Well, not utterly discredited. Perhaps the scope and scale of the alleged harm was discredited . . . maybe. After all, it is a chemical.
HIGHLIGHTS: Exposure to DDT, DDE, and DDD occurs mostly from eating foods containing small amounts of these compounds, particularly meat, fish and poultry. High levels of DDT can affect the nervous system causing excitability, tremors and seizures. In women, DDE can cause a reduction in the duration of lactation and an increased chance of having a premature baby. . . .
[. . .]
In animals, short-term exposure to large amounts of DDT in food affected the nervous system, while long-term exposure to smaller amounts affected the liver. Also in animals, short-term oral exposure to small amounts of DDT or its breakdown products may also have harmful effects on reproduction.
Browsing through the ToxFAQ suggests to me the decision to use DDT is strictly cost/benefit stuff. More people will live because of it than will become sick or die because of it. Guess we'll know in ten or twenty years.
What would Thomas Malthus say? :-)
More people will eat, too, if it is used against food pests, like the Medfly.
he Mediterranean fruit fly, or medfly, is one of the world's most destructive farm pests. It lays its eggs in fruit and vegetables, causing them to rot, larvae-infested on the ground. The medfly has menaced Latin America's fruit industry since its invasion early this century, depriving countries of food supplies and valuable export opportunities. The foremost victims have been small farmers, rural workers and the natural environment.