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The content of heavy metals in mineralised dental tissues is an indicator of the exposure of their mineral phase to heavy metals during the time of tooth development and dental tissue formation. Therefore, teeth have been used as bio-indicators which accurately reflect the environmental or dietary exposure of animals and humans to heavy metals. This study follows from the earlier work in which it was demonstrated that the teeth from bank voles inhabiting various environmentally polluted and non-polluted forests in Southern Poland were reliable indicators of exposure to heavy metals. Using analytical techniques employed in the earlier study heavy metal concentrations were obtained in the teeth of bank voles trapped in 1998-2000 to determine if efforts to clean up the environment could be detected in changes in heavy metal concentrations in the teeth. The results show that these efforts are reflected in lower concentrations of heavy metals in the teeth but that cross border contamination remains a problem.

Cadmium is well known for its toxicity to the animal body. However, its effect on pregnancy and the development of young animals is still not well understood. This study examined such effects, using bank voles captured from the wild to make the results closer to those which could be expected in the natural environment. One group of animals was fed 7 microg g(-1) cadmium in the food, a second 35 microg g(-1), and a third no cadmium, as a control. The concentrations of cadmium in the whole bodies of young bank voles were determined on the 3rd, 5th, or 10th day of life. The cadmium level in the bodies of animals exposed to 35 microg g(-1) of cadmium was significantly higher than in those from either the control group or the group receiving 7 microg g(-1) of cadmium, which did not differ from each other. The cadmium level did not change with animal age in any of the study groups. Concentrations of Zn, Cu, and Fe were also determined in the whole body of young animals, as cadmium is known to disturb the metabolism of these essential metals through antagonistic activity. Both Cu and Fe levels were negatively correlated with cadmium concentrations, while a positive correlation was found between zinc and cadmium in the young animal bodies. Also found was higher offspring mortality in the group receiving 35 microg g(-1) of cadmium in food. There was no difference in young animal body weight between the study groups.

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., (Copyright 1998 Academic Press.)