While DDT has been banned in most countries across the globe (with an exception for malaria control), for five decades, it has persisted in our environment and continues to cause disease in humans and animals. Despite that, in recent years, some have been calling for more use of DDT to fight not just malaria, but also West Nile Virus and the Zika virus.
In How to Sell a Poison, historian of medicine Elena Conis traces the history of DDT, its impacts, and the implications of the shifting science. In a masterful narrative style that reads like a novel, Conis tells the stories of ordinary people and the nascent environmental movement that sought to expose the chemical’s harms. Her book offers insights about the mechanisms of science denial, disinformation campaigns, and the role of politics and other social forces in shaping a nation’s approach to regulating a toxic substance.
Civil Eats spoke with Conis about the light that DDT’s story sheds on the many other toxic chemicals used today, how social inequality, race, and environmental pollution are linked, and why the tobacco industry funded a secret campaign to bring back DDT.
Why did you decide to write a book about DDT, and why now?
I grew up in the 1980s, a decade after DDT’s ban. I knew of it as one of our most toxic chemicals. I knew that it was responsible for the loss of major numbers of bald eagles and, where I lived in New York, a loss of osprey, among other birds. Then, as a graduate student, I attended a conference where some global health experts talked about the problem of malaria getting worse, particularly in places like Sub-Saharan Africa. They all mentioned the need to bring back DDT. That alone surprised me. But what surprised me even more was that nobody else in the audience seemed to find that strange, weird, or troubling. I carried these questions around for a long time: What had happened to DDT? Had its reputation changed? Had people reconsidered how toxic it was?
Fifteen years later, I became a historian of medicine. I had been a journalist focusing on health and medicine for a while, I got my PhD in history [at the University of California, San Francisco], and found an electronic archive at UCSF that contains scanned versions of corporate documents disclosed in the mid-1990s during hearings on the tobacco industry. I stumbled upon a couple of curious documents about DDT. It turns out the tobacco industry had an expressed interest in the return of DDT. That’s when I realized the chemical had a more complicated story. It had gone from war hero to public enemy to a third act a generation later, when we completely reconsidered it. It seemed like an interesting case study for understanding how we change our minds about science, who is involved in shaping what we know, and [shaping] technology based on our scientific knowledge.
As a society, we’ve been fighting about science for the past decade or so, with many people seeming to reject accepted scientific claims. And people who believe those scientific claims feel completely frustrated when they aren’t simply accepted as a matter of fact. DDT’s story to me showed how scientific facts can change depending on the context, the questions that we ask, and the interests pursuing the answers to those questions. It seemed a helpful case study for understanding why we fight about science and what we’re actually fighting about when we do. In the story of DDT, I found that the debates about the chemical were proxy battles for struggles over gender, race, class, and the economy.
You describe in shocking detail the ubiquitous, constant, large-scale spraying of homes, fields, pets, cattle, and entire American cities with DDT. Why was this chemical so widely used?
If you could put yourself in the shoes of people who first encountered this chemical on a large scale in the ‘40s and ‘50s, you would see that the earlier generation of pesticides and insecticides—those used before DDT—were so much more toxic. They were known poisons, compounds made with lead and arsenic. It was an accepted fact that if you were going to kill insects, you would use something that was poisonous to people. DDT wasn’t toxic in the same way. Animals and people could be exposed to a lot of DDT in the very short term and they would be okay.
The fact that we had something that could kill insects and not make us sick in the short term suddenly made DDT seem like the answer to everything. People became dependent on it really quickly because they didn’t have to go to great lengths to rid their houses of ants or roaches, or their whole community of flies or mosquitoes. DDT offered a way to keep things clean, salubrious, “healthy.” At the same time, it was a way to make agriculture more profitable—because with a sweep of DDT, farmers could eliminate some of the worst pests.
Despite these benefits, other countries did not use DDT in such huge quantities. The U.S. was unique in how abundantly it sprayed the chemical, even though it had actually been developed by a Swiss chemical company. Why?
DDT’s story was woven into the story we told during and after the Second World War about how the U.S. became a superpower. Americans constantly heard about how DDT had protected our troops, prisoners of war, and refugees from malaria and other devastating diseases. The chemical, they were told, had essentially transformed the war. So, DDT was accepted as part of this bigger project of seeing ourselves as a global leader.
The big companies manufacturing DDT were also subsidized by the federal government during the war. So, they emerged bigger and more powerful than they had ever been. Combine that power with the enormous American appetite for DDT and suddenly, it was huge. It just took off.
Thousands of other chemicals have since been released on the market and the federal government regulates only a tiny percentage of them. What lessons does your book offer about the regulation of chemicals?
The first takeaway is that DDT created a set of problems that we gradually became aware of and then we thought we solved by banning the chemical [in 1972] and later through the passage of Superfund [a program of the U. S. Environmental Protection Agency (EPA) established in 1980 to clean up hazardous waste dumps]. But here we are, 50 years later, and this chemical is still with us. It’s still affecting people’s health, and it’s still in wildlife, in birds, and in marine mammals, affecting their health too. It continues on in the environment, including in places we didn’t even know about or we allowed ourselves to forget about. We’ve been cleaning up DDT on land, but we recently discovered that loads of DDT were dumped into the Pacific Ocean, just off the coast of California. So, one of the big takeaways is that when we move with haste, we have no idea how long the health and environmental consequences of our technological developments are going to last.
Second, when we take steps to solve those problems, we also don’t have a good handle on the timeframe required for those solutions to be meaningful. We “solved” the problem of DDT by banning it and by cleaning up the environment. At one of the Superfund sites that I looked at, the EPA created a cleanup plan in the early ’80s that involved rerouting a river and monitoring fish over time to make sure that their DDT levels were going down. After 30 years of cleanup and monitoring, the fish had DDT levels that were considered safe [at the time], but today we don’t think that level is safe enough. The moment we create a technology or a chemical, we start running a race to understand all kinds of ways in which it’s going to reshape ourselves and our environment. We’re forever going to be playing catch up.
How did the science on DDT evolve and what are the lessons about science that this history exposed?
DDT was and still is one of the most well-studied chemicals we’ve created. It was so well-studied because it was used so extensively. During the war, men serving in the armed forces spent morning, noon, and night just spraying, spraying, spraying. They were covered in DDT all day. And everybody studied them—the manufacturers, the army—and concluded these men seemed fine. The war was over, they were discharged, and that was it. Then there were studies after the war to follow not just sprayers, but also people working in the factories that manufactured DDT. There were studies in which DDT was fed to prisoners. Typically, scientists would study a small group of men, ask a limited set of questions, and conclude that all was fine.
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