What do you do when a dreaded environmental pollutant saves lives?
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.