Heavy metal residues in plants cultivated on and in small mammals indigenous to old orchard soils.

Six vegetables and millet were grown on the site of an old orchard which had received heavy applications of lead arsenate and organic mercury fungicides for many years. Carrots and millet absorbed about 7 ppm (dry weight) of lead, the other crops containing smaller concentrations. Concentrations of arsenic and mercury showed only modest increases in crops grown on the orchard soil as compared to controls. Lead concentrations in kidney, liver, and bone tissue of meadow voles trapped in two old orchards were markedly higher (up to 300 ppm in bone) than control animals (up to 33 ppm). Intranuclear inclusion bodies diagnostic of lead poisoning were found in the renal epithelial cells of the proximal convoluted tubules in voles from lead arsenate treated orchards.