What Are “Forever Chemicals,” and Can I Avoid Them?

You may have been hearing a lot lately about “forever chemicals,” or PFAS (per- and polyfluoroalkyl substances), so called for their ability to stay in the body and environment for years and resist breakdown.

In this Q&A, Shelley H. Liu, PhD, Associate Professor of Population Health Science and Policy at Mount Sinai, explains what these chemicals are, why they are linked to cancer, and how to reduce your exposure. An expert on PFAS, Dr. Liu researches the wide-ranging health impacts of these chemicals, including identifying disparities in exposure burden across populations.

Shelley H. Liu, PhD

What are forever chemicals?

PFAS are a big class of man-made chemicals that have been around for decades. They are very useful to industry due to their stain- and water-resistant properties. They are used in all kinds of products from consumer products (like nonstick pans, carpeting, and textiles), to food packaging and firefighting foam. Because these chemicals are so widely used, they can be detected in the blood of more than 98 percent of Americans, including people who have not been exposed through their jobs. Because we may be continually exposed at low amounts to PFAS through everyday living, our accumulated exposure over time (such as over decades) to PFAS and other synthetic chemicals is a growing concern for our health and wellbeing.

What is the link between forever chemicals and cancer?

There is a lot of great ongoing research around PFAS and cancer. While emerging findings show concern, there is still a lot we don’t know. For example, there has been some early work showing potential links between PFAS and different types of cancer in what scientists call a “dose-response relationship,” meaning that higher concentrations of PFAS chemicals in the blood are associated with a higher risk of liver cancer or kidney cancer. This means that even if you can’t absolutely remove your exposure to PFAS, doing your best to reduce exposure over time could still be quite helpful. There is also very new research that suggests PFAS might be linked to hormonally-driven cancers, such as breast cancer, depending on whether you’re female or male and also your race and ethnicity. These are early studies right now, and we don’t quite know yet what those links are.

What products are forever chemicals commonly found in?

We don’t know every product that PFAS are in, but we do know some of the major ones. These include products with nonstick and water-resistant properties, such as nonstick pans and nonstick coatings in food packaging, as they are used as grease-proofing agents in fast food wrappers and take-out paperboard containers, as well as stain-resistant fabrics on your couches and carpets. Diet can also be another exposure source. For example, fish, such as freshwater fish, can sometimes be contaminated with PFAS, and there are many communities in the United States, including in New York, that have contaminated public drinking water. This spring, the U.S. Environmental Protection Agency proposed the first-ever enforceable federal-level regulation of PFAS in public drinking water, although this has not finalized yet. Private wells can also be contaminated with PFAS, and are not part of federal-level regulations. Unfortunately, PFAS are a pervasive problem because they are very stable molecules and resist degradation. Some PFAS can be eliminated fairly quickly from the human body, but others can remain for years (for example, three to five years), and they can accumulate in your organs, such as the liver. In the environment, PFAS can also be transported great distances by weather patterns and groundwater, and eventually make their way into public drinking water and food sources.

Who is most at risk?

Scientists are still researching which groups are at higher risk of exposure to PFAS and/or more vulnerable in terms of health impacts. We know that some people are highly exposed to PFAS through their occupation—for example, firefighters have high exposure to PFAS chemicals because PFAS are a major component of firefighting foam. When we think about non-occupational types of exposures, our research has shown that Asian Americans have a higher exposure burden to PFAS than other race/ethnicities, and we are researching why. It may be a combination of diet, consumer product use and immigration history, as PFAS are used and regulated and disposed of differently in other countries. The other way to think about who is at higher risk is to look at groups who already have poorer health or chronic conditions, and understand whether higher PFAS exposure may worsen their disease progression compared to people with a similar disease stage but with lower PFAS exposure. Perhaps their threshold of tolerance to cumulative PFAS exposure could be diminished. These are all ongoing and important research questions.

What are a few specific ways to reduce my exposure to PFAS?

A few ways to reduce your exposure include lowering your PFAS exposure through diet, using stainless steel cookware instead of nonstick when possible, replacing old nonstick cookware that contain coatings that may have worn off over time, and reducing use of paper and paperboard takeout containers. For babies and young children, carpeting may also be an exposure source. Some newer carpets are not treated with PFAS, so consider replacing old carpets with new ones. If your drinking water comes from private wells, it could be helpful to get your water tested for PFAS, and if you discover high PFAS contamination, consider using water filters, installing a reverse osmosis filtration system, which purifies water, or drinking bottled purified water (which is made with reverse osmosis filtration). In general, using water filters is helpful for PFAS and other contaminants, even if you have a public water supply. While it’s hard to eliminate PFAS exposure completely, it can be quite helpful in the long term if you can reduce your exposure. It would be helpful for our governments to regulate PFAS, and while there is some progress on this front, much more work needs to be done.

Is there a way to rid my body of PFAS?

Unfortunately, there are not many ways for your body to expel PFAS. They are extremely stable molecules, which is why they can remain in your body for years. As such, PFAS levels are often higher in older adults because they accumulate over one’s lifetime. However, menstruation, breastfeeding, and childbirth have been shown to be ways that PFAS are expelled from the body, though research shows that mothers can pass them to their babies. That said, there is no way to totally avoid exposure. You can even find PFAS in the Arctic because they get transported everywhere and persist in the environment. Further, PFAS are not the only concern. Over the last few decades, society has exponentially increased the production of all kinds of synthetic chemicals, some of which can eventually make their way into the human body, and we don’t yet know what that means for human health going forward.