Public Health

Forever Chemicals

What Physicians Need to Know

BY Alexander Bogdan, PhD, and Mohamed Mohamed, MD

Understanding PFAS

PFAS are a large family of man-made chemicals invented in the 1940s. Minnesota is one of 18 states that define PFAS as organic chemicals having at least one fully fluorinated carbon atom. There are only 19 states that have, or currently plan to have, a formal definition of PFAS.

The carbon-fluorine bond is one of the strongest known in chemistry, which gives PFAS useful properties, like resistance to water, oil, stains, heat and corrosion. Because of these properties, PFAS have been widely used in many products and industries. These include fabric and upholstery treatments, firefighting gear, nonstick cookware, medical devices, cosmetics and other everyday consumer products. It’s also used in many industrial and manufacturing processes.

The PFAS family includes thousands of different chemicals. Many of the most widely used PFAS are known for their persistence in the environment and building up in people’s bodies. Unlike most chemicals that build up in the body, PFAS are water soluble because of their unique chemical structure. The combination of being water soluble and lasting for a long time in the environment can lead to wide-spread contamination.

Two well-known examples — perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) — can stay in the human body for about three years. That’s why reducing exposure to PFAS is so important. It’s a balance of how quickly the body can get rid of these chemicals and how frequently new environmental exposures are introduced.

Most PFAS are not broken down by the body.

A Problem Revealed

In 2002, 3M notified the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Health (MDH) that groundwater at their Cottage Grove campus was contaminated with this group of chemicals the company had been manufacturing for nearly half a century. 

Further investigation showed the contamination wasn’t limited to the 3M site. It had spread across most of the groundwater (aquifers) and much of the surface water (lakes and rivers) of the eastern Twin Cities metro area, including the Mississippi River. As a result, the drinking water of hundreds of thousands of Minnesotans, both through public water systems and through private wells, has been affected.

Historically, drinking water was the biggest concern for PFAS exposure. Today in Minnesota, municipal water systems generally have improved monitoring and treatment, so consumer products are now the larger concern. Well water can still pose a risk, but there is currently no broad recommendation to test all wells.

Since 2008, MDH has tracked PFAS levels in the blood of East Metro residents who were exposed through drinking water before filtration systems were installed. Testing in 2008, 2010, and 2014 shows that PFAS levels have gone down, demonstrating that efforts to reduce PFAS in drinking water are working.

Protective Legislation

The Minnesota Legislature took steps to address the risks of PFAS exposure, enacting Amara’s Law in 2023, named for Amara Strande of Cottage Grove. Amara, who died at age 20 while battling a rare form of cancer, testified at the state capitol about living amid PFAS contamination. Although it is extremely difficult to tie any single health condition to a specific exposure, Amara and her family’s advocacy galvanized bipartisan support for one of the nation’s most stringent bans on PFAS. The first phase of the law took effect on Jan. 1, 2025, eliminating PFAS in nearly all products in 11 different categories. By 2032, Amara’s Law will end all nonessential use of PFAS in Minnesota.

Domestic production of some types of PFAS ended over 20 years ago, and some companies have pledged to stop manufacturing PFAS by the end of 2025. Because of PFAS that already exist in the supply chain and the persistence of PFAS in the environment, however, human exposure will likely continue for the foreseeable future.

PFAS Can Affect Human Health

In the past 20 years, we’ve learned a lot about the health risks of PFAS exposure. More important, this is not just a Minnesota or an East Metro problem. Studies show that almost everyone on the planet has come into contact with PFAS — from food and consumer products to household dust and drinking water. For most Minnesotans, the majority of PFAS exposure comes from non-drinking water sources. 

We also know that PFAS can reach babies throughout pregnancy and from breastfeeding, because many of these chemicals can easily cross the placenta and enter breastmilk.

PFAS can enter the body through swallowing (eating or drinking) and breathing. Once in the body, PFAS mostly attach to proteins in the blood, especially to albumin, and to a lesser extent tissue proteins.

Most PFAS are not broken down by the body. In fact, when some PFAS are metabolized they simply turn into another type of PFAS. The body gets rid of PFAS mainly through urine, but the kidneys can also reabsorb some PFAS, which makes them stay in the body longer. Depending on the type, PFAS can stay in the body for anywhere from about a week to more than eight years. For some people, especially those who menstruate, are pregnant or are breastfeeding, PFAS may leave the body more quickly. There is also some evidence that dialysis can help reduce PFAS levels in the body.

Growing Concerns

Concerns about PFAS began in the 1970s when the chemicals were first found in the blood of workers who handled them. In the 1990s, researchers began studying the health effects of PFAS in lab animals like rats and mice. By 1998, 3M provided evidence to the Environmental Protection Agency that PFAS were also found in the blood of people who were not exposed at work, likely because of widespread use in consumer products and industries.

Research from both lab and human studies shows that PFAS may cause health problems even when there are very low levels in the blood — lower than many other harmful chemicals. Recently, the National Academies of Sciences, Engineering and Medicine, or NASEM, (Guidance on PFAS Exposure, Testing, and Clinical Follow-Up; 2022) and the Agency for Toxic Substances and Disease Registry, or ATSDR, (PFAS Information for Clinicians; 2024) released information for clinicians on PFAS summarizing the health effect associations seen in the epidemiological data.

Both organizations found evidence of an association with:

• Increases in cholesterol levels
• Small decrease in birth weight
• Lower antibody response to some vaccines in children
• Renal cell carcinoma

ATSDR found evidence of an association with, and NASEM found limited/suggestive evidence for:

• Testicular cancer
• Pregnancy-induced hypertension or preeclampsia
• Changes in liver enzymes
• 
  

ATSDR found no consistent evidence of an association, and NASEM found limited/suggestive evidence for:

• Thyroid disease and dysfunction
• Breast cancer
• Ulcerative colitis

Some of these associations were found only with specific PFAS. For example, kidney and testicular cancer were associated only with PFOA.

PFAS may cause health problems even when there are very low levels in the blood.

Talking to Your Patients

It’s pivotal to convey what is and is not possible with the knowledge we have today. It’s also important to approach a patient’s concerns with compassion and empathy. When talking with a patient when there’s uncertainty here are some thoughts to keep in mind:



• Focus on their emotional needs and actively listen.
• Use clear, simple language; validate their feelings; and offer reassurance where you can.
• Emphasize your commitment to their care and support.
• Let them know that Minnesota is actively working to reduce PFAS exposures. 

There are no FDA-approved treatments to remove PFAS from the body. While we cannot erase past exposure, patients can take meaningful steps to reduce future exposure and improve their overall health.

Reassure your patients that PFAS likely contribute only a small amount to overall health risks, except in cases where people have a high level of exposure over a long period of time. This additive effect can be similar to other uncertain environmental exposures such as air pollution, microplastics or other industrial chemicals.

Clinicians Have a Critical Role

As a trusted source of health information, you play a key role in helping patients understand their risk and take steps toward safer living. Some thoughts to keep on mind include:

• PFAS are everywhere, but exposures vary.
• Exposure reduction is the best available intervention.

You don’t need to have all the answers — point patients to credible resources and support their broader health goals.

While PFAS are a health concern, people can usually do more for their health by focusing on known risks and keeping up with regular checkups and preventive screenings with their doctor.

Blood Testing for PFAS

There are blood tests that can tell us about the amount of PFAS in a patient’s blood. The results, however, have some important limitations. PFAS testing is not a routine clinical test, meaning insurance may not cover the cost.

Blood testing shows the amount of PFAS in your patient’s blood at the time of the test. It does not show how levels have changed over time, how your patient was exposed or what their current exposure is. Most labs test only for a small number of the thousands of different types of these chemicals.

At this time, PFAS blood testing cannot diagnose or predict illness or disease. Many health issues associated with PFAS, such as increased cholesterol and decreased thyroid hormone levels, are common. These health issues can be caused by many factors, and there is currently no way to know or predict if PFAS exposure has or will cause a health problem.

Reducing Exposure

The best advice a physician can provide is simple, clear guidance on what their patients can do to minimize their exposure to PFAS.

Avoid PFAS-containing consumer products

There are many labels and certifications for products made without PFAS, such as “PFAS-free,” “PFOA-free,” “PFOS-free,” or “fluorine-free.” These labels, however, may still allow small amounts of PFAS, and not all products are labeled. Products of this type include:

• Food packaging (microwave popcorn bags, fast food wrappers, pizza boxes)
• Nonstick cookware (use stainless steel or cast iron instead)
• Stain- and water-resistant clothing, carpets and upholstery
• Some personal care products (shampoo, dental floss, cosmetics)
• Some cleaning products, paints and sealants.

Also, PFAS can accumulate in fish. Direct patients to the Minnesota Department of Health’s Fish Consumption Guidance, especially for local waterbodies.

Know Your Water

The Minnesota Department of Health and the Minnesota Pollution Control Agency have online resources that monitor public water systems and track known sources of PFAS contamination. Patients on private wells may want to test if they live near a known contamination site. These resources include:

• MPCA Minnesota Groundwater Contamination Atlas
• MPCA What’s in My Neighborhood
• MDH Interactive Dashboard for PFAS Testing in Drinking Water
• MDH PFAS and Private Wells

Ongoing Work

In the East Metro, public health action is still underway. Many cities have constructed large water treatment facilities to remove PFAS from drinking water, and biomonitoring studies show that PFAS levels in people’s blood have gone down. Many private well owners in areas affected by the PFAS plume have received in-home granular activated carbon filter systems to reduce their exposure. This work continues as we learn more about how far the PFAS contamination has spread and how these chemicals affect health.

One thing is now clear. PFAS exposure is a potential health risk for everyone, not just for those who live near manufacturing and waste sites. For most people outside highly contaminated areas, drinking water isn’t the main source of exposure. PFAS are found in many everyday products, which means nearly everyone has been exposed in some way. Fortunately for Minnesotans, Amara’s Law is a great step toward reducing everyone’s exposure.

This article’s purpose is to give clinicians a foundation for understanding PFAS and tools to help guide patient conversations. While reducing exposure is important, the most helpful message clinicians can share is to encourage healthy habits. Many of the health issues linked with PFAS, such as high cholesterol, liver enzyme changes, pregnancy complications such as preeclampsia, and various types of cancer, are also associated with lifestyle factors, genetics and other environmental exposures. For example, obesity is a major risk factor for several of these same conditions.

Whether answering patient questions, interpreting uncertain risks or guiding people through potential exposure concerns, physicians play a central role in helping reduce risk from these persistent environmental concerns.

Learn more online about PFAS at the Minnesota Department of Health Per- and Polyfluoroalkyl Substances (PFAS) website.

Alexander Bogdan, PhD, is an epidemiologist and principal toxicologist in the Environmental Surveillance and Assessment section of the Minnesota Department of Health.

Mohamed Mohamed, MD studies, studies occupational and environmental health. He is collaborating with the Minnesota Department of Health on PFAS exposure and communication strategies for physicians.