Does WHO really oppose DDT use?

It is frequently claimed that the World Health Organization opposes the use of DDT against malaria. Even if we just confine ourselves to articles at Tech Central Station, the claim has been made by
Paul Driessen,
Nick Schulz,
Roger Bate,
Tim Worstall,
Duane Freese,
James Glassman,
Richard Tren and
John Luik.

Of course, given TCS's track record, you'd be well advised to check to see what the World Health Organization actually says about DDT. Here is the full text of the RBM Partnership Consensus Statement on Insecticide Treated Netting:

The RBM Partnership has received questions enquiring whether nation-wide application of indoor residual insecticide (house) spraying (IRS) for vector control might be a better option for malaria prevention in countries in the WHO Region for Africa (AFRO), rather than insecticide treated nets (ITNs).

In Africa, ITNs and IRS are both very effective for malaria vector control. There is mixed evidence concerning the relative cost-effectiveness of these two interventions: in some cases IRS appears to have been more cost-effective than ITNs, while in other cases the reverse was found. It is not therefore possible to make any generalized assertion, for the region as a whole, that either of these interventions will normally be more cost-effective than the other.

In any case, the choice between these two interventions depends not only on short-term epidemiological impact, but also on considerations of feasibility and sustainability in the long term and at the large-scale, and on the availability of appropriate delivery systems.

For example, in some countries, especially in Southern Africa and in the Horn of Africa, proportions of the population are exposed to unstable or epidemic malaria. In these circumstances, IRS has some important advantages: it has rapid and reliable short-term impact, and it can be targeted to the communities at highest risk, on an annual basis and in response to changing transmission patterns. IRS is, on the other hand, relatively demanding in terms of the logistics, infrastructure, skills, planning systems and coverage levels that are needed for a successful and effective operation. Nevertheless, such systems have been successfully and effectively maintained for many years in some African countries, especially those that contain large populations exposed to unstable malaria. Every effort should be made to sustain these systems in the future.

However, in most countries of Africa south of the Sahara, the vast majority of the rural population is exposed to stable malaria and the systems needed for large-scale IRS do not exist. In these countries, the critical question is not whether one intervention is slightly more powerful than the other, but which of the two offers better prospects of achieving high nationwide coverage and long-term sustainability. In these circumstances, ITNs have important advantages. As well as being less demanding than IRS in terms of infrastructure and organization, ITNs allow vector control resources to be targeted toward those most at risk in stable endemic settings, i.e. pregnant women and young children, hence best use can be made of initial resources. ITNs protect people who use them, and they also have community level benefits, giving protection to people without nets in nearby houses. These benefits are thought to increase incrementally with coverage, across all coverage levels, and will contribute to early gains in equity as programmes scale up. The minimum coverage at which ITNs might have a significant community effect at programme level is not yet established. ITNs can give protection of longer duration than IRS since a net in good condition gives reduced but still significant protection to the user even after the insecticide has worn off. This advantage will be further strengthened by the emerging development of Long Lasting Insecticidal Net (LLIN) technology, which greatly extends the effective life of the insecticide.

In high transmission and stable endemic malaria settings of Africa south of the Sahara, facing a choice of methods to implement and scale up, RBM strongly recommends that countries and RBM partners focus preventive vector control efforts on increasing coverage of insecticide-treated nets (ITNs) rather than investing in the creation of new large-scale IRS programmes.

So WHO says about DDT spraying: "Every effort should be made to sustain these systems in the future." So they don't oppose DDT use where it is the best option, they just think that it is not the best choice in some parts of Africa. TCS gets it wrong yet again.

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In fact, WHO was the most influential organization promoting DDT use in the 1950s. It was WHO's sad and scary experience with insecticide resistance in places such as Greece that caused the consensus position to shift away from blanket outdoor spraying of DDT for malaria control. The multi-pronged approach now recommended by WHO, in which DDT is used sparingly and judiciously, arose from that painful and hard-won experience. It is not the result of some knee-jerk, unreasoning antipathy toward DDT on the part of WHO; quite the opposite.

Not that the facts of the case ever made much difference to TCS.

"Not that the facts of the case ever made much difference to TCS."

You folks in the reality-based community will never learn. Winning is everything. Reality and truth are nothing. He who dies with the most toys wins. (Gee, I remember when that was understood to be sarcastic...)

I'm sure that Tim Lambert will be terribly glad to know that since November 2004 (when that piece came out) my views on the WHO and the use of DDT for controlling malaria have changed. Largely as a result of what Tim Lambert has been writing about the subject.

I am now aware that limited and controlled indoor spraying is both allowed and at times encouraged and that large scale agricultural applications are not (encouraged that is), primarily as a result of worries over resistance.

I am still worried about such things as the EU's insistence upon costly checks on produce from some countries that do use DDT (I think I've seen Uganda mentioned) as I regard it as a form of protection, a non-tariff barrier, in much the same way that some of the rules on slaughter (ie in Botswana, as I've been told by one of the EU's own aid officials) do.

But without wishing to sound too cloying I would like to say thank you to Tim for correcting my views on the matter.

Just to show the other side of the coin, there is a very influential book about what happens when inspection is absent from the food chain, The Jungle, by Upton Sinclair. published ~1900 which lead to the imposition of costly inspection of food processors in the US.

As long as domestic and foreign producers are held to the same standard, I think that it is useful (for example all cattle in Japan are tested for mad cow disease, and the Japanese government wants to impose the same inspection on imported US meat).

I am still worried about such things as the EU's insistence upon costly checks on produce from some countries that do use DDT (I think I've seen Uganda mentioned) as I regard it as a form of protection, a non-tariff barrier, in much the same way that some of the rules on slaughter (ie in Botswana, as I've been told by one of the EU's own aid officials) do.

Tim, all crops imported into the developed world are required to be checked for pesticide residue. So far as I know, the requirements for DDT are no more onerous than for other insecticides.

By Ian Gould (not verified) on 17 Dec 2005 #permalink

Synchronistically:

December 16, 2005
Op-Ed Contributor
Yes, We Have Bananas. We Just Can't Ship Them.
By TIM HARFORD
New York Times
Washington

AT this week's ministerial meeting of the World Trade Organization in Hong Kong, negotiators have once again hit an impasse over how and when to open the rich world's agricultural markets to farmers in the poorest countries. What few people have realized, however, is that poor countries don't have to wait for the World Trade Organization. There is plenty that they can and should do to help their own farmers to trade.

...
The real problem is elsewhere: three-quarters of delays are the result of red tape, not port handling or inland transport. These delays, caused by senseless bureaucracy, unnecessary forms and archaic inspection practices, can often be eliminated with a stroke of a pen by a country's chief executive. Even the more sophisticated reforms, like introducing electronic filing, or using software to guide sensible risk-based customs inspections, require only small outlays. What's more, such reforms increase the interception of smuggled goods and discourage corrupt customs officials.
http://www.nytimes.com/2005/12/16/opinion/16Harford.html

Responding to Tim W, I'd like to observe that he's one of the few people on the other side of this debate who's been willing to look at the evidence honestly (this also applies in other issues where Tim has been involved).

Most of the other participants on the TCS side have engaged in endless Clintonesque hairsplitting about what the term "ban" really means, followed by a return to the old lies as soon as they think no-one well-informed is looking.

By John Quiggin (not verified) on 17 Dec 2005 #permalink

Ian,
I have the impression (but no hard facts) that DDT testing is indeed more onerous. I'd love to know that actual truth of that.

I am firmly of the belief that things like the "Farm to Fork " program of identification of, say, meat, from a numbered animal all the way from field to plate is less about food hygiene within the EU and more to do with imposing non-tariff barriers on poor country imports.

As an example, this comment left at my blog:

"Tariff and quota-free access to the EU markets is useless to the Botswana beef farmer who has no access to a slaughterhouse that passes stringent EU criteria and so whose admirable product cannot be packaged or transported to the EU in an acceptable form to compete with EU beef."

Yes, I know, a comment on a blog is hardly conclusive evidence. Although I do know the person who left it and she is an EU aid official dealing with agriculture in Africa.

Perhaps I'm just excessively cynical about the EU but spurious "health n' safety" regulations are a classic non-tariff piece of protectionism.

Sorry, forgot to add about the Tim Harford piece. My day job involves imports and exports in and out of Russia and the CIS. You may have heard some of the stories of what can go on in such things but there are parts of the world where the bureaucracy scares even me.

Re #7 Robert McClelland

TCS is a political advocacy group created by corporations and political conservatives to advance their political agendas. TCS, CEI and many other conservative anti-regulation groups were started to counter the political success of the environmental groups.

For more info about TCS and its funding checkout sourcewatch
http://www.sourcewatch.org/index.php?title=Tech_Central_Station

By Joseph O'Sullivan (not verified) on 18 Dec 2005 #permalink

I am not sure why anyone thinks testing for DDT is fundamentally more difficult that testing for any other organic pesticide, basically sample prep, GC analysis with some sort of detector on the end. Very standard stuff. Since each country has a specific protocol, you could call up the local environmental agency and ask. Most of these are on the net.

The only issue would be if the allowed amount of DDT were much lower.

There are significant non-tariff barriers in the EU and lots of them are used in the way Tim W describes, but the DDT test isn't particularly onerous (the slaughterhouse regime was for the most part developed by the French as an opportunistic way to do an end run round the Treaty of Rome during the BSE years). If you were starting a DDT household spraying program, it would be a good idea to do the testing anyway to make sure that none of the DDT was being diverted irresponsibly to agricultural uses.

"I have the impression (but no hard facts) that DDT testing is indeed more onerous. I'd love to know that actual truth of that."

In the meantime, I'd love to know the source of your impression.

No specific source for the impression. It is just that, a general feeling or assumption. If I had a source I'd say "Look at this over here where so and so says this."

That's why I say it's an impression, not a fact or a statement by someone.

As Daniel points out above, the EU does use some (note the some) such rules as non-tariff barriers. As the EU is one of those insisting on the DDT testing it isn't a completely ridiculous assumption (it may be a wrong one, but not ridiculous) that it is being so used.

Unlikely really. Uganda doesn't really export much grain to the EU; most of its agricultural exports are cut flowers and value-added packaged vegetables (on which it is doubly important to be sure that there aren't any pesticide residues because consumers typically don't wash them). These products aren't really competing with domestic producers.