PT12 Metals and Bioaccumulation
Exhibit Hall
8:00 AM - Tuesday
(PT162) Total and organic mercury in Japanese wild terrestrial mammals.
Minagawa, M1, Watanabe, I1, Kuno, K1, Hayasi, M2, Makino, T3, Sasaki, H4, Abe, S5, 1 Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan2 Tochigi Pref. Museum, Tochigi, Japan3 Kanagawa Pref., Kanagawa, Japan4 Univ. Chikushi Jogakuen Junior College, Japan5 Amami Wildlife Conserv. Center Natural Environ. Bureau, Ministry of Environ., Amami, Kagoshima, Japan
ABSTRACT- Total and organic mercury concentrations and trace element concentrations (Li, Mg, Al, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, In, Cs, Ba, Tl, Pb, Bi, Th, U) were determined in the tissues of Japanese wild terrestrial mammals. Organic mercury concentrations in the liver of Javan mongoose was high. But organic mercury concentrations in Japanese terrestrial mammals were lower than those in marine mammals. The chemical form ratios (total mercury concentration/organic mercury concentration) were lower, too. In terrestrial mammals the chemical form ratio of the organs of Japanese weasel and Raccoon dog was high. In each species in Japanese terrestrial mammals except Japanese weasel, analyzed in this study, the higher organic mercury concentrations, and the lower the chemical form ratios were observed. It was suggested that organic mercury was demethylated in Japanese terrestrial mammals as marine mammals. In addition, the ability of demethylation of each species might be diverse. The demethylation ability of Javan mongoose and Raccoon dog was high, while Japanese weasel was low. In the liver of javan mongoose, in which total and organic mercury levels were high, mol concentration rates of inorganic mercury to selenium were almost 1, when organic mercury and selenium levels were high. The result seemed to be the detoxification process that after organic mercury is demethylated, inorganic mercury is combined with selenium and accumulated in the liver as low toxicity. And the mol concentration rate of organic mercury to selenium became higher, and it was also near to 1. The causes were not clear, so more investigation is required.
Key words: Selenium, Organic mercury, Java mangoose, demetylate