Paul Müller (1899–1965), Rachel Carson (1907–1964)
Typhus epidemics have accompanied us throughout history, generally during wars and famine. The disease was responsible for three million deaths during World War I and hundreds of thousands of deaths among Nazi concentration camp prisoners during World War II. DDT’s application to the clothing of more than one million persons during the winter of 1943–1944 averted a major typhus epidemic in Naples by killing the lice responsible for carrying the bacterium causing typhus.
DDT (dichlorodiphenyltrichloroethane or chlorophenothane) was synthesized in 1874, but it was not until 1939 that Swiss chemist Paul Müller, at J. R. Geigy in Basel, Switzerland, discovered its insecticidal properties. In particular, he found that DDT readily crossed the insect exoskeleton (cuticle) and fatally disrupted its nervous-system function. In 1948, Müller received the 1948 Nobel Prize in Physiology or Medicine.
DDT’s popularity stemmed from its effectiveness, very low cost, persistency after application to plants, and relatively low toxicity to mammals. Malaria, the most common human disease, affects some 250 million people worldwide and causes almost one million deaths annually. The World Health Organization initiated an international program in 1955 utilizing DDT to eradicate the mosquito vector of malaria.
HEALTH MIRACLE OR ENVIRONMENTAL DISASTER? DDT’s accolades were not to endure! Poor management of the malaria-eradication program, inadequate funding, and indiscriminate DDT use led to insect resistance and loss of effectiveness. Of far greater impact in DDT’s demise was Rachel Carson’s book Silent Spring (1962), which documented the disastrous effects the indiscriminate use of pesticides, such as DDT, were having on the environment. Its use was linked to extensive fish kills and a thinning of eggshells, most famously for the bald eagle.
Silent Spring not unexpectedly generated vituperative criticism from the pesticide manufacturers and others emphasizing DDT’s benefits to public health, although the book received overwhelming support from the scientific community and public and was instrumental in mobilizing a global environmental movement. The use of DDT was banned in the United States in 1972 and most developed countries by the 1980s.
SEE ALSO Quinine (1820), Chloroquine (1947), Malathion (1951), Artemisinin (1972).
The human body louse is the primary carrier of rickettsiae, the microbe responsible for causing epidemic typhus, one of history’s most significant human diseases. When applied to the skin as a powder, DDT very effectively kills body lice and persists on the skin long enough to kill young lice as they emerge from their eggs.