Chemicals found in some U.S. water supplies more toxic than previously thought, report says

A family of industrial chemicals turning up in public water supplies around the U.S. is even more toxic than previously thought, threatening human health at concentrations seven to 10 times lower than once realized, according to a government report released Wednesday.

The chemicals are called perfluoroalkyl and polyfluoroalkyl (PFAS). They were used in such goods as fire-suppressing foam, non-stick pans, fast-food wrappers, and stain-resistant fabric and carpet, but are no longer used in American manufacturing.

Water sampling has found contamination in water around military bases, factories and other sites.

Exposure at high levels is linked to liver damage, developmental problems and some forms of cancer, among other risks.

A draft of the report, by the U.S. Department of Health and Human Services' toxicology office, had set off alarms within the Trump administration earlier this year. A January email from a White House official, released under the Freedom of Information Act, referred to the findings as a "potential public relations nightmare."

The draft went under months of government review before Wednesday's publication, but the key finding — that the chemicals are dangerous at specific levels much lower than previously stated — was not changed.

The U.S. Environmental Protection Agency (EPA), which scheduled a series of hearings on the chemicals, said in May that it would move toward formally declaring the two most common forms of PFAS as hazardous substances and make recommendations for groundwater cleanup, among other steps.

U.S. manufacturers agreed in 2006 to an EPA-crafted deal to stop using one of the most common forms of the chemical in consumer products.

Environmental and health groups have said the report's findings would be essential for states that need to clean up PFAS-contaminated drinking water.

"After repeatedly pushing the administration to make these findings public, I'm very glad to see it release this study today," said Republican Senator Shelly Moore Capito of West Virginia. "The information contained in the report will help determine potential threats our communities face as a result of certain water contamination issues."

The findings will likely lead state and local water systems with the contaminant to boost filtering.

"This study confirms that the EPA's guidelines for PFAS levels in drinking water woefully underestimate risks to human health," said Olga Naidenko, a science adviser to the Environmental Working Group, an environmental watchdog organization.  

"The more we test, the more we find," she said.