More than 110 experts sound alarm over WHO’s ‘weak’ PFAS limits for drinking water | PFAS extension

More than 110 scientists and regulators around the world are sounding a public alarm over what they label as “weak” PFAS drinking water limits proposed by the World Health Organization, which they accuse of using shoddy science and “wrongfully dismissed hundreds of studies linking “chemists forever” to serious health problems.

Some have further argued that the guideline development process was corrupted by industry-aligned consultants who aimed to reduce stringent new PFAS limits proposed in the United States and weaken standards in the developing world. The chemicals have been called “forever chemicals” because of their longevity in the environment.

The limits would allow for far more PFAS in drinking water than allowed or proposed by the US Environmental Protection Agency, most US states, and some agencies within the EU. The WHO guidelines and justification are “inexcusable,” said Linda Birnbaum, former head of the US National Toxicology Program and EPA scientist.

“WHO ignored the last 20 years of science, whether it’s epidemiological data, animal data or experimental data, and said ‘there is so much uncertainty that we can’t do anything,'” he told the Guardian.

Birnbaum was among a group of prominent independent researchers who signed a public letter asking WHO to withdraw or revise the guidelines.

PFAS are a class of approximately 12,000 chemicals designed to make products resistant to water, stains and heat. They are used in thousands of consumer products and are believed to contaminate the drinking water of more than 200 million people in the United States. Independent research links PFAS to cancer, birth defects, liver disease, decreased immunity, kidney disease, higher cholesterol, and a host of other serious health effects.

WHO proposes drinking water limits of 100 parts per trillion (ppt) for PFOA and PFOS, two of the most studied PFAS compounds. The signatories of the letter say the level will endanger human health, and the EPA in June imposed new PFOA and PFOS advisory limits of 0.004 ppt and 0.02 ppt, respectively. The agency is expected to make the limits mandatory in the coming months, and some researchers suspect WHO is aiming to derail that effort.

WHO did not respond to a request for comment.

Some independent researchers say the evidence suggests that industry-related perpetrators played an important role in the development of WHO’s limits and justifications. Among them is Michael Dourson, whom Donald Trump appointed in 2017 to oversee the EPA’s Chemical Safety Division.

Withdrew its name after not getting enough support in part over its alleged history of producing industry-friendly studies backing up chemical companies’ safety claims, which the Environmental Defense Fund at the time termed “hired science” .

Emails published by the New York Times show his close relationship with the American Chemistry Council, even when he was an EPA adviser. The emails also showed that one of Dourson’s organizations at the University of Cincinnati, where he had previously worked, was accepting money from the American Chemistry Council and sending him a research paper for editing, which some labeled a violation. ethics.

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

Dourson told the Guardian that his most recent work has received no external funding and he has taken part in “very few activities on the WHO draft”. He added that he withdrew from the Trump nomination for procedural reasons.

Critics of the report also said positions taken by Joseph Cotruvo, a US consultant aligned with the nation’s water utilities and other industries, support part of WHO’s case for higher limits. Many utilities have opposed stricter PFAS regulations due to cost concerns, and Cotruvo has publicly downplayed the health risks and opposed stricter standards.

He told the Guardian that he had revised and amended the WHO document and called the idea of ​​industry influence “absolutely false”.

WHO also listed as a contributor Linda Bevan, a consultant who conducted research for PFAS maker Chemours, formerly DuPont, who supported the safety claims made by the company.

WHO cites a number of independent researchers as peer reviewers, which gives the guidelines an air of balance, but many contacted by the Guardian said they disagreed with WHO’s findings and signed the withdrawal letter.

A PFAS researcher at the University of North Texas, Katie Pelch, said she was unaware that she would be listed as a peer reviewer and added that the process was different from standard peer reviews. Her significant concerns have not been addressed and she has not reviewed a final draft.

Tony Fletcher, a researcher at the University of Leicester, raised similar concerns and said only some of his comments were addressed, while the final report was very different from what he had reviewed. He said the final copy contained far more references to Dourson’s work than the draft.

WHO justifies the high limits with the many blanket claims: there are “significant uncertainties and lack of consensus” on whether PFAS cause health problems, as well as no consensus between EU and US regulatory agencies on what should be the limits of drinking water. Dourson and Cotruvo have pointed to studies to support these arguments.

But regulators like the EPA and the New Jersey Department of Environmental Protection have raised concerns about the WHO guidelines, which the latter called “not protective of public health or scientifically sound” in a public WHO rebuke.

“NJ DEP has identified the need for many revisions in both the factual information and conclusions about health effects,” he wrote.

Jamie DeWitt, a researcher at East Carolina University, said some studies cited by the WHO were misrepresented in the draft and added: “The science has been distorted in ways that some might consider inappropriate.”

A certain level of uncertainty is inherent in chemical exposure studies, he added, but he said WHO is “inflating it” in a way that appears designed to preclude protective limits for drinking water.

“Unless we do experiments on humans where we give people prescribed amounts of chemicals, then we will never know 100% that a particular disease is caused by a particular [chemical] exposure,” he said, adding that multiple human studies of humans who have been inadvertently exposed to PFAS strongly link the chemicals to health problems.

The disparity in drinking water limits, DeWitt noted, was a result of regulatory agencies around the world working under different political leadership and regulatory guidelines at the local, state and federal levels.

“[WHO] I didn’t elaborate on why [the disparity] it exists,” DeWitt said.

The report also questioned some specific health issues related to PFAS, such as decreased immunity, which could affect the effectiveness of vaccines. WHO says the decline in immunity isn’t clear because there hasn’t been an increase in diphtheria or other diseases for which most Americans are vaccinated.

Cotruvo has previously made that argument publicly and told the Guardian that research has suggested that only very high levels of exposure could impact vaccines.

But DeWitt noted that the real problem was a weakened immune response, so even if cases of diphtheria or mumps didn’t increase, people were likely more susceptible to other illnesses. She added that similar problems existed in WHO’s analyzes of other health issues.

“There appears to be a lack of understanding of toxicological principles among those who wrote this study,” DeWitt said.

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