Cadmium & its adverse effects on human health.

Cadmium (Cd), a by-product of zinc production, is one of the most toxic elements to which man can be exposed at work or in the environment. Once absorbed, Cd is efficiently retained in the human body, in which it accumulates throughout life. Cd is primarily toxic to the kidney, especially to the proximal tubular cells, the main site of accumulation. Cd can also cause bone demineralization, either through direct bone damage or indirectly as a result of renal dysfunction. In the industry, excessive exposures to airborne Cd may impair lung function and increase the risk of lung cancer. All these effects have been described in populations with relatively high exposures to Cd in the industrial or in heavily polluted environments. Recent studies, however, suggest that the chronic low environmental exposure to Cd now prevailing in industrialized countries can adversely affect the kidneys and bones of the general population. These studies show consistent associations between various renal and bone biomarkers and the urinary excretion of Cd used to assess Cd body burden. The public health impact of these findings are still unknown. Further research is needed to ascertain that these associations are truly causal and not secondary to parallel changes in Cd metabolism and in the bone or kidney function occurring because of ageing or diseases unrelated to Cd exposure.