DDT has certainly had its ups and downs. The powerful and almost indestructible insecticide was hailed in World War II as the “savior of mankind” as it killed the fleas that carried typhus and the mosquitoes that spread malaria. Farmers increased their harvests by spraying it on crops to kill insect pests.

Rachel Carson’s explosive 1962 book “Silent Spring” practically put an end to its use. She charged that DDT was wiping out whole colonies of birds, especially eagles, by producing thin, vulnerable eggshells and warned against illness and genetic damage by accumulation in fatty tissue. Fishermen feared that the runoff would harm the lobsters.

Her campaign led to an international treaty barring 12 “persistent organic pollutants” including DDT, signed by the United States and other countries in 2001. Under pressure of the big environmental organizations, the United States and many other nations banned DDT completely.

The eagles have been recovering, slowly, but so have the malaria-bearing mosquitoes – and far from slowly. Malaria, which had been nearly wiped out, flourishes once more, especially in Africa and Asia. A reaction set in. The United Nations, with the World Bank and the World Health Organization, campaigned to “Roll Back Malaria” by 2010, but, since it relied solely on bed nets and drug therapies, fatalities continued to increase. More than 50 million people have died from malaria since the U.S. ban on DDT in 1972.

The Association of American Physicians and Surgeons in 2004 put the malaria epidemic toll in tropical countries at 300 million and deaths at more than 1 million a year, most of them pregnant women and children under 5. It called on the United States and the United Nations to permit, encourage and fund the use of DDT in tropical countries where malaria is prevalent and health authorities want to use it.

Last month, the World Health Organization finally reversed course and announced that it would begin actively promoting use of the pesticide in developing countries.

The head of WHO’s anti-malaria campaign, Arata Kochi, called on environmental groups to join the campaign. The Sierra Club and Environmental Defense, originally founded to fight DDT, as well as President Bush’s new malaria initiative, now support the limited use of DDT, such as spraying only the inside of houses and huts once or twice a year.

But the dispute goes on. Generations of school children have been taught that anything labeled anti-environmental is bad. And many teachers continue to assign “Silent Spring.”

They should take note of the fact that Rachel Carson never called for an absolute ban. She wrote in her book: “Practical advice should be ‘Spray as little as you possibly can’ rather than ‘Spray to the limit of your capacity.'”

That may be where the world ends up, 44 years later.