Book excerpt: Cadmium is widely dispersed in the environment. Human exposure to low levels occur as a result of natural processes as well as human activities such as mining, smelting, fossil fuel combustion and industrial use. Pollution of the general environment by cadmium has as yet only been related to the development of human disease in some special situations, such as itai-itai disease and renal dysfunction in Belgium and in China. However, the possibility of more widespread contamination and greater mobility of cadmium in the environment on the one hand and the advent of new data concerning the carcinogenicity of cadmium on the other, make this review of the "state of the art" in human risk identification and assessment timely. Recent studies on human exposure to cadmium metabolism and toxicology, renal dysfunction and related effects, and experimental and epidemiological evidence for carcinogenicity of cadmium are described.