The Show for April 28, 2026: PFAS and pregnancy, chimpanzee civil war and more

There’s a lot of concern about the health impacts about the class of chemicals known as PFAS. We’ll heat what new research finds about the risks of exposure by pregnant women. Plus, a lead researcher on the chimpanzee “civil war” in Uganda and what it says about humanity.

Transcript

MARK BRODIE: Good morning, it's the show here on KJZZ 91.5 in Phoenix. I'm Mark Brodie.

LAUREN GILGER: And I'm Lauren Gilger. Coming up, why some four-year colleges and universities are getting into the dual enrollment space. And a UA researcher documents a surprising and violent civil war between chimpanzees in Uganda. But first, the Trump administration is waiving environmental laws and spending billions on building a wall on the southern border. But in Texas, much of the border is marked by the Rio Grande River, and there they are putting in buoys. Big orange tube-like buoys designed to stop people from crossing the river. But our first guest this morning reports the planned hundreds of miles of buoys could have major consequences. Martha Pskowski is a climate reporter based in El Paso, Texas, for Inside Climate News, and I spoke with her more about it.

MARTHA PSKOWSKI: The buoys that are being placed in the Rio Grande are these massive orange cylinders. They're about 12 feet long and they're connected one to another, so there's no gap between them, so it's supposed to create a continuous barrier across the river that would stop anyone from getting over it.

LAUREN GILGER: OK, so that's kind of how they would stop migrants from crossing the river, which has been something that's happened on the Rio Grande for a long time, right?

MARTHA PSKOWSKI: Right, the idea behind the buoys is that if you have a barrier in the river itself, people don't even have the opportunity to get over to the other side and get on land.

LAUREN GILGER: Yeah, it sounds like the Department of Homeland Security went around environmental laws, waived contracting laws, expedited this process in lots of ways that we've kind of seen happen in various parts of the border, especially, you know, as we're seeing wall construction happen here in Arizona as well. What did DHS do here to get this buoy project underway?

MARTHA PSKOWSKI: This project really picked up momentum last year once there was funding for these contracts, and the first section is going in in the river near Brownsville, Texas, so there was a series of waivers last year that kind of cleared the way and then these contracts started going out for hundreds of millions of dollars, some of them over a billion dollars. I added up around $2 billion in contracts that reference the buoys. So, this first section in Brownsville, but then also contracts that have been issued for other parts of the river where they'll presumably go next.

LAUREN GILGER: OK, so your reporting here, Martha, on the possible environmental impacts of these buoys, if they end up being as extensive as the plan is, which is very extensive, what could those environmental impacts look like?

MARTHA PSKOWSKI: Right, the Rio Grande through South Texas and the Rio Grande Valley, you know, it's a dynamic river. So, over the last few years, it's been quite low because of the drought, but there are floods on the river, there have been hurricanes that have come up from the Gulf. So, one of the big concerns is just in a storm how are these buoys going to perform.

Customs and Border Protection says they're designed for a 100-year flood, but we haven't been able to see any specific technical information. And then just having these buoys in the river could really change the flow of the river. It could push the water in different directions, cause sediment to build up in new areas. So, something like this has really never been done on this scale, and there's a lot of questions about what impacts it'll have on the river.

LAUREN GILGER: Yeah, you talk to this geomorphologist, which is a great title to begin with, who was kind of studying the existing spherical buoys that are already on the river. What did she have to say? This was about flooding in particular.

MARTHA PSKOWSKI: Right, so this is Adriana Martinez, she studied these buoys that are in Eagle Pass, Texas, which the Texas government installed a couple years back. And this is a very small section of buoys compared to what the federal government is doing, but she did observe that, you know, when the water was low, the buoys would actually be sitting on the riverbed and then, you know, sand and sediment would build up around them, and the water was being pushed in different directions. She had concerns that it could change the Mexican side of the river. So, this was only a 2,000-foot section of buoys that she observed these changes on while the federal government is now planning to install hundreds of miles of buoys.

LAUREN GILGER: What would the full scale of this look like? How many hundreds of miles are we talking about here?

MARTHA PSKOWSKI: What the Customs and Border Protection has proposed so far is 536 miles of buoys. The first section they're doing is 17 miles in the Brownsville area. So, you know, if they build this whole chain of buoys, it would go all the way up towards the Amistad Reservoir in South Texas, you know, a significant chunk of the border between Texas and Mexico.

LAUREN GILGER: Yeah, yeah. And, Martha, this is all happening as we're watching the border really change, like unauthorized border crossings have dropped dramatically in recent years. How does that kind of context play into the, I guess, the necessity for a project like this?

MARTHA PSKOWSKI: Right, you know, at the moment, we're just seeing really low numbers of people attempting to cross the border. I live in El Paso, you know, anyone who lives on the border sees these ebbs and flows both in the number of people arriving and then the media attention that follows, but right now, you know, month to month there's very few people attempting to cross the border, being apprehended.

But that hasn't slowed down the Trump administration's border wall or border buoy plans. To the contrary, they're really moving quite quickly and implementing these projects, you know, in Texas, Arizona, a lot of different parts of the border. And, you know, the waivers specifically for Homeland Security to issue those waivers, you know, there is meant to be a homeland security justification for, you know, waiving all of these federal laws. So a lot of people are asking, you know, what's the urgency to do this when we're seeing such low numbers of people trying to cross the border.

LAUREN GILGER: Right. And you report that this project has really been going under the radar in a lot of ways. What's the reaction been like there in southern Texas, though?

MARTHA PSKOWSKI: I was reporting in Brownsville earlier this year and, you know, that's where the first buoys are going in and some local activists had a rally and have been going to county commissioner's court is what it's called in Texas, and a few counties have passed resolutions in opposition to the buoys and trying to raise this issue, you know, with their congresspeople or, you know, just get some more information from the federal government.

You know, a lot of people just don't know that this is happening. So, you know, in the Rio Grande Valley, in South Texas, people are trying to spread the word before the buoys extend to more areas of the river.

LAUREN GILGER: All right. Martha Pskowski, a climate reporter based in El Paso, Texas, for Inside Climate News. Martha, thanks so much for your reporting here. Thanks for coming on.

MARTHA PSKOWSKI: Thank you for having me.

MARK BRODIE: More and more Arizona high school students are taking part in dual enrollment programs. Maricopa Community Colleges says it had nearly 28,000 dual enrollment students during the 2024-25 school year. By way of full disclosure, KJZZ is licensed to the Maricopa Community College District. Helios Education Foundation is reporting an increase in participation across the state as well. Dual enrollment generally allows high school students to take college classes and earn college credit. And in some places, it's becoming so popular that four-year colleges and universities are starting to offer the program. Scott Carlson with the Chronicle of Higher Education has written about this. He joins me and Scott, for those who aren't familiar with the concept of dual enrollment, what exactly is it?

SCOTT CARLSON: Dual enrollment is this construction that has sort of popped up across the country in different forms in different states. But it's basically a situation where students in high school can step away from high school courses and take college courses for credit either in their high school or at the college campus. It's different in different settings. It's not always called dual enrollment, sometimes it's called college in high school, sometimes it's called concurrent enrollment, but it's basically that structure. And it was founded for a couple of different reasons. One is to give students some sort of sense of what college is going to be like. The other goal of dual enrollment at some level is to offer these courses at a reduced rate or a lower cost, sometimes they're free, and so the student is able to knock down college credits while still in high school at this lower price point, and that gives them a head start in their college journey.

MARK BRODIE: And typically, as you report, high schools have worked with community colleges and other sort of non-four-year colleges and universities to, you know, to offer these classes, but that seems like it's changing?

SCOTT CARLSON: Well, it was sort of conceived as a community college project. I mean, dual enrollment is where the community colleges have been able to support their enrollments by bringing these students in. But with that sort of promise that the community college is an open access kind of institution, and it allows the students to experiment, and it's typically lower cost. You're in courses with students that are also sort of trying out college in their own way. Um, so the community college was sort of the natural place where dual enrollment would grow up or become a thing. But what you find now is a lot of four-year institutions that are entering the dual enrollment space where they're able to, and compete for those students because of course in this environment in America right now with colleges, so many colleges are seeking students to create a pipeline for tuition which they need to stay afloat.

MARK BRODIE: Are there particular fields of study that you're seeing four-year colleges and universities trying to enter in the dual enrollment space?

SCOTT CARLSON: Not in particular. I mean, I think one of the things that colleges are trying to do is, is go at the prerequisites that students would be taking. Um, in those first year, first couple of years of college. There are instances where high schools are playing into kind of a CTE or Career and Technical Education environment or that kind of programming. That's all about helping students who come from lower-income backgrounds get into high-demand fields, areas where we really need workers. Cybersecurity, nursing, and so on.

MARK BRODIE: What kind of impact is it having on community colleges that four-year institutions are starting to get into this?

SCOTT CARLSON: Well, I mean, for community colleges, this is a major source of enrollment. And it has been really since the pandemic and maybe even before. There are some community colleges where 50% of the enrollment is dual enrollment. Um, they've been able to float the boat on high school students. So for community colleges, this is extremely important, a very important pipeline of students that they would end up recruiting over time. In a lot of cases, not in all cases, but in a lot of cases. Yeah. Um, so naturally the four-year institutions are going to look at that and say, you know, why can't we capture that market ourselves? Why can't we go for that? In some cases, they're barred from that, or there are barriers to them. For example, in Colorado, what is called dual enrollment is called concurrent enrollment there. And it's really reserved for the community colleges. If you're going to do dual enrollment at a four-year institution, you have to pay for it as a student or as a family. So, there are barriers there for the four institutions, but they're trying to work around that to get access to that pipeline of students.

MARK BRODIE: I mean, is there enough of a pool of students for both community colleges and four-year colleges to really have successful, thriving, robust dual enrollment programs?

SCOTT CARLSON: Um, not in some parts of the country, no. You know, in some parts of the country, in the Northeast, in the upper Midwest, for example, you're seeing this demographic decline. So the numbers of students that are coming out of high school are going to be dropping over the next couple of decades. Um, so that's a shrinking pool of traditional students that these four-year and two-year institutions would be going for. And now they have to seek out other sorts of populations. High school populations, you know, going for the students that are before college, is one of those areas that they're trying to exploit. The other area that a lot of colleges are looking for is the adult population. So students who went to college, knocked down some credits but never finished, what's the possibility of their bringing those students back in and allowing them to finish?

MARK BRODIE: One of the things that's so interesting about this happening now is that in Arizona very recently, the state allowed community colleges to offer four-year degrees. So like on the one hand, you have community colleges starting to do what four-year colleges traditionally had done. And then you also now have four-year colleges starting to do what community colleges had traditionally done.

SCOTT CARLSON: Yes. I mean, to some extent, this is mission creep, right? It's the institutions trying to find these other avenues to get students. It's also to some extent a function of the institutions trying to play to their mission and trying to help out the local economy. So the four-year programs that are popping up at community colleges, often that's popping up because they are in areas of desperate need for workers, so nursing, and cybersecurity, these other sorts of direct-to-job kinds of programs. Um, and the thirst, the hunger for those kinds of workers is just so high that the four-year institutions just can't serve the capacity. So more of the state policymakers and higher ed, you know, state higher education boards are turning to the two-year institutions as an option for that. Again, though, like I mean, there are wars between institutions or different types of institutions at some sort of subtle level in the sense that this does again, though, play to what these institutions need, which is bodies for tuition, which help to support the college itself.

MARK BRODIE: Well so how do you see this all playing out?

SCOTT CARLSON: Well, I mean, I see this continuing to be an area of competition. The fact that the states and the state higher education boards need to sort of figure out the rules around this is important for the students themselves and the consumer protection that the students need. Because transfer is always one of the big issues when it comes to coming out of transferring out of community college, right? And you don't want to complicate that process even more by making this college and high school process not clear, not set up, not not with a robust set of rules around how it's going to work for the student.

MARK BRODIE: Do you get the sense that policymakers are aware of some of these issues that they need to start to think about?

SCOTT CARLSON: So I think policymakers do feel that they need to deal with this, but there are so many intense interests on the part of the institutions, which are powerful lobbying organizations. So how do you mete this out among all of these different institutions ends up being a headache for a lot of these policy makers in different states, but it's an issue that they're going to have to hammer out.

MARK BRODIE: All right. That is Scott Carlson with the Chronicle of Higher Education. Scott, thanks so much. I appreciate it.

SCOTT CARLSON: Thanks, Mark.

LAUREN GILGER: Good morning. It is the show here on KJZZ 91.5. I'm Lauren Gilger.

MARK BRODIE: And I'm Mark Brodie. Coming up, what a civil war among chimpanzees can teach us about our own humanity. But first, the valley was once the destination for those with damaged lungs in search of clean dry air. In the early 1900s, white tents to house tuberculosis patients popped up around Scottsdale and Sunnyslope. For many years, families would move asthmatic kids to Phoenix. These days, though, we're better known for dirty air and high rates of valley fever. But you might not know that Arizona's hot dusty landscape makes it a hotspot for another chronic lung infection. Nontuberculous mycobacterial pulmonary disease, often called NTM. Not many physicians know how to diagnose it or where it comes from. Researchers at the Centers for Disease Control have called it a substantial public health concern. Infection rates around the world are increasing as the population ages and the climate changes. It's estimated that close to 300,000 people in the United States and thousands in Arizona have NTM lung disease. Long-time valley journalist Terry Greene Sterling is one of them. She was first diagnosed almost a decade ago. She still has it. For the uninitiated, her daily routine may sound a little over the top, but for her and others with NTM, it's become a way of life. This project, called Breathless, was supported by the Pulitzer Center.

TERRY GREENE STERLING: I haven't had a hot, steamy shower in years. When I'm drawing a bath, I'm sure to turn on the fan and open a window. It's just one of the many precautions I take to prevent additional exposure to a bacteria that can eat holes in my lungs. Arizona is teeming with nontuberculous mycobacteria, or NTM. It can make its way into the air from soil and water. It can be deadly. People over 65 or those with weakened immune systems or lung damage are vulnerable to the infection. And it's especially prevalent in warm climates. My exposure to NTM can change from day to day, inside and outside. I try to be discrete with the measures I take to avoid breathing in more of this bacteria or a different, more destructive one. It's become a normal part of my routine, but I'm sure my behavior can seem bizarre. When I wash dishes, I hold my breath to avoid breathing in steam. I boil my drinking water. I dodge misters in restaurant patios. I wear a mask while gardening. I blast air purifiers in my bedroom, writing room, and kitchen. I clean out my lungs every day with a nebulizer, and I'm meticulous about sanitizing my breathing equipment. Other than using the nebulizer, none of these precautions have been recommended by my doctors. But they make me feel like I'm doing something to protect myself.

ALEX PERRY: Nontuberculous mycobacterium are mycobacterium that live basically are environmental pathogens. So they live in the soil, they live in like the water supply. They can proliferate in our pipes, proliferate in our shower heads. Dust storms, I mean there are so many different ways that people can be exposed to.

TERRY GREENE STERLING: That's Dr. Alex Perry, an infectious disease doctor in Tucson. He's a clinical associate professor at the University of Arizona College of Medicine.

ALEX PERRY: I don't think if you have a, if you garden you're not trying to give yourself a, a lung infection. But it's just like this, these are, you know, unfortunately ubiquitous. Um, which is really frustrating for people because they're like what could I have done differently? And I'm like, not interact with the environment ever? Uh, and that's just no way to live.

TERRY GREENE STERLING: NTM lung disease has long been ignored by most medical and pharmaceutical professionals. For nine years, I've interviewed the few scientists, doctors, researchers, and health policy advocates who do focus on it. When he began this work, Perry quickly recognized a significant gap in patient care.

ALEX PERRY: There is this whole population of people that were kind of to a certain extent suffering, but more importantly like had this diagnosis but didn't really know what it meant, and really didn't have anybody to really talk to...

TERRY GREENE STERLING: One thing that makes me feel better is a breathing technique called autogenic drainage. It's a way to clean my lungs without machines. And I use an app on my phone as a guide. But some at-home practices, according to Dr. Perry, are dangerous.

ALEX PERRY: Some people want to, uh, you know if they use nebulizing they want to use different chemicals in nebulize, like some people want to use like cleansers, bleach, hydrogen peroxide, and like please don't do that. There's no such thing as a safe form of that in your lungs.

TERRY GREENE STERLING: Nontuberculous mycobacteria aren't just one species of bacteria. Some are more aggressive than others. Here's Dr. Charles Daley. He's chief of the Division of Mycobacterial and Respiratory Infections at National Jewish Health in Denver. He's also my doctor.

CHARLES DALEY: There are actually about 200 species now that are found ubiquitously throughout the environment, in water and soil. And they can produce a chronic progressive lung disease in some people. Um, why that happens we don't know, why some people get it and others don't. But once someone gets it, it can be very hard to treat. Treatment outcomes are sub-optimal, and it's one reason we're focusing a lot these days on drug development.

TERRY GREENE STERLING: It's important to know what species you have. That will dictate your treatment. The species in my lungs is a member of the Mycobacterium avium complex, or MAC. It has grown slowly, so I have managed to avoid the usual treatment of three strong antibiotics over the course of a year or more. Not only is NTM lung disease difficult to treat, it's often hard to track. Dr. Daley has no clue how, or where, or when I got infected.

CHARLES DALEY: We don't know how long it could have been in someone's body by the time they present. They think oh it's from that hot tub, you know, last week up in the mountains, but it might have been actually five years earlier, somewhere else.

TERRY GREENE STERLING: My symptoms showed up 12 years ago as an occasional cough. I started having frequent sinus and chest infections. I would often collapse on the couch and fall asleep as soon as I got home from work. After three years of this, a Phoenix pulmonologist diagnosed me with NTM lung disease. It's not contagious, yet it has a social stigma. It can be a messy and embarrassing disease. Some who have it feel judged for being exhausted, for coughing, for going to extremes to avoid further exposure. NTM lung disease often shows up in people who have bronchiectasis. Not to be confused with bronchitis, bronchiectasis means the airways are damaged, can't clean themselves, and are vulnerable to infections. Sometimes, even after years of antibiotics, the NTM infection doesn't go away, or a new species takes its place.

CHARLES DALEY: They go back to the same environment and then they get infected again. The recurrence rate for um MAC pulmonary disease um has been about anywhere from 25 to about 50%.

TERRY GREENE STERLING: Linnea B. Remson lives in Scottsdale. We met in an online group for people with damaged lungs. We occasionally get together for coffee or talk on the phone, just to check in on each other. Remson used to be infected by NTM. She took multiple antibiotics for 17 months before the bacteria was gone.

LINNEA B. REMSON: They made me sick. The treatment was almost as bad as the disease. Uh, gastrointestinal upset, uh, nausea, uh, I never I was never sure, you know, when I would be symptom-free and when I would have to run to the nearest bathroom.

TERRY GREENE STERLING: These possible side effects are why I'm trying to avoid taking antibiotics for as long as I can. Remson was taking antibiotics every other day. If she were to have a recurrence, she might have to take them every day.

LINNEA B. REMSON: I just can't even imagine that. Every other day was hard enough, and I began to um kind of plan my activities around the days that I would and would not be taking the uh antibiotics.

TERRY GREENE STERLING: Remson has been NTM free for a decade, and she takes extraordinary precautions to prevent a recurrence. In addition to the precautions that I take, she sets her hot water heater to a scalding 140 degrees. She takes extra oxygen on airplanes. She wears a mask when she's outside on high pollution days.

LINNEA B. REMSON: I've actually had people stop me in the store and say, "Why are you still wearing a mask?" And the answer is, "Because I still need to." And that's all there is to it.

TERRY GREENE STERLING: To me, all of this sounds perfectly normal, even though it's not. But new medicines are being developed. There's hope. Recently, I received the news that I've been dreading. My NTM infection may have gotten worse. I might have to take those antibiotics after all, and deal with the possible side effects. And if that happens, I'm ready. For KJZZ's The Show, I'm Terry Greene Sterling.

MARK BRODIE: There is increasing concern about the health impacts of being exposed to the class of chemicals known as PFAS. And a new study finds exposure by pregnant women to the so-called forever chemicals increased the chances of their babies being born prematurely and with low birth weights. It also increased the risk of infant mortality. The data come from New Hampshire, and one of the researchers says the study tried to isolate the effects of PFAS by themselves. Derek Lemoine and Ashley Langer are among the authors of the study. They're both economics professors at the University of Arizona and co-directors of the Consortium for Environmentally Resilient Business. They join me to talk about what they found. And Derek, let me start with you and how you went about doing this research. Because as you've written, you clearly cannot intentionally expose humans to PFAS. But you found a place where you could really measure the health effects of people who had exposure versus those who did not. How did that come to be?

DEREK LEMOINE: So if you want to think about, what do PFAS do to human health, you might imagine taking people into a lab and giving them PFAS. But as you said, we're not going to do that, we wouldn't, and we couldn't, for all kinds of reasons. So we want to find an experiment, what we call a natural experiment, some messy real world data, something that looks like an experiment, where some people were exposed to PFAS, some weren't. Ideally they don't really know who they are. They basically went about their lives the same as each other, except that some were drinking water that plausibly had more PFAS in it and some didn't. The trick was that we found a setting in New Hampshire where there were mothers living near contaminated sites, and we were able to get data on where their wells were, and the wells that were serving them, and some of their wells were upstream and down water terms, and groundwater terms from the contaminated sites, and some were downstream. And that was the variation we used.

LAUREN GILGER: And Ashley, it sounds like the findings were pretty dramatic in terms of the health impacts on newborns based on whether or not their mother lived upstream or downstream from these contaminated wells.

ASHLEY LANGER: Yes. We were very surprised at how substantial the effects were, how big they were. You know, we thought that there might be an effect on infant health. But we were fairly astounded by the fact that infant mortality was three times almost higher for the mothers who were receiving water from wells downstream of these contamination sites relative to very similar mothers at a similar distance from the contamination site, but who were receiving water from wells upstream. These were shocking to us.

MARK BRODIE: Ashley, obviously, you know, real world data can be a little bit messier than lab data. But is it possible or how much of these numbers do you think is attributable to PFAS versus any of the other variables that, that these mothers could have been affected by?

ASHLEY LANGER: So we've done a lot of checks and robustness, and really dug into these because we really wanted to make sure what we were getting at was PFAS and not something else. So these mothers, you know, they were controlling for things like whether they're differences in wealth, or education, or maternal health, smoking behavior, things like that. We don't see any difference between the mothers who are receiving water up gradient from these sites relative to down gradient in those types of demographic outcomes. We don't see differences in education, in any of these things, home values. So we are fairly convinced this is coming from where they're getting their water from. Now, we are looking particularly at contamination sites that had these older types of PFAS, um, that are now generally not used. There's some chance there are other types of PFAS that are released at the same time that could be in drinking water, but we ruled out a lot of other potential avenues by which these results could occur.

MARK BRODIE: So Derek, one of the things your paper looked at is the cost, the economics of this. And I want to ask you about that, because cleaning up PFAS is, of course, expensive. There's been a lot of talk about that around the country and here in Arizona. But you found the health costs of not cleaning up the chemicals are higher than the costs of actually cleaning them up.

DEREK LEMOINE: Yeah, thank you for bringing this point up. So as economists, we bring two things to this study. So one is a focus on like really nailing the causal effect of PFAS in the data, and the other is, once we've gotten an effect on health, we really want to monetize that to be able to compare it to the cost of cleaning up. Because that's the benefit of cleaning up PFAS is avoiding these negative health outcomes for mothers and infants, and then in addition to any other negative health outcomes PFAS might cause. And so we want to be able to compare that to the cost, and ask whether policies to clean up PFAS make sense. And any regulator such as the EPA right now that's thinking about cleaning up PFAS or do the same calculation. So we use outside estimates of the cost of being extremely low birth weight. So that imposes costs on babies throughout the rest of their lives in terms of higher healthcare costs, greater risk of mortality in the first year. It imposes costs in terms of lower wages later in life, and we use outside estimates of those costs. We can then extrapolate from our estimates in New Hampshire to the rest of the country, how many extra births of each type do we think there are. We can take our cost per type of birth, and combine them, and then we can get the total extra burden due to PFAS. It's a coarse estimate, but it's a back-of-the-envelope calculation based on something that we believe in pretty well for New Hampshire. The number we get is at least $8 billion. The idea is that it's probably, it's almost surely greater than that when you take into account we know we should add different kinds of costs, we just don't know how to add whether everything in one category is also in another category or to what degree they overlap. But it's at least $8 billion a year, and the estimated cost of cleaning PFAS up or complying with the recent EPA rule to clean PFAS up are under $4 billion a year. So that makes it look like a pretty good deal to bring PFAS toward that rule. If that rule is sufficient to avoid a lot of these negative outcomes we're finding for mothers and babies.

MARK BRODIE: Ashley, when you look at those numbers, roughly $8 billion in costs health-related, about $4 billion to clean, little less than $4 billion to clean. What comes to mind to you in that calculation?

ASHLEY LANGER: So we think that this $8 billion number is really conservative as the potential benefits of removing PFAS from drinking water in these places where it's contaminating the drinking water. That's just for these outcomes, for infant health. And so that doesn't address any of the other health outcomes that could happen. We're not looking at long-run cancers or any adult impacts that other studies have suggested might be there. As economists, we generally think about weighing costs and benefits, and here, if the costs of removing the PFAS are only $4 billion, and the costs of leaving it in are at least $8 billion, this looks like a really good deal, and a really good way to help infants over their entire lives.

LAUREN GILGER: Derek, I'm curious how you would hope that this data would be used outside of the sites that you're looking at in New Hampshire, given sort of what we know and what we don't know about PFAS, where it is, and how much exposure people might have to it.

DEREK LEMOINE: Yeah, there's a few ways that we would like to see some of these numbers used. So one is, as Ashley was saying, there's a burden for any new rule to clean up PFAS. That burden is going to fall on water utilities and therefore on their customers. There's also a health burden from having PFAS in the water that falls on their customers. And so one implication is that this study can inform ways of weighing those burdens. Are the costs customers pay worth the benefits they're going to receive? Another is that the kinds of PFAS we're studying are what are called long-chain PFAS. They really haven't been produced much in the U.S. since about 2010. But they are all throughout the soils. And so they're basically more or less nationwide. Their soils contain a large mass of these, and they're slowly migrating down toward groundwater. So these are going to be entering groundwater over the next decades and centuries. Not only are there implications for utilities cleaning up, but these kinds of PFAS can be cleaned up fairly effectively by the types of carbon filters that a lot of people have in their homes and pitchers or in their refrigerators. So there is also the idea that you could, if we know that certain populations are especially vulnerable, and in our case we're looking at a population of pregnant mothers that we show is fairly vulnerable to PFAS. Then you could also just have much better testing and information that we currently have about who is exposed to PFAS, and allow households to then take the actions at the household level to clean up some PFAS. So information itself might be a fairly cheap policy that could go a long way.

MARK BRODIE: Derek Lemoine and Ashley Langer are economics professors at the University of Arizona, and co-directors of the Consortium for Environmentally Resilient Business.

LAUREN GILGER: Good morning. It is The Show on KJZZ 91.5. I'm Lauren Gilger.

MARK BRODIE: And I'm Mark Brodie. You might have heard a fascinating bit of news in recent weeks. Researchers at the Ngogo Chimpanzee Project in Uganda published a paper documenting a deadly split among a large group of chimpanzees. For eight years, the chimps have been embroiled in what's being called a bitter civil war that has resulted in 24 killings, including 17 infants. It's an incredibly rare turn of events in chimpanzee behavior, and the story has been published all over the world. Our next guest this morning watched it happen with dismay. Jacob Negrey is a primatologist and assistant professor of anthropology at the University of Arizona, as well as co-director of the Ngogo Chimpanzee Project in Uganda. He told me their ongoing conflict says a lot about humanity, even if not everyone has wanted to hear it. I spoke with him more about it recently, beginning with his reaction to all of the attention the story has gotten.

JACOB NEGREY: I am just overwhelmed by the range of reactions to this story — some who see so much from their own lives and their own political experiences playing out in this chimpanzee mirror world, and other folks who are so deeply offended by any comparison between what we're observing in the chimpanzees and in humans. This story has in certain venues been described as a quote "civil war" unquote between chimpanzees, and that term as applied to these chimpanzees has really ignited diverse responses.

LAUREN GILGER: Yeah, I guess, I mean, are you surprised by that? It sounds like you were struck by it, but did it surprise you?

JACOB NEGREY: I was struck by some interactions I had in my department, actually, where other anthropologists were just so displeased that this was being described as a civil war between chimpanzees. I think for some folks, a civil war must involve nation-states, so from that perspective, I understand.

But I do believe that our story about the chimpanzees has a lot to tell us about shared social mechanisms for fissions in societies, for splits that perhaps, although we like to think that we are so exceptional and so special as humans, that perhaps some of our own social experiences are reflected in the lives of these animals to a pretty extraordinary extent.

LAUREN GILGER: Yeah. Ah, so it's fascinating. OK, we'll get to that in a moment. But let me back up for a minute, Jacob, and just ask you about what you saw happen with these chimps in Uganda. I mean, obviously, this is a well-observed, you know, group of chimpanzees there as part of this project.

But it sounds like this was almost a decade ago, more, that you started to see these kinds of divisions, this polarization within these clusters, as you call them, of chimpanzees. What did it look like?

JACOB NEGREY: Yeah, so I have been working at this field site, Ngogo, for about 13 years now. So when I started working at Ngogo, it was very clear that we were still looking at one group — what we call community — of chimpanzees, that they would come together to eat and to socialize. And then one summer in 2015, we began to notice that the chimps weren't all coming together.

We had chimpanzees in what we call the western subgroup no longer joining together with chimpanzees in our so-called central cluster. And it was quite obvious to us. We noticed this, that yeah, we had two distinct clusters.

We thought that this was just an indication that conditions at Ngogo, ecological conditions, were so good — to put it another way, that there was so much food at Ngogo — that these chimps didn't have to come together. So, yeah, none of us could have predicted in 2015 how this would play out. We were all genuinely shocked.

LAUREN GILGER: Right. So, I mean, talk about how this played out and watching it. Like, these are chimps that I think it sounds like you all as researchers there know kind of intimately — like they have names, you watch them, you're aware of them, they're aware of you, right? But you started to see like real violence happen, even to some infants.

JACOB NEGREY: Absolutely. So, we began to see when these two different clusters of chimps would come together, they acted more and more as if they were encountering a stranger group of chimpanzees. Chimpanzees are are quite fearful of strangers; if we were talking about humans, we might call them xenophobic. When they meet, there's a lot of fighting, there's a lot of screaming, there's a lot of running around. And as we've known for decades, there is lethal violence between chimpanzee groups.

And when we began to see this happening between different members of the Ngogo community, that's when we began to grow really quite concerned. And I do use the word concerned quite genuinely. We are scientists, but we are also deeply invested in these animals. We spend a lot of time to protect them as well. And so to see the relationships at Ngogo deteriorating into increasingly violent interactions was was genuinely disheartening to us.

And of course, to then see that ultimately in 2018 rise to the level of lethal violence was, although we had seen this on the horizon for a few months at this point, it was still shocking that it finally happened.

LAUREN GILGER: Yeah. So I mean, you mentioned at the beginning some of the reaction that you've got to this and some of the skepticism, like this this, you know, sort of pushback that we are as human beings closely related to or should learn something from what's happening in chimpanzee communities.

But you as authors here describe these results as as maybe a challenge to this idea that when humans go to war, right, including go to civil war, it's got to be something that's driven by these kind of cultural markers like religion, countries going to war. Do you think that this says something about humanity?

JACOB NEGREY: I may be biased in this regard. I've been watching these extraordinary animals for quite a long time now. Every time we as humans try to draw a a line in the sand between our species and say, "OK, humans do this and other living things do this," you know, "this is the thing that makes us human," inevitably we have to walk those claims back the more we learn about other living things.

And I personally think this is one of those cases, that although chimpanzees might not have religions, they might not have political ideologies, I do think that their social relationships have a great deal to tell us about our own. These animals live for a very long time. We think that some of our chimpanzees have lived into their 70s.

And so the depth of their relationships across time is quite striking. And so to see these chimpanzees be able to treat other chimpanzees that they have known for decades as enemies is truly striking. It's difficult to overemphasize from a scientific perspective everything we know about chimpanzees, just how unusual it is to see them turn on their long-term friends, for lack of a better word.

And so I think this story tells us a lot about the importance of maintaining social relationships for, you know, the good of society at large, that perhaps we like to think that our conflicts boil down to these big ideas like religion and political ideologies, but when it comes right down to it, I think it begins with how we interact with people and whether we interact with them affiliatively.

Are we occupying shared spaces? You know, are we coming together to perform basic human social functions? I think there is a lot to this — how we relate to each other on, you know, a personal level and how that may scale up to the societal level.

LAUREN GILGER: Mmm, super interesting. All right, we'll leave it there. Jacob Negrey is a primatologist, assistant professor of anthropology at the University of Arizona, as well as co-director of the Ngogo Chimpanzee Project in Uganda, joining us. Jacob, thank you so much for coming on. This is fascinating.

JACOB NEGREY: My pleasure. Thank you, Lauren.

MARK BRODIE: Lots to ponder there with those chimpanzees, huh?

LAUREN GILGER: Absolutely. There are like Netflix series about these chimps, it's wild. You gotta, you gotta go check it out.

MARK BRODIE: So interesting. All right, that'll do it for this Tuesday edition of the show. Thanks as always for being along. Remember to sign up for the show's weekly newsletter, it is called Radio Heads. You can sign up at theshow.kjzz.org. For Lauren Gilger, I'm Mark Brodie in Phoenix. Have a great rest of your day. Hope to have you right back here tomorrow.