HEAVY-METALS IN SOME SPECIES OF WATERFOWL OF NORTHERN ITALY

Concentrations of heavy metals (zinc, copper, cadmium, and iron) were measured in several tissues (brain, gizzard, leg-muscle, heart, breast -muscle, intestine, liver and kidney) of moorhens (Gallinula chloropus ), black-headed gulls (Larus ridibundus), and coots (Fulica atra) coll ected between autumn 1985 and spring 1989 in northern Italy. Cadmium c oncentrations in the liver and kidney of water-rails (Rallus aquaticus ) and in five species of Anatidae collected also were measured. High m ean (+/-SD) copper levels were detected in aerobic muscles such as hea rt (38 +/- 5 mu g/g dry weight (DW)) and pectoral muscles (35 +/- 7 mu g/g DW). Compared to other tissues, the iron content of brain was rat her low and constant, with a mean value of 160 +/- 17 mu g/g DW in moo rhens, 157 +/- 60 mu g/g DW in black-headed gulls, and 157 +/- 25 mu g /g DW in coots. Iron concentrations in tissues of moorhens from the Re no River were significantly higher than those from the Sile River. Cad mium was detectable only in the liver and kidney; there was a linear r elationship between cadmium levels in these two organs. The highest me an (+/-SD) cadmium concentrations were present in the kidney of black- headed gull (30 +/- 20 mu g/g DW).