By Janet Raloff
The pesticide DDT has a long and checkered history. Today, it evokes particularly contentious argument. Though environmentalists have come to demand this poison’s elimination from the face of the Earth, some tropical-disease specialists laud DDT as an irreplaceable weapon in their fight against malaria. Which view prevails may be a life-and-death matter for nearly a half-billion people.
First created in the late 19th century, dichlorodiphenyltrichloroethane’s insecticidal properties weren’t discovered until around 1939. Almost at once, communities throughout the developed world—led by those in the United States—embraced this low-cost, broad-spectrum insecticide. It quickly became the agent of choice for ridding croplands of pests, streets of mosquitoes, and homes of spiders and other nuisances.