Cadmium, copper, and zinc in Eurasian beaver (Castor fiber) from Bø, Telemark, Norway

Abstract

Heavy metals are elements present in all forms of life. Of those analysed for in the present study, cadmium (Cd) is toxic and non-essential while copper (Cu) and zinc (Zn) are essential elements, but toxic when certain levels are exceeded. There are also antagonistic interaction effects among these elements (Anthony and Kozlowsky 1982) and therefore naturally be treated as a cluster. Very little is known about the levels of these metals in beaver (Castor spp.). But we know that Salix spp., known as strong Cd accumulating plants (Madland 1997), are important in the diet of beavers, so elevated levels could be feared even in releatively unpolluted areas such as Bø. The aim of present study has been to investigate the levels of Cd, Cu, and Zn in Eurasian beaver (C. fiber), find their distribution among various organs and how they relate to age and an index of body fat content. For Cd we were also interested to see how the levels related to maximum allowable concentrations recommended by WHO.