WHO to scrap weak PFAS drinking water guidelines after alleged corruption

The World Health Organization (WHO) is poised to scrap controversial drinking water guidelines proposed for two toxic PFAS “forever chemicals”.

The move follows allegations that the process of developing the figures was corrupted by industry-linked researchers aiming to undercut strict new US PFAS limits and weaken standards in the developing world.

Many independent scientists charged that the proposed WHO drinking water guidelines for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were weak, did not fully protect human health, ignored credible research, and were far above limits set by regulators in the US and EU. The guidelines would have allowed far more PFAS in drinking water than what is allowed by the US Environmental Protection Agency.

Though the earlier guidelines were drafts, and proposed rules all go through a revision process, the WHO is conducting an entirely new review of scientific literature and disbanded the panel of scientists who developed the draft guidelines. It established a new panel with fewer industry-linked scientists and more regulatory officials, moves that have not happened in other revisions, said Betsy Southerland, a former EPA manager in the agency’s water division.

“This is unprecedented, but the WHO got unprecedented criticism,” Southerland said.

The WHO told the Guardian in a statement that the moves are part of “an ongoing process” and will include guidelines for other PFAS compounds.

PFAS are a class of about 15,000 chemicals typically used to make products that resist water, stains and heat. They are called “forever chemicals” because they do not naturally break down; they accumulate and are linked to cancer, kidney disease, liver problems, immune disorders, birth defects and other serious health problems.

The EPA found virtually no level of exposure to PFOA and PFOS in drinking water is safe, and this year set its legal limits for the compounds at four parts per trillion (ppt), which is the level at which testing technology can reliably measure and remove PFAS from water.

The WHO in 2022 proposed guidelines of 100ppt for PFOA and PFOS in drinking water. Though the guidelines are non-binding, they are considered important because environmental officials in many nations around the world will use them to set legal limits, and they will be referenced as industry mounts legal challenges to the US limits.

Scientists critical of the limits charged that the WHO ignored high-quality research to create a sense of doubt about the science around PFAS. EPA and EU regulators carried out an exhaustive literature review to find all human and animal studies, and used the best of those papers to establish their limits, Southerland said.

The WHO, however, ignored all human studies and determined most animal studies were “too flawed” to use, Southerland said. The organization concluded there was not enough research to set health-based guidelines, which she called a “shocking decision”.

“There is far more health data for these chemicals than has ever been available for any pollutant in the history of the WHO,” Southerland said.

Instead, the WHO largely based its guidelines on its review of technological research, but ignored most of those studies as well, Southerland said. The body concluded filtration systems could reliably remove PFOA and PFOS at 100ppt, even though US water utilities remove it below four ppt.

The decisions bear industry’s prints, researchers say.

They pointed to Michael Dourson, whom Donald Trump in 2017 nominated to oversee the EPA’s chemical safety division, but was forced to withdraw his name after failing to get enough support in part over his alleged history of producing industry-friendly studies that backed chemical companies’ safety claims.

Emails published by the New York Times show his close relationship with the American Chemistry Council, even while he served as an EPA adviser, including allowing the powerful industry group to edit a research paper.

The WHO document cites Dourson’s work at least 17 times.

Others involved in the process worked as consultants for or were paid by companies like chemical giant Chemours and the nation’s water utilities, which oppose strong PFAS limits.

Dourson said his and other scientists’ position on the guidelines was not influenced by industry. He said there is a high level of uncertainty in the human and animal studies, and the WHO’s approach was reasonable.

“They did a good survey of data and systematic review in their own way, and they said, ‘We cannot make a specific call because there is too much uncertainty,’” Dourson said. “This is a complex problem, any one person or, heck, any one group – it’s tough for them to get their arms around the whole thing.”

But casting doubt on the science is part of a broader industry effort, said Linda Birnbaum, a former head of the EPA’s toxics program.

“That is a tactic that some of the people who are protesting the EPA’s new regulations use,” she said.