RALEIGH, N.C. (AP) — North Carolina environmental regulators will start testing the state's major supplies of drinking water to learn whether people are ingesting industrial chemicals whose health effects are poorly understood, a state official said Friday.

Monitoring could start next month for nearly two dozen unregulated chemicals that the U.S. Environmental Protection Agency classifies as "emerging contaminants" needing more study, State Department of Environmental Quality spokesman Jamie Kritzer said.

The testing is an outgrowth of concerns that a Chemours Co. chemical called GenX used to make Teflon and other coatings was in Wilmington's chief water supply.

The broader testing, to include Norman, Falls and Jordan lakes, and the Yadkin and Catawba rivers, will focus on so-called perfluorinated chemicals similar to GenX, Kritzer said. Such compounds have been found across industrial countries from the U.S. and Germany to China. They are suspected, but not proven, as posing an increased cancer risk in humans.

"Most of these substances do not have health information associated with them, so we don't know a lot about them in terms of what their health risks are," Kritzer said.

Toxicologists and other specialists on a state science advisory board will use information developed from adding the lesser-known chemicals to existing testing for known harmful pollutants as they work to set standards for when health is at risk, he said.

GenX replaced a similar fluorine-based compound after neighbors of chemical-maker DuPont's Parkersburg, West Virginia, plant claimed in more than 3,500 lawsuits that the compound made them sick. DuPont spun off Chemours into a separate company two years ago. A jury in July 2016 found the two companies liable for a man's testicular cancer that he said was linked to a chemical released by the West Virginia plant. The two companies this year agreed to pay nearly $671 million to settle further lawsuits.

The extra testing comes after Duke University researchers said they've discovered perfluorinated chemicals in Cary's treated drinking water. The levels found in the water used by more than 200,000 people in Cary and other growing Raleigh suburbs is well below the EPA's health advisory level, WRAL reported .

"The water is safe to drink," Cary water systems manager Alexandra Jones said. "There's not a health concern from our perspective."

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