Groups release findings on arsenic, TCE

Two research groups have recently released reports on contaminants that are regulated in drinking water. Last week the National Institute of Environmental Health Sciences released a study that links lung cancer in mice to "human-relevant" doses of arsenic in drinking water. "This is the first study to show tumor development in animals exposed to very low levels of arsenic, levels similar to which humans might be exposed," Michael Waalkes, the lead author on the research paper, said in a statement. It should be noted that the lowest arsenic level tested was 50 ppb, or five times the maximum level allowed by current EPA drinking water standards.

The National Institutes of Health National Toxicology Program has also concluded that trichloroethylene (TCE) should be listed as a known human carcinogen, "based on sufficient evidence of carcinogenicity...in humans." TCE is currently listed as a probable human carcinogen and is already regulated in drinking water, so the immediate effect of the change may be muted. But calling it a known human carcinogen could increase public pressure and concern in those systems that must manage TCE in their source water.

Canadian Water and Wastewater Association