Saturday, February 26, 2005

DDT hoaxing

On February 17th, Tim Lambert wrote:

The Great DDT Hoax

Anti-environmentalist writers frequently claim that after DDT had all but eliminated malaria from Sri Lanka, environmentalist pressure forced Sri Lanka to ban DDT, leading to a resurgence of malaria:

Roger Bate in Politicizing Science: The Alchemy of Policymaking writes:
Some developing countries imposed a complete ban on the pesticide, as Sri Lanka did in 1964, when officials believed the malaria problem was solved. By 1969 the number of cases had risen from the low of seventeen (when DDT was used) to over a half million.

Ted Lapkin in Quadrant writes:

When Sri Lankan authorities agreed to ban DDT during the mid-1960s, rates of malaria infection exploded from twenty-nine cases in 1964 to over 500,000 a mere five years later.

Now when you think about it, the story that they tell just isn’t credible. If DDT spraying had almost eliminated malaria, and they got a new outbreak, then no environmentalists would be able to stop them from resuming spraying. So I went to the library to find out what really happened. And it wasn’t hard to find out. The definitive history of malaria is Gordon Harrison’s Mosquitoes, Malaria and Man and it turns out that, yes of course they went back to spraying. Harrison writes:

Sri Lanka went back to the spray guns, reducing malaria once more to 150,000 cases in 1972; but there the attack stalled. Anopheles culicifacies, completely susceptible to DDT when the spray stopped in 1964, was now found resistant presumably because of the use of DDT for crop protection in the interim. Within a couple of years, so many culicifacies survived that despite the spraying malaria spread in 1975 to more than 400,000 people.
So in 1977 they switched to the more expensive malathion and were able to reduce the number of cases to about 50,000 by 1980. In 2004, the number was down to 3,000, without using DDT.

And the reason why they stopped spraying in 1964? It wasn’t environmentalist pressure. With only 17 cases in 1963, they didn’t think it was needed any more.


The anti-environmentalist version of what happened is a hoax. That doesn’t mean that all the writers above were being deliberately misleading: they might be just repeating what another anti-environmentalist wrote and be unaware of the true story. AEI scholar Roger Bate, however, coauthored an entire book on DDT and Malaria which relies very heavily on Harrison’s history, citing him over twenty times.



And now, Tim has this post:

DDT Hoax Update

Ted Lapkin has objected to my reference to him in my post on the Great DDT Hoax. In his email he writes:

I would very much prefer, if possible, to keep things on an informal basis rather than a legal one. Thus this whole misunderstanding can be cleared up by a retraction and apology on your blog. In that event I would see no need to pursue matters further.
I offered to post his argument as to why he felt that I was wrong, but he declined, saying that it was a private communication. I have posted the paragraph above because I don’t think threats are entitled to privacy.


Everything Tim says in these posts sounds reasonable to me.

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