EPA Taps Outside Experts to Solve Teflon Enigma
The agency can't assess the risk of a chemical found in most people tested in the U.S.Jan 13, 2005 | Los Angeles Times The Environmental Protection Agency on Wednesday reported that a chemical used in making Teflon that has been detected in human bodies worldwide could cause cancer and developmental problems. But the chemical, pioneered by DuPont, has raised so many novel scientific questions that the federal agency asked outside experts to help nail down its risks.
The EPA's long-awaited draft risk assessment found "no notable health effects," including no elevated cancer rate, among DuPont workers exposed to the industrial chemical perfluorooctanoic acid, or PFOA. But in tests on laboratory animals, the EPA reported links to liver and testicular cancer, reduced weight of newborns and immune suppression, which raises the potential for some human health effects too.
The ubiquitous compound, used by DuPont for more than 50 years, has been found in the blood of nearly all people tested in the United States.
The chemical is used in the production of the famous non-stick cookware and hundreds of other products, but it is not found in the products after manufacture, so no one knows why so many people have it in their bloodstreams. The compound is considered essential to making fluoropolymers, which are used not only in cookware but in clothing, telephone cables, carpets, computer chips, chemical piping, car fuel systems and many other consumer and industrial products.
DuPont, one of the world's largest chemical companies, faces charges filed by the EPA last July that it violated federal law by withholding findings for 20 years that showed risks to its factory workers in West Virginia and to the public. The data showed that PFOA can be transferred from women to fetuses and infants and had contaminated drinking water in the Ohio River Valley. The case is pending and the EPA is seeking a penalty of millions of dollars.
Charles Auer, director of the EPA's Office of Pollution Prevention and Toxics, said the agency was "not attempting to offer any final conclusions about the risks of PFOA." Instead, he said, unusual issues concerning the Teflon compound have surfaced, testing the limits of toxicology, so the EPA created a special panel of its Science Advisory Board to explore them.
The questions focus on how to compare the effects found in animals with potential dangers to people. The chemical stays in the human body for years while most of it flushes out of rats' bodies within days. Also, no one knows how much people are exposed to, so it is difficult to evaluate data from animals ingesting specific doses.
Facing such uncertainties, Auer said the EPA could not complete its evaluation of the chemical's risks, the first step toward determining whether its use would be restricted.
An advocacy group, the Environmental Working Group, says that the EPA is playing down the health threats and that its report "tilts toward DuPont." The group contends there is adequate animal data to show that the chemical is carcinogenic and that the EPA ignored its rules in making that decision.
"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 Environmental Working Group. "We don't know if DuPont lobbyists played a role or if these were just agency mistakes. But for those who were expecting a thorough and fair review, this is a huge disappointment."
DuPont representatives welcomed the EPA's decision to create the panel, calling it "a critical action to evaluate data and assumptions" related to people's exposure.
"Although, to date, no human health effects are known to be caused by PFOA, the company recognizes that the presence of PFOA in human blood raises questions that should be addressed," the company said in a statement.
DuPont has said that 50 years of use and study support its conclusion that the chemical poses no danger to people.
But Auer said the EPA did not agree. "That's DuPont's opinion. Our view is there are a number of important issues where we need the input of scientific experts. We're not offering an opinion like the DuPont opinion," he said.
EPA officials are particularly concerned that rats are born with reduced body weight when their blood contains amounts of the chemical that are about 50 times more than the levels in some people's blood. That is generally not considered a safe difference to protect human health.