Accumulation of cadmium in and its effect on bank vole tissues after chronic exposure.

Cadmium is one of many metals that are not physiologically or biochemically essential to organisms. This element is extremely dangerous as it is easily absorbed and remains in tissues for a long time. Long exposure to high doses of cadmium may cause biochemical and functional changes in some critical organs. In this study, wheat grains contaminated with cadmium chloride were used to test the influence of cadmium on male bank voles (Clethrionomys glareolus). Doses used in the experiment were environmentally realistic: 0.25 microg g-1 (control), 15 microg g-1, and 40 microg g-1 cadmium (dry weight). The animals were given cadmium-contaminated food and clean water ad libitum for 3 and 6 months. After these exposures, the animals were killed and the kidneys, liver, and testes from each vole were collected for analyses. The concentrations of Cd, Cu, Zn, and Fe in the tissues were determined with an atomic absorption spectrophotometer. The formalin-fixed testes, kidneys, and part of the liver were embedded in paraffin and then stained with hematoxylin and eosin. Cadmium accumulation in the tissues was directly proportional to dose. The highest cadmium concentrations were found in the kidneys of animals fed the highest dose of cadmium. Histological examination of the tissues revealed some pathological changes in the structure of kidneys, liver, and testes.