Support for NPR and the following message come from the William and Flora Hulett Foundation, investing in creative thinkers and problem solvers who help people, communities, and the planet flourish. More information is available at Hulett.org. You're listening to Shortwave from NPR. A hundred years ago we didn't have non-stick pans, we didn't have Teflon, we didn't have Gore-Tex to make close waterproof, until scientists discovered a special family of chemicals, PFAS. Chemicals that repelled stains and dirt and water and oil that at first seemed like a miracle. So PFAS stands for Per and Polyfloral Alchol Substances. There are at last count over 10,000 different individual types of PFAS. They started to become widespread and industrial use, sometime I think in the 1940s. That's Melissa Furlong. She's an assistant professor of environmental health sciences at the University of Arizona. She's also an environmental epidemiologist, and because PFAS chemicals have all of these useful properties, she says we put them in a lot of different things. Applications that basically need to repel both oil and water. So like if you've got some stain-resistant furniture or stain-resistant carpet, there's a good chance it was treated with PFAS. You might find them on your cooking pans, rain coats, some pesticides. Maybe in your makeup and in you. If you are cooking with a non-stick Teflon pan, it's not like all of it is sticking to the pan. Some of the PFAS is coming off onto the food, and then you're exposed that way. If the PFAS has been applied to your carpet or if it's been applied to your furniture, then all of that sort of sheds into your environment. And once they get into our bodies, they're hard to get rid of. Instead of being excreted like normal environmental toxicants would be it they just get recirculated by the body. Because these chemicals don't break down easily in the environment or in the human body, PFAS are known as forever chemicals. Almost everybody has detectable levels of at least one or two of the different common PFAS species. My exposure is fairly constant, it's everywhere, and it also appears to be pretty toxic. The body of research on PFAS is still growing. We don't totally understand all the effects these chemicals might have on our health. So one place Melissa and her colleagues are looking for answers is in a group that's historically had some of the highest levels of PFAS, firefighters. So today on the show, what PFAS levels in firefighters tell us about these forever chemicals, and how the average person can think about limiting their exposure to them. I'm Regina Barber and you're listening to Shorewave, the science podcast from NPR. This message comes from Wise, the app for international people using money around the globe. You can send, spend, and receive an up to 40 currencies with only a few simple taps. Be smart, get Wise, download the Wise app today or visit Wise.com, tease and seize apply. Support for NPR and the following message come from the William and Flora Hewlett Foundation, investing in creative thinkers and problem solvers who help people, communities, and the planet flourish. More information is available at Hewlett.org. Melissa, you've been looking into like different ways firefighters could have gotten PFAS into their body. Let's start with their occupation. Where are the PFAS coming from on the job? Okay, so that's actually a really hard question. We're not 100% sure where the PFAS are coming from. So there are some things that we suspect firefighters might have increased exposure to. So PFAS is intentionally added to firefighter gear because it has oil repelling, water repelling, and heat repelling properties. So it's a very good protection for firefighters as they're entering the fires. However, there's a possibility, and many people have hypothesized that firefighters might be experiencing increased PFAS exposure directly from their gear. So the gear that's supposed to be protecting them is it actually increasing their PFAS. And then the other source is that PFAS used to be an essential component of a certain type of firefighting foam that was pretty commonly used. Ever since they figured out that maybe PFAS isn't that great for you. They started to phase PFAS out of those foams. They're still in some foams, but they're used a lot less. And we do actually see that firefighters who have a history of using these types of foams have higher levels of PFAS. So we do think that the foams themselves were probably a significant contributor to the PFAS. So there are several different potential sources where firefighters could be exposed. And the only one, the only occupational one were pretty sure is the source are the foams. And in your study, when you're like analyzing how PFAS might be getting into the firefighters, how are you doing that investigation? How are you getting this data? Yes, it's really hard. Ideally, you'd like to be able to follow the firefighters around to all the fires and have a standardized behavioral recorder who records everything. But that's just not possible because we have, there's about 8,000 firefighters in our study. And so we rely for the most part on self-report. So we have a fairly extensive survey. We asked the firefighters to fill it out when they enroll in the survey. We asked them to fill out an annual update. And then sometimes at like high exposure events will come back and get new samples and ask them to fill out more surveys. We also ask department liaisons to fill out surveys about how their stations are structured or whether they provide their firefighters with certain types of access to different hygiene equipment. And then for the PFAS, we just measured in their blood. Got it. We sent it to a lab. And we should say that this paper, it follows a similar paper in Australia where they're looking at levels of these chemicals in firefighters blood. And they found that firefighters that donated plasma and blood had lower levels of PFAS and ones who didn't. And your study is kind of like a start of that work here in the US. So how does this research compare? Yeah. So my colleague Jeff Burgess, who is actually the director of the Firefighter Cancer Cohort Study, and I, we put in an application to try to replicate the Australian study, but also extend it to look at health effects. But when we enrolled all the firefighters, we measured their PFAS and we asked them all of these questions. So we wanted to ask them at baseline if they had a history of plasma blood donation, along with all of these other occupational and lifestyle and behavioral characteristics. And then, and so that's what this paper is. It's not the results of the trial, but it's basically a bunch of information that we got at the very beginning. While we wait to figure out if plasma donation reduces PFAS and has health benefits. And one of the things that we see from the baseline is that people who reported a history of plasma donation had much lower levels of PFAS than people who did not report a history of plasma donation, people who donated a blood, also had lower levels, not as low as the plasma people, but still slightly lower levels. And so that is consistent with what the Australian study saw. And we're hoping that that's what we see at the end of the study. How do you hope all of this research helps firefighters in the future? Yeah. So we're hoping that larger organizations, larger firefighter organizations can take the body of literature, not just from this paper, but that we generate across all of our studies, and that others who do firefighter research can generate to come up with best practices and recommendations. And so there's an initiative called the Clean Cab Initiative that has already been rolled out across a lot of departments. It's not universally adopted across the United States. We hope it will be. And some of the things they encourage is basically, you know, you leave the fire at the scene. So when the fire is over, you do your on-scene decontamination, you rinse, you soap, on-scene, you take your gear off, you put it in a gear bag, you don't ever bring it into the cab. And there are some other components of it, but we're hoping that some of this research can basically help firefighters to protect themselves because we don't want firefighters to get sick. We know that firefighters are at increased risk for cancer, and we're trying to turn that around. And we're also hoping that we can learn some things that will help the general population. Yeah, I was going to say like, if I'm not a firefighter, I know many people aren't, should our listeners be concerned about PFAS levels like in their daily life? Yeah. Everyone should be concerned about their PFAS levels. Wow. Individual people can take a few meaningful steps, but some people take it too far, and it causes a lot of anxiety. And they'll just constantly find new exposures for PFAS, right, or they'll read a new article about microplastics, and it's the anxiety and the stress that can happen or not, they're not beneficial, right? So... Yeah, those are also bad for your health. Those are also bad, yeah, exactly. So mostly we want policymakers and, you know, manufacturers to be worried about the PFAS chemicals, and they should be concerned about how they're going to help reduce PFAS exposure. And then on an individual basis, there are a couple of recommendations. Yeah. Yeah. What are these recommendations? Yes. Yes. So we found that water filtration and bottled water were associated with lower PFAS. And then people who were on a well actually tended to have higher levels of PFAS. Generally, I think a lot of people think that because they're on a well, that it's pure water, it's perfect water, right, because it just comes from the ground, but they don't realize that there's potentially a lot of groundwater contamination that might be happening from, you know, like the paper mill down the road. And so you can test your water for some sort of common contaminants. You can also install a filter. I do think that anybody who's on a well and can afford it and can maintain it should get a filter. I'm on municipal water and I still use a reverse osmosis water filter because, well, the water in Tucson doesn't taste good, first of all. We're going to get we're going to get mail now. But there's also just, you know, there's a lot of chemicals that are flying around and swimming around out there that are not regulated and not tested for. And reverse osmosis is one of the more effective methods of water filtration. Melissa, thank you so much for talking to me about PFAS. I'm a hypochondriac and you actually made me feel slightly better. So thank you so much. You're welcome. It was fun to chat. If you liked this episode, follow us on the NPR app or wherever you get your podcasts. Also, you might want to check out our episode on the EPA rule on forever chemicals in tap water. Or the great Pacific garbage patch linked to those episodes in our show notes. I'm Regina Barber. Thank you for listening to Shorewave from NPR. Support for NPR and the following message come from the William and Flora Hulett Foundation. Investing in creative thinkers and problem solvers who help people, communities and the planet flourish. More information is available at huelett.org.