Bring Back DDT, and Save Lives

By Alex Avery And Dennis Avery
Copyright 2000 Wall Street Journal
July 28, 2000

New York City cancelled a concert in Central Park on Monday night for fear of the West Nile virus, a dangerous mosquito-borne disease. New York immediately forgot its fear of pesticides and began spraying to control mosquitoes. But DDT, the most effective mosquito control agent known, will not be used. In fact, if environmental activists have their way, DDT will soon be banned from the planet.

This is a mistake that could cost millions of lives across the globe.

For nearly 30 years, DDT has been banned from America's arsenal of pesticides because of concern for the environment. The United Nations Environment Program is now sponsoring a legally binding convention for a worldwide ban on DDT.

Strong opposition to a global DDT ban has arisen, however, from doctors and public health experts. The reason: a resurgence of mosquito-borne malaria in areas where it had previously been eradicated, including urban areas in South America, Asia and Africa. Globally, the number of malaria cases is increasing at an accelerating rate. Last summer, two boy scouts even contracted malaria while camping in New York state, an incident that was overshadowed by an outbreak of West Nile virus that killed seven people later in the year.

Earlier this year, a group of 380 scientists signed an open letter, arguing for the renewed use of DDT inside houses to fight the spread of malaria. As these doctors point out, the standard environmental concerns -- such as eggshell-thinning in raptor birds -- have nothing to do with spraying indoors. In poor, developing countries, small amounts of DDT are sprayed on the inside walls of homes and huts. The DDT mostly repels, rather than kills, the mosquitoes. Tiny amounts of DDT are used compared with the millions of pounds that were once sprayed on agricultural fields in the 1950s and 60s. The environmental consequences, as a result, would be negligible.

According to many experts, the de facto ban on DDT use is the main reason for the increase in malaria cases. After the U.S. and other industrialized countries outlawed DDT, the ban was gradually extended to countries in the developing world, leveraged through unconscionable restrictions in foreign aid dollars. Essentially, we blackmailed poor countries into dropping their most effective anti-malarial weapon.

The decline in DDT use was, predictably, followed by malaria epidemics. Sri Lanka stopped spraying houses with DDT in 1961 and subsequently had a major malaria epidemic. More than 100,000 people died during malaria epidemics in Swaziland and Madagascar in the mid-1980s, following the suspension of DDT house spraying. South Africa, which had stopped using DDT, began using it again this year after an ugly resurgence in malaria.

Why is DDT so important? Aren't there plenty of other pesticides that can be used? The answer is yes, and no.

DDT acts primarily as a mosquito repellent, not as a killer. Research by Don Roberts, of the Uniformed Services University of the Health Sciences, has shown that only 3% as many mosquitoes enter huts sprayed with DDT compared with huts sprayed with the most widely used alternative pesticide. Moreover, in DDT-sprayed huts, most mosquitoes immediately leave without biting. As Dr. Roberts notes from his uncomfortable personal research, "the whole time the mosquitoes were in huts sprayed with the other pesticide, they were actively biting us."

DDT's effectiveness as a mosquito repellent lasts for six months or more. This compares very favorably with the shorter duration and less effective nature of alternative pesticides that cost three to four times as much.

In a nutshell, nothing is as cheap, or as effective, as DDT. While wealthy nations can afford more expensive, less effective pesticides -- such as the pyrethroid that New York is currently spraying -- poorer nations have few alternatives to DDT other than death and suffering.

But isn't DDT a danger to people? So Rachel Carson claimed in her 1962 book, "Silent Spring." But as a recent article in the Lancet, a British medical journal, notes, we have yet to find a single significant health threat from DDT use even after 40 years of exhaustive research. Yet activists have succeeded in convincing the public that DDT is so evil that we should accept the suffering and death of millions in poor countries to save the world's paranoid wealthy from theoretical health risks we still can't identify. That is Ms. Carson's shameful legacy.

Dennis Avery is director, and Alex Avery is director of research and education, at the Hudson Institute's Center for Global Food Issues.