MERCURY, ZINC AND SELENIUM BIOACCUMULATION IN TISSUES AND ORGANS OF MEDITERRANEAN STRIPED DOLPHINS STENELLA-COERULEOALBA MEYEN TOXICOLOGICAL RESULT OF THEIR INTERACTION

Neutron activation analysis of 13 Mediterranean striped dolphins Stene lla coeruleoalba showed high mercury and selenium contaminations of ma in tissues and organs of these cetaceans. The mercuric contents were e xcessive, particularly in liver (from 68 to 2272 mug/g dry wt. basis), then in kidney, lung, muscle, heart and brain. The selenium concentra tions were also high in liver (from 45 to 1320 mug/g dry wt. basis), t hen in kidney, lung, muscle, skin and heart. The main way of contamina tion seems to be the food through trophic network, but skin and lung a re also able to play a part which must be elucidated. The average Hg/S e ratios in liver and kidney were respectively 1.82 and 1.59. Linear r elationship between mercury and selenium concentrations in tissues and organs, particularly in liver and kidney, were confirmed. The mercury and selenium interaction on a toxicological point of view was establi shed by a statistical approach; in the same way, intervention of zinc, metallothioneins and glutathiones have been discussed.