Exposure to metals.

Metals, particularly heavy metals such as lead, cadmium, and arsenic, constitute significant potential threats to human health in both occupational and environmental settings. Lead exposure is of particular concern because of ongoing exposure to thousands of workers in the US and recent research indicating that asymptomatic lead exposure can result in chronic toxicity manifestations, such as hypertension, kidney impairment, and cognitive disturbances. Mercury is neurotoxic, even at the relatively low levels of exposure seen in dentists' offices. Arsenic is clearly carcinogenic, and cadmium is now being recognized as a contributor to osteoporosis. This article reviews these and other issues of concern in the practice of primary care.