From the halls of the U.S. Congress to an international gathering in Zurich, policymakers, scientists, regulators, and others are responding to health concerns about a class of chemicals known by the acronym PFAS. NIEHS-supported research contributes new insights into the ways PFAS may affect the health of individuals and communities.

Per- and polyfluoroalkyl substances, or PFAS, possess a variety of useful qualities for industry and commerce. At the same time, they are highly persistent in the environment and are linked to effects on the immune system, hormone levels, neurodevelopment, pregnancy outcomes, cancer, and other health concerns, according to the U.S. Agency for Toxic Substances and Disease Registry.

The thousands of chemicals in the PFAS family show up in a range of common products.

Congressional hearing

NIEHS and National Toxicology Program (NTP) Director Linda Birnbaum, Ph.D., testified at a Sept. 26 hearing of the Senate Subcommittee on Federal Spending Oversight and Emergency Management. Subcommittee Chair Sen. Rand Paul, M.D., of Kentucky and Ranking Member Sen. Gary Peters, J.D., of Michigan opened the hearing, titled “The Federal Role in the Toxic PFAS Chemical Crisis.”

Subcommittee members also heard from representatives of the U.S. Environmental Protection Agency (EPA), Department of Defense, and Government Accountability Office. Representatives from communities in Michigan and New Hampshire testified on a second panel.

At the congressional hearing, Birnbaum said conclusions about health effects of PFAS are drawn from epidemiologic studies, biological plausibility and pathway studies in animals, mechanistic studies in human tissues and cell culture systems, and rapid high-throughput screening. (Photo courtesy of U.S. Senate)

Long-term concern

“The carbon fluorine bond is one of the strongest ever created by man, and it’s rarely seen in nature,” said Birnbaum, referring to a key feature of the structure of these chemicals. “The chemical composition of PFAS imparts high stability for consumer product design, but also makes PFAS extremely problematic in the environment, because they don’t easily degrade. In fact, PFAS remain in the environment for so long that scientists are unable to estimate an environmental half-life.”

Sen. Peters led off the discussion between senators and panelists by asking Birnbaum what chemicals the PFAS class reminded her of. She suggested that in terms of persistence, DDT was most similar. “Although it was banned 40 years ago [in the U.S.], it is still found in every one of us,” she answered. “This class of compounds … will be with us long after they stop being made.”

Zurich statement

Birnbaum’s chief of staff, Mark Miller, Ph.D., was one of an international group of co-authors who published a commentary on PFAS Aug. 31 in the journal Environmental Health Perspectives. The document calls for more collaboration among those researching, regulating, and using PFAS. It is known as the Zurich statement, because it grew out of a November 2017 workshop in Zurich, Switzerland.

“Building on a thought-starter document, workshop participants focused on current needs, common goals, and cooperative actions to address PFASs over the next 5–10 years, as well as on cooperative strategies and actions for maintaining and further strengthening the science–policy interface in the field of PFASs,” the authors wrote.

NIEHS-supported research

Weis said since the 1950s, more than 5,000 PFASs are estimated to be in current or former use in the world. (Photo courtesy of Steve McCaw)

NIEHS Toxicology Liaison Chris Weis, Ph.D., described the full range of NIEHS-supported research involving PFAS (see sidebar) when he spoke Sept. 12 before the National Advisory Environmental Health Sciences Council. He highlighted multiple pathways of PFAS exposure, including contaminated household water, food containers, clothing, and stain-resistant furniture.

After years of use as firefighting foam and in industrial processes, PFAS have been found in both surface and groundwater drinking sources, from which they can cause exposures through ingestion, inhalation during showering, and absorption through the skin.

The testimony on Capitol Hill and the statement from those who gathered in Zurich convey similar urgency that we learn more about how these chemicals affect the body, and how contaminated water can best be treated.

Citation: Ritscher A, Wang Z, Scheringer M, Boucher JM, Ahrens L, Berger U, Bintein S, Bopp SK, Borg D, Buser AM, Cousins I, DeWitt J, Fletcher T, Green C, Herzke D, Higgins C, Huang J, Hung H, Knepper T, Lau CS, Leinala E, Lindstrom AB, Liu J, Miller M, Ohno K, Perkola N, Shi Y, Smastuen Haug L, Trier X, Valsecchi S, van der Jagt K, Vierke L. 2018. Zurich statement on future actions on per- and polyfluoroalkyl substances (PFASs). Environ Health Perspect 126:84502.