The science and politics of DDT

by John Quiggin on September 18, 2006

Arguments about DDT have been going on for a long time in the blogosphere and similar circles. These debates typically involve a confusion between two unrelated issues

  • The bogus story, popular in rightwing circles, in which the US ban on agricultural use of DDT, inspired by Rachel Carson, is morphed into a global ban on DDT, bringing to an end a previously successful compaign to eradicate malaria
  • The real disputes, among malaria experts, about the relative merits of insecticide-treated bednets and spraying of house walls, and of DDT and alternative insecticides.

Now the two have coincided in the real world, with effects that may or may not be good. WHO recently appointed Arata Kochi as head of its malaria program. Kochi, who previously worked on the Stop TB initiative, has a reputation as a headkicker, but also as someone who gets things done. It’s worth noting that, while this kind of reputation is sometimes well-earned, there are often cases where the supposed accomplishments turn out be ephemeral or non-existent (remember ‘Chainsaw Al’ Dunlap, for example?).

Kochi has decided to shake up the ‘malaria community’ and an obvious line of attack is to line up with those among its critics who favor a bigger role for DDT. He’s just made a big announcement of a shift in favor of DDT, coinciding with the resignation of the WHO’s leading expert on insecticide spraying.

Reading the announcement and the NYT closely, the change in reality is much less than in rhetoric. Of the 17 African countries that now use interior spraying, 10 already use DDT, and it will almost certainly turn out that some of those who don’t have good reasons for choosing other pesticides (resistance, or harm to helpful insects that prey on pests in roofs for example).

And the substantive change in WHO guidance is much less dramatic than the rhetoric would suggest. WHO is now recommending the use of indoor residual spraying (IRS) not only in epidemic areas [as in the past] but also in areas with constant and high malaria transmission, including throughout Africa.

It’s far from clear that the change is backed up by a scientific analysis of the relative cost-effectiveness of the options. But, as with all the fads and fashions in areas like this, cost-effectiveness is not necessarily the most relevant criterion. The US appears willing to put in a substantial amount of extra money, and the US wants to push DDT. So, it’s probably better to please the donors, than make a stand on the science and risk losing the money.



dearieme 09.18.06 at 11:52 am

“the substantive change in WHO guidance is much less dramatic than the rhetoric would suggest. WHO is now recommending the use of indoor residual spraying … in areas with constant and high malaria transmission”. Rhetoric aside, that sounds quite dramatic to me; but then I live a quiet life.


keith 09.18.06 at 12:28 pm

“The bogus story, popular in rightwing circles, in which the US ban on agricultural use of DDT, inspired by Rachel Carson, is morphed into a global ban on DDT, bringing to an end a previously successful compaign to eradicate malaria”

Can you link to an exploration of this point? Thanks.


Barry 09.18.06 at 1:40 pm

Keith, go to Tim Lambert’s blog (linked from CT), an d look in the category ‘DDT’. You’ll find links to a number of right-wingers disseminating falsehoods about DDT.


BlacquesJacquesShellacques 09.18.06 at 5:06 pm

So how about a link to DDT site that tells the truth and demolishes the evil Bushitler Rethuglican MCChimpy Hallibrutes?

The abiding weakness of the left is the lust for power. I expect lefties to want to control, manage and ban harmless chemicals simply from that lust.

The abiding weakness of the right is the lust for money. I also expect righties to sell me poison for my corn flakes just to make a buck.

Let’s have some debate. All I’ve ever read are the righties and they sound mighty plausible. Point me to some good lefty sites and I’ll read with an open mind.


John Quiggin 09.18.06 at 7:00 pm

As noted, Tim Lambert has plenty, or you can visit my site and search for “DDT”.


rdb 09.18.06 at 7:21 pm

Deltoid’s DDT category

The Deltoid: DDT Ban myth that will not die 2006-06-29

He (Kochi) got his way and now he’s working on other areas:

For example, he wants to standardize mosquito nets so that, instead of a welter of competing styles that must be home-dunked in pesticide, a few makers of factory-coated nets, which kill insects for years longer, are left to compete on price. He dismisses “social marketing,” in which nets are branded and sold cheaply instead of being given away, as with an early Bush administration policy that flopped. And, despite the objections of environmentalists, he wants DDT sprayed inside huts to kill mosquitoes where they rest on walls as they wait for dark.

Do you think this will stop folks from claiming that the WHO opposes DDT use?

Also, in the Washington Monthly Joshua Kurlantzick argues that the DDT obsession of many conservatives is a distraction from the use of artemisinin combination therapy (ACT):

Oddly, malaria has become something of a conservative cause celebre in recent years. Sen. Brownback has become a dedicated advocate for combating the disease. At congressional hearings, he and fellow Republican Sen. Coburn display an impressive knowledge of the crisis and the deficiencies of USAID’s response. However, apart from a few such thoughtful exceptions, conservative energies have mostly been focused on another supposed solution: the insecticide DDT.

DDT, which helps kill malarial mosquitoes, was sprayed in America to eradicate malaria. But Rachel Carson’s vivid portrayal of the horrors wrought by the chemical in her seminal book Silent Spring caused DDT to be banned in 1972, and helped launch the modern environmental movement. For some conservatives, malaria policy has now become an unlikely tool in the anti-environmentalist backlash. The Weekly Standard, The Wall Street Journal editorial page, and National Review have dedicated more than 10 editorials in recent years touting the benefits of DDT (although some conservatives like Bate, Brownback, and Coburn do advocate both DDT and ACT). At malaria hearings for the Senate Foreign Relations committee, Republican members have repeatedly asked why the United States doesn’t promote DDT in malaria-stricken nations.

This preoccupation with DDT, however, is largely a distraction. Environmental leaders now agree that the pesticide should be used to combat malaria; few nations in Africa ban it; and USAID has agreed to spray DDT in countries like Ethiopia and Mozambique. What’s more, DDT is no silver bullet. Malaria experts agree that it reduces transmission, but emphasize that it must be combined with other interventions, including ACT. The furor over DDT has undoubtedly hampered efforts to provide better access to antimalarial drugs. When another malaria expert met with Senate staffers to discuss malaria in 2004 and 2005, they badgered him about DDT. “I tried to explain the reality,” he says, “and people in the U.S. say ‘That’s not what I was told.'” “DDT has become a fetish,” adds Allan Schapira of WHO. “You have people advocating DDT as if it’s the only insecticide that works against malaria, as if DDT would solve all problems, which is obviously absolutely unrealistic.”


keith 09.19.06 at 7:40 am

Thanks for the info. It is misleading, though, to rail against conservatives about this misinformation. DDT was the most famous/infamous environmental issue for a long time. My current issue of National Geographic states that it was essentially banned word-wide.


mikep 09.19.06 at 8:22 am

I have been following this debate and must say that I find the arguments of the those who say that indoor residual spraying with DDT is cheap and effective against malaria and that there has been considerable internatinal pressure not to use DDT convincing. Try this link

and tell me what is wrong with the argument and I might change my mind. But Tim Lambert is not convincing.


Tim Lambert 09.19.06 at 9:30 am

What is wrong with the argument is that Roberts does not tell you that Sri Lanka was forced to switch from spraying DDT to using malathion because the mosquitoes developed resistance. He then cherry picks a period from when they were using DDT and malaria rates were low and compares it with a period after they switched to malathion when malaria rates were high (because the civil war had disrupted the spraying program). And then argues that stopping DDT caused the rates to go up. And he gets the rates wrong in his comparison, making an error of about an order of magnitude in his favour. If you compare the five years up to 1975 (when they stopped using DDT) with the five years after, you’ll discover that rates went down.


BlacquesJacquesShellacques 09.19.06 at 4:20 pm

Lefites, help me here. I went to some of the suggested sites and found lots of stuff about who said what to whom about DDT use and the politics thereof and why it was bollocks. Which it usually was, and highly self referential too. But none of it was the factual and/or research underpinning for the proposition that DDT is a pollutant, that it is a carcinogen, that it thins the little birdies shells, and oughta be banned yadda yadda.

I went to and got reams of stuff to the effect that DDT is not carcinogenic or a pollutant in any reasonable concentration. Are they wrong? If so why and how? Point me to a source or a website please.


Stu 09.19.06 at 6:37 pm

It is not a matter of the left saying DDT should be banned versus the right saying it shouldn’t, rather it is a case of certain people saying that it shouldn’t be banned even though it isn’t (well, not for indoor spraying, agricultural spraying is a different matter and is where the shells issue comes in, and also this can increase the chances of mosquitoes developing resistance). This is why you are not finding reasons why it ought to be banned for indoor spraying, however you will find plenty of arguments for considering other options in particular circumstances since DDT is not always the most effective one.
Tim Lambert does link to numerous scientific sources about DDT. The reason that you find so much politics rather than science is that this is usually stirred up as an issue for political rather than scientific reasons.


albert 09.19.06 at 7:18 pm


Point me to a source or a website please.

Go to, search for “DDT” in publication “Science” or “Nature” then read until heart’s content.


J F Beck 09.19.06 at 10:14 pm

If you rely on Tim Lambert as a source of information on the use of DDT in the fight against malaria you will be well and truly misinformed – if you click that link you’ll find that none of the links to Lambert’s old blog work because he continues to bounce them. (He also bars me from commenting at his current blog because he knows damn near everything he writes about DDT is misleading nonsense.) Play Lambert’s much-hyped “DDT ban myth bingo” and see for yourself.


mikep 09.20.06 at 4:23 am

YOu might like to consider this story from East Africa. Note that it’s producer interests (including tobacco interests) who are in favour of a DDT ban.


albert 09.20.06 at 11:36 am

And if you’re taking the claims of seriously, then there’s little chance of an informed debate. Most of the points in their DDTfaq are misleading, untrue, or poorly reasoned. The section on “Bird populations increase during DDT years” shows no understanding of how DDT works in the environment. Most of their arguments are attempts to disprove a strawmanned claim with discussion of exceptional cases.


BlacquesJacquesShellacques 09.21.06 at 6:23 pm

Albert, you tell me JunkScience is no good. I fear your response is mostly logical fallacies. Not a good start to an discussion in which logic should rule.

Your response to me starts with the false premise that I take seriously. Why would you think that? They are a starting point only which you are free to demolish.

You also say “Most of the points in their DDTfaq are misleading, untrue, or poorly reasoned.” This is “Begging the question”; it still does not tell me why JunkScience is wrong or where I may find correct information and analysis.

I read Lambert’s stuff and just did not find anything substantive. It’s full of “Appeal to Belief” and more question begging.

So far the DDT use side wins handily by default. I’m gonna buy me a can and put it on my corn flakes.

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