DDT helped win the war and later became a major target of the book by Rachel Carson, Silent Spring, which helped launch the modern environmental movement.
The New Atlantis has an excellent article on the convergence.
“In the last days of September 1943, as the U.S. Army advanced to the rescue of Italian partisans — some as young as nine — battling the Germans in the streets of Naples, the enraged Nazis, in a criminal act of revenge against their erstwhile allies, deployed sappers to systematically destroy the city’s aqueducts, reservoirs, and sewer system. This done, the supermen, pausing only to burn irreplaceable libraries, including hundreds of thousands of volumes and artifacts at the University of Naples — where Thomas Aquinas once taught — showed their youthful Neapolitan opponents their backs, and on October 1, to the delirious cheers of the Naples populace, Allied forces entered the town in triumph.
“But a city of over a million people had been left without sanitation, and within weeks, as the Germans had intended, epidemics broke out. By November, thousands of Neapolitans were infected with typhus, with one in four of those contracting it dying of the lice-transmitted disease. The dead were so numerous that, as in the dark time of the Black Death, bodies were put out into the street by the hundreds to be hauled away by carts. Alarmed, General Eisenhower contacted Washington and made a desperate plea for help to contain the disaster.
“Fortunately, the brass had a new secret weapon ready just in time to deal with the emergency. It was called DDT, a pesticide of unprecedented effectiveness. First synthesized by a graduate student in 1874, DDT went unnoticed until its potential application as an insecticide was discovered by chemist Paul H. Müller while working for the Swiss company Geigy during the late 1930s. Acquainted with Müller’s work, Victor Froelicher, Geigy’s New York representative, disclosed it to the American military’s Office of Scientific Research and Development (OSRD) in October 1942. Examining Müller’s data, the OSRD’s experts immediately realized its importance. On Guadalcanal, and elsewhere in the South Pacific, the Marines were losing more men to malaria than they were to the Japanese, with the entire 1st Marine Division rendered unfit for combat by the insect-borne disease. Without delay, first Geigy’s Cincinnati factory and then the giant DuPont chemical company were given contracts to produce the new pesticide in quantity.
“By January 1, 1944, the first shipments of what would eventually amount to sixty tons of DDT reached Italy. Stations were set up in the palazzos of Naples, and as the people walked by in lines, military police officers with spray guns dusted them with DDT. Other spray teams prowled the town, dusting public buildings and shelters. The effects were little short of miraculous. Within days, the city’s vast population of typhus-transmitting lice was virtually exterminated; by month’s end, the epidemic was over…
“But events took another turn with the appearance of Rachel Carson’s book Silent Spring. A former marine biologist and accomplished nature writer, Carson in 1958 contacted E. B. White, a contributor to The New Yorker, suggesting someone should write about DDT. White declined, but the magazine’s editor, William Shawn, suggested that Carson herself write it. The ensuing articles, supplemented by additional material, became Silent Spring, for which Carson signed a contract with Houghton Mifflin in August 1958.
“Carson based her passionate argument against pesticides on the desire to protect wildlife. Using evocative language, Carson told a powerful fable of a town whose people had been poisoned, and whose spring had been silenced of birdsong, because all life had been extinguished by pesticides.”