A Perspective on DDT

By P. M. DeMarco, Ph.D.
Rachel Carson Homestead
www.rachelcarsonhomestead.org

News in the last month has included a report of the World Health Organization approving the use of DDT in limited situations for the control of malaria in Nigeria. The issue has resurrected the concerns about DDT raised by Rachel Carson’s book, Silent Spring. Following its publication, Rachel Carson was both lauded as a hero, and vilified as a hysterical female. A bit of context maybe appropriate as a backdrop for this renewed debate.
In 1958 when Rachel Carson began work on her book, DDT was all the rage, widely touted in all the media as the savior of mankind, the answer to pests and diseases of all kinds. Broadcast spraying of crops and fogging of neighborhoods occurred all over the world as part of public health campaigns to control malaria, typhus, and insect pests such as fire ants. Reports of poisonings, death of wildlife and illness especially in children were dismissed, or not directly proven to be the result of DDT use. When Rachel Carson began her writing, pharmacologists and scientists had begun to question the wisdom of the increasing toxicity of insecticides used broadly in the public. Insects had already within a few years begun to show resistance to DDT, precipitating the development of even more toxic chemicals. President Kennedy and Congress convened independent investigations on pesticide policy.

Rachel Carson’s testimony before the Subcommittee on Reorganization and International Organizations of the Committee on Government Operations regarding Environmental Hazards, Control of Pesticides, and Other Chemical Poisons on June 4, 1963 summarizes her position on the matter. After reviewing a large body of evidence, Rachel Carson presented two significant conclusions:
“All the foregoing evidence, it seems to me, leads inevitably to certain conclusions. The first is that aerial spraying of pesticides should be brought under strict control, and should be reduced to the minimum needed to accomplish the most essential objectives. Reduction would, of course, be opposed on the grounds of economy and efficiency. If we are ever to solve the basic problem of environmental contamination, however, we must begin to count the many hidden costs of what we are doing and weigh them against the gains or perceived advantages.
The second conclusion …is that a strong and unremitting effort ought to be made to reduce the use of pesticides that leave long-lasting residues, and ultimately to eliminate them. I concur with this recommendation of the President’s Science Advisory Committee, for I can see no other way to control the rapidly spreading contamination I have described.”

In her testimony, Rachel Carson made six recommendations for legislative action:
1. Citizens have a right to be secure in their own homes and property against the intrusion of poisons applied by other persons.
2. The government should establish new programs of research and education of medical professionals, because physicians are generally unaware of the wide distribution of pesticides, their toxicity, and their effects on human health.
3. Restrict the sale and use of pesticides to those who have been trained in their safe use and application, and who are capable of understanding the hazards and following directions.
4. The registration of chemicals used as pesticides should be the function of all agencies, rather than the Department of Agriculture alone.
5. The hazards of pesticides are compounded by the fantastic number of chemical compounds in use as pesticides, whose great proliferation has been driven more by economic competition that by actual need. New pesticides should only be approved when no other existing chemical or other method would do the job.
6. I hope the government will fully support research on new methods of pest control in which chemical use will be minimized or entirely eliminated. One of the outstanding values of biological controls for insect pests is that they are specifically adapted to a particular species or group of species. We must search, not for a super weapon that will solve all problems, but for a diversity of options, each precisely adjusted to its task.”

Please contact the Rachel Carson Homestead Association if you would like to read the full text of Rachel Carson’s testimony. www.rachelcarsonhomestead.org