Lead, zinc, cadmium and fluoride in small mammals from contaminated grassland established on fluorspar tailings

The total body concentrations of Pb, Cd, and fluoride were higher at the contaminated grassland site established on fluorspar tailings compared to an uncontaminated control site for all three species of small mammal, Apodemus sylvaticus, Microtus agrestis and Sorex araneus. Zn was also higher in M. agrestis and S. araneus but in A. sylvaticus it significantly decreased and, overall, there was good evidence of homeostatic control of Zn in all three species even at the high dietary intakes at the tailings dam. Accumulation in kidney, liver and bone(femur) showed the expected pattern with Pb and fluoride highest in bone and Cd in the kidney for both the control and the contaminated sites. The only exception was S. araneus at the contaminated site were Cd was highest in the liver rather than the kidney. The accumulation of Pb, Cd and fluoride at the contaminated site was in the decreasing species order S. araneus > M. agrestis > A. sylvaticus in terms of total body concentration or target organ concentration. This order probably reflected the decreasing dietary intake rates of the three species although physiological interspecific differences may be of significance. For example, S. araneus showed considerable capability for bioconcentrating Cd to much higher total body than dietary concentrations at the high dietary intake rates at the contaminated site.