What are the health effects?

The health effects of PFOS, PFOA, PFHxS, and PFNA have been more widely studied than other per- and polyfluoroalkyl substances (PFAS). Some studies in humans with PFAS exposure have shown that PFAS may:

  • Interfere with the body’s natural hormones;
  • Increase cholesterol levels;
  • Affect the immune system; and
  • Increase the risk of some cancers.

Scientists are still learning about the health effects of exposures to mixtures of PFAS.

For the most part, laboratory animals exposed to high doses of one or more of these PFAS have shown changes in liver, thyroid, and pancreatic function, as well as some changes in hormone levels. Because animals and humans process these chemicals differently, more research will help scientists fully understand how PFAS affect human health.

Page last reviewed: January 21, 2020