PFAS and your health

child kissing mother's pregnant belly

Most people living in the United States have PFAS in their blood. Scientists continue to study health impacts of these chemicals, including in Colorado. We continue to learn more about how these chemicals affect health.

Potential health impacts

Whether PFAS chemicals harm health depends on many factors. These factors include amount of exposure, age, genetics, and health history. Research involving humans strongly suggests exposure to certain PFAS chemicals, including PFOA and PFOS may:

  • Increase cholesterol levels.
  • Decrease how well the body responds to vaccines.
  • Lower infant birth weights.
  • Increase the risk of certain kinds of cancer (PFOA).

Though additional research is needed, it is likely other PFAS may have health impacts like PFOA and PFOS. There is some evidence that certain PFAS may:

  • Increase the risk of serious conditions like high blood pressure or preeclampsia in pregnant people.
  • Cause changes in liver function. 
  • Impact levels of thyroid hormones. 

Research involving animals can also help us understand potential health impacts of PFAS chemicals. Learn more on the CDC’s PFAS health effects page.

Medical tests for PFAS

Health care providers can measure PFAS chemicals in your blood, but this is not a routine test most doctors order. These chemicals are at low levels in almost everyone’s blood. They can stay in the blood for several years after exposure. Testing can tell if a person’s level is lower than, the same as, or higher than the blood levels of the general population. Unless you are participating in a study, we don’t recommend testing your blood. Currently, the results don’t show whether PFAS chemicals caused your health problems. The test also would not dictate treatment or next steps. 

Read "Talking to Your Doctor about Exposure to PFAS"

2016 EPA health advisory for PFOA and PFOS

In 2016, EPA set a health advisory level of 70 parts per trillion (ppt) for PFOA and PFOS in drinking water. Health advisories are a "study of studies" that consider all the available science at that time. When EPA issues an advisory, scientists keep studying the chemical's health impacts. Health advisories are not regulations and are not enforceable.

The 2016 health advisory says that if either PFOA or PFOS, or the two added together, exceed 70 ppt, people should take action to reduce exposure. 

Health-based guidelines to be updated

Based on new science, EPA currently is working to update health-based guidelines and develop a drinking water regulation for PFOA and PFOS.

In November 2021, EPA released draft documents it will use to develop regulations and health guidelines. This new information is currently under review by the agency's Science Advisory Board and may change before final health-based recommendations are determined. 

Read about EPA's November 2021 draft health effects documents. 

We will update this page as new information becomes available. 

As EPA works toward a PFAS regulation and associated health-based guidelines for drinking water, there are steps you can take to reduce your exposure. 

  • If your drinking water comes from a public water system, contact the system for the most current information on PFAS testing and results. 
  • If you use well water for drinking, cooking food like soup or rice, or gardening, test your well water for PFAS. EPA has a list of labs that can test for these chemicals. We recommend testing for as many PFAS contaminants as the lab offers. 
  • If you are concerned about levels of PFAS in your drinking water, consider installing a reverse osmosis system or using bottled water. Keep in mind that bottled water can be expensive and has an environmental impact. Both bottled and treated water may lack fluoride, which is important for oral health. 


For questions about PFAS, interpreting well testing results, and potential health impacts: Toxcall, (303) 692-2606 or