Does a chemical used to make Teflon hurt people's health?
There soon may be an answer. People living near DuPont plants in Ohio and West Virginia will be offered free screening tests to see whether a chemical called PFOA is affecting their health.
DuPont is using $70 million paid to settle lawsuits filed by its plants' neighbors to pay for the tests. Plaintiffs claimed the company deliberately withheld information and misled people about the health threat posed by PFOA. A separate study, to be paid for by DuPont and conducted by independent researchers, will look for evidence linking PFOA in drinking water to health effects. If proven, DuPont must pay for medical monitoring.
Robert Rickard, PhD, DuPont's chief toxicologist, says PFOA poses no known health threat.
"There is an extensive database, both in toxicology studies and in worker studies," Rickard tells WebMD. "The workers had the highest potential exposure of any population — and there are no known health effects of PFOA in this worker population. We are in the process of conducting the largest study to date on workers and we have not found any effects associated with PFOA, other than a slight increase in cholesterol that may or may not be caused by PFOA."
Not so says toxicologist Tim Kropp, PhD, senior scientist with the watchdog group Environmental Working Group.
"PFOA is the most persistent chemical we know of," Kropp told WebMD in a January 2005 interview. "And it affects an amazing array of organs: liver, kidneys, some evidence in animals of neurological effects; it affects cholesterol and fat processing, pancreas, and mammary glands. In addition to that, these compounds cause four different types of cancer in animals. If you stack PFOAs up against dioxins and other contaminants, it looks bad. Everyone needs to take this seriously."
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PFOA 'A Likely Carcinogen'
To evaluate the threat posed by PFOA, the EPA convened a science advisory board of 17 distinguished scientists. Their preliminary report, released last month, recommended that the EPA should consider PFOA a "likely carcinogen in humans."
The preliminary report also suggested that the EPA pay attention to other possible effects of PFOA on humans — including damage to the immune system and to the brain and nervous system.
These findings are based entirely on animal studies. While PFOA does indeed readily cause cancer in some animals, it's not at all clear that it works the same way in humans. And even if it does, it's not yet clear what dose or what kind of exposure might be dangerous.
Mary Dominiak, coordinator for the PFOA investigation underway at the U.S. Environmental Protection Agency, stresses that the expert panel's report is not yet final.
"We are still at an early stage in our assessment," Dominiak tells WebMD. "We don't have any information that should prompt anyone to be frightened of PFOA at this stage — or the action we are taking would be quite different. We are still trying to assemble the information we need. We are trying to put together this jigsaw puzzle so we can see what the picture is. And when we do, we will know better what changes we need to make to make sure any risk is fully controlled."
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PFOA "Widespread" — But No Cookware Danger
PFOA — also known as C8 — is used to make Teflon and other products such as stain-resistant clothing and carpet, fast-food packages, and other products. It can be detected in people who live nowhere near PFOA plants
"It does appear to be widespread in humans," Dominiak tells WebMD. "There are a number of ideas as to where it comes from. But we do not have a good understanding of all the sources of PFOA in the environment and the path it would take to get into people. That is where we are going with our investigation."
Dominiak says that while PFOA is used to make Teflon, the high heat used in the manufacturing process burns off virtually all the PFOA in the product.
"We do not expect to see significant PFOA in something like a frying pan," she says.
DuPont's Rickard stresses this point. "With pots and pans, there is no exposure to PFOA," he says. "That is based on studies we have conducted, and also on studies in Denmark and in China. There is absolutely not a consumer issue with this."
EWG's Kropp isn't so sure. He says that heated Teflon pans may, indeed, give off PFOA. But even Kropp says that's not the main issue. He's most worried about PFOAs being released, over time, as the products that contain them break down.
That also worries the EPA's Dominiak.
"One of the things we are trying to deal with is what happens if you have many, very tiny sources of PFOA that contribute to the environment," she says. "That single source is not significant by itself. It is just that there are lots of them."
With more and more PFOA-containing products being made every day, eventually most of them will put PFOAs into the environment. And the stuff, once released, lasts for a very long time.
"Really, the focus of our investigation is not whether PFOA might pose a risk at levels currently being found," she says. "We are asking whether levels that might make that kind of risk might exist in the future, as more PFOA is released into the environment. So there may not be a risk now, but may be a risk later if steps are not taken."
Some of those steps are being taken DuPont officials say.
"At DuPont plants, we've made a 98 percent reduction in PFOA air and water contamination," Rickard says. "In the manufacture of PFOA, which we started in 2002, our process has 99 percent less emissions than the previous process."
Whether that will be enough remains to be seen.
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SOURCES: Environmental Protection Agency, "Science Advisory Board Draft Report," June 27, 2005. Environmental Working Group. DuPont Co. Mary Dominiak, coordinator of POFA investigation, EPA, Washington. Robert Rickard, PhD, chief toxicologist, DuPont Co., Wilmington, Del. Tim Kropp, PhD, senior scientist, Environmental Working Group.