Arsenic Risk Assessment

Inorganic arsenic is a natural contaminant but is also released into the environment from anthropogenic uses. Arsenic exposure is a major environmental and occupational public health concern worldwide. Of primary concern for arsenic exposure are drinking water, food, and inhalation. Arsenic affects multiple biological systems and causes cancer in skin, lung, bladder, and other tissues. It is also associated with noncancer health effects such as skin lesions (one of the earlier recognized health effects), cardiovascular disease, diabetes, pulmonary effects, neurological impairment, and developmental and reproductive toxic effects. Inorganic arsenic is metabolized to mono- and dimethylated arsenic compounds before excretion in urine. During metabolism of inorganic arsenic, trivalent mono- and dimethylated arsenicals are produced, which are more toxic than the pentavalent forms. This chapter summarizes the risk assessment conclusions for inorganic arsenic and related compounds from the state, federal, and international health agencies.