Editor's note: This article was updated on July 27, 2016 at 3:35 p.m. A previous version had an incorrect range for the blood test results. The results ranged from .3 to 1125.6 micrograms per liter.
NORTH BENNINGTON — The results from PFOA blood tests of nearly 500 area residents found an average level that's about five times the national average, according to the state Department of Health.
The results of blood tests for the potentially harmful chemical that turned up in private wells showed a "geometric mean" — a type of average — of 10 micrograms per liter, or parts per billion (ppb). The results ranged from .3 to 1125.6 micrograms per liter.
Most Americans have between 2 and 5 micrograms per liter of PFOA in their blood, according to information from the Centers for Disease Control and Prevention (CDC).
The DOH announced the results on Tuesday morning. The agency held eight blood draw clinics in April, May and June. The CDC paid to test the samples.
Participants voluntarily had blood drawn after the man-made chemical, a suspected carcinogen, was found in private wells. State officials believe the contamination source is the former ChemFab/Saint-Gobain site in North Bennington. The study involved 477 adults and children and included past and present North Bennington and Bennington residents, and former ChemFab/Saint-Gobain employees.
The results "are not unexpected," according to DOH Commissioner Harry Chen.
"What we don't yet know is how the PFOA blood level for an individual correlates with the PFOA level in his or her drinking water," Chen said in a statement. "It will take several months for Health Department experts to complete an in-depth analysis which will include drinking water and questionnaire data."
DOH says it mailed results back to each participant and, if the individual requested it, to each one's health care provider.
PFOA, or perfluorooctanoic acid, was used for decades to make the nonstick coating Teflon, which was used on pans, wire insulation, carpets, tapes and foams. Exposure to PFOA has been linked to kidney and testicular cancers, as well as high blood pressure and cholesterol and thyroid problems. Local private wells were tested over concerns of past manufacturing activity at the Chemfab/Saint-Gobain site. Of the 483 wells tested since February, 249 were found to have PFOA levels above what the state says is safe. PFOA was not detected in the local municipal systems.
Residents of nearby Hoosick Falls, N.Y., were also found to have elevated PFOA blood levels. A study of more than 2,000 residents found an average of 23.5 micrograms per liter.
According to DOH, the test result cannot tell if the amount of PFOA in a person's blood caused a current health condition or will cause future health problems. The agency says it has sent health care providers a summary of health outcomes that are strongly correlated with PFOA.
"We've been working to keep everyone informed as we get more information," Chen said in a statement. "I understand that seeing the blood test result can renew your worry, and I encourage everyone to talk with their doctor if you have specific concerns about your health as it relates to your test result."
The study's results will be published on the DOH website by the end of the year.
Contact Ed Damon at 802-447-7567, ext. 111.