The first government-sponsored look at health effects from apparent drinking water contamination around a DuPont Co. fluoropolymer plant found no evidence that the pollution harmed people. But critics said the study was limited because it did not consider cancer or risks to children.
The study, funded by the National Institute of Environmental Health Sciences, said that people living around DuPont's Parkersburg, W.Va., factory had blood levels of perfluorooctanoic acid that were 60-80 times normal. It said there is no evidence that the elevated exposure caused liver, kidney, and thyroid damage or elevated cholesterol levels.
The study did not, however, give PFOA a clean bill of health because it did not look at development risks for children or at cancer, the major concerns of the Environmental Protection Agency's ongoing review of PFOA, said Tim Kropp, senior toxicologist with the Washington-based Environmental Working Group. The 326-person study was too small to look at that, he said.
The study said that other research has found links between PFOA, also called C8, and cancer in rats. The EPA currently is considering labeling PFOA a ``likely'' human carcinogen. PFOA is used in the manufacture of fluoropolymers.
Edward Emmett, the study's lead author and professor of occupational and environmental medicine at the University of Pennsylvania, said the study does not address cancer but said preliminary indicators do not point to risks.
He said it found no toxic effects on livers, which are seen in rats where cancer is present, and current cancer statistics show no elevated general cancer risk in Washington County, Ohio, where the study was conducted. Washington County is across the Ohio River from the DuPont plant.
But the study still recommended caution, suggesting that residents whose residential water is contaminated with the chemical use bottled or spring water, and it urged more efforts to remove the chemical from water supplies. The study found that water was the major source of PFOA contamination, and it urged particular caution for sensitive groups, like pregnant women.
Most troubling, the study found the highest levels of C8 in the blood of young children and older adults, which is ``the exact opposite of what we'd like to see from a public health perspective,'' Emmett said in a statement.
Some animal studies have found links between high levels of PFOA and developmental and maturational deficiencies, Emmett said.
Environmental Working Group said the study found PFOA concentrations in people at 106 times that in drinking water, because the chemical is hard to eliminate and can take as many as 20 years to leave the body.
DuPont said the results of the study are consistent with data that shows no human health effects from PFOA.
The company last year settled lawsuits by agreeing to pay at least $107 million to clean up water systems in nearby communities and run more tests, after PFOA was found in drinking water of 80,000 people in West Virginia and Ohio. Emmett's study is independent of that DuPont-funded work.
The settlement agreement also could force the company to pay an additional $235 million if studies find PFOA exposure harmed residents. DuPont said it is paying for an independent study of health risks, as part of that settlement, and has agreed to pay for bottled water for about 12,000 of the most-affected residents.
In a related development, a coalition of North Carolina environmental groups earlier this month called for that state to investigate how the chemical got into ground water around DuPont's Fayetteville, N.C., PFOA manufacturing plant.