New York Times
23 December 2002

Fighting Malaria With DDT
The world is losing the war against malaria. Once considered near eradication, malaria today kills more than a million people a year in Africa alone. One reason is that wealthy nations have limited the use of one of the best weapons, a pesticide that once saved hundreds of millions of lives.

For most Americans, DDT is a symbol of the perils of playing God with nature. DDT accumulates in animals that eat insects, traveling up the food chain and weakening the eggshells of birds of prey. It was banned in the United States in 1972.

DDT is one of 12 persistent organic pollutants that an international treaty had scheduled for a global ban. But at the urging of medical specialists, the United Nations in 2000 rightly exempted DDT for use in malaria, saying that it should be banned only when a safe substitute is found. But there are still too many obstacles preventing nations that need it from using DDT when appropriate.

Today, malaria control relies mainly on insecticide-treated bed nets and drugs, most of which have lost effectiveness as malaria grows resistant. DDT, which is sprayed on the inside walls of houses twice a year, is used in only about 24 countries. Wealthy nations that banned DDT at home will not pay for its use elsewhere. But the poorest nations depend on such donations. America used DDT to eradicate malaria, as did southern Europe and India.

DDT is hardly risk-free. It poisoned the environment because farmers sprayed it on crops, a use properly banned today. But very little DDT is needed to spray houses twice a year. The evidence about DDT's effects on humans is inconclusive. The uncertainties must be weighed against a demonstrated effectiveness in fighting a disease that now kills 1 in 20 African children. DDT also costs one-quarter the price of the alternative, pyrethroids.