“In this now universal contamination of the environment,” Carson wrote, “chemicals are the sinister and little-recognized partners of radiation in changing the very nature of the world—the very nature of its life.”
The Competitive Enterprise Institute—to its credit—acknowledges that Carson did not call for the banning of pesticides in Silent Spring. But they claim Carson’s caveat about their value in fighting disease was so overwhelmed by her general disapproval of their use that “negative publicity” around Silent Spring halted the use of DDT against malaria, notably in sub-Saharan Africa, where some 90 percent of the world’s malaria cases occur.
It’s true that Carson found little good to say about DDT or any of its toxic cousins—the chlorinated aromatic hydrocarbon insecticides developed in the years after World War II and after the Swiss chemist Paul Muller had won a Nobel Prize for discovering DDT. But it’s a stretch to see how the mood surrounding Silent Spring was the prime cause of DDT’s exit from the fight against malaria. And, as the New York Times and other publications proved, it was understood by anyone who took time to read Silent Spring that Carson was not an absolutist seeking to stop all pesticide use.
DDT had been effective against malaria in Europe, in Northern Africa, in parts of India and southern Asia, and even in the southern United States, where the disease was already being routed by other means. But these were mostly developed areas. Using DDT in places like sub-Saharan Africa, with its remote and hard-to-reach villages, had long been considered problematic. It was an old story and one still repeated: Africa was everybody’s lowest priority.
And in any case, the World Health Organization had begun to question its malaria-eradication program even before Silent Spring was published. One object lesson was that the heavy use of DDT in many parts of the world was producing new strains of mosquitoes resistant to the insecticide. Much as it can happen with antibiotics, the use of an environmental poison clears susceptible organisms from the ecosystem and allows those with immunity to take over. The WHO also faced declining interest in the disease among scientists and sharp reductions in funding from the international community.
When the recently created Environmental Protection Agency banned DDT for most domestic uses in 1972, this ruling had no force in other parts of the world and the insecticide remained part of the international anti-malaria arsenal. The United States continued to manufacture and export DDT until the mid-1980s, and it has always been available from pesticide makers in other countries.
One result is that DDT is still with us—globally adrift in the atmosphere from spraying operations in various parts of the world, and also from its continuing volatilization from soils in which it has lain dormant for decades. The threat of DDT to wildlife—as a deadly neurotoxin in many species and a destroyer of reproductive capabilities in others—has never been in doubt. Carson’s claims in Silent Spring about DDT’s connection to human cancer and other disorders have not been completely resolved. The National Toxicology Program lists DDT as “reasonably anticipated to be a human carcinogen.” The same holds for two of its common break-down products, DDD and DDE, which are also suspected of causing developmental problems in humans.
These are cloudy but worrisome presumptions. DDT is stored in fat tissues—including ours—and that storage amplifies with repeated exposures over time, as well as through food chains, with unpredictable consequences. We walk around with our personal body-burden of DDT, a poison we still consume both from its decades-old residuals and its ongoing uses. If Rachel Carson hoped to end the use of DDT and our exposure to it, she did a lousy job.
In 2006, the World Health Organization announced a renewed commitment to fighting malaria with DDT, mainly in Africa—where the WHO had never lifted its approval for this purpose. The move was backed by environmental groups, as it surely would have been by Rachel Carson had she been with us still.
William Souder’s On a Farther Shore: The Life and Legacy of Rachel Carson, is out as of Sept. 4.