PFAS, or perfluoroalkyl and polyfluoroalkyl substances, are ubiquitous fluorinated organic compounds found widely in manufactured products, from firefighting foam to stain-resistant carpets. These water- and oil-repellent compounds are known to degrade slowly over time, and have been found in humans, drinking water, and even in Arctic ecosystems.
What do we know about human exposure to PFAS? How can contaminated media be treated? How can these compounds be controlled, and how can exposure be prevented? Last month, the Environmental Health Matters Initiative of the National Academies of Sciences, Engineering, and Medicine hosted a two-day workshop that brought together experts and stakeholders from academia, research, government, and industry to address these and other important questions about PFAS.
The term “PFAS” describes a group of chemicals, rather than one distinct chemical. Not every chemical in the PFAS group has been carefully studied, and research has yet to define the properties of every PFAS compound, how they act in the environment, and what their effects could be in humans. Steve Korzeniowski, a representative for FluoroCouncil, cautioned that PFAS “are extremely different in terms of chemistry, in terms of property … calling everything PFAS is really not appropriate when you look at the functionality.”
Understanding PFAS Exposure
Tom Webster, professor of environmental health at Boston University’s School of Public Health, explained that exposure can happen when people ingest, inhale, or touch PFAS. Ingesting water that is contaminated by PFAS is one route to exposure, and some evidence shows that PFAS in one’s diet can also lead to exposure. Two less-studied paths to exposure are indoor exposure, which can happen when a person inhales air or ingests dust, and exposure through contact between the skin and personal care products.
Jennifer Field, professor of environmental and molecular toxicology at Oregon State University, said that manufacturing waste containing PFAS compounds can be found in air emissions, landfill waste, and wastewater treatment plants. PFAS also get into the food chain through irrigation or environmental contamination, and can be transferred to fetuses through breast milk or cord blood. Around 6 million people in the U.S. live with drinking water that contain PFAS at levels higher than the EPA recommendation, making drinking water a key issue for exposure.
Webster noted that many uncertainties about PFAS exposure remain: dietary exposure, indoor exposure, dermal exposure, and exposure to newer PFAS all require more research.
Controlling and Preventing PFAS Exposure
Throughout the workshop, experts pointed out opportunities for progress in controlling and preventing PFAS exposure. Holly Davies, a senior toxicologist at the Washington State Department of Health, noted that prevention can make expensive cleanup efforts unnecessary, and that the economic benefits of preventing exposure are numerous.
Assessing alternatives is one possible route, and could identify safer compounds to replace PFAS in manufacturing. A number of panelists said that a variety of experts and disciplines should be involved in alternatives assessment, and that some alternatives will require changing manufacturing processes and training requirements for those who work with these chemicals. Projects are already underway to implement safer alternatives for PFAS in firefighting foam, carpets, and cosmetics, as well as paper and cardboard that come in to contact with food.
Carla Ng, assistant professor at the University of Pittsburgh, described a framework for characterizing essential uses, suggesting PFAS only be used when they are critical to the functionality of a product. This approach would reduce exposure by simply limiting the amount of PFAS ever produced.
Others proposed improving communication about PFAS. While some panel experts were wary of numbing the public with too many environmental health warnings or product labels, others emphasized the importance of open communication with communities exposed to PFAS.
Moving Forward
Challenges in controlling and preventing PFAS exposure remain. Davies remarked on the lack of basic information on the chemical makeup of products containing PFAS. Others stated that most of the information about PFAS is proprietary and protected by businesses, including how much of these compounds are being produced and where. Research funding lacks coordination, and a considerable portion of the financial burden of dealing with PFAS contamination has fallen to taxpayers. Regulation and cleanup efforts are often spread across a patchwork of local, state, and federal requirements.
Linda Birnbaum, director of the National Institute for Environmental Health Sciences and the National Toxicology Program, added, “What goes around comes around. Maybe that’s the story of PFAS … the fact that they will keep coming around if we keep putting them in to the environment.”
View recordings of the event here.
The National Academies of Sciences, Engineering, and Medicine’s Environmental Health Matters Initiative convenes leaders from various sectors to share their knowledge and insights on how to solve a wide array of environmental health challenges.
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