In 1992, Sandy Wynn-Stelt and her husband Joel bought a house they loved in a wooded area near Grand Rapids, Michigan. Twenty-four years later, Joel abruptly died of liver cancer; the year after that, state authorities knocked on Sandy’s door to ask if they could test the private well that supplied her home’s drinking water.

That water, it turned out, had 38,000 parts per trillion of per- and polyfluoroalkyl substances, otherwise known as PFAS. And the results were even higher on repeat testing. The chemicals had leached into her and her neighbors’ wells from the surrounding aquifer, into which the Wolverine Worldwide shoe company had been dumping its tannery waste for years.

The attorney Wynn-Stelt hired suggested she get her blood checked for PFAS, and when her stratospherically high levels came back, “everybody’s jaw hit the floor,” she says.

Her doctor, initially flummoxed, knew of a study that had found high cancer and disease risks in thousands exposed to PFAS over the course of a half-century near a West Virginia DuPont plant (an event that received renewed attention after the 2019 release of the film Dark Waters). Soon after, Wynn-Stelt was diagnosed with thyroid cancer — a very treatable condition with an excellent prognosis, but still a shock.

Wynn-Stelt feels lucky her doctor took her seriously and responded proactively. She’s since helped create a medical education video aimed at clinicians, but realizes many patients and providers still struggle to find a way forward when PFAS exposure is on the list of health concerns. “How do we get doctors to pay attention to that along with the 3,000 other things?” she says.

PFAS isn’t just one chemical, but thousands of different chemicals used in a range of industrial processes, many of which involve making products slick, nonstick, or waterproof. Unlike some other synthetic chemicals, they’re extraordinarily hard to break apart: They degrade especially slowly in the environment and in human bodies, leading to the moniker “forever chemicals.”

For decades, companies dumped PFAS directly into the natural environment, including rivers and aquifers, contaminating drinking water in many parts of the US. Additionally, consumer products shed the chemicals onto surfaces in our homes and into the food we eat. As a consequence, experts believe most people have some quantity of PFAS in their bodies.

In early April, the Environmental Protection Agency set the first national limits for six PFAS chemicals in drinking water; water purveyors will have five years to comply. While that’s an important step, it doesn’t address the broader problem of the US’s broken policy regulating the chemical industry’s safety practices — policies made even more favorable to industry under the Trump administration.

“The number of PFAS that are going out into our environment under the aegis of trade secrecy is very substantial,” says Alan Ducatman, a retired physician who led several PFAS research projects at West Virginia University and now consults for consumer health advocacy groups.

In a world where our environment’s safety is so closely tethered to capitalist interests, understanding how to manage and make decisions about environmental risks rests on patients and providers — even though it shouldn’t. Here’s what you need to know about assessing your PFAS exposure risk, getting tested, and working with a health care provider to find a way forward.

Do I need to worry about PFAS?

High PFAS levels are associated with a range of health problems, including high cholesterol, some cancers, and immune system disorders; some health consequences linked with the chemicals also appear to be present with low blood PFAS levels.

While their health risks are concerning — and scientists still have a lot to learn about them — it can be helpful to think of PFAS in the context of some other common toxins, says Ducatman. If you had “the choice between smoking a pack [of cigarettes] a day or being in one of those high-PFAS populations,” he says, “high-PFAS population is way safer.” However, health-minded people can avoid cigarettes, while they don’t have the option of not drinking water — and the more experts understand about PFAS’s links to human disease, the more concerned they get.

A reasonable first step toward understanding your own PFAS risk is looking into the safety of your drinking water over the years and reviewing your employment history. That’s because people with high PFAS levels typically get them either by drinking contaminated water on a frequent basis or through extended on-the-job exposure, said Jamie DeWitt, a PFAS researcher who directs Oregon State University’s Environmental Health Sciences Center.

It’s not as straightforward as it should be to get information about the PFAS levels in your drinking water. The Environmental Working Group maintains a map of tap water levels from all over the US, but its data is far from complete — for example, no data from New York City is included.

Several experts told me that for people in metropolitan areas, the best way to get information about your local water source is by contacting your water purveyor directly. Your mileage may vary: Although my local paper reported recent monitoring (mandated by the Unregulated Contaminant Monitoring Rule of the Safe Drinking Water Act) showed PFAS in Atlanta drinking water, details were not readily available from the Atlanta Department of Watershed Management on the website or over the phone.

Smaller water utilities not covered by that rule might not gather this data, and if you get your water from a private well, you’d need to get it tested to know if its water contains PFAS, says DeWitt.

“If you’re exposed to less than four parts per trillion” — the level set by the EPA in the latest regulations — “you can generally anticipate that your health risks are relatively low. Not nonexistent, but relatively low,” DeWitt says. People whose drinking water has higher levels and hasn’t been filtered (more on that later) may be at increased risk.

When it comes to assessing your occupational risk, you can start with the PFAS exposure history on the US Agency for Toxic Substances and Disease Registry website. At highest risk are people who work in facilities that produce PFAS chemicals, and people whose jobs use products that contain lots of PFAS, including firefighters, carpet installers, ski waxers, and people in hospitality who handle a lot of food packaging.

You can also ask your doctor to help you assess your risk. Even if they don’t have expertise in environmental health, lots of information and training is available to get them up to speed: Several experts recommended the resources on the clinician section of the PFAS REACH (Research, Education, and Action for Community Health) website, and the lengthy but well-organized document published by the National Academies of Sciences, Engineering, and Medicine (NASEM).

What does PFAS testing look like?

If you or your provider determines you’re likely to have been exposed to a relatively high amount of PFAS, the next step is getting your levels tested. Insurance companies don’t typically cover these tests, and it costs between $300 and $500 out of pocket.

Although tests aren’t done by most hospital labs, Quest Diagnostics recently began offering a PFAS test. Usually, the test is done on blood obtained through a routine blood draw, although some tests can also be conducted on urine.

Ducatman cautions that testing is somewhat limited in what it can tell you. “What people want to know is two things: ‘What’s my PFAS levels,’” he says, “and ‘What are my risks from that,’ which the test doesn’t interpret for you.” That’s partly because the levels testing labs define as normal are sometimes based on old data — and partly because the industries that produce PFAS are constantly creating chemicals to replace the ones restricted by regulation, he said.

To explain what makes PFAS testing so complicated, says Courtney Carignan, an environmental exposure scientist at Michigan State University, it’s worth comparing the chemicals to another well-described environmental toxin: lead. It’s much simpler to identify in the environment and in people, partly because it’s just one substance. “The thing that makes PFAS more difficult is that there’s so many of them,” she says, “so we are playing this whack-a-mole game.”

While commercially available PFAS tests might not yield data on all of the thousands of PFAS chemicals that could be in a person’s body, it’s still a reasonable place to start when it comes to understanding the individual risk of health outcomes related to these chemicals.

How can I minimize the negative consequences of high PFAS levels?

When a patient comes to a health care provider with abnormal results from a PFAS test, there’s a non-zero chance they’ll get a blank stare. “That’s the way health care practitioners are educated — toxicology is just a really small piece of their education,” says DeWitt.

Again, patients can point their providers to resources published by PFAS REACH and NASEM to help guide the way forward. These organizations differ slightly in their approaches to medical monitoring for PFAS effects, but both recommend that people with high blood levels of the chemicals get blood and urine tests on a regular basis to check for high cholesterol and abnormal liver, kidney, and thyroid function. They also recommend regular urine tests to check for certain kidney conditions, regular screening for testicular cancer and ulcerative colitis (which usually starts with a physical exam and may involve some testing), and screening for breast cancer (which may mean getting more mammograms than otherwise recommended).

Experts also recommend providers speak with patients about the likelihood of PFAS transmission to newborns through pregnancy and breastfeeding, and inform them that high levels of the chemicals may inhibit responses to vaccines.

There’s no Food and Drug Administration-approved treatment to lower PFAS levels.

What everyone can do to prevent PFAS exposure to begin with

Although it’s almost impossible to completely avoid contact with PFAS, you can take some steps to reduce your exposure. Filtering your drinking water can help lower its PFAS levels, whether you do it with the first-line (but pricey) reverse osmosis under-sink filters or the cheaper (but still pretty good) carbon filters in pitchers, sinks, and refrigerators.

It can also help to avoid waterproofing and stain-resistance treatments for carpet and upholstery, and to minimize eating food that’s touched take-out containers and wrapping, whose nonstick surfaces may contain PFAS. Many other consumer products contain these chemicals; referring to a list of PFAS-free products can help consumers make decisions that limit exposure.

Whatever decisions you make, be aware there’s some uncertainty that’s unavoidable when it comes to these extraordinarily common chemicals. Wynn-Stelt tries to minimize her risk but really wants to see industry take more responsibility for reducing consumers’ exposure, both by reducing PFAS use and clearly labeling products that contain the chemicals. “Knowledge is power,” she says, “and consumers really can drive the economy.”