Per- and Polyfluoroalkyl Substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic chemicals. Found in many everyday products, they are linked to a range of health concerns.

Overview

Per- and polyfluoroalkyl substances (PFAS) are a large, complex group of human-made chemicals found in many everyday products. They are used in food packaging, nonstick cookware, clothing, carpets, and firefighting foam. Over time, PFAS may leak into the soil, water, and air.

PFAS molecules generally have multiple linked carbon and fluorine atoms. Because the carbon-fluorine bond is one of the strongest known, these chemicals do not break down easily in the environment. Some PFAS persist and can accumulate over time. That is why some people call them “forever chemicals.”

Human exposure to PFAS is widespread but varies by geography and occupation. Research studies have established links between exposure to some PFAS and several health conditions.

It is important to note that there are thousands of variations in PFAS chemicals, which can make them hard to study. Health effects associated with PFAS exposure include:

  • Immune system effects: PFAS exposure may reduce the immune system’s ability to fight infections. The National Toxicology Program (NTP), an interagency program, concluded that two types of PFAS (PFOA and PFOS) suppressed the antibody response and were a hazard to immune system function in humans.
  • Cancer: Exposure to PFAS may increase the risks of some cancers. Exposure to certain PFAS may be linked with increased risks of kidney and testicular cancers. Positive associations with specific PFAS have also been observed in some studies of other malignancies including cancers of the breast, thyroid, ovary, and pancreas as well as childhood leukemia.
  • Liver changes: PFAS are known to accumulate in human blood and some body tissues including the liver.
  • High cholesterol: PFAS exposure has been linked to increased cholesterol levels.
  • Small decreases in birth weight: Increased levels of some PFAS in pregnant women may be associated with lower birth weight.
  • Pregnancy-induced hypertension: PFAS exposure has been linked with increased risk of hypertension during pregnancy (preeclampsia).

Risk Factors

People are most likely exposed to PFAS in these ways:

  • Contaminated water or food: Eating and drinking PFAS-contaminated water or food is a primary route of exposure.
  • Everyday products: Using products made with PFAS, such as stain-resistant clothing, carpets, and nonstick cookware, can lead to exposure.
  • Air: Breathing air containing PFAS is another route of exposure.

Because PFAS break down slowly, if at all, people and animals are continuously exposed to them, and the amount of PFAS in the blood can build up over time.

Prevention Guidance

Reducing PFAS exposure can be challenging because these chemicals are so widespread. However, research points to several strategies:

  • Effective ways to remove PFAS from water include activated carbon treatment, ion exchange resins, and reverse osmosis. These water filtration technologies can be used in public treatment facilities, water systems in buildings, or homes.
  • Studies show folate may reduce PFAS accumulation in the body, which may protect against adverse birth outcomes and boost immune health.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on PFAS.

Community Support

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH. 

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH supports research to better understand the possible health effects of exposure to PFAS chemicals. This work happens in three main ways: NIH funds research grants primarily at universities, but also at nonprofit research centers and a few small businesses; some NIH scientists conduct PFAS research at in-house laboratories; and NIH collaborates with federal partners.

Current research areas include:

  • How, where, and the extent to which people are exposed to PFAS
  • How PFAS can affect organs and systems in the body
  • What health effects are associated with exposure to PFAS
  • How and where PFAS move through the environment, such as through water, air, and dust
  • How to identify, detect, and measure PFAS in the environment
  • How to develop technologies and devices to remove or destroy PFAS
  • What are effective ways to tell people about PFAS risk and what they can do to prevent or reduce their exposure

NIH 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.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.