In my book, How to Sell a Poison: The Rise, Fall and Toxic Return of DDT, I delve into the story of the toxic chemical. Back in the 1940s, when DDT was first developed, “economic poisons” were chemicals designed to kill pests that otherwise caused high-cost damage. In the broader sense, however, the term “economic poisons” can describe how the Invisible Hand often steers scientists, medical professionals and governments away from reasoning and toward profit. In America, this phenomenon intensified as a rising world superpower clamored for post-war profit at any cost. Today, our government institutions, and especially our scientific ones, have a duty to rebuild the public trust that this process eroded over the last half century.
In the late 1940s, Lester Petrie came face-to-face with these economic poisons. Petrie was head of the Georgia Division of Industrial Hygiene, responsible for investigating the problems posed by chemical encounters in workplaces. Yet ever since the war, his division’s work had become more complicated. Before, the job largely involved making sure that people working in factories didn’t come in contact with chemicals or equipment in ways that harmed them. Now he was hearing more and more about chemical poisonings in people’s homes and farms. Most of them were caused by what those in his line of work called “economic poisons,” newly developed synthetic chemicals that killed insects ranging from the annoying to the deadly. DDT was one of them.
Before long, Petrie had compiled a harrowing collection of poisoning cases. Most were crop-dusting pilots choked to death by their own cargo. One was a woman who died after eating blackberries grown nearby a sprayed cotton field. A group of small farmers wrote him to say DDT sprayed on neighboring farms was killing their bees and chicks and making them sick. People used to kill insects on crops, when necessary, using compounds that contained the well-known poisons arsenic and lead. It troubled Petrie that the economic poisons seemed as deadly as the older poisons, and that people clearly didn’t know.
Petrie himself, after all, had been sure DDT in particular was safe, because of reports and assurances from the U.S. government during the Second World War. Now he wondered whether he ought to create a warning for it, as he had just done for another economic poison, tetraethyl pyrophosphate or TEPP. He reached out to FDA pharmacology chief Arnold Lehman, who had so helpfully reviewed the TEPP warning he had drafted for farmers in his state. “A few days ago,” he wrote, “I noticed a news item in the paper cautioning against the spraying of barns with DDT. I would appreciate very much your sending me all of the new information you may have available concerning the toxicity of DDT.” This time, Lehman didn’t reply.