Effect of soil pollution with metallic lead pellets on lead bioaccumulation and organ/body weight alterations in small mammals.

Using small mammals as bioindicators, the bioavailable status and ecotoxicity of lead was investigated in an acidic sandy soil environment polluted with metallic lead pellets from shotgun ammunition. Average concentrations of lead in kidney, liver and bone tissue of wood mice (Apodemus sylvaticus), bank voles (Clethrionomys glareolus), and shrews (Sorex araneus) were strongly elevated, compared to tissue levels of conspecifics collected from an adjacent unpolluted area. All shrews and some bank voles collected from the shooting range exceeded the critical renal Pb concentration of 25 micrograms/g dry weight, considered diagnostic of lead intoxication in mammals. The geometric mean renal Pb concentration in shrews was 270 micrograms/g dry weight, with an upper range of more than 1,000 micrograms/g. The population of shrews and bank voles from the shooting range also showed a significantly increased average relative kidney weight (kidney-to-body weight ratio), which is indicative of lead poisoning. The results suggest that metallic lead pellets deposited in an acidic sandy soil are transformed to a chemical form of lead, probably Pb2+, which is toxic to organisms and which can readily enter the terrestrial food chain.