Paul Hermann Müller won the 1948 Nobel Prize in Physiology or Medicine for discovering the high efficiency of DDT as a contact poison against several arthropods.
Müller, a Swiss chemist, studied compounds that could control insects carrying diseases or damaging crops. In 1939, his research identified dichlorodiphenyltrichloroethane, commonly called DDT, as an unusually powerful and persistent insecticide.
DDT became especially important during and after World War II because it helped control lice and mosquitoes. Lice can transmit epidemic typhus, while mosquitoes spread malaria and yellow fever. Its use contributed to major public-health campaigns, including malaria-control programs.
The Nobel recognition concerned the insecticidal discovery, not the later environmental controversy. Rachel Carson’s 1962 book Silent Spring helped draw attention to DDT’s persistence and effects on wildlife. Many countries subsequently restricted or banned agricultural use, although limited public-health uses have continued in some places.