How Good Intentions Kill
Dec 8, 2000
BY BANNING THE USE OF DDT WOULD COST LIVES AND WEALTH IN THE DEVELOPING WORLD, SAYS ROGER BATE
Since 1995 the United Nations Environment Programme has been negotiating a legal treaty under which a dozen chemicals will be eliminated or restricted by international agreement. The fifth and final negotiations, where the delegates are to decide on the final treaty text, take place in South Africa this week.
The UNEP and its green supporters feel they are making the world a safer place by eliminating chemicals that they consider are not only dangerous and environmentally damaging but also unnecessary. However, for many people - mostly poor and living in developing countries - these good intentions are in effect a death sentence. DDT, the pesticide reviled by so many people throughout the world, is one of the 12 chemicals to be listed.
While developed countries have no need for DDT and will certainly not miss its passing, the pesticide is used in many developing countries in the fight against malaria. DDT is sprayed on the insides of houses and kills the anopheles mosquito that spreads the lethal disease. Not only is it cheap and easy to use but it is also remarkably effective - more so than many of the more expensive alternatives.
DDT was first used in the second world war to kill the lice that spread typhus. Its value in malaria control was quickly recognised and, according to the US National Academy of Sciences, by 1970 it had saved more than 500m lives. But the pesticide was also used in agriculture during the 1950s and 1960s and it was this use, and the subsequent accumulation up the food chain, that raised concern from environmentalists.
Agricultural uses of DDT harmed wildlife and prompted a ban in the west but many countries, especially in Africa, retained the pesticide for disease control. Dissatisfied, environmentalists applied pressure for DDT to be eliminated completely and in 1995 UNEP took up the cause. In the past decade environmental groups and, more scandalously, aid agencies have urged developing nations not to use DDT. Already Belize, Mozambique and Bolivia have been pressured to stop using it by aid agencies. The result has been more malaria and more deaths.
Not long after DDT was removed from malaria control in South Africa in 1996, disease rates rocketed, particularly in northern KwaZulu Natal. A serious problem was that Anopheles funestus mosquitoes developed resistance to synthetic pyrethroids - the main alternative to DDT - making the switch an expensive and futile exercise. According to Rajendra Maharaj, head of vector control at the South African department of health, it is unlikely that A. funestus would ever have returned had DDT remained in use.
One need only compare malaria rates in South Africa, Swaziland and Mozambique to see the effect of banning DDT. Swaziland never halted DDT spraying and infection rates range between 2 and 4 per cent. A short distance over the border in South Africa, infection rates average about 40 per cent. In Mozambique, infection rates are over 80 per cent, owing in part to the collapse of the malaria control programme during that country's war. The cash-strapped Mozambican government is now trying to control the disease by using pesticides that are four times as expensive as DDT.
DDT is now back in use in KwaZulu Natal and according to Jotham Mthembu, head of the malaria control programme at Jozini in KZN, conditions have improved. Gerhard Verdoorn of the Endangered Wildlife Trust, the South African green group, has given his approval to the use of DDT and even trained sprayers. "DDT is used in tiny quantities and there is simply no prospect of any environmental damage arising from its use," he says.
Malaria kills more than 1m people and afflicts more than 300m every year throughout the world.
Not only are people unable to work effectively when ill, causing enormous losses in productivity, but the disease also scares investors away because of the prospect of having one's workforce - local and expatriate - ill and unable to work. Jeffrey Sachs of the Harvard Centre for International Development estimates that malaria destroys about 1 per cent of Africa's wealth every year.
At the UNEP meetings this week, bureaucrats from the developed world are deciding the fate of many millions of people at risk from malaria in the developing world. Even if UNEP does not ban DDT for malaria use, it is certain to be "listed", entailing onerous reporting requirements.
Last year the World Health Organisation said 23 countries used DDT for malaria control. Yet only 14 have asked for exemptions. Mexico and Colombia have stockpiles but the rest may be concerned that they will lose donor aid if they ask for exemptions to spray DDT for malaria control. Merely placing DDT on the UNEP list will make it more expensive, reduce its use and expose more people to malaria.
DDT is safe and cheap - and it saves lives.
Dr Roger Bate is a director of Africa Fighting Malaria, an aid agency in South Africa