DDT
In wartime, often one of the biggest sources of casualties and deaths is not the enemy, but nature. Illness, particularly the types of illness carried by insects and pests, can decimate armies. The military was concerned about typhus, which had caused some 2.5 million military and civilian deaths in World War I, as well as mosquito-borne illnesses, like malaria and yellow fever. By the late 1930s, scientists were actively looking for an insecticide that could be used on clothing and blankets to prevent insect activity from lice and mosquitos.
In 1939, Swiss chemist Paul Muller realized that a chemical compound discovered in the 19th century, dichlorodiphenyltrichloroethane, or DDT was an effective way to mothproof wool fabrics. Researchers in the U.S. soon realized that DDT worked well as an insecticide at low doses.
U.S. soldiers were issued DDT power, and entire towns and islands were sprayed with DDT. The use of DDT dramatically reduced soldier’s deaths from pest-related illnesses, and World War II may be the first conflict in which more individuals died from combat injuries than illness.
Questions about the safety of DDT appeared early on in its history, but it was not banned in the United States until 1972. As early as 1946, scientists recognized that the chemical could concentrate in fatty tissues, and serious criticisms were published in the 1962 book, Silent Spring. While DDT led to ongoing health and environmental issues, it also inaugurated an era of chemical solutions in the world of agriculture. The market success of DDT led to the development of a wide range of other pesticides, used extensively for a number of decades.