Kirsten Weir has an excellent article in Salon on DDT and Rachel Carson. Weir took the time to talk to actual scientists and found:
Socrates Litsios, a historian and former scientist for the World Health Organization (the agency that has headed global malaria control efforts since the 1960s), says the assertion that “Silent Spring” and the DDT ban led to millions of deaths is “outrageous.” May Berenbaum, head of the Department of Entomology at the University of Illinois at Urbana-Champaign, who has studied mosquitoes and malaria, says that “to blame environmentalists who oppose DDT for more deaths than Hitler is worse than irresponsible.” …
[Africa Fighting Malaria’s] Tren, who is allied with libertarian and free-market think tanks, such as the Institute of Economic Affairs, believes that anti-insecticide sentiment scared donors away from DDT programs. “By the late 1960s and early 1970s, the donor nations were starting to withdraw support from insecticide-spraying programs and from the use of DDT,” Tren says. “I am confident in saying that the anti-DDT crusades harmed malaria control and cost lives.”
That is misleading, say Litsios and Clive Shiff, a malaria researcher at the Johns Hopkins Bloomberg School of Public Health who has participated in malaria programs in Africa for decades. They stress that aid organizations weren’t anti-DDT during that period, they were pro-medicine. Through the ’70s and ’80s, most countries, on the advice of the WHO, “changed their approach to malaria control from insecticide treatment to treating people with chloroquine” — which kills the parasites that cause malaria — “because that was a way they could impact the mortality of the disease,” Shiff says. “I don’t think the ban of DDT in the U.S. had any impact on malaria control programs in Africa, certainly not in southern Africa where I was working.” …
Public health workers generally agree that balance is the best approach: spraying houses, hanging bed nets, tracking outbreaks and treating those infected with malaria. DDT has a place in that strategy, but it is not the silver bullet it’s often made out to be. Today, a variety of insecticides are available for indoor residual spraying. DDT, says Shiff, “is just one important tool.” And not always the best tool.
Mosquitoes can evolve resistance to any insecticide. In India, DDT-resistant mosquitoes were reported as early as 1959. “Insects will develop resistance to insecticides,” says entomologist Berenbaum at the University of Illinois. “This is one sure thing you can count on.”
Mosquitoes, Berenbaum says, can develop resistance in any number of ways — biologically, biochemically, even behaviorally. In some regions, mosquitoes might develop resistance by becoming physically immune to the effects of DDT. In other populations, mosquitoes might evolve new behaviors, such as avoiding inside walls and resting on the unsprayed outer walls of homes after biting their victims.
Relying on insecticide alone to control malaria ignores big pieces of the puzzle, Berenbaum says. Mosquitoes may be the carrier, but it’s the Plasmodium parasite that causes malaria. “It’s not just the mosquito. There’s a pathogen involved, and there are people involved. To reduce this extremely complicated situation to one bad guy is beyond simplistic,” she says. …
As for the DDT debate in vogue at the moment, Berenbaum says, “it’s all emotional and not rational.” She fully agrees that malaria is an international tragedy, and she doesn’t “place the lives of ospreys above the lives of people,” she says. But neither would Berenbaum pin her hopes on one insecticide — a point Carson herself understood half a century ago. “Carson’s point wasn’t that DDT was evil,” Berenbaum says. “It was that if you put all your eggs in one basket, that basket’s going to break.”
If you want to know the history of Africa Fighting Malaria, read this.
(Via Ezra Klein.)