Hazards to wildlife from soil-borne cadmium reconsidered

Cadmium is a toxic element that should be included in environmental risk as sessments of contaminated soils. This paper argues, however, that hazards t o wildlife from cadmium have often been overstated. The literature contains only meager evidence that wild animals have been seriously harmed by cadmi um, even at severely contaminated sites. Although some researchers have rep orted that wildlife have accumulated concentrations of cadmium in their kid neys that were above suggested injury thresholds, the thresholds may be dis puted, since they were well below the World Health Organization criterion o f 200 mg/kg (wet weight) of cadmium in the renal cortex fur protecting huma n health. Recent risk assessments have concluded that soil cadmium concentr ations less than 1 mg/kg are toxic to soil organisms and wildlife, which im plies that background concentrations of cadmium naturally found in soils ar e hazardous. An examination of the databases used to support these assessme nts suggested that the toxicity of cadmium has been exaggerated.