A practical guide to PFAS – what to know and how to reduce exposure at home

PFAS, short for per- and polyfluoroalkyl substances, turn up in rain jackets, nonstick pans, stain-resistant furniture, food packaging, and, in many places, drinking water. These "forever chemicals" have been part of everyday life for decades and have been detected in the blood of nearly everyone tested for them.

Exposure has been linked to cancer and a range of other health concerns, according to the United Nations Environment Programme.

The University of Arizona hosted the National PFAS Conference in Tucson last week, drawing researchers, government staff and affected communities from across the country. Melissa Furlong, an assistant professor at the College of Public Health, studies what PFAS do once they are in the body, work that includes a close look at firefighters, who carry some of the highest levels. She spoke with Lo Que Pasa about what these chemicals are, where they go once they are inside us and how best to reduce exposures to PFAS.

PFAS are called "forever chemicals." Is that about their molecular structure?

Their structure plays a part, but the name comes from how long they last. Most modern chemicals get metabolized fairly quickly, or they break down in the environment over time. PFAS don't. They can persist in the environment for an immeasurable amount of time, and in the body for years.

For the average person, not a firefighter, not living near a contamination site, how does PFAS get into the body?

It depends on how you're exposed, but for the general population, a lot of it has historically come through the water supply. Some comes through food, including food packaging, and possibly the food itself, though that's more unclear. Beyond that, PFAS are simply all around us. Because they resist oil, water and heat, they're used in a lot of products. They're used to waterproof clothing, for example, and to make furniture stain-resistant. So everyday products are a genuine route of exposure, well beyond the dramatic contamination cases people tend to picture.

What are some at-home tips for minimizing PFAS exposure?

One of the biggest sources is via drinking water. Many municipal providers have started treating water for PFAS, but if you are on well water, it would be worth getting it tested for PFAS or installing a water filter. The EPA is considering rolling back new regulations on PFAS in water, so if you are on municipal water and the regulations get rolled back, it would probably also be worth getting a water filter.  It is very important to regularly maintain your filters and change them on a scheduled basis, or contaminants can build up over time. Also, I'd avoid treating furniture with water- or oil-repellant treatments. You can minimize or stop using Teflon-coated pans, especially those with scratches. The other major thing you can do is vacuuming and dusting your home regularly as it can help keep PFAS out of your environment.

Image

When people hear "PFAS is linked to cancer," they tend to picture acute poisoning. What's the exact link between the two?

It's a different kind of risk. Most people think of poisoning as exposure to extremely high levels of a compound, with acute and rapid effects. With PFAS, lower amounts build up over years, and any effects can take a long time to surface. Most people with very high PFAS exposures don't realize it. Most of what we know comes from studies of people who lived near industrial sites with badly contaminated water. Findings from those populations are backed by studies in animals and cells. However, there are health effects that may occur in communities with lower levels of PFAS also. In 2023, an expert panel convened by the World Health Organization reviewed two of the oldest and most-studied compounds in the family, PFOA and PFOS, and classified PFOA as a human carcinogen, with the clearest links to kidney and testicular cancer, and PFOS as a possible carcinogen.

What's the biggest open question in PFAS science right now?

There are two. The first is the replacements. We've done a reasonable job evaluating the health effects of the legacy PFAS that have been around a while. But as those get pulled from the market, new substitute chemicals come in to take their place, because we still want things to be water- and oil-resistant. Those substitutes are largely untested. Often, we don't even know exactly what they are, they can be hard to measure in the body, they tend to have shorter half-lives, and we don't yet know what they do to health.

The second is everything beyond cancer. People are now running studies in pregnant women and in older, more vulnerable populations. We've focused a lot on cancer, but what about neurological effects? What about autoimmunity and the immune system? We're starting to see signals in our molecular signatures that point in those directions, with only limited epidemiological evidence so far, because we've only just started a lot of this work.