Arsenic and human health: epidemiologic progress and public health implications.

Elevated concentrations of arsenic in groundwater pose a public health threat to millions of people worldwide, including severely affected populations in South and Southeast Asia. Although arsenic is an established human carcinogen and has been associated with a multitude of health outcomes in epidemiologic studies, a mode of action has yet to be determined for some aspects of arsenic toxicity. Herein, we emphasize the role of recent genetic and molecular epidemiologic investigations of arsenic toxicity. Additionally, we discuss considerations for the public health impacts of arsenic exposure through drinking water with respect to primary and secondary prevention efforts.