Copper, zinc,cadmium and metallothionein in wild animals from the Quaderna Valley

While some trace elements as Cu and Zn are essential for many biological functions, Cd is considered only for its toxicity and rises the greatest biological and environmental concern, due to the increasing contamination of soil caused by human activities. The reported research is part of a project carried out in our laboratory on ecotoxicological risks and detoxification mechanisms in terrestrial and aquatic animals environmentally exposed to heavy metals (1,2). In the present study, we analysed the concentrations of Cd, Cu and Zn in terrestrial wild animals from the Quaderna Valley, a partially unpolluted area, 15 km SW of Bologna. In addition, in two selected species, fox and badger, we isolated metallothonein (MT) in kidney and liver. Cd, Zn, and Cu concentrations were determined by atomic absorption spectrometry (AAS) in selected tissues of fox, badger, hare, pheasant, quail and snail. MT was isolated by gelfiltration chromatography from liver and kidney of fox and badger. MT was detected by AAS by measuring Zn, Cu and Cd concentrations in the eluted fractions. Due to their essentiality in biological systems, Cu and Zn were present at detectable concentrations in all samples, showing similar levels in the examined species, with the exception of high levels of Cu in snail, due to the presence of hemocyanin. Cd was found in detectable amounts only in the kidney and liver; the kidney metal concentrations varied between a minimum of 0.26 mg/kg wet wt in fox to a maximum of 3.93 mg/kg wet wt in badger. The highest kidney Cd levels found in quail and badger are due to the earthworm-based diet, as previously reported for woodcock (1). This is confirmed by the presence of Cd-MT in the gelfiltration pattern. Overall, the reported data are indicative of a low metal environmental contamination. AKNOWLEDGEMENTS: Work supported by RFO 2004