A large number of studies have examined possible relationships between levels of per- and polyfluoroalkyl substances (PFAS) in blood and harmful health effects in people. However, not all of these studies involved the same groups of people, the same type of exposure, or the same PFAS.
These different studies therefore reported a variety of health outcomes. Research involving humans suggests that high levels of certain PFAS may lead to the following:
- Increased cholesterol levels
- Decreased vaccine response in children
- Changes in liver enzymes
- Increased risk of high blood pressure or pre-eclampsia in pregnant women
- Small decreases in infant birth weights
- Increased risk of kidney or testicular cancer
At this time, scientists are still learning about the health effects of exposures to mixtures of different PFAS.
One way to learn about whether PFAS will harm people is to do studies on lab animals.
- Most animal studies have tested doses of PFAS that are higher than the doses people experience from environmental exposure.
- These animal studies have found that PFAS can cause damage to the liver and the immune system.
- PFAS have also caused low birth weight, birth defects, delayed development, and newborn deaths in lab animals.
Humans and animals react differently to PFAS, and not all effects observed in animals may occur in humans. Scientists have ways to estimate how the exposure and effects in animals compare to what they would be in humans.
Additional research may change our understanding of the relationship between exposure to PFAS and human health effects.
