Vermont Legislature SmartTranscripts:

[Rep. David Durfee (Chair)]: Retired from University of New Hampshire. You can let us know all about yourself. Why don't we do a quick around the room, just introductions, so you know who we are. And we're a small committee. We've got one member who's still coming along, but I think maybe we could start, Gregory Greg if you'd like.

[Rep. Jed Lipsky (Clerk)]: Jed Lipsky, I represent Lumbaughlin District, town of Stowe.

[Rep. Richard Nelson (Ranking Member)]: Thank you. Richard Nelson, Orleans one, which is down at Derby.

[Rep. David Durfee (Chair)]: Thank you. David Durfee, I represent Shaftsbury in Bennington County as well as Sunderland and Bostonbury.

[John L. Bartholomew (Vice Chair)]: John Bartholomew from Heartland, and also represent Windsor and West Windsor. You can see my picture from my bedroom window. Richard Burtt, representing Caledonia and Belle Peachin. I can see New Hampshire from the top of my hill. It's about 50 miles away.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: It's mostly

[Rep. Richard Nelson (Ranking Member)]: the Presidential range.

[Rep. Michelle Bos-Lun (Member)]: I'm Michelle Bos-Lun. I represent Windham 3, which is Westminster, Rockingham and Brookline in Northern Wyndham County. And I can't see New Hampshire from my house, but I can from my mother's house, which is right next door.

[Rep. Richard Nelson (Ranking Member)]: We're talking about seeing New Hampshire. We own a farm in Canaan, Vermont. We're up

[Rep. Jed Lipsky (Clerk)]: there. Excellent. See it from my house. Alright.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: And I live in the Southeastern Corner of New Hampshire, which is where Durham is located. And I can't see Vermont, but I can almost see the Atlantic Ocean.

[Rep. David Durfee (Chair)]: Appreciate you making the drive in any case.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah. Just for the record, I was asked if I would be willing to come, and I am here and not being paid. So I just decided I feel strongly about the subject that you're studying and trying to come to a decision about. And I'm very happy to be here. And I appreciate the work that you do, because I think informed policymaking is critically important in all phases of our democracy, and agriculture is no exception. So I appreciate that. I've had the opportunity to appear in front of Congress over issues related to herbicide use and the effects of genetically modified crops on driving a dramatic increase in herbicide use in The United States. I've been in the field of education and research and outreach, though I never had a formal extension appointment for about forty two years, working out west in Nebraska for fourteen, Penn State in Pennsylvania, in the Appalachian Ridge Valley area, where I actually spent a lot of time on apple orchards in Pennsylvania for seventeen years. And then I moved to the University of New Hampshire in 2018 to help with a restructuring of the life sciences program there, and retired about a year and a half ago. I have a big birthday coming up. I turned 70 on April 6. And so, remain active through things that I do in writing. I remain active with folks that are continuing to conduct research at Penn State and at the University of New Hampshire. And I remain active doing some consulting work as an expert in the field that relates to the subject that you guys have been studying. Thinking about I'm I'm not big on talking head education. In other words, I could easily have decided, and you guys would have regretted that I would come with an hour long PowerPoint presentation. But rather what I've done is I've tried to pull together about ten minutes worth of thoughts that I think are germane to your decision making. And then I wanted to just open it up for conversation. And I'm here, and then I will turn around and drive back to Durham, hopefully getting back late for dinner tonight with my wife. Provided to Patricia a bio that has sort of some of the things that that describe the background.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: If folks were to, like in a thumbnail sketch, describe my background, I have done a lot of work on integrated pest management over the years in crops, mostly

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: on farm through what we call participatory farmer led research. I have a strong background in ecotoxicology and the movement of pesticides on the landscape. And the ecotoxicology part of that looks at how the movement of those pesticides influences the biological reality, both in the ag fields and outside of the ag field. The field edge, for example, we spent about ten years with about 10 graduate students who now teach at different schools and things, looking at how the drift of herbicides undoes pollinator plant networks by damaging plants in the field edge, taking away floral resources from those pollinator insects, and resulting in a decline in pollinator diversity and abundance. That would be an example of some of the things we've done. I've always had an interest in our work not sitting on a shelf somewhere where one or two other academics will go pull it out every fifth or seventh year or something, but actually to help have some of it at least help inform policy. And so I've had that interest for the last twenty years or so of my professional life. Okay. Enough of that. In 1979, in a peanut field in North Carolina, we were applying herbicides in backpack sprayers. And we're young and strong and hot, because it's hot when you're out there with a backpack sprayer in a peanut field. And when it came to we would apply all these different treatments, and then you go back and compare how did they work at controlling the weeds. How tolerant was the crop when we applied the herbicide to the crop and weed. And I was struck at how reluctant our fields crew, a bunch of mostly young guys in their twenties and thirties were to take the backpack that had paraquat in the tank because of concern over human exposure for the applicator. You, I think, heard from folks that have talked about how careful we are with the regulation of protective equipment when a restricted use herbicide is applied in the field, which includes wearing a Tyvek suit zipped up to the top of your neck and a respirator on your face with eye protection. The reality, I will say, is that that is a very hard set of restrictions for anyone to follow in the field. Now I'm going back a long time when I talked about myself being 28 or 30 when I turned 70 in April. But if you ask folks that work in the field, young folks today, how they feel about applying Paraclot, there is a concern about this herbicide that is unequaled in any other herbicide that's available in The United States to apply to any crop in The United States. You've heard that there are ways that we measure the toxicity, these pesticides, that there is acute toxicity. That's like, say, if I'm spraying it and I inhale it, and it knocks me down to my knees, which happened to me once in North Carolina. It takes your breath away because it directly affects membrane integrity when it hits. That's the acute effect. So we measure that after I graduated college, I worked in a laboratory where you establish LD50s, lethal dose fifty percent of the test population you're studying. That's where fifty percent of the test population dies at a certain dose of, let's say, a solvent that's made for scrubbing steel before it's sealed into something, or or a herbicide that's applied to a field. The LD 50 for paraquat is one hundred and fifty milligrams per kilogram of body weight of a mammal. 150 per one hundred fifty milligrams per kilogram of body weight of animal or human, us being an animal, a mammal.

[Rep. Jed Lipsky (Clerk)]: The

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: overwhelming majority of other herbicides are orders of magnitude less toxic. So a hundred and fifty milligrams per kilogram for paraquat, two thousand to ten thousand milligrams per kilogram for most of the other herbicides we use. Okay, so it's over an order of magnitude to two orders of magnitude more toxic from an acute toxicity point of view. Who does that affect? In reality, that acute toxicity is the applicator. It's the handler. It's the field worker in an orchard, or in the adjacent orchard block when this orchard block's being sprayed, and paraquat moves over into the adjacent orchard block. So so when when my colleague said, why don't you take the paraquat tank? I I don't really wanna work with this today. It's ninety ninety degrees. I'm not gonna close my Tyvek suit because I'm dying of heat. And I've reviewed cases of exposure of farmers, ranchers from across the country in my consulting work, where routinely they will admit I didn't follow the clothing strictures of the label closely because I simply couldn't be out in the field for five days in a row spraying something with a Tyvek suit, a respirator, eye protection, etcetera, etcetera. This is a point that has frustrated me, and I have testified in front of congress over is EPA setting label constraints that are near impossible to meet in practice by farmers and ranchers and orchardists on the ground. And that this is a point we could argue with some of my EPA colleagues about, and I have. But if you go out on a farm and you watch what's being done versus what's prescribed on the label, particularly in the case of protective clothing on a restricted use pesticide, is very difficult to conform to that. And there have been recent surveys pointing out just how frequently people are using paraquat off label. So from an acute toxicity point of view, it was surprising to a lot of people, myself included, to see in a 2025 EPA report that came out in October 2025, so super recently, that EPA's estimate of volatility of the herbicide was way off. So volatility is the movement of the herbicide after it's settled on the surface, and then it goes from being settled on the surface like a leaf tissue, and then it moves as a vapor in the air phase as a gas, basically carried by the wind or not by the wind, by diffusion. Right? You could have a completely still day, then it's moving by diffusion. A breezy day, it's it's being physically moving the vapor in the direction of the downwind direction. The volatility estimate was so far off that it was 4,000 times under estimated. 4,000 times, not four times, not 40 times, but 4,000 times. The general thinking on the part of EPA, because they take these these vapor drift measurements, and then they feed them into physical models that they can then under this kind of breeze, the herbicide will move this far, and it will the dilution profile will look like this. The inputs for those models, the so called perfume models, were 4,000 times off. So what how does that translate in practice on an apple orchard or a vegetable field in Vermont, it translates in some disturbing ways. Not surprisingly, right, if it's if they were forced out of there. They concluded in this report that concentrations of paraquat of concern to human health move at a distance of somewhere around 2.7 miles. So we're not just talking about a field worker crew picking apples or or maybe pruning in the adjacent orchard block. We're talking about housing for the migrant workers in the orchard. We're talking about a school down the road from that orchard, etcetera. This come this this is a long distance for the compound to be moving. When we see volatile movement of a herbicide, you're tending not to see concentrations that would result in acute exposure. Because usually acute effects are driven largely by the dose, the concentration that you're inhaling. And by the time it's out two miles out, you're inhaling a lower concentration than is going to be the kind that will cause acute poisoning, but will have chronic effects on human health. This is quite concerning and has really you know, and anyone that's looking at that kind of data, like a science person or an EPA person is like, oh my god. We're working on the on the reregistration of Paraquat, and now we're learning in sixty three years later, right after it was registered, we're learning that we were 4,000 times off on the volatility estimate. Not good. The the so when we when I was saying that about the clothing and and please, I also talked long. So I sit here, I said, I'll talk for five to ten minutes. It's already twenty after. I don't want to use up all your time if you have questions. So let me keep moving. I'm sort of slowing down here. Basically, I guess, the thing that is very concerning then about chronic toxicity and chronic exposure is that our vapor movement estimates are off. And studies, epidemiological studies, you go out and you just say, you survey a large number of humans in a local area, and you have information to happen, how frequently did you apply paraquat? How far from an ag field did you live, etc? And then you look at the likelihood or the probability that people contracted Parkinson's. Was that higher when you use paraquat, when you live near a field than if you lived far away from a field or you didn't use paraquat? And those studies generally are concluding and some of them are meta analyses where they take six or 10 paper studies that are like longitudinal studies over thirty years, right, like long term sample of five years sample, the same group at ten years, they're finding a increased likelihood of developing Parkinson's disease on the order of sixty four percent if they were in close proximity to where paraquat was used. So there there is data that would support the argument that the probability of problems arising from its use in nearby fields is elevated when you live near or used paraquat. One thing that I and I was quite naive about, but I learned a lot about when I was working in apple orchards in Pennsylvania was the housing for field workers on every orchard that I was in. And we were in about 20 orchards every day for two summers measuring bees and measuring weeds and and looking at the pesticide use profiles. And the housing for most all of the field workers is right nested in the orchards. And many of the orchards are being sprayed. One block is sprayed when you have a crew a couple of blocks over, certainly well within a quarter mile or or two miles or so. And I it it led me to think a lot because I don't have a background in working with immigrant well, it was all immigrant labor in Pennsylvania. The the extent to which the field workers are involved both in harvesting the fruit, pruning the fruit, often mixing the herbicide, and sometimes applying the herbicide that there is this sort of uneven exposure that's going on by the very nature of the crops you grow and the reliance on human labor to help produce that crop and get it out of the field. So enough on toxicity. A couple of things I wanted to say about places that have stopped using paraquat. And let's take apples as an example, as a crop. China produces an order of magnitude more apples than any any other country in the world. 47 I I looked this up just yesterday morning. 47,573 kilotons. US produces 4,000. So order order magnitude less, four thousand four twenty nine. Turkey is the second leading apple producer in the world. 4,818, about the same as Us. Kilotons, Poland is the next, fourth at 4,265 kilotons. Pariquat is banned in China, where they produce an order of magnitude more apples than we do. Pariquat is banned in Turkey, which is the second leading apple producer in the world. And Paraquat is banned in Poland, the fourth leading apple producer in the world. The only apple producer in the world that uses Paraquat that's in the high end of apple production is The US. So what does that mean? It means, obviously, that farmers turn to alternatives when they don't have something available to use. Paraquat was registered and used in China, in Turkey, and in Poland, and it's now banned and not used there. I had the good fortune to visit some former students in Spain and learned a year and a half ago that Spain is the market garden for the rest of Europe. So most of the apples, most of the fruits from Spain go north. And Spain has banned the use of paraquat as well. I asked several Can

[Rep. David Durfee (Chair)]: we just pause for a question?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yes, please.

[Rep. Michelle Bos-Lun (Member)]: So I'm wondering, you've mentioned these countries that grow lots of apples and they don't use paraquat. What do they use? Because that's the question I've asked this to a number of folks here in Vermont, and there doesn't seem to be a strong awareness of a good method to grow baby apple trees except for paraquat in Vermont So in this what do they do in these other places?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Use a lot of cultural practices, but they also use herbicides and a lot of them get in the same way that we use a lot of herbicides, but not paraquat. So they have alternatives. Those alternatives and I could rattle them off, I could also provide Is them in it

[Rep. Michelle Bos-Lun (Member)]: glyphosate or is it one of the

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: other? Some of the most common ones are glyphosate, glufosinate, carfentrazone. Another one that's commonly used is pyrafluffin. So there's quite a list. I would say of those, that would be commonly used for, let's say, baby apple trees and shoots coming off of baby apple trees and concern about injuring them. It would be carfentrazone, glufosinate, pyraflupine, be glyphosate, although glyphosate is not preferred by most

[Rep. Michelle Bos-Lun (Member)]: apple What we heard here is that the both of the G starting chemicals can kill the baby plants. Yes. So are you saying that those other those other pesticides could kill the weeds, but not the baby plants that presumably that would be the case because otherwise they wouldn't be using that?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yes. Yes. So they would. At some of these, for sure, you some of these compounds, you have to be more careful with their use. No question. Fosinate is fairly widely used for sucker suppression in apples and young trees. But you have to be more careful than you would be with parafat. For our Ventrazone is there's a higher level of prop safety, apple prop safety to it at that young age. So there's a lot of nuances in the way that those alternatives would be used. But there are And I'm not just listing things that you just because I could pull them up somewhere. Are practical things that farmers would do and are doing, like the Pennsylvania orchards I was working on, they were doing that.

[Rep. Michelle Bos-Lun (Member)]: They were using some combination of those that you

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: just Yes, yes. Yes. So

[Rep. Jed Lipsky (Clerk)]: And

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: do

[Rep. Michelle Bos-Lun (Member)]: you happen to know how Vermont climate wise compares with the parts of Pennsylvania where a lot of apples are grown? Would you say they're fairly comparable or more like we get more we're we're more I mean, I know that the moisture can be an issue.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: I would say that it's it's quite similar. Would say, although

[Rep. Michelle Bos-Lun (Member)]: I I I recollection too. Used to live in Central PA.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: You know, it's it's it's it's colder here than it is there. They're in the Appalachian Mountains, and most of the apple production is Gettysburg and Yep. West to the Appalachians. So it's not that unlike here. Yeah. Yeah. Thanks. So yes. Sure. Yeah.

[Rep. Jed Lipsky (Clerk)]: One

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: thing that I would say that I've I've observed and and saying this is something that would evoke quite a like, if I was here with some of the folks that spoke before, would evoke quite a animated discussion that we could have about this is there is this idea of the sanctity of the toolbox. And if you ask some of the speakers that came before me about this, that it would be an interesting thing to hear what their thoughts are. But there is this concern that many in ag production have, that you give them an inch. Other words, you take paraquat away. And then next year, this committee is going to make 20 more herbicides unavailable to them next year. Therefore, their toolbox becomes depleted. They have fewer things that they can do their thing with. Right? Grow their apples, grow their vegetables. I think this is this is a problem when that skews our objectivity about what some of these tools are doing. And I think we're dealing with an exceptional herbicide here that I described the ways in which it's exceptional from a toxicity point of view. It's basically, from a you know, weed weed jargon is you'll hear people call it chemical mowing when you apply paraquat. You're you're killing the tops. It doesn't go below ground, doesn't go into the roots of the plants. And I argue and withstand by the fact that the toolbox is already plumbed with a good five to seven practical chemical mowing herbicides that can be used in crops that are grown in in Vermont and and and grow the crops safely. One of the things that the Spanish field advisers told me when Paraquat was banned there and their fruit orchards was farmers are very creative about figuring out ways to get the job done. If they don't have Araquat, they will look to parfentrazone and something else to to achieve that we control that they're working to achieve. The other thing that I would say is that agriculture is not static. Like once things change, one cool thing that's changing is that Vermont leads all New England states in cover crop adoption. Cover crop adoption is a form of weed management. From the period 2012 to 2017, cover crop adoption in in Vermont increased 117% compared to some of its neighboring states that were in the 20 to 30% range of adoption. That's weed control. That's soil building. That's a way of reducing reliance on paraquat. So there's a lot of ways that we can think about alternatives. Herbicides are one of the ways that we think about alternatives. And so I will stop talking. I've talked longer than I said that I would by a lot, not 4,000 times as much, and see if you have questions.

[Rep. David Durfee (Chair)]: Yeah. But before we open it up for questions, I just wanted to two things that you mentioned numerical. The sixty eight percent, I think that was the number when you were talking about elevated risk. Sixty four

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: percent, yeah.

[Rep. David Durfee (Chair)]: Can you frame that in terms of statistical significance? Would be, at what level would we be able to say, okay, yeah, that's clearly a noticeable increase, or a meaningful increase rather?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah.

[Rep. David Durfee (Chair)]: This would be

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: So, so we we could think of something I don't wanna sound like I'm invading your question. I'm I'll try to answer it. Likelihoods and probabilities are not something that we would fit a distribution around, but we derive a probability of something being higher or lower from a population of individuals through these epidemiological studies. This would have been I don't know the specifics of that very study. But actually, 64% comes out of a meta analysis of it, I think 13 individual studies, some of them in California, some of them in the Mid Atlantic states. And you couldn't place a statistical test to determine if the probability is is something that's going to apply in every place that you dropped a pin on the landscape, but it is higher significant, know, that's that's a that's a significantly higher percentage probability of occurrence.

[Rep. David Durfee (Chair)]: Mixing up two related statistics and probability maybe. And so when you said, you don't want to sound like you're evading the question. I think you're not evading the question, but I'm asking maybe not quite the right question. So guess I'm thinking if we know there's an incidence, a normal incidence of something, Parkinson's is what we're talking about, the results of this study are showing that it's this much more, sixty four percent more likely looking over lots of different areas. That's right. And we can interpret that if we think that's a lot or not a lot. I mean, sounds like a lot, but Yeah,

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: that's, that's right. I mean, I would, it's sixty four percent over overall. And what was there? There were some other cases where it was one hundred and fourteen percent. But so sixty four percent is a significant finding that it would be elevated in that way. The thing that happens with these epidemiological studies that's that makes a number that maybe doesn't sound as large as it as it might sound, make it profound is that there are all these other things that happen in the life of an individual. Right? So this a study might include 1,900 human subjects that agreed to participate in this survey. One person to let you know, pumped gas and got a lot of gasoline on their hands was also exposed to paraquat was also exposed to this that and the other thing house cleaners. So these epidemiological studies then try to break out the paraquat effect out of the noise in a population of individuals that have been exposed to other things during the course of their lifetime. So to find a signal for one thing in a population of a thousand or 2,000 people is quite a profound finding when you have all this noise from all this other stuff, smokers, drinkers, turf grass, pesticide applicators, etcetera, etcetera, etcetera. Yeah.

[Rep. David Durfee (Chair)]: Representative Bos-

[Rep. Michelle Bos-Lun (Member)]: Yeah, I was kind of you kind of answered my question already, but I guess in terms of this the in trying to find this population that would have the increased rates of Parkinson's, are they? Do you happen to know, did they find like, are these mostly the pest icide applicators that were having the direct contact? Or is it more likely people that would have had a more remote like you're talking about the volatility and like it could it could carry for two miles? Are they finding populations in school kids that were in a schoolyard next to an apple orchard? Or what kind of settings like?

[Rep. Richard Nelson (Ranking Member)]: Yes,

[Rep. Michelle Bos-Lun (Member)]: I

[Rep. John O'Brien (Member)]: think I do.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Okay. And Here's one. Yes, a 2024 study, California Central Valley, agricultural paraquat dichloride use in Parkinson's disease in California Central Valley. They break out the exposure into classes, mixers, handlers, handlers, and spraying. Residents that never sprayed or mixed, that lived within a distance of the fields that were being sprayed in the Central Valley.

[Rep. Michelle Bos-Lun (Member)]: Yeah.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: They then have the GPS coordinate for that family in that house and the fields that are nearby to determine how far they were from the fields that were being sprayed in the Central Valley. And for people that are mixing and spraying it, it's a twofold increase likelihood of having Parkinson's disease. That's again, a likelihood or probability estimate. We don't obviously do tests on humans. So this derived from those kinds of epidemiological studies. But they also found in here elevated rates of Parkinson's with proximity to the fields.

[Rep. Michelle Bos-Lun (Member)]: With the residents

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: that never handled paraquat, right? Field workers that are in fields are more likely to be near fields that were sprayed with paraquat. They are, they have a higher signature for Parkinson's than if you hadn't been in the field. Yeah.

[John L. Bartholomew (Vice Chair)]: Thank you. Representative, if you follow me. When you alluded to the difficulty of studying human populations, because there is just no way to control for variables. So it's difficult to get those data. But one thing I did wanna make clear since we're online is when you mentioned LD50s, that LD50 tests had never been done scientifically on humans and are almost never done in animals now, just because I didn't find any misunderstanding going out over you.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah, for sure. If if I if I wasn't clear.

[John L. Bartholomew (Vice Chair)]: No. I mean, I just Yeah. You you were clear to me, but I just wanna make sure that

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah. So those just just for the record, the LD fifty data that we were looking at, most of that is derived where you have a mammal test system that's understood to be close to a human system. The rat is a common test system organism, and those LD50s are done in rats.

[John L. Bartholomew (Vice Chair)]: Laboratory and more medicine for a long time, and the LD50 tests are almost never approved anymore. But in any case, what I was wondering now would be Meaning you apply some possible toxin to a population of animals and half of them die. That would be LD50. It's a lethal dose? Methal dose, yeah. So what I'm wondering wondering

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Determined by a titrated or they're subjected to a small amount, and now the group are subjected to a little more, and you fit a curve, and the point at which fifty percent of the animals are dying is the LD50.

[John L. Bartholomew (Vice Chair)]: So getting to my question. Yes. We've been told that this stuff binds very quickly to soil and organic matter, that its volatility is low, and that it becomes inert, which not sure I understand. Is that true? And if it is true, after it binds, does it break down?

[Rep. Richard Nelson (Ranking Member)]: What are the breakdown products like? Do you know? Yes. So

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: the loss off foliage is extremely high. Volatility loss off of surfaces varies a lot. It's strongly positively charged and soil particles are strongly negatively charged, so they tend to bind and be less volatile off bare surface. But it's extremely volatile off of foliage. So let's say you go out and spray paraquat on apple trunks with grass around it, or it's sprayed over the top of a weedy hedge row or field edge or something like that. The volatility loss off of a plant surface is extremely high. And that was one of the ways in which the EPA discovered their gross underestimates of volatility loss that were reported in October 2025 paper came to light. If you do these very highly controlled studies so a lot of these volatility studies, at least early on, are done on little soil columns in a laboratory to derive the vapor pressure score for the compound. But when you take it out in the field and then you apply it to other surfaces that are commonly in the field, like the plants. That was where the mistake was made. And that was data that was actually provided to the EPA in the fall from the manufacturer of the herbicide Syngenta, admitting that they had underestimated the volatility by 4,000 times.

[Rep. Richard Nelson (Ranking Member)]: What about breakdown products?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: And breakdown by products, it persists for quite a while in the soil. I don't have the breakdown dynamics in my head. But it is strongly bound to the soil once it hits the soil surface, once it hits a negatively charged clay sand, it's not so tightly bound to because sand is not negatively charged, so it doesn't form a bond with sands, but it tends to be bound to the soil. And it persists. It's less the degradation of paraquat or any herbicide when it's bound to soil is greatly slowed. It would tend to accumulate on those negatively charged clay surfaces if it was used repeatedly and exceed the rate of degradation because of that bound effect slows the breakdown.

[Rep. Richard Nelson (Ranking Member)]: Everybody does fantastic. When was that paper published that you were citing?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: One was published in 2024.

[Rep. Richard Nelson (Ranking Member)]: 2024. I and we got a link. We received the link today from Steve Brunell, our director of pesticides here at State of Vermont. There's a link to our California study and I have a note here saying that California did a study recently just just in completed and found no bank at Parkinson's out of California.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: He may be referring to the California Department of Ag. There was a report that was issued, but they reviewed this paper along with many other papers. Is that meta analysis that I mentioned, I think it was 13 papers, concluded that in some cases, were elevated rates of Parkinson's. In other cases, they seemed unconvinced by the data in the papers, which surprised me. I'd be I'd be happy to share that California report with you.

[Rep. Richard Nelson (Ranking Member)]: We have we have it. In here, and I went on reading it. I I'm a I'm a applicator. Yep. I've never used barracquat. Yep. Don't don't grow apple trees, so Yep. Don't eat it on my corn.

[Rep. Jed Lipsky (Clerk)]: Yep.

[Rep. Richard Nelson (Ranking Member)]: Don't intend on using it. But I am one of the people that fear about my toolbox. Yep. Seen in my toolbox got hit hard two years ago here. Okay. Yeah. And so I fear about the rest of my toolbox.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah. Okay. I I would I would say about and I respect the toolbox idea, but I but I do question, and I'm not questioning you, but I would question the fact that we can't go into the toolbox and ask, are there things that we've got in there that we would be better off not having in the toolbox? I believe that this is one of those compounds.

[Rep. Richard Nelson (Ranking Member)]: I don't use a four fifty eight Winchester Magnum top white dead deer either.

[Rep. David Durfee (Chair)]: I know there are several hands up, but I think Representative Burtt was next.

[Rep. Richard Nelson (Ranking Member)]: Thank you, chair. A study on the volatility. Yes. Is that done? You said this fall came out?

[Rep. Gregory "Greg" Burtt (Member)]: Yes. So very recent.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yes. Yes. So what happened was Syngenta, companies are required when they have data that influences how the EPA looks at that compound. If they find that their data are off, they're required to report to EPA that they made a mistake or or that they learned something new that they didn't know before. In the 2025, the October 2025, the EPA issued a report updating what they understood to be the new nature of the vapor volatilization losses. And that's where that 4,000 times number appears. And that data probably was received by EPA in the 2025 or something like that, because the report came out and they would have had to have gone in and looked at how that influenced the model outcomes and all of that. Are you aware of whether or not the EPA is

[Rep. Gregory "Greg" Burtt (Member)]: planning to make any adjustments on the label potentially based off of this data?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Know that they're doing a lot of reviewing of Paraquat and reruns of models and reassessment of whether or not Paraquat should be used in The United States. It's also the case that there are a number of factors that influence what's given priority with regard to reviews of compounds and technologies in anything, including agriculture, that border on being political, and whether or not the current director of the EPA pushes to move certain things ahead or that another director of the EPA would have moved ahead, that those are decisions since those are appointments. There's a certain amount of that that goes on. I do know that they're very concerned about that data. And they are running model simulations and looking at the label that exists for Paraquat. And the reregistration decision is definitely gonna be at least informed by it, if not influenced by hopefully influenced by. Yeah.

[Rep. Jed Lipsky (Clerk)]: Question that

[Rep. David Durfee (Chair)]: I Okay.

[Rep. Richard Nelson (Ranking Member)]: Representative Lipsky? Yeah. I would say,

[Rep. Jed Lipsky (Clerk)]: professor, that a representative Burtt's question was on the same track that I was Okay. If there are EPAs coming out with Yeah. New warnings or bans or distractions. But because you answered that very clearly

[Rep. John O'Brien (Member)]: Yeah.

[Rep. Jed Lipsky (Clerk)]: You don't know. Yeah. And, also, you acknowledge that some of the political objectives under some of the leadership in numerous agencies

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah.

[Rep. Jed Lipsky (Clerk)]: At this time in history is suspect in for those who are. So my only question would be, you referred to a word called metadata. Yes. Is that where artificial intelligence takes a dozen studies and somehow reads them all and then comes out with a finding?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yeah. There there

[Rep. Richard Nelson (Ranking Member)]: That

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: was something something like that. There are a number of ways in which you can take studies, multiple studies published in different papers and different reports, and actually extract the essence of that data in a way that you can analyze across 11 studies and then derive added meaning from that meta analysis, meta being the bigger analysis of these smaller pieces of epidemiological data. So that one paper is one in which that was done, 11 or 13 other studies were distilled into one bigger study. Thank you. Yeah. One thing that's interesting to just to point out, and I didn't, there's an interesting paper by a guy by the name of Nathan Donnelly that might be helpful to read. And by the way, I'm happy to send anything if it's helpful.

[Rep. Richard Nelson (Ranking Member)]: That would be helpful. Send a system, agree with that as well.

[Rep. David Durfee (Chair)]: Yeah. Send anything to Patricia.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: So this guy, Nathan Donnelly, who works out West, is a guy that looks at patterns of behavior with regard to agencies and pesticides globally. And what he found in this very interesting paper is that The US lags way behind China, Brazil, the EU on banning pesticides. Like, we a quarter of the pesticides buy pounds. Was just rereading this last night. The order of the pesticides by weight that we use in The United States have been banned in China. So it's not just paraquat, it's other things. And Donnelly argues that if that there are changes that we would need to we need to make federally in EPA in order for us to get rid of some of the bad actor compounds that have already been gotten rid of by other agricultural countries that produce in a way similar to ours, meaning kind of higher end conventional technological kinds of ways of production. And I think that one of the intriguing, and I think progressive things that's going on with a state ban, considering a state ban, is that you're saying, I don't need to wait five or ten years for the federal government to take this on. We wanna act now with the data that we have to make the decision that we think is best for Vermont. And I'll send that paper along. It's just an interesting point that he makes in that paper that Yeah.

[Rep. David Durfee (Chair)]: I know we had more questions. I just wanted to quickly ask you to address the question whether the growing techniques or approaches used in the other countries you mentioned, and the approach that we take increasingly in this country with more concentrated planting. So I'm thinking of apples here. Do those compare?

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: The methods of production that I personally witnessed in Spain are very similar to Pennsylvania. And I'm sure to hear certainly to New Hampshire, orchards and fruit production. And I would think that it would be very similar in China. In fact, China's methods production are even more concentrated than they are here in Vermont, maybe closer to the Pacific Northwest apple production methods. But yeah, so I think that the production systems are actually quite similar. It's probably the case that there's more labor in Chinese agriculture, and that could influence how the alternatives work and don't work. But when you're producing at the level that they are, you're using really high input, high concentrated fruit production methods to get those kinds of yields.

[Rep. David Durfee (Chair)]: We're nearing the end of our time, but I think everybody on this side had a hand up. Why don't we start with representative Bob?

[Rep. Michelle Bos-Lun (Member)]: Mine'll be quick, actually. I'm just noticing today that it's very interesting that right before lunch, we met with somebody who is the state pesticide expert who told us more or less, this is a quote, it stays where it's sprayed. I just wanted to confirm from your perspective, that is old news and not accurate. And it actually can move quite a large distance and be dangerous because of that, right? That's correct. I mean, I just wanted to make it crystal clear.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: That's correct.

[Rep. Michelle Bos-Lun (Member)]: Okay. Yes. So it

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: seems So it's possible that I don't know the individual. I don't know who you spoke to. It's possible that they haven't seen some of these late releases. This is very recent, October. Remember I the date I had it

[Rep. Michelle Bos-Lun (Member)]: up Yeah, if you my could last 12 send us the studies, we can share with them and

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: make sure October we're 2025, so just a couple of months ago. Yeah.

[Rep. Michelle Bos-Lun (Member)]: Okay, thank you. I

[Rep. Richard Nelson (Ranking Member)]: think representative Burtt, I'm good. O'Brien. Yes, professor.

[Rep. John O'Brien (Member)]: Representative Nelson referenced, we spent a lot of time on neonicotinoids the last couple of years. And what was interesting about that was that there wasn't this obvious sort of toxicology to humans, but it came up mostly because honeybees were being affected. And this seems almost like the opposite. My question anyway is the opposite. It's so obviously toxic to humans, paraquat. But has there been studies done on the rest of the living biota world that's affected by use of paraquat? Everything from songbirds to insects, pollinators, where it's the biota in the soil or right at the surface level. Because it seems like it's going to be really deadly there and whether it once again, agency said it doesn't bioaccumulate. And I can see also by the volume of usage in an apple orchard strip, it's a relatively small amount of inferior, but he said it's used as a desiccant on soybeans and peanuts and cotton and potatoes sometimes. So that's a huge amount of this being used in a very wide space. I guess you could just speak to that sort of human world.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: Yes, yes. So in the time that I've been working, been a little black box has become this enormous sort of thing about soil quality and the life of the soil. We didn't know very much about this in the 70s and 80s. And we are much further along in understanding the microbiome of the soil, the life of the soil. My feeling is that we can know some things about the influence of pesticides on the microbiome of the soil, but there's a lot we don't know about that. A compound like paraquat is a is a membrane disrupting herbicide. That's how it kills weedy plants. It doesn't move very far in the plant at all. It moves the distance of maybe two or three cells out of a width of maybe 20 cells. And it dissolves, it interacts with the lipid membrane of those cells. In the same way, if I inhale it, it has effects. Obviously, you don't do that, but effects on the integrity of your respiratory system. So it's not well understood what is happening to understand the microbiome. The fact that we're just learning about how volatile it is, is part of the reason why I don't think we know a lot about that either. We we we're were very concerned as agriculturalists about the movement of things like twenty four d and dicamba. These are other herbicides that are known to be volatile. And a number of people were studying what happens when it's supplied. Some of it gets bound to the soil, some of it's on the leaves, some of it moves over to the field edge. And we were doing that work for about fifteen years. I would say that there will need to be more of that work on paraquat going forward to understand what effect drifted paraquat at high concentrations. Because if you're just adjacent to the field edge, it's gonna be high concentration exposure of the plants in the edge and the effect of that drift undoing, for example, pollinator networks. It's poorly understood at this time. I I can tell you that we were able to study this in enormous detail with dicamba in two four d and its strong effects. I mean, you you're knocking out broadleaf plants that have flowers that are host for pollinators, natural enemy insects that eat bad insects in the apple crop that are their alternate host plant is in the field edge. Now that alternate host plant is not in the field edge because you've either stressed it or killed it. Those are the sorts of things. We don't know much about that, about Power Quad.

[Rep. David Durfee (Chair)]: All right. I think we should wrap up. We're a little bit over. Thank you very much, Doctor. Mortensen, making yourself available. Driving from far away New Hampshire to be here. Very interesting and helpful conversation.

[Rep. John O'Brien (Member)]: That's good.

[Dr. David A. Mortensen (Retired UNH Professor, invited witness)]: I made a note of two things to send you. If you think of other things, Patricia has my email. And I did put together what turns out to be maybe half to two thirds of my main books in a little two page piece. But I did add some additional stuff over the last couple of days since I wrote this. So I'll leave these with Patricia, if anyone would like to see them. Great.

[Rep. Michelle Bos-Lun (Member)]: Can put him into the record along with Patricia.

[Rep. Richard Nelson (Ranking Member)]: Okay. He comes with a truly product, so he can pass him out.

[Rep. David Durfee (Chair)]: All right, we'll take a break. We'll start up again.