ABSTRACT
Arsenic in drinking water is a worldwide problem affecting the lives of millions of people. High levels of arsenic in local soil or rock contaminate the local water supply. In the United States, the federal government has struggled for many years to establish standards of arsenic in the drinking water. The US Environmental Protection Agency has recently lowered the standard from 50 ppm (50 µg/ l) to 10 ppm. This standard will require additional treatment of a number of municipal water supplies, particularly in western United States (see map in presentation). The standard is being lowered because chronic exposure to low levels of arsenic can cause skin cancer and others illnesses. Even at the new standard of 10 ppm, there is a risk of cancer.
