A toxic chemical long used to make non-stick or water-repellent coatings may be more dangerous than believed — perhaps unsafe at any level, a leading environmental group warned Thursday.
Perfluorooctanoic acid, or PFOA, was used to make DuPont's popular Teflon coating for decades. DuPont phased out its production after a 2006 settlement with federal regulators, who had linked it to birth defects and cancer in animals — and accused the company of failing to report those hazards for more than two decades.
In the meantime, PFOA spread worldwide. Traces of the compound have been found in the blood of nearly every American and in the bodies of polar bears in the Arctic and dolphins in India's Ganges River. And now the Environmental Working Group (EWG), a nonprofit watchdog group, said the US Environmental Protection Agency's (EPA) current safety standard for PFOA in drinking water is more than 1,000 times too high.
The current EPA standard for PFOA is 0.4 parts per billion — a concentration comparable to half a teaspoon of water in an Olympic-sized swimming pool. But Bill Walker, who wrote the new EWG report on the chemical, said the number should be 0.0003 parts per billion, or 1,333 times lower than the EPA's figure and more than 300 times below the agency's proposed permanent safe level.
The EWG figure suggests that PFOA may be in the same league as substances like asbestos or lead, "of which we know there is basically no safe level of exposure," Walker told VICE News.
"We're not prepared to go that absolute on this, but the truth of the matter is that it appears to be hazardous at very, very, very low levels of exposure," he said. "In practicality, when you're talking about these very, very tiny levels, there just may not be a safe level of exposure."
The report, by Walker and EWG chemist David Andrews, builds on an earlier study by researchers from Harvard University and the University of Massachusetts (UMASS). Those scientists concluded that levels of PFOA in human blood that were greater than three tenths of a nanogram — a billionth of a gram — per milliliter could cause adverse consequences. That's about 400 times lower than the EPA's current level.
But the Harvard-UMass study had an uncertainty factor of 10, meaning that the threshold could be as low as three hundredths of a nanogram per milliliter. And the EPA calculates that it would take drinking 100 times that much water for the compound to build up to that level in the blood, the EWG researchers divided that concentration by 100 to produce their estimated safe level of drinking water.
"We took their data and completed the math and came up with a more exact level of 0.0003 parts per billion," Walker said.
Phillippe Grandjean, who teaches environmental health at Harvard and was the lead author of the previous study, told VICE News that the EWG methodology squares with his results.
"It seems that we are in agreement," he wrote via e-mail. "These calculations are approximations, so small differences can occur depending on the details ... We published our own calculation in 2013 and our estimate was similar."
The current EPA standard is a temporary one; the agency has proposed a permanent safe level of 0.1 part per billion. But even that is more than 300 times what the EWG believes is safe, Walker said.
DuPont admitted no wrongdoing in the 2005 settlement, which included a then-record-setting civil penalty of $10.3 million. It agreed to pay another $6 million-plus to investigate how PFOA gets into the environment, as well as provide filtration systems for a half-dozen public water systems downstream from the Parkersburg, West Virginia factory where it produced PFOA.
It still faces a lawsuit by more than 3,500 people in the Ohio Valley who say they got sick from PFOA-contaminated water; that trial is scheduled to begin in September, the EWG report notes.
An EPA study conducted before the settlement found residents of some Ohio communities had PFOA concentrations of 298 to 369 parts per billion (ppb) in their blood. By 2009, that had dropped more than tenfold, but still remained much higher than the average 5 ppb found in the general American population.
PFOA can also be produced by the breakdown of chemicals from a related family that's used to make water- and stain-repellent coatings on other products, according to the EPA.
DuPont stopped production of PFOA at the end of 2013, two years ahead of the EPA's schedule, said Janet Smith, a spokeswoman for Chemours, a DuPont spinoff company that inherited the fluoropolymer business. Its products now use chemicals that don't break down to produce PFOA, Smith told VICE News.
She said the company supports "sound science-based regulation of PFOA," and defended the current standards.
"The US EPA has dedicated significant resources to evaluating PFOA from a regulatory perspective, and we believe the Agency has reviewed the available data that is relevant to this question," Smith wrote. "We do not believe the Grandjean paper includes the most current available data. More importantly, we don't believe the paper includes data to support a conclusion that the interim health advisory level set by EPA in 2009 is not low enough."
Grandjean responded, "They should read my paper from 2013 and the report from EWG released today."
Walker said the PFOA issue shows why the law that governs how toxic chemicals are regulated is "completely broken." The Toxic Substances Control Act was passed in 1976 and is up for renewal in Congress.
"They did phase it out over a period of time, but in the meantime they've been introducing replacements for it which are chemically related and which appear to have some of the same health effects," Walker said. Current US law allows companies to introduce chemicals into the market "without any assurance to consumers that they're safe," he said.
The EPA did not respond to inquiries from VICE News. The agency has laid out a set of principles it said it wants to see in a re-authorized toxic substances law, among them the power to assess the safety of both new and existing chemicals "in a timely manner."
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