05/11/2023
What Are PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a large, complex group of synthetic chemicals that have been used in consumer products around the world since about the 1950s. They are ingredients in various everyday products. For example, PFAS are used to keep food from sticking to packaging or cookware, make clothes and carpets resistant to stains, and create firefighting foam that is more effective.
PFAS molecules have a chain of linked carbon and fluorine atoms. Because the carbon-fluorine bond is one of the strongest, these chemicals do not degrade easily in the environment.
How can I get tested for PFAS?
Through a project funded by NIEHS, the Silent Spring Institute created a fact sheet that explains the process for testing blood for PFAS levels.
How Are People Exposed to PFAS?
Human exposure to PFAS is widespread but variable by geography and occupation. PFAS are used in the aerospace, automotive, construction, and electronics industries. Over time, PFAS may leak into the soil, water, and air.
People are most likely exposed to these chemicals by consuming PFAS-contaminated water or food, using products made with PFAS, or breathing air containing PFAS. Because PFAS break down slowly, if at all, people and animals are repeatedly exposed to them, and blood levels of some PFAS can build up over time.
One report by the Centers for Disease Control and Prevention, using data from the National Health and Nutrition Examination Survey (NHANES), found PFAS in the blood of 97% of Americans. 1 Another NHANES report suggested blood levels of PFOS and PFOA in people have been reduced since those chemicals were removed from consumer products in the early 2000s. However, new PFAS chemicals have been created and exposure to them is difficult to assess.
NIEHS conducts or funds research that aims to understand more about PFAS exposures and any subsequent health effects.
Why Be Concerned About PFAS?
Multiple health effects associated with PFAS exposure have been identified and are supported by different scientific studies. Concerns about the public health impact of PFAS have arisen for the following reasons:
Widespread occurrence. Studies find PFAS in the blood and urine of people, and scientists want to know if they cause health problems.
Numerous exposures. PFAS are used in hundreds of products globally, with many opportunities for human exposure.
Growing numbers. PFAS are a group of nearly 15,000 synthetic chemicals, according to a chemicals database (CompTox) maintained by the U.S. Environmental Protection Agency.
Persistent. PFAS remain in the environment for an unknown amount of time.
Bioaccumulation. People may encounter different PFAS chemicals in various ways. Over time, people may take in more of the chemicals than they excrete, a process that leads to bioaccumulation in bodies.
Because there are many types of PFAS chemicals, which often occur in complex mixtures and in various everyday products, researchers face challenges in studying them. More research is needed to fully understand all sources of exposure, and if and how they may cause health problems.
NIEHS supports research to characterize and better understand the possible health effects of exposure to PFAS chemicals.
This work is conducted in three main ways:
NIEHS funds research grants primarily at universities, but also non-profit research centers and a few small businesses.
Some NIEHS scientists conduct PFAS research at in-house laboratories.
NIEHS also collaborates with federal partners.
Current research areas at NIEHS include:
How, where, and the extent to which people are exposed to PFAS.
How PFAS can affect organs and systems in the body.
How and where PFAS move through the environment, such as through water, air, and dust.
Determining ways to identify, detect, and measure PFAS in the environment.
Development of technologies and devices to get rid of or destroy PFAS.
Determining effective ways to tell people about PFAS risk and what they can do to prevent or reduce their exposure.
NIEHS research is used by federal and state regulatory, environmental, and public health agencies to develop new standards to protect the health of people throughout the world. NIEHS is not a regulatory agency.
Other federal agencies, such as EPA and CDC, also conduct research related to PFAS.
PFAS science continues to evolve. There is still much to be learned, particularly in assessing human health effects of exposure to PFAS.
