Some immunological effects of lead, cadmium and methylmercury

Environmental contaminants may alter one specific or several segments of the immune response. It is often necessary to examine each parameter (humoral, cell-mediated and macrophage) to assess the extent that each is involved. Lead and cadmium exposure results in suppression of many aspects of the immune response of animals. This suppression often occurs at very low subclinical dosages and therefore is detrimental to the health of animals and perhaps man by methods other than the typical well-documented toxicity which results at larger dosages. Methylmercury has been shown to inhibit the primary, secondary and memory immune response but few studies have described possible effects on T lymphocytes and macrophages. The effect that methylmercury imposes on the immune system needs further investigation.