ABSTRACT
Land application of biosolids can affect domestic animals and wildlife through the direct ingestion of soil, plant materials, or feed grown on biosolids-amended soil. The US Environmental Protection Agency, in promulgating the 40 CFR Part 503 regulations, considered the uptake of potentially toxic chemicals or elements that can affect the animal or accumulate in body parts that may become part of the human food chain. Smith et al. reported that dietary sewage sludge increased detectable levels of five of 22 pesticides measured in the adipose tissue after 68 days. Levels of Fe and Pb in livers and kidneys were increased as compared to controls, but not beyond levels reported for animals fed conventional diets. In another trial, animals pastured on the range received supplements with cottonseed and sewage sludge. Both supplements increased calf weights over unsupplemented controls. Biosolids-exposed cattle had higher concentrations of Cd and Zn in kidney and higher Pb concentrations in bone tissue than for the control cattle.
