You are using an outdated browser.
Please upgrade your browser
and improve your visit to our site.
Skip Navigation

So Long, DDT. See You Around Soon.

The United States banned the incredibly toxic pesticide DDT in the early 1970s. But it never went away.

Illustration by Erik Swanson

In the 1940s, the pesticide DDT exploded in popularity. Corporations and governments sprayed the chemical for decades, ignoring warnings that it might poison the environment and endanger human health—until countries finally began outlawing its use for precisely those reasons. On episode 47 of The Politics of Everything, hosts Laura Marsh and Alex Pareene talk with Elena Conis, the author of How to Sell a Poison: The Rise, Fall, and Toxic Return of DDT. They explore how corporations dismissed the dangers of DDT to protect profits, how pioneering environmentalists like Rachel Carson fought back, and why harmful chemicals may continue to cause problems long after their usage has ceased.


[Clip] Remember the name: Pestroy DDT! It spells certain death to all insects I’ve mentioned so far and others too. There must be a catch to it. Maybe Pestroy hurts humans too? No sir, it harms only us: the citizens of Bug-land!

Laura: Go back to the 1940s, and you can hear a lot of jovial, confident ads like this one for a miraculous new substance: DDT.

Alex: A lot of those ads are on YouTube now. When you watch, you want to reach through the screen and stop the people in them from picking up those cans of DDT.

Laura: In one, there’s a woman, a 1940s housewife wearing a checked apron and holding a paintbrush. She’s literally slathering the walls of her home with a coat of DDT. In another, there’s a man spraying DDT under his couch cushions.

Alex: There’s even one where a scientist stirs DDT into his food and eats it to prove how safe it is.

Laura: It’s easy to see these images and hear the midcentury announcer voice and think that this carefree attitude belongs to the past.

Alex: But though DDT was eventually banned, it was never fully banished—and it is just one of many poisonous chemicals sold to Americans for use in our homes and gardens.

Laura: Today on the show, we’re talking about how a poison becomes a household product.

Alex: And once it’s out in the world, can you ever really get rid of it? I’m Alex Pareene.

Laura: And I’m Laura Marsh.

Alex: This is The Politics of Everything.


Laura: DDT is thought of as an example of successful environmental regulation. It’s a dangerous chemical that was banned in part because of the efforts of Rachel Carson. Her book Silent Spring exposed the poisonous effects of the pesticide and spurred sweeping change in the 1970s. A lot of people know that part of the story, but what they may not know is that DDT didn’t actually disappear. We’re talking today with Elena Conis, the author of How to Sell a Poison: The Rise, Fall, and Toxic Return of DDT. Elena, thanks so much for joining us.

Elena Conis: Thank you so much. It’s a pleasure to be here.

Laura: Can we just establish: What is DDT?

Elena: Very simply put, it’s a chemical that kills insects. DDT stands for dichloro-diphenyl-trichloroethane, and for obvious reasons the popular way of referring to it became DDT.

Laura: Why was it used in the first place? Where did it come from?

Elena: It was synthesized for the first time back in the 1870s. In the 1930s, a Swiss chemist was looking for new chemicals to kill bugs. At the time, we were using some really toxic things to control insects on crops and elsewhere—things that contain lead and arsenic. This chemist was going through some compounds to see if there was anything better out there, and he stumbled across DDT. It became an incredibly important chemical during World War II, because as something that was so much safer than the previous generation of insect killers, people started using it in ways that we had never used insecticides (as they were then called). They started dusting them and spraying them on people, spraying them in their bedrooms, on their mattresses, on their clothing.

Laura: So it’s really this chemical that’s associated with the midcentury.

Elena: It really is.

Laura: One of the things I remember hearing about DDT is that it was particularly useful in controlling malaria.

Elena: Yes. This is part of the reason why it became so popular in World War II. We very quickly realized that if you covered areas where mosquitoes were breeding with DDT, you could really reduce the spread of that disease. So in World War II, we sprayed—especially in the Pacific—entire islands with DDT. We sprayed it from above using war planes that were rigged with massive tanks so that the DDT was really just rained down. Of course it didn’t just kill the mosquitoes. It killed flies and beneficial insects too. It had these unintended consequences that folks immediately weren’t too concerned with.

Alex: It sounds like it was treated as sort of a miracle chemical. We were using it with abandon. At any point were people then concerned about side effects? Were they concerned that it might actually not be a miracle chemical?

Elena: Absolutely. This was a chemical that was being tested in the 1940s by folks in a lot of different places. U.S. government scientists were just one group that was studying DDT. The Nazis were studying it at the same time, and they actually were really worried about its unintended consequences, so they shelved it and decided not to use it. In the U.S. there were scientists who were working in the entomology division, essentially, of the U.S. Department of Agriculture, who were just so taken by its power that they decided to move forward with it. Then there were scientists at the Food and Drug Administration who were really worried about some of its effects and said, “We should probably study this for at least seven, eight more months before we go any further.” The Army said, “OK, thank you for your opinion, you guys can keep studying it—we’re just going to go ahead and use it.”

Laura: It seems like there are two things here. One is that the poison that’s around could harm other animals—including humans—directly. The other is that even if it didn’t, just removing a huge chunk of the ecosystem—removing all insects—is also really bad, because insects do things. They keep plants healthy, they pollinate things, they contribute to soil health—all this stuff that you need to have a functioning agricultural system or ecosystem. You have to have some insects.

Elena: Absolutely. There was this farm columnist who also had a radio show back in the 1940s, Channing Cope. A bunch of DDT manufacturers sent him DDT because they were like, “Oh, he’s got a huge audience. Let’s get him to talk about it on his show.” He put it on his screens and on his door and on his cat and his pig and on his wife—he put it everywhere. After a couple of days, he was like, “This is an incredible chemical. And it also really scares me, because if we kill all the insects we’re going to be living in a world without flowers, without fruits, without vegetables. What are we going to be left with?” Some people heard that and they were really alarmed, and some people heard it and said, “That’s an exaggeration. You’re going too far. Don’t worry, it’s never going to get that bad.”

Laura: So there were concerns from early on. What brought this to Rachel Carson’s attention?

Elena: Late in the 1950s, she heard about a lawsuit on Long Island where somebody was suing both the local and federal Departments of Agriculture for spraying DDT to control a pest that was affecting large shade trees. This person’s name was Marjorie Spock. Her brother was the famous pediatrician Benjamin Spock. Marjorie Spock was trying to grow all of her food on her two-acre piece of land on Eastern Long Island. She didn’t want it sprayed with DDT, and her property got sprayed anyway. She was a person of some means, and she decided to take it to court. She got a judge to agree to hear the case, there was an article about it in a local New York paper, and Carson heard about it. When Marjorie Spock heard that Rachel Carson was interested, she flooded her with articles, journal articles, letters—just a ton of material. Once Carson started going through Spock’s papers, she would write back to Spock saying, “This is a gold mine, holy moly. There’s so much important information here.” To make a very long story short, so Silent Spring began.

Alex: You always want a sort of obsessive person of means to be a source for you when you’re looking into a story.

Elena: So true. One of the things that Spock had, which was apparently really unusual, was a fax machine called a Thermofax. She could make copies and send text transmissions from her house. In 1957, this was unheard of.

Alex: So we’ve been talking about DDT. We’ve asked what it is, where it came from. But we should establish the actual science that was uncovered here. It’s bad for people, right? DDT is not a miracle chemical. It’s harmful.

Elena: I will say that now we accept the idea that DDT is a toxic chemical. It’s been linked to several different kinds of cancer. It is also persistent, which means that once it gets into a living body—this can be a person or an animal—it builds up in its fat, so it sticks around for a long time and you can accumulate more of it over time. You can take in very little for a very long time and then all of a sudden have a toxic dose in your body.

Laura: Was there any research conducted into its effects on people?

Elena: There were some studies carried out by some scientists at the [Centers for Disease Control and Prevention] who fed DDT to prisoners. The prisoners were reportedly, on paper, all quote-unquote volunteers who signed up to swallow DDT and a cup of milk every morning. The scientist who led these studies insisted that it was absolutely harmless. He fed the DDT to these prisoners for 18 months and then followed up with them a few years later, and he insisted that they were in perfect health. But when Carson looked at those studies, actually, she was very skeptical, and she looked really closely at them and realized that some of their findings had been exaggerated and misrepresented—namely that the scientist who carried out the study said that all of these men had stayed in the study and didn’t have any ill effects, and she noted that actually some of those men dropped out of the study, and you didn’t ask them questions about this and you didn’t test these kinds of things about their health. So we knew and didn’t know, for a while, the full extent of its effects on people, but by the 1990s, 2000s—now jumping way ahead in time—we certainly did.

Alex: So DDT is not the miracle chemical that it was promoted as. After a short break, we’ll talk about what happened when Rachel Carson revealed that to the world.


Laura: Before the break, we talked about this huge enthusiasm for DDT after World War II. Rachel Carson’s book Silent Spring told a very different story. Elena, what happened as a result of her reporting?

Elena: One of the effects of her book was to bring loads of attention to these pesticides and in particular their downsides. New studies were launched, and there were also high-level investigations: President Kennedy launched an investigation into pesticides; a lot of states, like my state, California, did the same; and very quickly lawmakers all over the place decided to introduce laws to curb or stop the use of some of the chemicals that she listed in the book, DDT among them. As you can imagine, this was incredibly controversial, and the folks who were manufacturing and selling these pesticides weren’t so keen to see them banned and coming under fire—so they pushed back.

Laura: I’m interested in the kinds of arguments they made. Reading your book, it struck me that the manufacturers of DDT did something we’re pretty familiar with from the tobacco industry.

Elena: Yeah, they did. One of the first things that they did was they attacked Carson herself. They said, “This is not a trustworthy person. She’s not a scientist.” They called her a Communist and a spinster. They just tried to take her personally down. The other thing that they did was deny everything. This is something that the tobacco industry became famous for later. They said, “What are you talking about? Everything’s a chemical, don’t worry. Grandma uses chemicals in home canning, they’re harmless. Chemicals are only dangerous in large doses, but even water is dangerous in large doses.” But behind the scenes, they were having these monthly meetings, like, “Shoot, what are we going to do? This is a big problem.”

Laura: Something I thought was interesting, because I think it still shapes the way we think about diseases like cancer, is that the DDT companies basically tried to say, “Oh, well, if you have cancer, that’s because you have a bad diet, or it’s your lifestyle, or you lost the genetic lottery.” These are all things that we still say about cancer, and undoubtedly they are all factors, but being exposed to poisons every day that we cannot control at all—whether it’s through pollution in the air or chemicals in our food—surely also is going to be a huge factor in causing diseases like cancer. Those companies kind of won the argument long term, in that those are not the first things we go to when we hear about a cancer diagnosis.

Elena: I think that’s a really good point. In the long term, they were the winners in that communications war. The interesting thing is that for a long time they were able to say, “There just isn’t enough evidence linking chemicals to cancer.” That created the space for this other set of arguments to take hold.

Laura: Were there any particular groups behind these arguments?

Elena: In the late ’70s there was this organization that was launched, the American Council on Science and Health. One of their main objectives was to convince the American public that their personal lifestyle choices were the reasons why cancer, in their view, seemed to be on the rise. In their view, cancer was only on the rise because we were getting better at diagnosing it and because people were living longer, and we were seeing more of it as a result. So they popularized the idea that it’s about lifestyle, diet, lack of exercise—at the same time that folks in the industries themselves were spreading the idea that there wasn’t enough evidence yet, they’re still studying this.

Laura: That’s really become the dominant approach.

Elena: I think you’re right. I think in the long run that view has prevailed. It’s super complicated to say why, because part of it is also that the whole smoking issue is happening concurrently with all of this, and there is one really powerful example of where personal behaviors did contribute to a lot of cancer. So it was easy for different industries to point fingers at each other, and it was easy to at least hold up this one example that seemed to prove without a doubt that personal behavior was the main source of the problem.

Laura: That’s the other thing I find fascinating about this DDT story. Clearly you have a villain here—the people making DDT—but when you look at that period in history there are, like, dozens of other industries doing equally harmful things. You can see this explosion of poisons and toxins almost wherever you look, whether it’s in cleaning products or in pesticides or in the food supply with the switch to processed foods. Another thing we’ve talked about is the abundant use of asbestos. I mean, almost every way you turn in the 1950s, you’re basically running straight into something highly toxic or carcinogenic.

Alex: Leaded gasoline.

Laura: That could be a whole other episode. It’s almost surprising that this issue ended up getting so much traction because there’s such a roster of other culprits out there at the same time.

Elena: I think there are a few reasons for this. On the one hand, there are reasons that have to do with the fact that chemicals at the time seemed to solve a lot of problems, and then they did solve a lot of problems. That’s number one. The manufacturers of DDT in the 1940s were the big guys. Sherwin-Williams was one that we still know of today. Monsanto was another, and Dow Chemical. But it was also manufactured by what we would now call mom-and-pop shops. People would just make it in their shop and then sell it to their local community. It had an element of familiarity and trust. This is linked to something sort of paradoxical: DDT was off-patent, and the large companies started to see it as a money loser. There was just too much competition.

Alex: It was generic.

Elena: Everybody was making it. Some of the companies were like, “We’re actually losing money, so let’s stop making this. Let’s invest in other chemicals.” DDT kind of became the chemical industry’s fall guy after a while. Like, “Let that one take all the blame. Everybody knows about it because it’s so famous. Let’s just let it be banned”—which it ultimately was, effectively, in 1972—“and then we’ll make some new, patented proprietary substitutes and sell those at a much higher profit.” So it served them too.

Laura: That’s so interesting. If there had been a patent in place or intellectual property for someone to defend, we may never have seen that ban.

Elena: That’s very true. It may also have been used really differently too. It simply may have been far less accessible; its accessibility is also what made it less effective over time, because insects started to develop resistance to it. So there’s that other part of the story too: The more DDT we used, the more we had to use, because it just wasn’t killing bugs as efficiently in the 1950s and the 1960s as it had been in the 1940s. We really painted ourselves into a corner.

Alex: I’m amazed sometimes that we survived to the twentieth century.

Elena: Not everyone did, and we’re going to look that way at the twenty-first.

Alex: Yeah. I’m at the age where, in the late 80s, early 90s we were celebrating these wins, like acid rain. We fixed acid rain! We banned DDT. Everything’s on the up and up, the animals are coming back, everything’s going great. DDT is still treated as, I think, a victory—a success for regulation. There was public outrage, the government responded, and it got this dangerous chemical off the streets.

Laura: The “law and order” approach to DDT.

Alex: At the same time, I remember reading a few things—mostly in the conservative press, in around the 1990s—being like, “We need to bring back DDT!” There was a lobby to bring it back.

Elena: This is exactly why I wanted to write a book on this. Like you, I remember having that same feeling in the late 80s and 90s. We had stopped so many problems. We had banned DDT, acid rain, the ozone layer, the whales were back. We were doing OK. And then in the early 2000s, I was a graduate student in public health. I was at a conference, attending a talk on malaria. All of a sudden, the folks at the front of the room—the experts—were saying, “We really need to bring DDT back.” And everybody in the room was like, “Oh yeah, we need to bring back DDT.” And I was like, “What did I miss? The thing we banned, because it killed all the bald eagles?” Then it was all over the place. I think what made that argument powerful in the early 2000s was that it was coming from a couple of places. It was coming from public health experts, people who were devoted to public health and global health and genuinely interested in controlling skyrocketing rates of malaria, particularly in sub-Saharan Africa. At the same time, the argument was picked up by conservative pundits and people who weren’t exactly transparent about who they were but were also saying, “Yeah, we need to bring back DDT.”

Laura: What was their interest in bringing it back?

Elena: They were saying it for a completely different reason. On the surface, they said, “We need to bring back DDT because it’s the best way to control malaria.” But underneath, they saw DDT as this important morality tale. One of the folks who was very active in spreading the idea that we needed to bring back DDT was somebody named Roger Bate, who had founded something called the European Science and Environment Forum. He wrote op-eds about DDT for places like the Los Angeles Times and The Wall Street Journal. His argument was, “DDT’s story is this great example of how the liberals got things wrong. We can really spin this story and show that the greens wanted DDT banned to save birds, and then by banning it ended up causing millions of preventable deaths around the world due to malaria. If we hadn’t banned DDT to begin with, millions of more people—especially children in sub-Saharan Africa—would be alive today.” He saw this as a way to divide liberals among themselves—divide them and pit them against each other.

Alex: DDT becomes a club with which to hit the idea of regulation, right?

Elena: Absolutely, the idea of regulation, and then added to that the idea that we should trust environmentalists and those who believe in supporting environmental values. The irony is that they weren’t successful in bringing DDT back. They didn’t necessarily even really want to bring DDT back. We didn’t bring it back. We brought back the idea that it was valuable, wrongly banned. Ironically, while I was working on this book, we actually started finding long-lost DDT, and some scientists in my home state of California over the last couple of years have actually found loads of it that was dumped decades and decades ago off the coast of California. Now barrels and deposits of DDT are in the Pacific that we’re aware of, that we weren’t aware of just 10, 15 years ago. We’ve just barely started to find what’s out there. It seems to be linked now to disease among marine mammals, particularly the California sea lion. So DDT is, in a way, coming back—but not in the way that the conservative pundits of the early 2000s were hoping for.

Laura: Are there any companies that are allowed to use DDT now? New uses of DDT, not what you call legacy DDT—the stuff that was dumped.

Elena: In the U.S., we still have an exception that allows DDT to be used in a public health emergency. So if there was some epidemic that was transmitted by insects and we felt we had no better way to kill off those insects and protect public health, DDT is still allowable for that. We now have a global convention, the Stockholm Convention, that countries the world over have signed on to, agreeing to phase out DDT’s use, among a list of other persistent chemicals. There are now very few places where DDT is used and only one place that’s manufacturing it left in the world. But again, it’s allowable under that convention for public health use too.

Laura: So would that be, for instance, if there were some global pandemic of Zika, DDT might be deployed to fight that?

Elena: It absolutely could be. In fact, when Zika was here in the U.S. five or six years ago, there were folks saying, “Is now the time to use DDT? Is now the time to bring it back?” There were some people—a very small number of people—who were like, “Yeah, this is the moment.” Then there were others who were like, “We have better chemicals now. We don’t need to resort to that.”

Laura: The title of your book includes the phrase “the toxic return of DDT.” What do you mean by that?

Elena: By the late ’70s, we were so aware of the ecological harms of DDT that we agreed that communities and areas that were heavily contaminated with it should be cleaned up. We set these cleanup targets, these levels that we wanted to bring DDT down to, and now—in the 2020s, looking back—we realize those levels aren’t low enough and DDT is still in fish. In some heavily contaminated communities, we can still find it in birds and still at toxic levels. This is decades after it was banned. Epidemiological studies show that there are intergenerational effects of DDT: Women who were exposed to it when they were young in the 1940s and 1950s seem to have an elevated risk of breast cancer, and ongoing research has shown that their daughters and then their granddaughters seem to have elevated risks or a higher frequency of risk factors for that disease too. So now we’re talking two generations down the line.

Alex: So you write  about the toxic return of DDT and that we’re finding these stockpiles of it that were dumped in the ocean years and years ago. But in an important sense, banning it didn’t mean it actually just disappeared from our own environment.

Elena: We develop these chemicals, in some cases think we solve these problems through bans and through environmental cleanups like I mentioned before, but the chemicals in some cases don’t just go away. Part of DDT’s power was its persistence, and we’re still dealing with that persistence. For me, it’s really a lesson about these kinds of unintended consequences, and how long down the line we’ll still be figuring out exactly the problems we created, and the extent and duration of them.

Laura: I think what the story of DDT really shows is that banning something is this last resort that is better than not banning—because you stop creating DDT—but you really have to do what those scientists in the 1940s were asking, which is wait. Regulate this before it poisons anyone.

Alex: Before you spray it across the entire globe.

Laura: Before you create these huge reserves of it that you then have to go and bury in the sea, just waiting for them to leak into the ocean and leach into the soil. Caution is the best way to approach all of this stuff.

Elena: Yeah. And if you’re going to implement a ban, what are you banning? Are you banning the thing or the practice that it’s used in? Pesticide use actually only went up after we banned DDT. We use replacement pesticides that are just as toxic but on a different timescale and to different people who are exposed in different ways. Part of the moral of the story is, “Wait, move more slowly.” Part of it is also, “Think about the larger system in which this technology is embedded in.” I guess the moral of the story, going back to the “bring back DDT” movement of the early 2000s, is “know that these technologies have different meanings for different actors.” There may be people weighing in with their opinions who are just playing some other game entirely. We may not even be aware. We’re listening, but we might not be aware.

Alex: Well, thank you, Elena.

Laura: Thank you.

Elena: Thank you, guys.

Alex: The Politics of Everything is co-produced by Talkhouse.

Laura: Emily Cooke is our executive producer.

Alex: Myron Kaplan is our audio editor.

Laura: If you enjoyed The Politics of Everything and you want to support the show, one thing you can do is go wherever you listen to the podcast and rate it. Every rating and review helps.

Alex: Thanks for listening.