In the early 1990s, unprecedented arsenic
poisoning in Bangladesh brought international
attention to the toxic effects of naturally
occurring arsenic in drinking water. In recent
years, exposure to arsenic in drinking water has
also been identified as a health concern in regions
of the United States where bedrock contains
unusually high levels of arsenic, such as areas of
New Hampshire, Maine, Michigan and regions
in the Southwest and Rockies. Arsenic is number
one on the U.S. Environmental Protection
Agency (EPA) list of hazardous substances and is
commonly found in Superfund sites around the
country.