Sunday, April 11, 2004
DDT to fight Malaria?
A very thought-provoking article by Tina Rosenberg in the NYT magazine asks whether it is time to turn back to DDT in order the deal with the menace of Malaria. I remember when I was in school in India, DDT was treated like any other chemical and the municipality would send out sprayers with DDT in order to control Malaria. So, when I first Rachel Carson's Silent Spring and other western commentaries on the subject, I was not-so-pleasantly surprised. In this piece, Rosenberg agrees that DDT is not a good idea in America, but under the right conditions it could well be Africa's only chance against Malaria.
I dont know enough about the subject to comment any further. I do know however that Malaria is a serious, yet under-rated killer. It kills over 2 million people a year and many hundreds of millions of people more are laid low (an economic disaster) every single year. Given these facts, it's disturbing that no pharmaceutical company devotes any time or money to develop an anti-Malarial drug (of course, Africans cannot pay for it). I also know that Malaria was rampant in the United States for a long while, until a whole host of methods, including the spraying of DDT, brought the disease under control and virtually eradicated it. Rosenberg's point is that the West discovered the downside of pesticides like DDT *after* the eradication of Malaria and so its much easier to diss its use, thereby decreasing the possibility of its control or eradication in Africa.
To Americans, DDT is simply a killer. Ask Americans over 40 to name the most dangerous chemical they know, and chances are that they will say DDT. Dichloro-diphenyl-trichloroethane was banned in the United States in 1972. The chemical was once sprayed in huge quantities over cities and fields of cotton and other crops. Its persistence in the ecosystem, where it builds up to kill birds and fish, has become a symbol of the dangers of playing God with nature, an icon of human arrogance.
Yet DDT, the very insecticide that eradicated malaria in developed nations, has been essentially deactivated as a malaria-control tool today. The paradox is that sprayed in tiny quantities inside houses -- the only way anyone proposes to use it today -- DDT is most likely not harmful to people or the environment. Certainly, the possible harm from DDT is vastly outweighed by its ability to save children's lives.
No one concerned about the environmental damage of DDT set out to kill African children. But various factors, chiefly the persistence of DDT's toxic image in the West and the disproportionate weight that American decisions carry worldwide, have conspired to make it essentially unavailable to most malarial nations. With the exception of South Africa and a few others, African countries depend heavily on donors to pay for malaria control.
Instead, the malaria establishment in developed nations promotes the use of insecticide-treated nets that people can buy to hang over their beds. Treated bed nets are indeed a useful tool for controlling malaria. But they have significant limitations, and one reason malaria has surged is that they have essentially become the only tool promoted by Western donors. ''I cannot envision the possibility of rolling back malaria without the power of DDT,'' said Renato Gusm-o, who headed antimalaria programs at the Pan American Health Organization, or P.A.H.O., the branch of W.H.O. that covers the Americas. ''Impregnated bed nets are an auxiliary. In tropical Africa, if you don't use DDT, forget it.''
William Ruckelshaus, the head of the newly created Environmental Protection Agency, banned DDT in 1972. It remains one of the most controversial decisions the E.P.A. has ever taken. Ruckelshaus was under a storm of pressure to ban DDT. But Judge Edmund Sweeney, who ran the E.P.A.'s hearings on DDT, concluded that DDT was not hazardous to humans and could be used in ways that did not harm wildlife. Ruckelshaus banned it anyway, for all but emergencies.
Ruckelshaus made the right decision -- for the United States. At the time, DDT was mainly sprayed on crops, mostly cotton, a use far riskier than indoor house spraying. There was no malaria in the United States -- in part thanks to DDT -- so there were no public health benefits from its use. ''But if I were a decision maker in Sri Lanka, where the benefits from use outweigh the risks, I would decide differently,'' Ruckleshaus told me recently. ''It's not up to us to balance risks and benefits for other people. There's arrogance in the idea that everybody's going to do what we do. We're not making these decisions for the rest of the world, are we?''
I dont know enough about the subject to comment any further. I do know however that Malaria is a serious, yet under-rated killer. It kills over 2 million people a year and many hundreds of millions of people more are laid low (an economic disaster) every single year. Given these facts, it's disturbing that no pharmaceutical company devotes any time or money to develop an anti-Malarial drug (of course, Africans cannot pay for it). I also know that Malaria was rampant in the United States for a long while, until a whole host of methods, including the spraying of DDT, brought the disease under control and virtually eradicated it. Rosenberg's point is that the West discovered the downside of pesticides like DDT *after* the eradication of Malaria and so its much easier to diss its use, thereby decreasing the possibility of its control or eradication in Africa.
To Americans, DDT is simply a killer. Ask Americans over 40 to name the most dangerous chemical they know, and chances are that they will say DDT. Dichloro-diphenyl-trichloroethane was banned in the United States in 1972. The chemical was once sprayed in huge quantities over cities and fields of cotton and other crops. Its persistence in the ecosystem, where it builds up to kill birds and fish, has become a symbol of the dangers of playing God with nature, an icon of human arrogance.
Yet DDT, the very insecticide that eradicated malaria in developed nations, has been essentially deactivated as a malaria-control tool today. The paradox is that sprayed in tiny quantities inside houses -- the only way anyone proposes to use it today -- DDT is most likely not harmful to people or the environment. Certainly, the possible harm from DDT is vastly outweighed by its ability to save children's lives.
No one concerned about the environmental damage of DDT set out to kill African children. But various factors, chiefly the persistence of DDT's toxic image in the West and the disproportionate weight that American decisions carry worldwide, have conspired to make it essentially unavailable to most malarial nations. With the exception of South Africa and a few others, African countries depend heavily on donors to pay for malaria control.
Instead, the malaria establishment in developed nations promotes the use of insecticide-treated nets that people can buy to hang over their beds. Treated bed nets are indeed a useful tool for controlling malaria. But they have significant limitations, and one reason malaria has surged is that they have essentially become the only tool promoted by Western donors. ''I cannot envision the possibility of rolling back malaria without the power of DDT,'' said Renato Gusm-o, who headed antimalaria programs at the Pan American Health Organization, or P.A.H.O., the branch of W.H.O. that covers the Americas. ''Impregnated bed nets are an auxiliary. In tropical Africa, if you don't use DDT, forget it.''
William Ruckelshaus, the head of the newly created Environmental Protection Agency, banned DDT in 1972. It remains one of the most controversial decisions the E.P.A. has ever taken. Ruckelshaus was under a storm of pressure to ban DDT. But Judge Edmund Sweeney, who ran the E.P.A.'s hearings on DDT, concluded that DDT was not hazardous to humans and could be used in ways that did not harm wildlife. Ruckelshaus banned it anyway, for all but emergencies.
Ruckelshaus made the right decision -- for the United States. At the time, DDT was mainly sprayed on crops, mostly cotton, a use far riskier than indoor house spraying. There was no malaria in the United States -- in part thanks to DDT -- so there were no public health benefits from its use. ''But if I were a decision maker in Sri Lanka, where the benefits from use outweigh the risks, I would decide differently,'' Ruckleshaus told me recently. ''It's not up to us to balance risks and benefits for other people. There's arrogance in the idea that everybody's going to do what we do. We're not making these decisions for the rest of the world, are we?''
