抄録
Concentrations of 21 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) were determined in the liver and muscle of Baikal seals (Pusa sibirica) (n = 44) collected from Lake Baikal, Russia in 2005. Most of the elements, such as V, Mn, Cu, Zn, Se, Hg and Mo, showed higher concentrations in liver than in muscle. However, Cs was found at higher levels in muscle than in liver. Liver and muscle concentrations of essential elements Cu and Zn were higher than other essential elements in Baikal seals. On the other hand the levels of non-essential elements Cd and Hg were comparable to or lower than the corresponding levels in other seal species. Significant age dependent accumulation was observed for Mn, Cu, Sr, Cd and Hg in liver and muscle, V, Se, Mo and Ba in liver, and Zn in muscle. Significant correlations were observed between concentrations of the following trace elements V-Cd, Mn-Cu, Mn-Cd, Cu-Sr, Cu-Cd, Cu-Hg, Rb-Cs, Sr-Ba, Sb-Tl, Ba-Pb and Tl-Bi in both liver and muscle. Generally, the molar ratio between Se and Hg is known to be 1:1 in marine mammals which show high levels of Se and Hg, however no such pattern was observed in the present study due to the low level of these elements. Concentrations of V, Cr, Mn, Co, Cu, Zn, Se, Sr, Mo, Ag, Cd, Sb, Cs, Hg, and Tl in Baikal seals collected in 2005 were comparable to those in the seals collected in 1992. On the other hand, concentrations of Rb were significantly higher in 2005 samples, suggesting that environmental contamination by Rb in Lake Baikal seems to have increased during the last decade.
