ABSTRACT
Although effects of metals are dependent upon such variables as host species and exposure parameters, including route, dose, and duration, the conclusion reached in most immunotoxicological studies is that heavy metals act to suppress immunocompetence. The most consistent finding in experimental and epidemiological studies evaluating the effects of metals on immune functions is a decreased host resistance to infectious agents. Immunotoxicity of metals may occur via direct effects on a specific component of the immune system or,
alternatively, via inhibition of immunoregulation, which can result in immunosuppression, hypersensitivity reactions, or autoimmune disorders. It has been postulated that metal toxicity may, at least in part, be due to autoimmunity, since an autoimmune disorder exists for all the major target organs affected by heavy metals.
