ABSTRACT
Soils contaminated with heavy metals such as Cd, Zn, Pb, Cu, Cr, Se, and Ni are of environmental concern because of the potential for contamination of surface or ground water, off-site contamination by wind-transported material, redistribution of contaminated soil or sediment,. uptake by vegetation, and bioaccumulation in food chains (Chaney et aI., 1998b). Human disease has resulted from cadmium (Nogawa et aI., 1987; Kobayashi, 1978; Cai et aI., 1990), selenium (Yang et aI., 1983), and lead in soils. Livestock and, wildlife have suffered Se poisoning at many locations with Se-rich soils (Rosenfeld and Beath, 1964; Ohlendorf et aI., 1986); high soil molybdenum first harms ruminant livestock. Soil metals have caused phytotoxicity to sensitive plants at numerous locations, especially where mine wastes and smelters caused contamination of acidic soils with Zn, Ni, or Cu (Chaneyet aI., 1998c; Li and Chaney, 1998).
