Abstract
OVERVIEW: Annual cases of waterborne illness in the United States are estimated to number about 900,000, but most experts believe the incidence to be much higher. The U.S. Environmental Protection Agency regulates the nation's drinking water supply, setting maximum allowable levels for 87 known natural and synthetic contaminants; but thousands more go unregulated. This article describes selected contaminants and their known health effects, which range from acute gastroenteritis to cancer and reproductive and developmental effects. It discusses which populations are more vulnerable, outlines assessment, and elucidates nurses' roles in patient education and as community advocates for safer drinking water.