Tags: DDT, malaria
Malaria, Politics and DDT
The Wall Street Journal, May 23, 2009
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.
WHO is not saying that DDT shouldn’t be used. But by revoking its stamp of approval, it sends a clear message to donors and afflicted countries that it prefers more politically correct interventions, even if they don’t work as well. In recent years, countries like Uganda, Tanzania and Zambia have started or expanded DDT spraying, often with the help of outside aid groups. But these governments are also eager to remain in the U.N.’s good graces, and donors typically are less interested in funding interventions that WHO discourages.
“Sadly, WHO’s about-face has nothing to do with science or health and everything to do with bending to the will of well-placed environmentalists,” says Roger Bate of Africa Fighting Malaria. “Bed net manufacturers and sellers of less-effective insecticides also don’t benefit when DDT is employed and therefore oppose it, often behind the scenes.”
It’s no coincidence that WHO officials were joined by the head of the U.N. Environment Program to announce the new policy. There’s no evidence that spraying DDT in the amounts necessary to kill dangerous mosquitoes imperils crops, animals or human health. But that didn’t stop green groups like the Pesticide Action Network from urging the public to celebrate World Malaria Day last month by telling “the U.S. to protect children and families from malaria without spraying pesticides like DDT inside people’s homes.”
“We must take a position based on the science and the data,” said WHO’s malaria chief, Arata Kochi, in 2006. “One of the best tools we have against malaria is indoor residual spraying. Of the dozen or so insecticides WHO has approved as safe for house spraying, the most effective is DDT.” Mr. Kochi was right then, even if other WHO officials are now bowing to pressure to pretend otherwise.