The EPA is asking an outside panel of scientific experts to comment on the agency's research on the potential health risks of perfluorooctanoic acid, a synthetic chemical used in making non-stick Teflon cookware and hundreds of other products.
The EPA said last week that perfluorooctanoic acid, known as PFOA, or C-8, has been detected in "very low levels" in the environment and in the blood of the general U.S. population, and that studies indicate PFOA "can cause developmental and other adverse effects in laboratory animals."
The chemical's effects on humans are not known, the agency says, nor does the EPA "have a full understanding of how people are exposed to PFOA," which the agency says is not found in products after their manufacture.
The EPA, which has been studying the potential health risks of PFOA and similar fluorochemicals since 2000, issued a draft assessment of the potential risks of PFOA on Jan. 12. The agency on its Web site said the purpose of having the draft assessment reviewed by scientific experts is to "ensure the most rigorous science is used in the agency's ongoing evaluation of PFOA." The panel of scientific experts will meet with the EPA in late February, and its review is expected several months later.
The draft risk assessment includes an analysis of how PFOA causes liver tumors in rats, according to the EPA. The agency, though, says the draft does not provide any new conclusions regarding PFOA exposure and potential health concerns for humans.
PFOA has hundreds of applications
PFOA is used primarily to produce its salts, which are used as essential processing aids in the production of fluoropolymers and fluoroelastomers. Fluoropolymers have hundreds of applications in many industrial and consumer products, including soil-, stain-, grease- and water-resistant coatings on textiles and carpets; uses in the automotive, mechanical, aerospace, chemical, electrical, medical and building/construction industries; personal care products; and non-stick coatings on cookware.
Finished fluoropolymer and fluoroelastomer products are not expected to contain PFOA, according to the EPA, leading the agency to wonder how the chemical has found its way into the general population's bloodstream.
DuPont 'welcomes' EPA's report
Wilmington, Del.-based DuPont, one of the major producers of PFOA, issued a news release on Jan. 12 that said the company "welcomes the EPA's draft risk assessment and the formation of a science advisory board as important steps in addressing questions about PFOA." The company over the past five years has reduced PFOA emissions from its U.S. operations by 98 percent and has designed systems that capture and recycle or destroy PFOA, according to the news release.
The Jan. 12 statement from DuPont came on the heels of a news release the company issued the day before reporting that the results of an "initial-phase" health study of more than 1,000 workers at its Washington Works plant near Parkersburg, W.Va., showed no connection between PFOA blood levels and liver problems, blood counts, prostate cancer, leukemia or multiple myeloma.
The DuPont study, however, revealed a 10 percent increase in total cholesterol (most of which was in the LDL fraction) and a spike in triglycerides among some workers with PFOA levels higher than 1,000 parts per billion -- levels 200 times higher than that found in the general population. The study data did not indicate whether PFOA was the cause for the increases in serum cholesterol or triglycerides, according to DuPont.
The DuPont study found no associations between PFOA exposure and "good cholesterol" (HDL) and CRP, another indicator of cardiac risks. The study also observed "slight" increases in uric acid and iron among employees with the highest PFOA blood levels.
"The association of PFOA with the increases in total cholesterol and the other end points in this study was observed in people in an industrial setting. Given the extremely small levels of PFOA exposure generally seen outside the work setting, it is my medical opinion that no association would be seen in the general public," said Sol Sax, M.D., DuPont's chief medical officer.
The results of the study, which was reviewed by five universities on DuPont's Epidemiology Review Board, were released to all employees who participated in the study, according to DuPont.
Advocacy group assails EPA report
The Environmental Working Group accused the EPA of underestimating the human health risks of PFOA in a "post-election tilt toward DuPont," according to a news release issued by the advocacy group last week.
"There's a big difference between sound science and tilted science, and at every turn in this important process, EPA officials favored DuPont," said Ken Cook, president of the Environmental Working Group. "We don't know if DuPont lobbyists played a role or if these are just [EPA] mistakes. But for those who were expecting a thorough and fair review, this is a huge disappointment."
According to the Environmental Working Group, "The Agency substantially tilts the [draft risk] assessment in DuPont's favor first by summarily discounting and then by outright ignoring significant scientific studies pointing to increased risks for heart attack, stroke, breast cancer, testicular cancer and numerous other health harms."
The group also points out that the EPA has accused DuPont of withholding the results of human blood sampling from the area around DuPont's facility in West Virginia. DuPont has denied the EPA's claims.
Last September, DuPont agreed to pay as much as $343 million to settle claims filed by residents near the company's Washington Works plant that said the plant's PFOA emissions contaminated drinking water in the area. That settlement has not finalized yet.