What are PFASs and Are They Linked to Cancer?

  • PFASs are a class of chemicals that have been used since the 1940s in a wide variety of consumer products.
  • Several PFASs have been linked to cancer and other diseases, but the disease mechanism is unclear.
  • Federal and state authorities have begun actions to limit levels of certain PFASs in the environment.

Per- and polyfluoroalkyl substances (PFASs) are chemicals whose ability to repel oil and water has led them to be used in a wide variety of consumer products, such as non-stick cookware, water-repellent clothing, stain-resistant fabrics and carpets, some cosmetics, and food containers that resist grease and oil.

They’re highly stable chemicals, so they can persist in the environment for long periods of time. As a result, some PFASs are present today in groundwater, soil, and human and animal bloodstreams. Most people in the United States and other industrialized countries have traces of them in their bodies, according to the Centers for Disease Control and Prevention (CDC).

Numerous studies have linked PFASs to illnesses, including cancer, but little is known about how they affect health and the doses at which they’re dangerous. The Agency for Toxic Substances and Disease Registry reports that research suggests that exposure to certain PFASs may:

  • affect growth, learning, and behavior of infants and older children
  • lower a woman’s chance of getting pregnant
  • interfere with the body’s natural hormones
  • increase cholesterol levels
  • affect the immune system.

The U.S. Environmental Protection Agency (EPA) has issued non-binding limits for some PFASs in water supplies, but a recent report by the CDC suggested that the chemicals may pose a threat to human health at far lower levels than the EPA’s recommended limits.

Earlier this year, EPA Director Scott Pruitt announced the agency will begin a process of setting limits on two PFASs, known as PFOA and PFOS, that are among the most studied PFASs. The agency plans to publish recommendations on cleaning up the two chemicals in groundwater and is considering whether to regulate other chemicals in the PFAS family.

While these steps garnered praise from some groups, several environmental advocates charge that they don’t go far enough. The Delaware Riverkeeper Network said the plan “lacks any sense of urgency and offers no timely relief to people exposed to these highly toxic compounds in their water,” National Public Radio reported.

In 2006, the eight major U.S. manufacturers of PFASs agreed to eliminate the use of PFOA and PFOA-related chemicals in their products and in emissions from their facilities by 2015. While all the manufacturers met this goal, the chemicals are still produced in other countries and can be imported into the U.S. in a range of consumer products. And the chemicals’ durability guarantees they will remain in the environment for years to come.

Concern about the health effects of PFASs prompted some states to take regulation action before the federal government’s latest initiative. Pennsylvania, for example, has been working to reduce PFAS levels in soil or groundwater that has been found to be contaminated. Blood tests on 235 residents of the town of Horsham and two neighboring townships — located near a military base which used firefighting foam containing PFASs — found that most had levels of four PFAS chemicals that exceeded the national average, National Public Radio reported. Some of them had illnesses, including elevated cholesterol, hormone disruptions, and cancer, that have been associated with the substances.

A CDC fact sheet includes some common questions about exposure to PFASs, along with recommendations for people concerned about such exposure.