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Kimberly Garrett: Rainwater all over the globe has had detectable PFAS levels, tissue in arctic mammals, Arctic fish places where arguably there's no source of PFAS anywhere nearby
Chai: per and PLU rockle substances, better known as forever. Chemicals were invented in the early 19 hundreds to make things non-stick and water resistant,
Micah: but decades of use left us with a problem.
These chemicals don't break down, and now we're only beginning to grasp their serious risks to our health and the environment.
Alissa Cordner: The more PAS are out there, the greater everyone's risk of these associated health outcomes will be. Now, does that mean that everyone is going to get kidney cancer? No, but it means that.
Everyone who has PFAS exposure will have a higher risk of getting kidney cancer than they would have otherwise.
Micah: In this episode, we dig into the complex world of PFAS. We'll break down what they are, explore the alternatives, and learn about the research program that's helping communities understand their impact.
I'm Chai Nussbaumer. And I'm Micah Schweitzer. This is Balancing the Future from METTLER TOLEDO.
Chai: On this show, we delve into the world of science and technology and explore its transformative impact on our lives.
Micah: What are PFAS and why are they referred to as forever Chemicals? Maybe the person to start this off would be Kimberly Garrettberly as the chemist here.
Kimberly Garrett: PFAS or Per and Polyflor al Substances, uh, refers to a broad range of chemicals that are characterized by their environmental persistence and their use in industrial products that we want to be very persistent.
Micah: That's the voice of Dr. Kimberly Garrettberly Garrett. She's an assistant professor and environmental health researcher at the City University of New York.
Kimberly Garrett: They're also characterized by something that we call Amity, which means that they repel both oil and water, which is a really unique characteristic and. The kind of chemical, uh, structure that gives them this persistence and this resistance is the carbon fluorine bond.
And so this is one of the strongest bonds that we have in chemistry, and it is very, very hard to break. So we're not necessarily thinking of something that will break down in the sun through lysis or breakdown with just kind of environmental oxidation processes. It's something that takes a lot of, uh, in many cases, intentional energy application.
To break. And so we can see how that is very useful for products that we want to be, you know, waterproof or non-reactive or chemical resistant. But that also means that they take those properties out into the environment, uh, and they last a very, very long time and can be taken through environmental processes and cycles, like the water cycle.
For example, we found PFAS in rainwater very far from any source of PFAS. So we know that they kind of travel around the globe.
Micah: And how many types of these chemicals are there? I
Alissa Cordner: think the question of how many PFAS there are is a really interesting one because depending on where you draw the boundaries chemically or where you draw the boundaries, in terms of broad categories of PFAS or even types of uses.
Chai: And that's the voice of Dr. Alissa Corder. She's a professor of sociology at Whitman College and the co-director of the PFAS Project Lab. We'll come back to what that project's all about a little later.
Alissa Cordner: So the number of PFAS that our lab refers to is an A-U-S-E-P-A count that has consistently increased over the last, uh, at least the last decade that we've been tracking it.
And at this point, it's actually over 14,000 individual PFAS in this computational toxicology database. There are other ways you can count the number of PFAS where you end up with really different numbers, some much lower. There are other chemistry based definitions that rely on different understandings of that carbon fluorine bond that might get you counts actually over a million PFAS.
And so depending on how you're defining this chemical class, you end up with really different numbers. All of that said, though it is reasonable to talk about something like 15,000 PFAS that we might be interested in as scientists, as regulators, or as people wanting to do something about, uh, PFAS as a broad chemical class,
Micah: isn't the volume indicative of how useful these chemicals are?
Alissa Cordner: It is indicative of, of their utility in terms of their chemical functionality. But I think it's also indicative of the complexity of chemistries. There's a distinction between an individual compound that say a producer might be intentionally manufacturing and all of the other chemicals that might be produced inadvertently or knowingly as byproducts as.
Intermediate steps in that chemical transformation process. And so when we think about PFAS as a class, it's important not just to think about one individual compound that might be well studied and well recognized because it is the intentional. Outcome of very, very complex chemical transformations, but also to think about the full life cycle of producing and using that individual chemical.
Because what we have seen with studies that actually try to track. The full PFAS pathway is you end up with a lot of other chemicals produced as intermediaries, produced as transformation byproducts produced as breakdown products. So, so yes to the utility, but it, uh, it also is a little more complicated.
Kimberly Garrett: Um, I would agree that I think that the number of compounds that are potentially in use speaks to the. Reliance on these chemicals by all different kinds of industries and manufacturers. Um, but it doesn't mean that they're always absolutely essential in their use. Um, there's been a long history of these chemicals being developed and used, and Im into the environment with no pushback and very little safety testing, or at least published safety testing.
And so there hasn't been really a burden put onto manufacturers too. Test for safer alternatives or anything until fairly recently. And so I don't know if it's a product of these are just absolutely magical chemicals that do all of these things that no other chemical could do, so that the burden of, of finding alternatives and other chemicals has not been there.
Chai: So what could replace P FFAs? It depends on the industry, but there are some real alternatives already out there.
Micah: Take food. Packaging companies are starting to experiment with bioplastics. These are plant-based materials designed to do the same job without sticking around in your body or the environment forever.
Chai: If you'd like to hear more, we have an episode all about Bioplastics linked in the show notes.
Micah: Firefighting foams are another area where PFAS was used for decades. But during the 2025 Toronto airport crash, the first ever fluoride free foam was put to the test and it worked. So at
Chai: least in some areas, a step-by-step shift is happening.
Micah: Of course, the reason we're even talking about alternatives is at least partly due to the health risks associated with PFAS exposure.
Kimberly Garrett: Some of the main ones that we see are kidney and testicular cancer, as well as dyslipidemia and the way that your body handles and stores fats. The list grows as we learn more and more about different chemicals.
Uh, we're finding evidence that PFAS can be endocrine disruptors and are associated with other types of cancers as well as liver disease. The National Academy of Sciences. Engineering and medicine issued a report in 2022 looking at human health exposure data to PFAS, so looking only at human health data.
And they found, uh, strong associations between PFAS exposure and four different health conditions. So decreased antibody response, uh, dyslipidemia, decreased infant and fetal growth, and increased risk of kidney cancer. And so those were the strongest associations, but not the only associations that they found.
Alissa Cordner: A lot of the focus has been on individual PFAS, but there are very strong arguments for thinking about the health impacts of the chemical class overall, not just the small number of chemicals that are well characterized in terms of toxicity. The other thing though is that PFAS are a class of chemicals that.
As Dr. Garrett was just mentioning, target a broad range of organ systems. So this isn't a class of chemicals where we're thinking about one discrete health outcome or even targeting one or two organ systems. We're talking about looking at health effects across many different organ systems in the human body and also across the lifecycle from fetal development all the way through full adult life health impacts.
Micah: And where are we getting exposed to these PFAS?
Kimberly Garrett: We've been exposed for a very long time, and we are just now starting to understand that a lot of our exposure to PFAS comes through drinking water Again. When it comes from those environmental sources, everything flows downstream into drinking water and uh, that's where a lot of.
Public health research is focused right now, but we also wanna take a look at the upstream sources. So in our homes there are PFAS in much of our outdoor equipment, furniture, carpets, uh, any of those kinda waterproofing sprays, we're often not aware of the exposure because. Our products aren't necessarily labeled saying they have PFAS in them, but we're also exposed through things like waterproof mascara and cosmetics.
And something that I see in the news almost every week is PFAS found in certain products. And it just speaks to the ubiquity of these chemicals in our manufacturing and our, our product systems.
Micah: So we can have them around us, we can ingest them, we can have them on ourselves. They're ubiquitous.
Kimberly Garrett: Yes. Yeah.
Um, some other categories that I forgot to mention are, uh, food packaging as well as, uh, occupational exposure, not just in, you know, places that manufacture products that, that have PFAS or the PFAS chemicals themselves, but also in firefighting, uh, PFAS because of their low reactivity. So they, um, kind of snuff out the fire by creating a non-reactive layer, uh, over the fire, and they've been used.
For decades as well as we're finding PFAS in the uniforms and the turnout gear for firefighters.
Alissa Cordner: There's also a lot of concern about PFAS exposure through the food system, and that can happen through contaminated water used to irrigate crops. It can happen when. The sludge left behind after the wastewater treatment plants process wastewater.
When that sludge is applied to agricultural land, it can happen through air deposition from nearby facilities. Uh, and all of those pathways can lead food supplies to have varying levels of PFAS, which then can be a major exposure source for for people.
Micah: And how widespread is PFAS contamination globally and are there areas where it's more concentrated?
Kimberly Garrett: As far as we can tell, it's everywhere. I've been really struck by the, uh, scope of different environmental media that we have studied and tested for PFAS. As I mentioned earlier, rainwater all over the globe had detectable PFAS levels. Tissue in arctic mammals, Arctic fish, you know, places where arguably there's no source of PFAS anywhere nearby.
And so we see this on a global scale nearly everywhere. Uh, and on a, a smaller, I guess, more continent or country scale. Uh, in the United States, we've done several representative studies of blood serum and found that over 97% of blood samples from Americans contain PFAS chemicals.
Chai: PFAS were invented less than a century ago, and yet they've already spread around the globe.
For decades, the public had no idea forever. Chemicals were even out there, let alone how harmful they can be.
Micah: But things started to shift in the early two thousands as surge of PFAS. Research took off. The story spread through the media and across the early internet, pushing the issue into the public eye.
Chai: The PAS Project Lab was founded in 2015. Their mission is to study the social, scientific and political dimensions of PFAS. They produce research on the contamination crisis and work with the affected communities.
Alissa Cordner: The primary audience for a lot of our work, we think of as being the communities that are directly impacted by PFAS. Contamination and community can be an actual geophysical place that. Might be impacted by a specific source of PFAS contamination. So we have done direct support work with community groups and community representatives who have questions about what's happening literally in their backyards.
And we're able to use our research and our general understanding of PFAS as well as the sort of resources and privileges that come with our status as university researchers. We can use all of those things to provide information that we hope would be, um, accessible and useful to community groups. We also do a lot of work too.
Take data that is technically available but isn't actually very usable, and to turn that into tools that are publicly accessible. So we have a database of nationwide governance actions in the US that looks at regulatory and legislative actions at the state and federal level related to PFAS. And then we have a couple of databases of known and likely PFAS, contamination sites, known sites.
These are. Actual sources of PFAS contamination, so not necessarily a drinking water detection in a community, but a source of contamination. Could be a military base or an airport that used fluorinated firefighting foam, or a chemical manufacturing plant that. Released PFAS containing waste. So we have, at this point, over 2000 known contamination sites.
And then we have, uh, a similar database and then map of what we call presumptive, PFAS, contamination sites. And these are sites where. In the absence of high quality testing data, we think it's reasonable to proceed as though contamination is very likely because there is a very likely source of PFAS containing waste or firefighting foam or industrial activity.
And those two databases, both of which are publicly available, feed into our PFAS contamination sites and community resources map.
Micah: Now you mentioned the public perception has been growing over the years that the PFAS Project Lab has been in existence. How's the regulatory environment evolving?
Alissa Cordner: There has been a lot of action in the US and some action in other parts of the world. The European Union has a proposal for a really far reaching ban on PFAS.
That, to my knowledge, has not been finalized and is still in that proposal. As we talked about earlier, there are questions about what counts as A-P-F-A-S and one of the big. Question marks in the European Union's proposed. PFAS ban is, what are those exemptions going to be? Which parts of PFAS as a class actually won't be covered by the ban?
So very curious to see what ends up happening when that ban is finalized. Um, here in the US there has been much more action. In the last, say, five years than there was in the previous 40. Some of that action has happened at the federal scale, although until very recently, the US Federal government was lagging behind some of the efforts at the state level, and so some of those things that have happened.
In individual states around the US would be things like a drinking water regulation or drinking water testing standard bans on PFAS, in particular, product categories or labeling or disclosure requirements in product categories, testing initiatives and investigative orders. For example, requiring all landfills to test for PFAS in their lead shade.
Lots of different types of actions, both regulatory things coming out of. Executive branch agencies and legislative bills coming out of the legislative bodies, um, happening at the state levels.
Micah: If the use of PFAS in the future were to be reduced and its prevalence were to decline, there's still the, the fact that this chemical class is called Forever Chemicals.
What about all the PFAS that are already in human bodies, in environmental systems and so on,
Kimberly Garrett: right? So that's exactly why we need to turn off the tap. Now, PFAS have been used. Since the 1940s in various forms, and that means that we have a lot of cleaning up to do. And so part of my work, identifying potential PFAS sources in the environment, I work on that, um, presumptive contamination map that, that Dr.
Cord mentioned, uh, is to see, you know, where is PFAS coming from? Where should we focus our attention? Uh. Be that through, you know, individuals, um, and the products that we consume or, you know, arguably more effectively up the chain of regulation, of journalism, of mostly regulation, right? Where should we focus our attention because they are everywhere in our environment.
And so something that's really essential is to turn off the tap and stop producing. New PFAS chemicals because we already have enough. We already have enough to work with.
Micah: And how do you work with the ones that are already out there?
Kimberly Garrett: There are a variety of destruction mechanisms, and something that I think gets misconstrued is that not every destruction technique works for every PFAS.
So if there are, you know, tens of thousands of PFAS chemicals, some of them. We'll break down with incineration, but a lot of them we're finding are not fully broken down by incineration and instead break down into smaller other PFAS chemicals. They're. Are different ways to treat different environmental media.
So drinking water, reverse osmosis treatment seems to be pretty effective against most PFAS. Chemicals, treatment of soil can be very different. Treatment of products containing PFAS, typically that's gonna be either fil or incineration and landfills. Leak and incinerators, uh, as I mentioned, don't necessarily break down all PFAS,
Micah: but doesn't treating it as a class rely on an agreement on what constitutes A-P-F-A-S.
Kimberly Garrett: Yes, and that is a subject of much debate. The OECD in Europe has one definition, which is fairly conservative. We see even in the United States state by state. Definition of PFAS vary. And we've seen that those definitions have been influenced by PFAS manufacturers to say, oh, well, some of these are PFAS, some aren't.
So just like, you know, the long chain versus the short chain. And we're seeing that overall long versus short chain may have different chemical properties, but not so different that they're not still associated without adverse health outcomes. And this same environmental persistence that's so concerning.
Alissa Cordner: The definition of what counts as A-P-F-A-S has to be a policy decision. There is nothing in the practice of science that says this is A-P-F-A-S, and this isn't it. This inevitably is a policy decision, and the different definitions can be. Based in scientific logic and based in scientific rationale to a lesser or greater extent.
But those definitions still have to be formalized and regulated by responsible parties or by governing bodies. So what could end up happening is that a government system like the European Union or a government, um, of an individual country like the United States says, here is the definition of PFAS, and we will take.
This suite of regulatory actions on all compounds that fall within this chemical class
Chai: in the us. The go-to definition of PFAS is simple. Any chemical with at least one fully fluorinated carbon atom, easy to say, easy to understand, and broad enough to cover a lot more complicated definitions. Tried to catch edge cases, but sometimes they miss dangerous compounds entirely.
Micah: But how do we decide which chemicals to allow and which to ban? That's where policy comes in. One approach is the essential use framework. If PFAS is truly necessary for society and can't be replaced, it stays.
Chai: But if it's non-essential, like carpets, rain jackets, or firefighting foams where safer options already exist, then it's out.
Micah: So what you're describing is, sounds to me like an ideal scenario where a definition is reached and regulatory action is taken based on that definition to look at it from the other angle, I suppose. What if we just continue with business as usual? What are the risks? What are the consequences?
Kimberly Garrett: We'll have continued pollution of with PFAS chemicals business as usual.
We've seen that it is contaminated so much drinking water around even just the United States. We've seen that it's in environmental media all over the globe. We've seen that it's the reason that people can't. Fish or subsistence hunt or gather foods different ways. There limits specifically because of the amount of PFAS contamination.
I do some work with the tribal PFAS working group and um, one of their main concerns is the impact that this has had on their traditional life ways and. The ways that they continue those today, right? Subsistence hunting, fishing, farming. That's one impact that I, I've seen. Same with, you know, its persistence through all of our products.
I've seen headlines about PFOS being found in, you know, like seltzer water, for example. Uh, and people say, oh, why are they adding PF os to seltzer? They're not necessarily, it's because it's in the drinking water, right? So we see this persistence and this, this ubiquity of PFAS, and so that would only increase, right?
Alissa Cordner: I think that, that, that answer is right on it. The more PAS continued to be used, the more PFAS will be. Out in the environment exposing people, exposing wildlife for decades and generations to come. And PFAS appeared to impact human health at extremely small concentrations. The health-based drinking water standards in the US regulate two PFAS per, in particular, at four parts per trillion.
It's a very, a very low concentration, yet that's not even the health-based standard because the health-based level is actually zero parts per trillion because of the cancer causing nature of these individual PAS. So we're talking about the more PFAS are out there, the greater. Everyone's risk of these associated health outcomes will be.
Now, does that mean that everyone is going to get kidney cancer? No, but it means that everyone who has PAS exposure will have a higher risk of getting kidney cancer than they would have otherwise.
Micah: In terms of a timeline for. Finding a common definition and heading towards a, a world with a significantly reduced use of these chemicals. What are you imagining?
Alissa Cordner: There's. Relatively quick. If the European Union's proposed ban on PFAS isn't full of exemptions, that's a huge market that then will be covered by one of these very broad inclusive definitions of lots and lots of PFAS.
There's potential for action to be very quick in the eu, and we do have in the US some state based. Action that is very all encompassing. For example, Maine has what is essentially a ban on all PFAS with various timelines and implementation caveats. Michigan is moving in that direction as well. There could be a tipping point that would get us there relatively quickly, five, 10 years.
Kimberly Garrett: I wanna, uh, highlight that California has been having a lot of success with PFAS regulation and getting it out of, um, certain types of products. They've been trying to get just a general product ban, but that's changed a little bit. But when individual states pass some kind of regulation about PFAS in products, then that impacts the company's whole, right?
The manufacturer's whole process. California being its own kind of. Super economy within the United States has a lot of sway, and we can see the impacts of California having protective legislation move into just the products that are widely available in the us.
Micah: Last question that I wanna ask, maybe briefly from both of you, since you'll have different perspectives on this. What would you say to somebody who's interested in applying their knowledge or entering a career around PFAS research regulation, the kind of work that you're doing?
Kimberly Garrett: First, I would say welcome.
Something that I would say to people of the, the Science in Clinician is to. Remember what brought you into science, and remember that you're part of a community too. How would you feel if you found out that your drinking water had PFOS in it? Right? Because that's unfortunately very likely. I would say just come in with an open mind and be ready to learn, and be ready to use your skills as a scientist to communicate information to people who are genuinely interested and excited to hear about what you have to say.
Alissa Cordner: And from a social science perspective, I would highlight two things. One is the value of working with people across disciplines and across. Communities, whether those are intellectual communities or physical communities, I think there's tremendous value in a social scientist working with a toxicologist and chemist that strengthens all of the work that everyone is doing.
Chai: We've been speaking to Dr. Alyssa Corder and Dr. Kimberly Garrettberly Garrett of the PFAS Project Lab. Micah, what were some of your key takeaways from this conversation?
Micah: Well, first of all, it's hard to ignore the fact that PFAS are being found all around the world, um, even in the tissue of arctic mammals and fish, and the contamination is so widespread despite the fact that PFAS have only been around for about a hundred years.
Chai: But it's really encouraging because there are alternatives out there like the essential firefighting, foam replacements, and even bioplastics. That really offer PFAS free solutions.
Micah: And I also thought it was really interesting to hear about how lab science and sociology can collaborate, um, in an interdisciplinary way to improve public health, which is what we were hearing about in the context of the PFAS project lab.
Chai: This has been balancing the future from Meddler Toledo.
Micah: What questions about science and technology would you like answered in a future episode?
Chai: Let us know by leaving a review or if you listen on Spotify, leave us a message in the comments section
Micah: and be sure to subscribe wherever you get your podcasts.
