Becker and Posner’s ignorance about DDT

Gary Becker and Richard Posner have written a pair of posts about DDT and there is much wrong with what they have written.

Becker writes:

The world Trade Organization (WTO) declared in 1998 a “war on malaria” that aimed to cut malaria deaths in half by 2010. Instead, deaths from malaria have been increasing, not falling. The reason for the failure of this malaria war is mainly that in the name of environmentalism, the WTO and other international organizations rejected the use of an effective technique, namely spraying DDT on the walls of homes in malaria-infected areas.

It was the World Health Organization (WHO), not the WTO. And far from rejecting the use of DDT in that period, the WHO endorsed it.


What is especially disheartening about the huge number of deaths from malaria, and a fact that sharply distinguishes malaria from Aids, is that malaria deaths could be greatly reduced in a cheap way without requiring any fundamental changes in behavior, A small amount of DDT sprayed on the walls of homes in vulnerable malaria regions is highly effective in deterring malaria-bearing mosquitoes from entering these homes.

As is spraying other insecticides or providing the residents with insecticide-treated nets. The problem is funds to pay for this and infrastructure to deliver it.

Finally recognizing this, a couple of weeks ago the WTO relaxed its support of the ban on DDT, and instead supported spraying of DDT on house walls in malaria-ridden areas.

DDT is not banned and WHO has always supported its use.

This decision is likely to influence the position on DDT spraying of the World Bank, UDAID, and other relevant organizations.

The World Bank already funds DDT spraying as does USAID.

In any case, by the end of 1972, DDT’s use in the United States was effectively banned. That ban soon became common in all rich countries, and in most poor countries too, as they responded to pressure from international organizations and Western governments.

The agricultural use of DDT in the US was banned in 1972. Use in public health was not. The Stockholm treaty on Persistent Organic Pollutants permits the use of DDT against malaria. The ban on the agricultural use of DDT has undoubtedly saved lives by slowing the spread of resistance.

One unintended consequence of the DDT ban was a devastating comeback by malaria and some other diseases after they had been in retreat.

As already noted, DDT was not banned. The main causes of the resurgence of malaria was the evolution of resistance to DDT and anti-malaria drugs.

The USAID has been a strong advocate of mosquito bed nets as an alternative to DDT. Mosquitoes operate mainly from dusk until dawn, so netting over beds can be effective if used persistently and correctly. Unfortunately, in many African countries bed nets are not readily available, and they are often not used to protect children since poor families may only have one or two nets. Moreover, families frequently do not bother to use these nets during some of the hours when mosquitoes are still active. So while bed nets could be a useful part of an overall strategy against malaria, they are not a good substitute for DDT.

Yes, bed nets don’t work if they are not available, but money spent on DDT spraying could instead be used for buying nets. The new long lasting nets appear to be more cost effective than DDT in the long term. And yes, bed nets don’t work if people don’t use them. But neither does DDT if they refuse to allow spraying or re-plaster their walls.

The ban on using DDT in houses to fight malaria is an example of environmentalism that lost all sense of proportion. As has happened with nuclear power and in other environmental situations, exaggerated claims about negative environmental effects of DDT on humans were publicized, and these claims were further exaggerated after being picked up by the media and politicians.

What has really happened is that exaggerated claims about negative effects of a non-existent DDT ban were publicized, and these claims were further exaggerated after being picked up by the media and politicians.

As a result of the hysteria against the use of DDT for any purpose, millions of lives were lost unnecessarily during the past several decades to malaria and some other insect-borne diseases. These deaths occurred only, I repeat only, because of international pressure on African and other poor countries not to use DDT and certain other pesticides in fighting malaria and other diseases caused by insect bites.

This is completely untrue. It is a right-wing fantasy and is grossly irresponsible for Becker to report it as fact. DDT has not been banned and it is not a magic bullet against malaria.

Richard Posner also has a post. He writes:

The Stockholm Convention on Persistent Organic Pollutants (2001) bans DDT but with an exception for its use against malaria, and the puzzle is why the exception is so rarely invoked, South Africa being a notable exception. An even greater puzzle is why the Bill and Melinda Gates Foundation, which is the world’s largest foundation and has made the eradication of malaria a priority, is spending hundreds of millions of dollars searching for a vaccine against malaria but nothing (as far as I know) to encourage indoor spraying with DDT.

Here’s the solution to the puzzle: Gates is a smart guy and has studied the problem more carefully than Posner. They had a massive program that tried to eradicate malaria with DDT spraying in the 60s and it failed. DDT is a useful tool against malaria and it is being used for that, but it won’t eradicate malaria. Gates is right to fund research into a vaccine and the development of new drugs and insecticides. (We desperately need new drugs and insecticides because the parasites and mosquitoes keep evolving resistance to the ones we have.)

Comments

  1. #1 Bob
    September 25, 2006

    3 billion and counting….

  2. #2 Anonymous
    September 25, 2006

    Thanks Tim. This is very disappointing performance by Becker. It is bad enough to get the facts so egregiously wrong, but even worse is his failure to pause before concluding that the rest of the rest of the world has suspended cost-benefit analysis and is complicit in mass murder. It is a salutary lesson in how prejudice (in this case against “environmentalism”) can cause the complete suspension of critical faculties even in otherwise great minds.

    [Point of correction: the reference to _"Posner"_ should be _"Becker"_]

  3. #3 Alan Adamson
    September 25, 2006

    Good work, and thanks, Tim. The minute I saw the Becker-Posner posts, which I normally quite like, I started monitoring your site.

  4. #4 frankis
    September 25, 2006

    If Becker and Posner had the sense of Bill Gates or much of the moral values they’ve probably heard about in church, they’d have to be ashamed of themselves. You know – I don’t think we’ll be hearing any repentance from them.

  5. #5 Dano
    September 25, 2006

    Gates is right to fund research into a vaccine and the development of new drugs

    You’d think pHrma would be all over this, developing a new drug to sell to people, marking it up at first so it’s expensive and rich people buy it and…oh, wait: never mind.

    Best,

    D

  6. #6 Chuck
    September 25, 2006

    Mr. Lambert asserts “DDT was not banned”. However, he fails to examine if there are various de facto bans.

    For example, a current newspaper web page has a story from which I took the following quotations:

    Agro-exporters say return of DDT will be devastating

    “The developed country markets where these exports are sold all have very strict guidelines on DDT and products contaminated by DDT. In most cases, any traces of DDT contamination will lead to immediate destruction and banning of the product. The impact on the economy of Uganda would be devastating,” the statement from the agricultural exporters noted.

    . . . .
    In April, the head of the Economic, Trade and Social sectors desk at the European Union delegation to Uganda, Tom Vens, told The EastAfrican that the EU had warned the government against the use of DDT.

    “We have advised the government that it is taking a risk if it goes ahead with this DDT use,” he said. “We, however, leave it to them to decide. But nothing will happen, at least on the official side, if they decide to use DDT in strict compliance with the Stockholm Convention,” he said.

    . . . . .

    “If the strict controls that should be put in place when DDT is used are not fully adhered to, there is a risk of contamination on the food chain. It would not automatically lead to a ban of food products, but it will mean that that particular consignment cannot be sent to Europe,” he added.

    =========================
    See http://www.nationmedia.com/eastafrican/current/News/News250920063.htm

  7. #7 frankis
    September 25, 2006

    Dr Lambert has actually examined the matter in detail Chuck, check the “DDT” entry under “Categories” in the above left sidebar.

    The bans are on agricultural use, not on indoor residual spraying for disease vector control, and remain a “good thing” as all the quotes from your article appear to confirm.

  8. #8 QrazyQat
    September 25, 2006

    Chuck, if people are using DDT for malaria control, and they are, then claiming there’s a ban “defacto” or otherwise, just doesn’t make sense. And of course your story refers to the use of DDT on crops, not malaria control. Even reading the first paragraph of what you quoted makes that clear, if one actually takes the step of reading it.

  9. #9 Hans Erren
    September 25, 2006

    In 1998 I made summary maps for the ‘ Chemical Waste Management in Tanzania ‘ – project which comprised an inventory on Obsolete pesticides in Tanzania. The total numbers were: 296 m3, plus 280847.72 liters plus 355899.92 kg “obsolete pesticides”.

    [Pesticide Pollution Remains Severe after Cleanup of a Stockpile of Obsolete Pesticides at Vikuge, Tanzania](http://ambio.allenpress.com/ambioonline/?request=get-abstract&issn=0044-7447&volume=33&issue=8&page=503
    )

    Sara Elfvendahl, Matobola Mihale, Michael A. Kishimba, and Henrik Kylin

    AMBIO: A Journal of the Human Environment: Vol. 33, No. 8, pp. 503-508.
    Submitted: 18 April 2002
    Revised manuscript received 10 Dec. 2003. Accepted for publication 16 Dec. 2003.

    High levels of DDT residues and hexachlorocyclohexanes (HCHs) were found in soil, well water, and surface water around a collapsed pesticide storage shed at Vikuge Farm, Tanzania. Residues of DDT and HCHs were found at three soil depths down to 50 cm. Surface soil samples contained up to 28% total DDT and 6% total HCH residues. Water samples had concentrations of up to 30 µg L−1 of organochlorine pesticides. Other compounds detected were aldrin, azinphos-methyl, carbosulfan, γ-chlordane, chlorprofam, heptachlor, hexazinone, metamitron, metazachlor, pendimethalin, and thiabendazole. Although the visible remains of pesticides have been removed, the remaining soil is itself hazardous waste and poses a risk to the environment and the inhabitants of the surrounding villages. These findings show the necessity to follow up the environmental situation at former storage sites of obsolete stocks of pesticides, and that the environmental problems are not necessarily solved by removing the visible remains

    http://english.people.com.cn/200605/08/eng20060508_263856.html

    Tanzania lifts ban on DDT so as to fight malaria

    The Tanzanian government has lifted the more-than-one-decade-old ban
    on insecticide DDT in a bid to boost the country’s fight against
    malaria, local press reported on Monday.

    English newspaper The Citizen quoted Tanzanian Health Minister David
    Mwakyusa as saying over the weekend that the move was aimed at
    strengthening the efforts to fight malaria.

    Malaria surged back in the wake of the introduction in 1992 of a
    total ban on the use of DDT in Tanzania, according to local
    available statistics.

  10. #10 Chuck
    September 25, 2006

    Re: Frankis

    Look at the story—it’s about anti-malarial use of DDT. The agricultural interests in Uganda are OPPOSED to doing so for fear of exclusion by governments or boycotts by consumers of their products.

    Chuck

  11. #11 frankis
    September 26, 2006

    Chuck, my intended meaning was that because a ban on agricultural use is indeed a good thing, news that exporters may be nervous about the possibility of misuse or accidental contamination of their crops with DDT is also good because it suggests that the message has been understood. Any use made of DDT (or other insecticides) may be more responsible partly because those exporters will be watching and neither they nor anybody else – the possibility of dirty tricks excepted – will want to see their ag exports banned for contamination. I’m assuming that the exporters’ fears would not in fact suffice to produce a de facto ban by the government; that if there are good epidemiological reasons for using DDT for IRS that that is what will happen, and that the fears of contamination would at worst lead to strict regulations and supervision rather than a de facto ban.

  12. #12 Tim Lambert
    September 26, 2006

    Uganda’s exporter’s concerns are not unreasonable. From the [IWMI study](http://www.iwmi.cgiar.org/pubs/working/WOR95.pdf):

    >Two malaria control and insecticide control specialists, who were interviewed for this study, believe that Kenya has the capacity to control DDT from its import to its end use. Four other interviewed specialists, however, believe that Kenya does not have this capacity. A survey conducted by Egerton University supports the latter interviewees’ conclusions, revealing that seven percent of households in the Nakuru district use DDT on their farms, despite Kenya’s 18-year ban on agricultural use of DDT (Ramas 2004). As Kenya is currently not able to enforce its complete ban on DDT, questions should be raised about Kenya’s capacity to regulate DDT use if it is reintroduced for malaria vector control.

  13. #13 Eric Wallace
    September 26, 2006

    I have to admit that while I’ve read a number of statements reagarding the WHO’s attitude toward DDT, I’m having trouble making heads or tails of it. Tim, you state that the WHO has always supported the use of DDT, but what do I make of this press release from the WHO which contains statements like this:

    WHO actively promoted indoor residual spraying for malaria control until the early 1980s when increased health and environmental concerns surrounding DDT caused the organization to stop promoting its use and to focus instead on other means of prevention. Extensive research and testing has since demonstrated that well-managed indoor residual spraying programmes using DDT pose no harm to wildlife or to humans.

    The remainder of the press release certainly makes it sound as if this is a policy change (e.g, it is described as a “reassessment”).

    I wonder if even the WHO knows what it thinks about DDT.

  14. #14 JB
    September 26, 2006

    There are clearly two issues here.

    The first is coming up with an effective approach to malarial control that is flexible enough to work in the many coutries affected. It is reasonable to assume that this will probably involve a combination approach: education about malaria, insecticide impregnated bed nets, indoor spraying, antimalarial drugs, etc. (It is unreasonale to assume that any one of these alone will be adequate.)

    It is also reasonable to assume that if the affected countries are left to fend for themselves — ie, if they do not get the needed money and other resources from the developed countries — the results will be disappointing. While the amount of money involved for a combination program of indoor spraying and bed nets may be a lot for a country like Uganda, it is peanuts for a country like the US. These countries should not have to choose between one method and another because of cost. They should be put in a position where they can decide — based on effectiveness, not cost — which method or combination of methods is best for their own country.

    There is clearly a second issue involved here. Some of the people who write about this issue are clearly playing the “blame game” — blaming the environmental movement (opposition to DDT) for the resurgence in malaria in many countries (particularly in Africa). They believe (or at least write as if they believe) that oppositon by environmenal groups to DDT use is at the root of the malaria resurgence.

    There is just one small problem with this belief, as Tim and others have pointed out: the facts simply do not support this thesis.

    There has been no worldwide ban on DDT use and while it can play a role in the control of malaria, DDT is not a “silver bullet” that will eradicate malaria (never has been, never will be). Anyone who believes otherwise simply does not understand the very basic concept of “resistance development to chemicals” in insect populations(they should take a basic biology course.)

    In the past, use of DDT has led to resistant mosquitos. One has to factor this into the “malarial control equation”. If one does not and one places all the eggs in the insecticide (DDT or any other) spraying basket, one is doomed to fail.

    Actually, it is not unreasonable to assume that at least some of those who are now playing the blame game with DDT have ulterior motives: “The environmentalists were wrong on DDT and look what happened: millions of people died . What if they are also wrong on global warming, lead, rainforest destruction [insert long list of peeves about environmentalists here]. How many people will die then?”

  15. #15 Hans Erren
    September 26, 2006

    Looks like we are playing semantics here.

    Where do the stockpiles of “obsolete pesticides” in Tanzania come from?

    What was banned in 1992?
    Wat was lifted in 2006?

    what is the meaning of the phrase:

    DDT was blacklisted as one of 12 persistent organic pollutants under the 2001 Stockholm Convention.
    http://english.people.com.cn/200605/08/eng20060508_263856.html

    When is a ban not a ban?

  16. #16 Dano
    September 26, 2006

    Hans tries to play the game of asking questions to cast doubt.

    Yawwwwwwnnnn.

    [becomes bored with commenters' pathetic rhetoric]

    Best,

    D

  17. #17 Hans Erren
    September 26, 2006

    No Dano I am serious.

    The statement “There wasn’t a DDT ban” is falsified by the evidence from Tanzania. I shared a house in Tanzania with the project leader who made the country wide inventory of obsolete pesticides in 1999.

  18. #18 Hans Erren
    September 26, 2006

    http://www.angolapress-angop.ao/noticia-e.asp?ID=438535
    “Tanzania lifts ban on DDT so as to fight malaria

    DAR ES SALAAM,05/08 – The Tanzanian government has lifted the more-than-one-decade-old ban on insecticide DDT in a bid to boost the country`s fight against malaria, local press reported on Monday.

    English newspaper The Citizen quoted Tanzanian Health Minister David Mwakyusa as saying over the weekend that the move was aimed at strengthening the efforts to fight malaria.

    Malaria surged back in the wake of the introduction in 1992 of a total ban on the use of DDT in Tanzania, according to local available statistics.

    It is now alleged as one of the three killer diseases in Tanzania where a third of all the out-patients at hospitals and clinics are malaria-related. Malaria claims the lives of some 100, 000 people a year, of whom 70 percent being children under the age of five years old.

    HIV/AIDS and tuberculosis are the two other killer diseases in the east African country.

    DDT, or fully known as dichloro-diphenyl-trichloroethane, came to be used as an insecticide after World War II because of its effectiveness against mosquitoes that spread malaria and against lice that carry typhus.

    But DDT was blacklisted as one of 12 persistent organic pollutants under the 2001 Stockholm Convention. “

  19. #19 Doug Clover
    September 26, 2006

    Not sure what Hans is talking about but I have a copy of the Stockholm Convention sitting on my desk and it says clearly (well as clear as these conventions ever say anything).

    Acceptable purpose:
    Disease vector control use in accordance
    with Part II of this Annex

    That will be on page 24.

    On page 25 there is a lot more about how DDT will be regulated.

    Including this bit

    3. In the event that a Party not listed in the DDT Register determines that it requires DDT for disease
    vector control, it shall notify the Secretariat as soon as possible in order to have its name added forthwith to
    the DDT Register. It shall at the same time notify the World Health Organization.

    A lot of bother over a banned chemical.

    see for your self at

    http://www.pops.int/documents/convtext/convtext_en.pdf

    Also there is more in the “Guidance for completing the questionnaire by each Party that produces or uses DDT, for the evaluation of the continued need for DDT in disease vector control”

    including this reporting requirement
    Module 3 CONTROL OF DDT SPRAYING AND RESISTANCE MONITORING

    see http://www.pops.int/ddt_info/default.htm

    Doug

  20. #20 JB
    September 26, 2006

    Hans:

    What you cite above indicates that one country — Tanzania — had a ban on DDT.

    But one country’s ban does not a worldwide ban comprise. In particular, it does not show that any of the orgnizations such as WHO, World bank or USAID had policies that required client countries to implement bans.

  21. #21 Hans Erren
    September 27, 2006

    indeed, one country is not a worldwide ban.

  22. #22 Ian Gould
    September 28, 2006

    High levels of DDT residues and hexachlorocyclohexanes (HCHs) were found in soil, well water, and surface water around a collapsed pesticide storage shed at Vikuge Farm, “Tanzania. Residues of DDT and HCHs were found at three soil depths down to 50 cm. Surface soil samples contained up to 28% total DDT and 6% total HCH residues. Water samples had concentrations of up to 30 µg L−1 of organochlorine pesticides. Other compounds detected were aldrin, azinphos-methyl, carbosulfan, γ-chlordane, chlorprofam, heptachlor, hexazinone, metamitron, metazachlor, pendimethalin, and thiabendazole. Although the visible remains of pesticides have been removed, the remaining soil is itself hazardous waste and poses a risk to the environment and the inhabitants of the surrounding villages.”

    Hans, care to comment on Per’s claims about how wonderfully safe DDT is?

  23. #23 per
    September 30, 2006

    care to comment on Per’s claims about how wonderfully safe DDT is?

    ian

    in faith you should also point out that tim’s first link, the ATSDR report, and the lancet article cited in our recent discussions had explicit statements (which i directly cited) about the safety of DDT. Maybe you should explain why you think these are wrong ?

    yours

    per

  24. #24 idlemind
    October 1, 2006

    I hadn’t really thought of it before, Tim, but “The ban on the agricultural use of DDT has undoubtedly saved lives by slowing the spread of resistance” has a clear analog in the development of antibiotic resistance from the pervasive use of antibiotics in farm animals.

  25. #25 Ian Gould
    October 2, 2006

    I’m not interested in debating you Per – why sdon’t you explain to Hans why the clean-up he took part in was quite unnecessary given the benign nature of DDT?

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