ONE Health Live
Examining the issues of importance to animals, humans and the environment to help those across the food production system better understand the issues from a science-based perspective.
ONE Health Live
'Forever chemicals' create supply chain concern
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"Forever chemicals" are not just a headline, they are a supply chain problem. We sit down with Dr Jerry Shurson from the University of Minnesota to trace how PFAS contamination can start in everyday products and industrial uses, then travel through air and drinking water into soil, crops, livestock feed, and the food we rely on.
We break down what PFAS are, why they persist for so long, and why scientists struggle to answer the question everyone asks: “What, if any, level is safe?”
With more than 15,000 PFAS compounds in circulation and limited toxicity data for many of them, setting clear dietary guidelines and food safety thresholds becomes incredibly hard. We also explore the One Health stakes, including the links to neurological issues, reproductive harm, and cancers that researchers have associated with PFAS exposure.
A major theme is the circular bioeconomy. Recycling nutrients through manure, compost, and sewage biosolids can be good for sustainability, but it can also recirculate PFAS back into soils where chemicals can accumulate and enter plants and animal-derived foods like meat, milk, and eggs. We talk through what can actually be done today, from water sampling and filtration options like reverse osmosis and activated carbon to asking manufacturers about PFAS use, and why meaningful progress requires coordinated global action plus stronger research funding and regulation.
If this helped you see PFAS differently, subscribe, share the episode with a friend, and leave a review so more people can find the conversation.
Welcome And Guest Introduction
SPEAKER_00Welcome to One Health Live, where we examine the topics of importance to animals, humans, and the environment. Our goal is to help those across the food production system better understand the issues at hand from a science-based perspective. In One Health Live, we strive to be thought-provoking and fact-based as we bring you the latest in news and insight. I'm Sarah Muirhead, and with me today is Dr. Jerry Shearson of the University of Minnesota's Department of Animal Science. Welcome, Jerry. Thank you for being with us here today.
SPEAKER_01Well, thank you, Sarah. It's great to be here.
What PFAS Are Used For
SPEAKER_00You've been doing some work in the area of sustainability and one health, and specifically looking at what are commonly referred to as forever chemicals and trying to determine their risks to humans, animals, and the environment. But before we dig into that, uh talk with us a little bit about synthetically produced chemicals. What have you been looking at? What have you been working with, and what are you commonly finding?
SPEAKER_01Yeah, these um there's actually more than about 15,000 types of synthetically produced chemicals that are classified as PER and polyfluoroalkyl substances. Now that's kind of a mouthful, so a lot of people abbreviate uh this category of these synthetically produced chemicals as PFAS, or oftentimes they're called forever chemicals. And these chemicals were developed to really do a lot of things, mostly to improve our quality of life without really knowing their unintended consequences on the health of plants and animals, humans, and ecosystems. In fact, PFAS chemicals are used in more than 200 different industrial and consumer product applications. Probably the most commonly referred to application is uh they're a big part of firefighting uh foams used to put out fires. Uh, they're also used as um oil, water, and stain repellents in a lot of the carpets and upholstery and clothing that we use in our daily lives. Uh they're found in household and industrial cleaning products, nonstick cookware that we have in our kitchens, uh, the Teflon coating, for example, paints and varnishes and sealants, cosmetics, shampoos, lotions, dental floss, food packaging, including fast food containers, pizza boxes, candy wrappers. And I think by now you're getting the idea that the list goes on and on.
SPEAKER_00Sounds like they're everywhere. So, but but why should why should we care?
SPEAKER_01Well, because there are so many different types of these PFAS chemicals, and they're used in so many products that we're exposed to every day in our daily lives. Uh, they're virtually in all parts of our environment, including the air that we breathe, our drinking water, and the food that we eat. And these PFAS chemicals are not only widely distributed in all ecosystems around the world, but they got their nickname forever chemicals, because they don't break down in the environment. And as a result, they accumulate in soil and water, plants and animals and ecosystems and our food supply. And these PFAS chemicals are also very mobile, so they're constantly spread from one location to another. And as a result of this constant exposure to these chemicals that are found everywhere, we, along with plants and animals, are contaminated with them. And they have been found in every organ, tissue, and physiological system in the human body. And they have been shown to be associated with numerous adverse health effects, including brain and neurological dysfunction, things such as Parkinson's and Alzheimer dementia, cerebral palsy, stroke, behavioral disorders, along with reproductive problems such as miscarriages, premature births, um, infertility, and they've been associated with various types of cancer such as liver, breast, testicular, and kidney cancer. And what's also quite amazing, I think, is that uh these compounds can even be genetically transferred from adults to their their children, next subsequent generations of people.
SPEAKER_00We hear a lot about a circular bioeconomy and food system where recycling and reuse happens. Do you do these types of systems increase the health risk associated with these forever chemicals?
SPEAKER_01Yeah, I I mean I think it's abundantly clear that we urgently need to evolve uh our current system into a more of a circular bioeconomy and food system uh to take the enormous pressure we're putting on our our take off some of the enormous pressure that we're putting on our finite natural resources and start recycling them for continued use while moving away from our what I often refer to as our current take, make, consume, dispose, and pollute uh economic model. And you know, we've we've got a long way to go in in creating a fully functional circular economy because current estimates indicate that uh globally uh we're only about seven seven percent circular. So as we continue to move toward this goal of creating a more circular food system and and create you know create or achieve the many benefits of doing so, we also need to be aware and carefully think about the trade-offs and the unintended consequences that can occur. So, in a circular economy, we recycle materials such as manure produced from livestock farms, compost from municipal waste, and biosolids from sewage treatment plants as nutrient sources for agricultural soil applications. Now, PFAS are found in all of these different waste streams and they don't break down, which means that these nutrient sources, as they're applied to soil, uh PFAS accumulates over time and it can adversely affect soil health, and uh they're readily absorbed and affect plant and animal and human health. So the the human health risks actually increase from direct exposure to PFAS from inhalation and of contaminated air, uh consumption of contaminated food and drinking water, and uh even through physical skin contact.
SPEAKER_00You mentioned plants, uh so what you're saying then are plant-derived foods then can be a significant source in some cases of PFAS.
SPEAKER_01Yes, there's no question that plants and plant-derived foods are a significant source of PFAS. Plants become contaminated through exposure of contaminated air, water, and soil. And uh a limited number of studies have been conducted to determine concentrations and distribution of the different types of PFAS chemicals. And remember, there's over 15,000 types of these things floating around in our environment, and they've been trying to identify locations within plants such as roots and stems, leaves, fruit, and heads produced under various conditions around the world. And what it looks like at this point, and there's a lot more work that needs to be done, is that the plant shoots are the main parts of the plants that accumulate PFAS compared with some of the edible portions. But again, it depends a little bit on the specific type of PFAS compound and the type of plant. Uh increasing PFAS concentrations have been found from everywhere from the roots to the above-ground edible parts of certain types of plants. And so far, we know that all types of fruits and vegetables and other plants do have the capability of absorbing and accumulating various types of PFAS chemicals uh in various parts of these plants, which uh again occur from atmospheric deposition, and especially when they're grown on soils that are amended with sewage uh biosolids, which I mentioned earlier are particularly high in PFAS concentrations, and and also when they're raised in conditions from uh contaminated irrigation water. Uh the geographic location and the the closeness to the proximity of where PFAS production is taking place from various industries are some of the main factors that determine the likelihood of consuming food with high concentrations of PFAS.
From Feed To Meat Milk Eggs
SPEAKER_00So then for livestock that would be consuming the grass, the grain, is the result that the meat, milk, eggs perhaps could be contaminated with PFAS and putting human health at risk?
SPEAKER_01Yeah, I mean, similar to what I just mentioned with what we know about contamination of plants, especially fruits and vegetables, uh uh there's been a limited number of studies conducted to determine the types and concentrations of PFAS in grains such as corn, wheat, oats, canola, for example, are a few of those that have been targeted in some of these studies. And as well as different types of plant biomass, the forages that are fed and used as bedding for livestock. And so, as we might expect, there are large differences in PFAS concentrations among plant species, but there's generally a greater accumulation of PFAS in the vegetative portions of plants, especially the stems or the straw, uh, compared with the grains portion. However, the the main determinant of PFAS concentrations in grains and forages is what the concentration is in the soils where they're grown. Um, I'm thinking of a study that I quoted or mentioned in this paper that we published uh some time ago, where research results have shown that applying sewage biosolids to soil used to grow soybeans, for example, resulted in a dramatic uptake of PFAS in the soybeans. And uh other studies have documented that sewage biosolids contain, again, high concentrations of PFAS. And so when we apply those continuously to the same cropland over time, uh they accumulate and increase the concentrations in the grass and the crops that are grown on that soil. And so when livestock and poultry consume PFAS contaminated grains and forages, uh they end up producing meat, milk, and eggs that are also contaminated with PFAS. So it's it's just an ongoing chain of events here of passing it from uh one location in our food system on to the other. And and this is important to know, I think, because food is the primary route of human exposure to PFAS, especially uh from contaminated animal-derived foods. In fact, uh most of the studies that have been published up to this point have shown that fish and and seafood uh generally have the greatest concentrations of PFAS among all types of foods. Uh, but some sources of meat, milk, and eggs contain concentrations of these forever chemicals that are comparable to those that are found in fish and seafood. So uh as we learn more, uh we know that you know animal-derived foods generally have greater concentrations than plant-derived foods, but um at the same time, there are some analytical challenges to quantify these compounds and foods and and animal feed, which does make it a little bit difficult to establish advisory uh human health dietary guidelines of maximum tolerable levels of of PFAS consumptions in in our food.
SPEAKER_00So we really don't know if there is a safe level of PFAS exposure for for humans or or animals? Is there something that uh or even what should be avoided when it comes to what we consume? It sounds like that's still something that uh needs to be looked at in more depth.
SPEAKER_01Yeah, the I mean the the simple answers to your questions are no and no. There is no safe level of PFAS, and it's impossible to avoid uh all consumption of food, water, and consumer products because these chemicals are everywhere. Uh the science to evaluate the toxicology effects of PFAS on humans and animals, uh, you know, it's continuing to emerge. We're in the early stages, but there are many challenges for conducting uh safety risk assessments, which are further compounded by you know several practical, political, social, economic, and scientific types of challenges in developing uh and implementing regulations. Uh, for example, I'm thinking about results of one study that showed that 68 different PFAS compounds were detected in food contact materials, but toxicity data are only available for about half of those compounds found in food packaging. So there are a lot of unknowns. Um we also know that you know regions like the European Union, uh, our neighbors to the north and Canada have developed probably the strictest regulations aimed at reducing and controlling and prohibiting the production and use of some types of these chemicals. And in the EU, uh, they've also established an analytical reference laboratory with some guidelines on estimating maximum possible concentrations, but they've only focused on really four types of compounds. Remember, four out of 15,000 is not very many. Uh, and and they've they've provided some initial guidelines for maximum levels in complete feeds for livestock and poultry, and uh avoiding exceeding some maximum concentrations in foods of animal origin. But uh here in the U.S., uh federal PFAS regulations are actually being eliminated, which is unfortunate. And any regulatory action uh that has been uh put into place has been deferred to individual states. So there aren't any federal regulations here in the U.S. or or even guidelines for hazardous limits of PFAS and ag soils or even government policies or incentives to remediate contaminated air, water, and soil. And um several states, however, have implemented some bans or restrictions on PFAS and various industrial and consumer products. But uh we really need a dramatic increase in federal funding to conduct some of the essential research that we need to fill a lot of these knowledge gaps that I'm describing uh to help us understand feed and food safety risks uh in our system.
SPEAKER_00Sounds like a significant one health issue. Uh, is there something that that needs to be done on a large scale? I know you've just outlined a few things, but are even on a global scale, are there some also are there some like practical things that consumers can adopt to minimize their individual risk? What would be kind of your words of wisdom going forward for this?
SPEAKER_01Yeah, as I often mention when I get the opportunity to share these ideas and and concepts with various audiences, um, global one health problems like PFAS require complete global participation. Uh we all live in a shared global environment, and um I think that's necessary to develop and implement uh potential solutions. This is a pretty complex problem, but I think as I try to remind people, the first step in attempting to fix a major one health problem like this one is to increase our scientific and public awareness of what are the types of health effects that PFAS cause on the environment and soil and plants and animals and humans. And once we acknowledge that PFAS has become a major one health problem, we can start exploring and potentially developing meaningful solutions to mitigate uh some of their detrimental effects and uh increasing public awareness can also help motivate people to advocate for laws and regulations that uh limit our exposure to these chemicals. Uh we haven't seen enough of that yet, and and I would encourage people to learn more about it and become more actively involved in saying, hey, we need to focus more on this. Uh some of it's beginning to occur in in some U.S. cities and states where they've implemented regulations that uh either prohibit PFAS use in food packaging, and some manufacturers are beginning to voluntarily phase out PFAS use and some of their food contact materials, but we need more activity. And the reason that this is important is that we really don't have any remediation technologies that can be used at this point to remove PFAS from air, and there's only a limited number of methods that we can use to remove it from contaminated water and soil. Uh, drinking water is one of our major sources of PFAS exposure for humans in many parts of the US, and so sampling and water testing uh for contamination is important, and if it is contaminated, uh we can install water filtration systems that uh use reverse osmosis membranes or even activated carbon, uh, which have been shown to be fairly effective in removing these compounds. But uh not a lot of attention has been given in this area either. Uh I always tell a lot of uh people that ask questions about this topic uh consumers should be asking marketers and manufacturers of the products they're purchasing if they're using uh PFAS chemicals and some of these materials, and uh kind of vote with your dollar, so to speak, make purchasing choices based on the need to send a message that uh we need to find alternatives. So it's in a lot of ways, Sarrett, it's virtually impossible to source foods from low-risk origins because uh we don't have a traceability system, we don't have PFAS testing going on, and there's really kind of a disconnect between food production and consumption in the global economy and the food system that uh we currently uh use and work in. So I think what we need is really a coordinated, going back to your question, a coordinated global effort of coordination and cooperation, uh some robust scientific research and data sharing so that we can develop standardized regulatory frameworks and develop safer alternatives to PFAS if we're going to have, I think, a realistic chance of fixing this one health problem.
SPEAKER_00Well, hopefully what we're doing here today is creating some awareness, like you say. Uh it's kind of the the starting point is to create that awareness and let people know and people can start thinking and exploring um just uh you know more more data and more science behind this. Dr. Jerry Shearson, University of Minnesota. Thank you so much for your time here today.
SPEAKER_01You're welcome.
SPEAKER_00Likewise, we want to thank all of you for being with us today on this episode of One Health Live. If you would like to hear more conversations on the issues of importance to animals, humans, and the environment, subscribe to this podcast on your favorite podcast channel. Until next time, have a great day and thank you for listening.