What is PFAS—and Why Should You Care?
While toxicity studies have raised important concerns, there is still much we do not know about the effects of PFAS on human health and the environment. Out of the hundreds of known PFAS compounds, only a small number have been studied extensively.
Doctors and health gurus are always telling us to drink more water for our health—but what if that water is contaminated by a potentially toxic chemical?
In 2016, dozens of communities across the country were hit with unsettling news: PFASs had been found in their drinking water. A study of groundwater across the country found these chemicals in drinking water in 27 states, impacting 6 million Americans. Many of these communities are near military bases, airports, and industrial sites.
If you are in one of the affected areas, how concerned should you be? Here's what we do—and don't—know about these unfamiliar substances lurking in the water.
So, what's a PFAS? PFAS is an abbreviation for per- and polyfluoroalkyl substances, and it's not just a single chemical. PFASs encompass a whole family of manmade chemicals that contain a carbon and fluorine atom backbone. There are hundreds of known PFAS compounds with varying functional groups, which can include other elements such as oxygen, hydrogen, or sulfur.
PFAS compounds came into common use in the 1950s and '60s and are now used in hundreds of industrial processes and consumer products. They are considered useful because they are resistant to heat, water, and oil. Consumers may be exposed to PFASs in non-stick cookware, grease-resistant paper, fast food wrappers, microwave popcorn bags, stain-resistant carpets and fabrics, water-resistant clothing, cleaning products, and personal care products.
PFASs are also used in industrial processes and, notably, in firefighting foams. PFASs are a component of many of the firefighting foams used by the military, airport authorities, and local fire and rescue agencies. It is these foams that are most often implicated when PFAS is found in groundwater or in the environment.
The Problem with PFAS
PFAS chemicals do not occur in nature, and some of them take a very long time to break down in the environment. Our bodies don't do a good job of breaking them down, either, so they have the potential to build up in the organs and tissues of humans and animals. Animals further up the food chain—such as humans—may accumulate even more of the chemicals in their bodies when they eat plants or animals that have been exposed to PFAS.
There are concerns that PFAS chemicals may have toxic effects on humans and animals. Some animals exposed to high levels of PFAS show changes in hormone levels and in liver, thyroid, and pancreatic function. Some studies in humans have suggested that PFAS may affect the development of fetuses and young children, leading to possible growth, learning, or behavioral problems. Other studies have pointed to possible links to cancer, immune system disorders, and fertility problems.
Some PFAS compounds, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), are no longer manufactured in the United States because of concerns about their toxicity. But because of their persistence in the environment, humans and animals can still be exposed. PFAS chemicals can travel through air or water and end up a long way from the place where they were manufactured or used. PFAS compounds have been found in polar bear tissues in remote arctic areas and in seals in Antarctica.
While toxicity studies have raised important concerns, there is still much we do not know about the effects of PFAS on human health and the environment. Out of the hundreds of known PFAS compounds, only a small number have been studied extensively. We do not know how much PFAS exposure is safe for humans or whether there are important differences in toxicity between different PFAS compounds. And we do not fully understand how PFAS compounds break down in the environment over time and how they travel.
These gaps in our understanding make it difficult to set regulatory limits for PFAS exposure or provide advice for people living in areas where PFASs have been detected. So far, the U.S. Environmental Protection Agency has set lifetime health advisories for only two PFAS chemicals: PFOA and PFOS, both found in firefighting foams. EPA has monitored several additional "long-chain" PFAS compounds (compounds with six or more carbon atoms), including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonates (PFSAs). Long-chain PFASs are believed to be more toxic and more persistent in the environment.
Additional research is sorely needed to better understand the human health and environmental concerns related to PFASs and figure out how to reduce exposure risks and clean up PFAS-contaminated sites. Important questions include:
- What levels of PFAS are safe in drinking water or in food such as fish?
- How does toxicity vary among different PFAS compounds?
- How much PFAS leaches out of consumer products such as non-stick pans, food wrappers, and personal care items?
- How long does it take for PFAS to break down in the environment on its own?
- What is the best way to clean up sites contaminated with PFAS and reduce human and environmental exposure risks?
The PFAS Detectives
Researchers at Battelle are working to better understand the scope of PFAS contamination and develop new methods for PFAS detection and remediation. They are also conducting toxicology studies to understand how PFASs affect different body systems.
Detecting PFASs in the environment takes specialized equipment and analytical methods. Right now, commercial laboratories only have analytical methods to accurately detect about 24 of the PFAS compounds. New methods are needed to accurately detect other PFASs.
Based on what is known so far about health impacts, the EPA has set lifetime health advisory levels for PFOS and PFOA at just 70 parts per trillion. In other words, for every trillion water molecules in a sample, there can be only 70 molecules of PFOS or PFOA (individually or combined). Other PFASs may also have health effects at these very low levels. That means that researchers must use analytical equipment capable of detecting the compounds at ultra-low levels.
One of the problems researchers run into when analyzing PFASs is their ubiquity in industrial and consumer products, including lab equipment. To get accurate measurements for environmental samples, researchers must be careful to avoid PFAS contamination from sampling equipment or laboratory instruments. Battelle has the capability to collect and analyze environmental samples to improve the accuracy of the results. Accuracy is critical to truly understand how much PFAS is in the environment, where is it coming from, how it travels, and where it ends up.
Currently, Battelle is one of a small number of labs across the country accredited for PFAS analysis through the Department of Defense Environmental Laboratory Accreditation Program (DoD-ELAP). This allows Battelle to analyze samples from U.S. Navy bases and other military sites where PFAS contamination is suspected. Battelle is also working with the U.S. government to develop new strategies for PFAS cleanup and remediation, including methods to break down PFASs in the environment into less harmful chemical components.
Understanding the Implications of PFAS Exposure
EPA is starting to give more attention to PFAS compounds. They sampled drinking water in several communities between 2013 to 2015 under the Unregulated Contaminant Monitoring Rule (UCMR3) program. They have also asked some companies to stop use of some PFAS compounds in manufacturing under the 2010/15 PFOA Stewardship Program. This will help some, but there are many products containing PFAS still in use. In addition, persistent PFASs will remain in the environment for a long time after manufacturers stop producing or using them.
Many military bases were used for firefighting exercises for a long time. Sampling and analysis of groundwater around many of these sites have shown the presence of PFAS compounds used in firefighting foams. Some of the communities where PFASs have been found in drinking water are near these bases. The U.S. Navy and Air Force have put programs in place to evaluate PFAS contamination and reduce risks for surrounding communities.
However, teasing out the causes and effects of PFAS exposure in these communities is not easy. Blood tests can be used to measure the levels of some kinds of PFAS in the body. But because humans are exposed to so many different PFAS compounds through consumer product use, it is difficult to determine how much exposure is due to a specific cause. Until further toxicology work is done, it is also hard to know whether or not the levels of PFAS found in drinking water present a true risk to human health.
What Consumers Can Do to Reduce PFAS Exposure
Consumers in areas impacted by PFAS contamination should check with their local water boards to find out if any advisories have been set for their drinking water. You can find out if your community is affected here. People in communities with detectable levels of PFAS in drinking water may want to use bottled water for drinking and cooking and avoid eating fish caught in the local area. Showering and bathing are considered safe; PFAS is not believed to be absorbed through the skin in significant amounts.
Consumers worried about exposure from commercial products may want to avoid microwave popcorn, non-stick cookware, stain-repellant treatments and paints and sealants containing PFAS. However, there is limited data about how much PFAS leaches out of these kinds of products. After drinking, inhalation is considered to be the most likely route of exposure. People should avoid directly breathing in fumes from PFAS-containing paints, coatings and stain-repellant treatments.
Avoiding PFAS exposure entirely is not possible. However, CDC surveys show that PFAS levels in people’s blood are dropping as companies reduce their use of PFAS in products. Researchers are continuing to study the human and environmental exposure risks and look for ways to reduce PFAS contamination in the environment. In the meantime, people in areas impacted by PFAS contamination should take sensible precautions.
Dr. Ramona Darlington is a Senior Research Scientist on the Battelle Environmental Services team. An experienced Remediation Engineer, Ramona works with government and commercial clients to evaluate environmental contamination and develop remediation plans for challenging contaminants, including PFASs.