Key points
- PFAS can enter the body through a variety of sources like contaminated drinking water, contaminated foods, or dirt or dust containing PFAS.
- All PFAS can leave the body over time through urine, blood, or breast milk.
- Young children may be more likely to be exposed to PFAS because they may chew on contaminated items and put their hands into their mouths.
Overview
Nearly all people in the United States have measurable amounts of per- and polyfluoroalkyl substances (PFAS) in their blood. Your PFAS blood levels will tell you the amount of PFAS in your body. PFAS blood levels are determined by how much PFAS you have been exposed to minus how much PFAS have left your body (also called excretion).
Exposure and excretion are different for each person. For example, two members of the same household may have very different PFAS levels in their bodies.
Exposure
Exposure happens when a person breathes, eats, drinks, or touches a chemical and it enters their body.
PFAS can get into our bodies when we:
- Drink water from PFAS-contaminated municipal sources or private wells.
- Eat foods produced near places where PFAS were used or made.
- Eat fish caught from water contaminated by PFAS.
- Eat foods packaged in material that contain PFAS.
- Swallow or breathe in contaminated soil or dust.
- Accidentally swallow residue or dust from consumer products containing PFAS, such as stain resistant carpeting or water repellent clothing.
Research has suggested that exposure to PFOA and PFOS from today's consumer products is usually low. For most PFAS, exposure from showering, bathing, or washing dishes in water containing PFAS would also be low, especially when compared to exposure from contaminated drinking water.
Young children may be more likely to be exposed to PFAS because they tend to chew on toys and fabrics and often put their hands into their mouths. Children can also be exposed by drinking formula mixed with PFAS-contaminated water or breast milk from persons exposed to PFAS. PFAS can also be transferred from the mother to the baby during pregnancy.
In communities affected by PFAS-contaminated drinking water, water can be the main source of exposure. For other communities, exposure sources can vary.
For information on workplace exposures, please visit the National Institute for Occupational Safety and Health (NIOSH) PFAS webpage.
Excretion
Exposure is the process whereby substances, like PFAS, leave the body.
- Some PFAS leave the body slowly over time, mostly through urine. People who have kidney disease may not excrete as much PFAS from their body through their urine as healthy individuals.
- Some PFAS routinely leave the body in blood during menstruation. Those who menstruate may excrete more PFAS than those who do not.
- Some PFAS can leave the body in breast milk. Those who breastfeed may excrete more PFAS from their bodies than those who do not.
All of these factors could affect PFAS levels measured in your blood. While PFAS blood test results can tell you the amount of certain PFAS in your blood, the test results will not provide information to pinpoint a health problem and will not predict future health outcomes.
You can talk with your healthcare provider about the benefits and limitations of PFAS blood testing.