were found. Tissues of Ladoga ringed seal were to a greater extent contaminated with the heavy metals studied than the tissues of the White Sea pinnipeds.