Experimental accumulation of lead from soil through earthworms to common shrews.

Common shrews (Sorex araneus) were fed on earthworms containing high concentrations of lead. Both the earthworms and shrews originated from uncontaminated areas, but earthworms for the "lead" group of shrews were reared in the laboratory for 3 or 4 weeks in highly Pb-polluted soil from near an old lead smelter. The control group of shrews received the same amount of earthworms from the uncontaminated area. The acceptance of the experimental food by shrews was significantly lower in the lead group, indicating that the shrews were able to detect the lead in their food. After 2-31 days of feeding, the shrews in the lead group had significantly higher Pb concentrations in their liver, kidney, bone, and pelt than did the controls. Both the number of deaths during the experiment and the proportion of individuals with changes in kidney histology were significantly higher in the lead group.