There is evidence that exposure to PFAS can cause harmful effects on human health. If humans or animals ingest PFAS (by eating food or drinking water that contains PFAS), these chemicals are absorbed and can accumulate in the body. PFAS remain in the human body for a long time. As people are exposed to PFAS from various sources over time, the level of PFAS in the body can increase to the point where it may cause adverse health effects.
Laboratory animal studies suggest that PFOA and PFOS can cause adverse effects on reproductive and immune systems, as well as development, and on organs such as the liver and kidneys. Both chemicals have caused tumors in animal studies. The most consistent findings from human epidemiological studies are elevated cholesterol levels in exposed individuals, with more limited data related to:
Disruption of thyroid hormones (in the case of PFOS).
Low birth weight, Effects on the immune system, Cancer (in the case of PFOA), and Disruption of thyroid hormones (in the case of PFOS).