The U.N. is reversing its position supporting the use of indoor spraying of DDT to prevent malaria in Africa.

In 2006, after 25 years and 50 million preventable deaths, the World Health Organization reversed course and endorsed widespread use of the insecticide DDT to combat malaria. So much for that. Earlier this month, the U.N. agency quietly reverted to promoting less effective methods for attacking the disease. The result is a victory for politics over public health, and millions of the world's poor will suffer as a result.

The U.N. now plans to advocate for drastic reductions in the use of DDT, which kills or repels the mosquitoes that spread malaria. The aim "is to achieve a 30% cut in the application of DDT worldwide by 2014 and its total phase-out by the early 2020s, if not sooner," said WHO and the U.N. Environment Program in a statement on May 6.

Citing a five-year pilot program that reduced malaria cases in Mexico and South America by distributing antimalaria chloroquine pills to uninfected people, U.N. officials are ready to push for a "zero DDT world." Sounds nice, except for the facts. It's true that chloroquine has proven effective when used therapeutically, as in Brazil. But it's also true that scientists have questioned the safety of the drug as an oral prophylactic because it is toxic and has been shown to cause heart problems.

Most malarial deaths occur in sub-Saharan Africa, where chloroquine once worked but started failing in the 1970s as the parasite developed resistance. Even if the drugs were still effective in Africa, they're expensive and thus impractical for one of the world's poorest regions. That's not an argument against chloroquine, bed nets or other interventions. But it is an argument for continuing to make DDT spraying a key part of any effort to eradicate malaria, which kills about a million people -- mainly children -- every year. Nearly all of this spraying is done indoors, by the way, to block mosquito nesting at night. It is not sprayed willy-nilly in jungle habitat.

So, millions will continue to die as environmentalists applaud.