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WASHINGTON -- More research needs to be done on per- and polyfluoroalkyl substances (PFAS) chemicals and their adverse health effects, experts said at a House hearing Tuesday.

"'If you are a public health researcher, these are the chemicals for you, because PFAS have now been associated with an adverse impact on every major organ system in the human body,'" Elsie Sunderland, PhD, professor of environmental chemistry at Harvard T.H. Chan School of Public Health in Boston, said at a hearing held by the House Science, Space, and Technology Subcommittee on the Environment. Sunderland was quoting from a speech by Linda Birnbaum, PhD, former head of the National Institute of Environmental Health Sciences.

"However, we have only anecdotal understanding of PFAS exposure sources for the U.S. general population, despite their presence in all of us," Sunderland said. "Exposure research falls outside of the mandate of most ongoing research programs. Typically this would fall within the mandate of the EPA [Environmental Protection Agency], but both our internal and extramural research has been substantially underfunded over the past decade."

Subcommittee members agreed. "While this issue is extensive in all communities across the country, it has disproportionate impacts on small communities who have trouble bearing the expense of remediation," said subcommittee chair Rep. Mikie Sherrill (D-N.J.). "It's concerning how little we know about these harmful chemicals and even further, how limited our understanding is about what we still need to learn."

However, there was some disagreement about whether all PFAS are universally bad. "The hazard and risk profiles of various PFAS are immensely different," said Rep. Stephanie Bice (R-Okla.), the committee's ranking member. "A broad, categorical ban on PFAS would be detrimental to our manufacturing sector, and actually put lives at risk by reducing safety. Using certain PFAS in a controlled responsible manner is safe and effective. Understanding the distinct properties of each of these chemicals will allow us to continue the important uses and benefits of PFAS technologies."

"Scientific research has determined that not all PFAS chemicals entail the same risks, and I believe this signals that more research is needed to better understand the individual properties and characteristics of PFAS," said Rep. Michael Waltz (R-Fla.). "Increased research can help us determine how to best remove legacy PFAS that are harmful to human health and the environment, and additional research can also lead to alternatives that retain the most valuable properties of PFAS."

On the other hand, Rep. Haley Stevens (D-Mich.) noted that last month, "the EPA sounded the alarm bell and asked its Science Advisory Board to review new analyses and data that suggests that two [PFAS] chemicals, which have been found in many drinking water and surface waters in Michigan and around the country, are far more toxic than previously." Stevens is a co-sponsor of the , a bill passed by the House that designates PFAS as hazardous substances.

Members on both sides of the aisle seemed particularly interested in work being done by , a non-profit research firm based in Columbus, Ohio, to develop a way to destroy PFAS. "Our transformational innovation is powered by supercritical water oxidation," explained Amy Dindal, director of environmental research and development at Battelle. "We call our technology the 'PFAS Annihilator' as it destroys PFAS and contaminated water to non-detectable levels in seconds, leaving inert salts, carbon dioxide, and PFAS-free water behind ... Battelle is ready to scale and deploy the PFAS Annihilator."

Sherrill noted that the U.S. doesn't currently have any nationwide standards for acceptable levels of PFAS chemicals, and asked witnesses whether such standards would be helpful. "Uniform standards would definitely help our entire country," said Abigail Hendershott, executive director of the Michigan PFAS Response Team. "Michigan has had to come up with our own standards for water quality values for surface water, drinking water standards, and groundwater clean-up criteria, and having uniform settings across our country would certainly make a better, consistent message."

Sunderland agreed. "I think uniform standards are very helpful for avoiding confusion among the public," she said. "One thing that we see leading to the diversity of drinking water standards right now is the fact that different agencies are picking different health outcomes to develop these risk-based limits. So agreeing on which health effect [to target] and perhaps focusing on the most sensitive health effects for protecting the most vulnerable populations -- such as children -- is very important."

One particular concern was the PFAS found in the foam used by firefighters. "One of the concerns about PFAS that hits close to home for me as a combat veteran is hearing of elevated levels of PFAS and brown water on our military bases, and the health risks this poses to our military members and their families," said Waltz. "High concentrations are mostly due to the use of aqueous film-forming foam concentrates to put out fires quickly and effectively. Replacing this foam with a reliable non PFAS alternative has proven incredibly difficult."

Rep. Dan Kildee (D-Mich.) agreed. "The people of Oscoda [Michigan] have been dealing with this because the military used firefighting foam containing PFAS that has leached into the former Wurtsmith Air Force base, into their drinking water," he said. "And even though the base has been closed for 30 years, the people of Oscoda are still dealing with these impacts."

He noted that PFAS Action Act -- which has not been voted on in the Senate -- would require both military and civilian airports to find alternatives to PFAS-containing firefighting foam, "and to help with the transition, this committee was able to secure $95 million in the Build Back Better Act -- which hopefully will come to the President's desk in the not too distant future -- to replace firefighting foam containing PFAS."

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