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Environmental and Health Impacts of PFAS

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a large group of human-made chemicals that have been used in industry and consumer products worldwide since the 1950s.

PFAS do not occur naturally, and some are widespread in the environment. They are found in people, wildlife and fish all over the world. Some PFAS can stay in a person's body for a long time and do not break down easily in the environment.

In April 2024, the U.S. EPA finalized maximum contaminant levels (MCLs) for six types of PFAS. The MCLs set enforceable drinking water standards individually for PFOA and PFOS at 4.0 parts per trillion (ppt) and PFNA, PFHxS and GenX at 10.0 ppt. In addition, EPA set a MCL at a hazard index of 1 when a combination of two or more of PFNA, PFHxS, PFBS and GenX are present in a mixture.

To date, the Wisconsin Department of Health Services (DHS) has recommended groundwater enforcement standards for 18 PFAS. You can find more information about DHS’ recommendations on their PFAS webpage.

An enforceable state public drinking water standard of 70 ppt for a combination of PFOA and PFOS went into effect in August 2022. The DNR will need to complete rulemaking to bring Wisconsin’s enforceable standard into compliance with EPA’s new standards. Until the rulemaking process is complete, the public drinking water standard of 70 ppt for a combination of PFOA and PFOS will remain in effect. Updates on the rulemaking process are available on the NR 809 Safe Drinking Water Standards Update webpage.

Environmental Impacts

Drinking Water and Wells

PFAS can reach groundwater and surface waters, such as lakes and rivers, when products containing PFAS are spilled, or disposed of, on the land surface. PFAS have the ability to move easily through some ground surfaces and can reach groundwater that is used for public water supplies or for private drinking water wells. Lakes and rivers that are used as sources of drinking water can be contaminated when PFAS are spilled into the water or when PFAS in the air settles into the water.

Drinking water or eating food that contains PFAS are the main ways people are exposed to these chemicals (please see the “Health Impacts” tab for more information). At the request of the DNR, DHS reviewed scientific literature to determine if there is sufficient toxicological information to recommend a groundwater quality standard for some PFAS compounds. DHS recommended health-based groundwater enforcement standards for 18 of the 36 types of PFAS evaluated.

The links below provide information about the quality of Wisconsin's water and information to help private well owners and users understand their water and maintain their wells.


PFAS in soil may pose a direct contact risk to humans or result in chemicals entering the groundwater and surface water.

The DNR's Remediation and Redevelopment (RR) Program maintains a web-based spreadsheet with soil residual contaminant levels (RCLs). These were calculated using U.S. EPA's regional screening level (RSL) web calculator and following the procedures in NR 720.12 for determining soil direct-contact RCLs protective of human health.


PFAS can be emitted into the air as vapors or fine particles. PFAS then travels in the atmosphere by sticking to small particles of material suspended in the air. Only two PFAS compounds, ammonium perfluorooctanoate and perfluoroisobutylene (PFIB), are currently regulated as hazardous air contaminants in Wisconsin.

There is little existing research on the health impacts from PFAS in air. Currently, the U.S. EPA does not have an approved sampling method for PFAS in ambient air. Furthermore, health benchmarks that estimate safe exposure levels are available for only a few of the many PFAS compounds that are present in the environment. The lack of test methods and emissions standards for PFAS compounds in air makes further study necessary.

For more information on air quality in Wisconsin, see the air quality monitoring webpage and the air pollutants and standards webpage.

Fish and Wildlife

PFAS are known to accumulate in animals exposed to contamination, and we continue to learn about the possible impacts of this exposure. The DNR does not have a way to predict how much PFAS might be in any individual wild animal based solely upon PFAS in the environment.

Studies looking at fish consumption and PFAS accumulation in humans provide evidence that fish can be a source of exposure for people who consume fish. Following the DNR's fish consumption advisories can provide the health benefits of eating fish while reducing potential risk from contaminants.

Health Impacts

Exposure Routes and Health Impacts

The main ways people can be exposed to PFAS include:

  • Drinking contaminated municipal or private well water.
  • Eating fish with high levels of PFAS.
  • Eating food grown or raised near places that used or made PFAS.
  • Eating food packaged in material made with PFAS.
  • Swallowing contaminated soil or dust.
  • Using some consumer products, such as ski wax, nonstick cookware and stain and water repellant sprays for fabrics.

Not all PFAS have the same health effects. Research suggests that exposure to high levels of some PFAS may:

  • Increase cholesterol levels.
  • Decrease how well the body responds to vaccines.
  • Increase the risk of thyroid disease.
  • Increase the risk of some cancers.
  • Increase the risk of serious conditions like high blood pressure or pre-eclampsia during pregnancy.
  • Lower infant birth weights (the decrease in weight is small and may not affect health).

While completely avoiding contact with PFAS is not possible, taking actions to reduce your exposure to them could limit your risk of negative health impacts. Some possible actions you can take include understanding if PFAS are in your drinking water, learning about PFAS in consumer products and following fish consumption advisories.

More information about the health effects of PFAS and protecting yourself from PFAS exposure is available on the Wisconsin Department of Health Services (DHS) website. Information about PFAS in fish and wildlife is available on the Consumption Advisories and PFAS page. To learn more about actions taken by the U.S. EPA to address PFAS and health impacts of exposure to PFAS, visit the U.S. Environmental Protection Agency and the Agency for Toxic Substances and Disease Registry websites.


Wisconsin Resources

Additional Resources