Join host Vonnie Estes and Dr. Linda Lee, an environmental chemistry expert from Purdue, as they delve into the world of PFAS chemicals. This episode demystifies the “forever chemicals,” exploring their impact on food, especially produce, and potential health risks. Understand the widespread presence of PFAS through products and the environment, and learn about ongoing efforts to manage their impact. With insights into contamination sources, exposure levels, and consumer choices, this episode equips listeners with the knowledge to make informed decisions about PFAS in their daily lives.

Key Takeaways

• PFAS are a large family of chemicals that do not degrade naturally, leading to widespread environmental persistence and bioaccumulation.
• Major sources of PFAS contamination include firefighting foams, industrial applications, and everyday consumer products like nonstick cookware and water-repellent fabrics.
• The presence of PFAS in drinking water and agricultural produce poses significant health risks due to their potential to accumulate in human tissues.
• Regulations and consumer awareness around PFAS are crucial for mitigating exposure, particularly concerning non-essential uses in consumer goods and food packaging.
• The episode highlights the importance of choosing PFAS-free products and being informed about food origins, particularly in regions with known environmental contamination.

Guest Resources

• Interstate Technology and Regulatory Council (ITRC) PFAS Fact Sheets
• Purdue University Environment & Chemistry at Purdue University Website

Listeners are encouraged to dive into this episode to deepen their understanding of PFAS, their potential risks, and practical steps toward minimizing exposure. Stay informed and engaged with "Fresh Takes on Tech" for more conversations that push the boundaries of innovation and technology in food and agriculture.

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0:00:24 Intro Speaker: Let’s get into it.

0:01:06 Vonnie Estes: So let’s get into it. This is one of those episodes where we leave the fear behind and bring the science forward. Linda, welcome to the show. It’s so glad to have you.

0:01:15 Vonnie Estes: So let’s start with the basics. What are PFASand why are they suddenly dominating the news cycle?

0:02:02 Linda Lee: And then most recently there’s been huge news around the draft risk assessment that EPA put out for two of the most infamous PFAS. PFOs and PFOA. They put out a draft risk assessment for how high they can be in biosolids to not cause issues when biosolids are used as fertilizer. So I think those two things is really what is driving a lot of the news. And then obviously concerns about their toxicity because of growing research that shows that they can have adverse human health and ecological effects.

0:02:44 Linda Lee: Yeah, so that’s a little tricky. So in the natural environment, PFAS, I always say they just multiply because you have big PFAS that can have places where microbes can attack to make smaller PFAS. So one PFAS that we oftentimes call a precursor can be broken down into several PFAS that are what we call the terminal, like the end products of a microbial process. So under natural conditions, they don’t go away. And that’s one main concern of any chemical class that doesn’t go away. Nature cannot do anything but dilute them at best. And so it is somewhat accurate, but it’s not accurate in the sense that now we are starting to develop more and more technologies that can offer destruction of these chemicals under high temperature, added chemicals, high pressures.

0:03:56 Vonnie Estes: So you said that there’s thousands of different compounds. What unifies them? What’s the difference between them? And why does that matter for public understanding and policy?

0:04:37 Linda Lee: And then what makes them different is that they can have different, what we call polar functional groups. So they’re like soap, they’re surfactant. So they have part of their compound likes to be in fats and oils, and the other part of the compound likes to be in water. And so that other part of the compound that’s polar and likes to be in water, there can be lots of different options. And then you can have lots of different attachments. So that’s kind of how we end up with thousands. And plus they have something might have eight perfluorocarbons, but they might not be in a straight line, they might be branched off.

0:05:47 Linda Lee: So if we ate vegetables that have longer chain PFAS in them, those could accumulate in our body. And they like to go to protein. So they’re in our liver, our blood or kidney or muscles. Now we know they like to travel to the brain as well on phospholipids. So we don’t want anything that hangs out in our body long. And that’s what’s unfortunately a bad side of the chemical. They have great properties, but they like to stay in our body a long time. So PFOs, we talked about that one can stay in your body for six to seven years, meaning if you never get exposed again, it’ll take six to seven years for half of it to leave your body and another six to seven for half of it to leave your body.

0:06:56 Vonnie Estes: So how do they get into the environment to begin with? Where do these come from?

0:07:31 Linda Lee: Unfortunately, people didn’t realize the unintended consequence, which was that they don’t naturally break down and that they do build up in our body and that they have adverse effects. The other sources. So that, that, that we have a lot of military bases, a lot of airports, of a lot of fire stations that all have been training and using these foams and, and nobody was going out there and cleaning them up. So now when there’s a hydrocarbon fire, someone’s out there after it’s been put out. Because first we have to save lives now, right?

0:08:28 Linda Lee: So all those things, and then they’re in our cars, they’re in everything. They made our life much easier. Quality of life got better. Again, we didn’t know all these negative effects of them. And so even now, even for chemicals that have been phased out, they’re in our products that are in our homes, things that we keep for decades and decades. And we wash our clothing, we wash our carpets and things go to the wastewater treatment plant, and then these chemicals end up in the biosolids that have historically been used for their fertilizer value.

0:09:27 Linda Lee: And then once they’re in the environment, and then there’s also direct discharge from industry for years into the air and into our waterways. So that affects our groundwater also, that’s used for irrigation and wet dry deposition, which is why we have background PFAS everywhere now.

0:10:02 Linda Lee: Yeah, so it’s not the easiest question to answer because it kind of depends where you live and I’ll explain that. But yes, you’re still being exposed in your office, your cars, your homes, because, you know, most people aren’t just going to gut their whole home and throw it out. Okay, but so that is, you know, we’re still being exposed that way. But exposure pathways and how it affects your body are different. So we know if you’re drinking water with PFAS in it. So if you’re ends up, you have a drinking water well that ended up being, you know, you’re exposed all the time.

0:11:06 Linda Lee: That’s not really sufficient. It’s like the days of, oh, this does not have bpa, but there was actually lots of other molecules that were just like BPA with one little variation. You know, it has to be, you know, all of them. So you can now buy furniture and carpets and dish and cookware. That our PFAS free companies advertise that they are selling PFAS free or going to be PFAS free by a certain date. So that’s very encouraging.

0:12:01 Linda Lee: Our biggest concerns that we worry about is what’s in dairy and livestock. Because they eat so much grass that can accumulate some of the PFAS and they eat 25 pounds a day is nothing for a cow to eat. And they’re building up these bioaccumulative PFAS that don’t remember their half lives. They’re faster in animals than humans, but they’re still very short. They’re still not short half lives. And so I think consumers of milk and cattle need to know where their things are coming from.

0:13:12 Vonnie Estes: If you’re talking it doesn’t get taken up by the plant.

0:13:45 Linda Lee: What I’ve learned, I’m not a plant physiologist, has to offload into the phloem and to get there. And it doesn’t actively offload, except for the really short chains that might be mistaken for a little fatty acid or a little amino acid. So we know that corn. And when we think about cattle and the corn cob, those are safe things to eat or to feed your cattle. Where it all likes to be is in the storage compartments, the leafy above ground.

0:14:46 Linda Lee: So you’re eating wet lettuce, which 90% of it or more is probably water. So people need to be mindful of that. And it’s less in spinach, but it’s in again, the above ground leafy materials that we eat. When we talk about root vegetables, it can migrate into the root through the soil and it can also get into the root vegetables through active transport. Potatoes are kind of different. They’re only going to really get diffusion from the soil into the potato because they’re actually tubers and they’re not what we think of root vegetables. And if you were asking me, a non plant person, I’d say, oh yeah, a root vegetable, a potato too. But it’s different.

0:16:00 Vonnie Estes: Well, how you, how much of a risk is that? I’m just concerned about people hearing this saying, oh, my lettuce and all my spinach is contaminated in comparison. And looking at cooking on a pan that has a coating or wearing rain gear or other things, how do we look at the level of risk of eating leafy greens?

0:16:50 Linda Lee: You will not get 100% transfer of a chemical in your vegetables from your vegetables and things transferred into your body from any of your food products. So that’s one thing. Just because it’s there doesn’t mean it got transferred into your blood. You know. So for example, when you take medicine, it’s not unusual for 40 to 90% of it to end up in your urine. It never, it doesn’t transfer into your body.

0:17:54 Linda Lee: Heavily concerned about. And what, you know, I always tell people, do what you know, understand where your food comes from when you can. If it’s in an area. There are areas that we know were heavily impacted by industrial impacted biosolids, like Maine, where they’ve just had lots of farmland that, that has lots of PFAS, both from biosolids land applied and also from irrigating with water that was contaminated from a military base. And they never even knew. And then they found out.

0:19:11 Linda Lee: We get concerned about PFAS and fish because sometimes you say, oh, I’m a healthy eater, I eat lots of vegetables and I eat lots of fish. Okay. Gotta know where your fish comes from because, you know, and we, you know, it used to be we always want fish from, you know, a certain, like the ocean or from, you know, natural water body. But some data suggests that the fish that we’re getting from the ponds where they generate them, you know, the, what are they? Aquaponics or the aquaculture that those are actually, you know, tend to be safer with less PFAS potential in the fish than, you know, the wild ones just because we don’t know what water bodies have been contaminated and there’s less control.

0:20:27 Linda Lee: So I think that that’s true for, for produce too. And I think it’s more limited to some of the areas that have been heavily impacted. Although I have to say we don’t always know all the areas because not everybody’s area has been thoroughly tested. But when you start to see it showing up in the cattle or the milk in your area, then you have to be a little more attentive because our produce also being grown on those same soils, then you might want to be more attentive.

0:21:02 Vonnie Estes: Yeah, no, that’s really helpful. So some advocacy groups are calling for a complete ban on PFAS and food. Is that reaction rooted in science? Is that possible?

0:21:47 Linda Lee: So that’s, that would be like an essential use. There’s some essential uses for national security purposes like the semiconductor industry. They are trying to replace all their PFAS related chemicals. But right now you can’t just, it’s complicated. You can’t just replace it instantly. It takes, it’s sometimes a five to ten year process and we need, you know, everybody also wants their chips for their phones and their Cars and their computers and everything. Right.

0:22:43 Linda Lee: So it’s. I’m always telling my husband, could you please buy the vegetables that are not all wrapped up tightly in this plastic? I don’t. I want the vegetables off the open bins, please, not have these tightly bound, you know, And I said, because, you know, we don’t need to create plastic waste. And plus, I don’t want that plastic stuff coming off the plastic in my. In my food. Not just PFAS, just anything. You know, it will be very challenging to do a complete ban on PFAS and food, because are you going to check every single package and you’re going to check every farm 55 times?

0:23:47 Linda Lee: And first we got to get the packaging problem out of the way because PFAS in the packaging, which is a little easier to address, although. So I think we’re up to about 80% of packaging that can be. Do its function in packaging. Paper, paper plates and all that. They can do their function without pfas. You can buy pfas free paper plates now. You can buy pfas free plasticware. So these are things that consumers can control as far as PFAS in their diets.

0:24:24 Linda Lee: A lot of people? Yes, they will be labeled because that’s. And you probably have to pay a little bit more, but they will be labeled because that’s a good marketing strategy.

0:24:39 Linda Lee: When I go to a PFAS conference and they’re serving coffee and cups that I know are not PFAS free. I’ll go up and I’ll say, well, let me just get my dose of PFAS really quickly. First. I got hot coffee in these. But there really is options. There are options now. So just in the last year and a half, there are options.

0:25:12 Linda Lee: Right? So I want to say two things. First of all, when we’re talking about adverse effects of PFAS, obviously our most sensitive people, women that are pregnant, are carrying unborn children that are growing and then young children. So I think the biggest concern, I do think baby food should definitely, that’s where we should focus our. If we want to start looking at PFAS and food and ensuring that our food is nearly clear of PFAS, we want to focus on food for babies and toddlers first.

0:26:22 Linda Lee: So that’s one thing that the produce industry could do. The other thing is to recognize that depending on what’s being, you know, whether it’s fresh food or food that’s being processed, the actual manufacturing process could have PFAS in it, not intended to get in the food. But it’s in a lot of our things that you want something to go smoothly. You know how we spray WD40 like to, okay, well, PFAS, a little bit of PFAS and things really helps things move slowly, you know, so it’s, it’s kind of interesting how much we depend on them. We just have no idea. So I think operators can question, like if they’re growing their own things, they can question where they’re growing it. If they’re getting it from other people, they, they could ask for some kind of certification from where they grow.

0:27:43 Linda Lee: But it doesn’t mean that that’s very significant for it to transfer into your vegetables.

0:27:55 Linda Lee: Yes, we are.

0:28:03 Linda Lee: I wanted to say one other thing. I’m sure just like the wastewater industry, the produce industry wants to know are we going to be liable for somebody coming back at us? I wouldn’t expect that that would happen unless it would kind of be like when all of a sudden E. Coli gets picked up in a vegetable. If all of a sudden FDA somebody grabs some vegetables and find out it’s really rocket high in PFAS.

0:28:48 Vonnie Estes: So for people who want to go deeper into this topic or who want to keep up on it, do you have some recommendations of where people can find trustworthy science based information?

0:29:28 Linda Lee: And they’re all the time updating those fact sheets. It’s a consortium of individuals, high level individuals that kind of donate their time to helping to keep all that up to date. So that’s you. And they have a really nice, the left panel gives you nice index and you can cruise through there to find out, you know, and click on something and it’ll take you right there. And that, that can be helpful.

0:30:46 Linda Lee: That’s really the best you can do for right now.

0:31:09 Linda Lee: Thank you, Bonnie.