DDT works

Contra John Quiggin and Tim Lambert, DDT is usually the most cost-effective anti-malaria treatment, and remains scandalously underused
May 23, 2008

The environmentalist assault on the chemical DDT has come at an extremely high cost in human life. It is impossible to know how many people have died needlessly from malaria, yellow fever, leishmaniasis, dengue fever and other insect-borne diseases in the absence of DDT, but it must be millions.

Many environmental groups cut their teeth pushing for bans on agricultural uses of DDT. Rachel Carson's book Silent Spring (1962) was the starting point for much of this, although Carson is certainly not to blame for the environmental crusade that occurred against the chemical after her death in 1964. Silent Spring made important points about the dangers of overuse of agrochemicals, of which DDT was a major component. But it was short on good medical science. For example, Carson led the reader to believe that in one instance, after spraying DDT, a housewife developed leukaemia and died within three months. Such a claim has no scientific validity; in terms of danger to humans, DDT is one of the safest insecticides ever developed.

But while there were serious concerns about the bioaccumulation of DDT up the food chain, and it was rightly phased out for use in agriculture, it still had a valid role in combating public health menaces, notably disease-bearing mosquitos. Not satisfied with having DDT outlawed for agriculture, environmentalists increased pressure for a total ban in the late 1980s and early 1990s.

By 1997, the World Health Assembly had bowed to this pressure, passing a resolution to restrict the use of insecticides in public health, and the United Nations Environment Programme was beginning negotiations towards what would become the Stockholm convention to phase out global use of DDT and 11 other chemicals. Several major environmental organisations were demanding a total ban on DDT by 2007. I attended the negotiations in Geneva in 1999 and Johannesburg in 2000, and recall the change in the position the more responsible green groups took when several hundred malaria scientists, including three Nobel laureates, and some ministries of health from southern African nations demanded that DDT remain available for public health use.

John Quiggin and Tim Lambert purport to restore Rachel Carson's reputation, trashing me and an organisation I helped found, Africa Fighting Malaria, in the process. Their article amounts to a half-baked conspiracy theory that breaks down with a cursory review of the facts. The authors' hope is that by branding me a tobacco lobbyist and claiming the tobacco industry is bankrolling the campaign for DDT, they will convince others to dismiss DDT advocates as industry stooges. They are sadly mistaken.

First, the tobacco industry never established the European Science and Environment Forum (ESEF). That allegation was addressed in the Lancet in 2000. ESEF was formed in late 1994 to debate climate change. The vast majority of its funding came from two foundations: the Marit and Hans Rausing Foundation, and the May and Stanley Smith Charitable Trust. The latter became interested in the DDT debate and provided funding through ESEF for the US chapter of Africa Fighting Malaria in 2003.

Second, I was never a tobacco lobbyist. After I wrote two articles on tobacco-related topics in 1996 and 1997, I consulted for Philip Morris, at their request, on international health for a total of about a month in 1998. I never lobbied for the company or promoted cigarettes in any way. I subsequently wrote to Philip Morris asking them to provide funding for a campaign to rehabilitate the use of DDT. This letter, which is now on the web, is the source of nearly all Quiggin and Lambert's suppositions. Yet I never even had the courtesy of a reply. Philip Morris never funded the campaign, and I haven't spoken with the company in at least seven years.

Thus without tobacco industry funding, Richard Tren and I set up Africa Fighting Malaria in 2000 in South Africa. Neither of us have had any contact with the tobacco industry since its formation, other than to criticise it. The tobacco industry has publicly opposed the use of DDT for malaria control, largely because of concerns that contaminated plants would not be accepted for production in the EU and other developed countries. AFM led the public outcry against British American Tobacco in 2006 when it opposed the use of DDT in Uganda, absurdly worrying about contamination of its product.

Quiggin and Lambert probably found this information when Googling for "Africa Fighting Malaria" and "tobacco." It is readily available on AFM's website, along with a list of the organisation's funders. AFM does not accept money from malaria control industries—drugs, insecticides or mosquito net manufacturers—nor any governments. Further, a quick look there will show that far from saying that DDT is a panacea, as Quiggin and Lambert assert, AFM continues to explain how complex a disease malaria is, requiring all available techniques to combat it.

Quiggin and Lambert claim that I have managed to pull the wool over the eyes of mainstream journalists, a backhanded compliment. In fact, the New York Times, the Washington Post, the Wall Street Journal, the Economist and Nature have all reported correctly on DDT, based on credible and available scientific evidence. As these publications pointed out, although DDT was granted an exemption for public health in the Stockholm treaty and the World Health Organisation (WHO) approved its use for malaria control, no aid agency was purchasing it and some, such as the World Bank and the US government, were actively discouraging its use.

While Chinese and Indian government-backed companies continue to produce DDT for their own public health programmes, and for export, no western company has produced DDT for over a decade. Major chemical companies such as Bayer, Dow Chemical, Du Pont and BASF produce alternative products, and have incentives to see DDT phased out. Bayer actually agitated against the use of DDT, abusing its position as private sector delegate to the Roll Back Malaria Partnership, as reported in the Financial Times. AFM was alone among advocacy groups to raise this as a concern.

The reality is that DDT is probably the most useful insecticide ever used for public health. Despite what Quiggin and Lambert say, the public health provisions of the 1972 US delisting of DDT have been used several times after 1972 in the US to combat plague-carrying fleas, in Colorado, New Mexico and Nevada. DDT still has a place in malaria control, one that has expanded because of sensible recent policies from WHO, the Global Fund and the US government. Quiggin and Lambert are wrong to dismiss WHO's 2006 support as a restatement of old policy. While DDT has been a WHO-approved insecticide for decades, for many years WHO officials did not promote its use, instead tending to push for insecticide-treated nets. Following WHO statements supporting DDT, some developing-country governments, such as Uganda, have been emboldened to say they want to spray the chemical, even in the face of opposition from local business lobbies.

The environmental movement is not entirely to blame for preventing sensible uses of DDT, but it's not surprising that it is trying to cleanse history. Its reputation has been dented because of its apparent callousness against the use of a life-saving chemical. Its line, repeated by Quiggin and Lambert, is that environmental groups dropped total opposition to DDT during the Stockholm negotiations. This is misleading. To their credit, some groups, such as the Sierra Club, have come forward with guarded support for DDT. Other groups, such as the South Africa-based Endangered Wildlife Trust, have provided admirable practical assistance to malaria control programs using DDT so that environmental contamination is minimised.

But opposition remains, and groups like Pesticide Action Network North America continue to push for a phase-out of DDT from malaria control programmes. In India, a country with a malaria problem lowered because of DDT, Sanjiv Gopa, toxics campaigner for Greenpeace India, said in December 2003, three years after the final Stockholm negotiations, that, "It is clear that the Indian government should phase out and substitute DDT immediately as required by the POPs [Stockholm] convention."

While I regret that Quiggin and Lambert continue to parrot these anti-DDT sentiments, there are many ill-informed arguments for the use of DDT to be found, especially online. I may not have done enough in the early years of this decade to respond to those excesses, and may even occasionally indulged in them myself, but for many years I have tried to be logical. I even gave a partial defence of Rachel Carson in the Washington Post last year, absolving her of responsibility for the irrational things her followers have done.

I first proposed the idea of a pro-DDT campaign because I thought it was scientifically valid; I still do. Furthermore, I thought WHO and other international bodies were dangerously applying environmental regulation; they still are (the 1997 anti-insecticide World Health Assembly resolution still stands). Having spent time in malarial areas (sometimes under bed nets) and having had the disease myself, I welcome any intervention that saves lives. DDT remains underused. It is no panacea, but it is still the most cost-effective method of malaria prevention in most locations. I wish the tobacco industry had funded the campaign I proposed back in 1998, but they didn't. Quiggin and Lambert's attempt to rewrite history will not change it. DDT has saved innumerable lives. Stifling Africa's efforts to use it against malaria has likely cost many more.