Health effects and risk assessment of arsenic.

Humans can be exposed to arsenic (As) through the intake of air, food and water. Although food is usually the major source of As exposure for people, most adverse effects are seen after As exposure from drinking water. The two main reasons for this situation are that most food arsenicals are organic and have little or no toxicity, and in many cases, As exposures from drinking water sources are to the more toxic inorganic form and occur at relatively high doses, e.g., hundreds of micrograms per day. In various parts of the world, As in drinking water is associated with such effects as gastroenteritis, neurological manifestations, vascular changes, diabetes and cancers (bladder, lung, liver, kidney and prostate). After reviewing the As database, the U.S. Environmental Protection Agency promulgated a maximum contaminant level for As in drinking water of 10 micro g/L.