Myths and Facts about DDT

October 14, 2004

DDT saved lives without hurting people or the environment
by Donald E. Waite
Donald Waite
October 2004

Dichlorodiphenyl-trichloroethane was first introduced for commercial use in the United States in 1947. It was the most effective of all of the synthetic insecticides, and the least costly to produce. As mentioned previously, it was widely used during World War II to control lice, and thus typhus, by dusting humans with a ten percent powder.  It is poorly absorbed from the skin (unless formulated in petroleum distillates). In spite of many studies no evidence has emerged to date that any harmful effects resulted from this application to people. On the other hand our troops were spared the disease and pestilence that could reasonably have been expected.  In Naples, Italy in January 1944, during a typhus epidemic, over one million civilians were dusted with ten percent DDT, and the incidence of the disease fell sharply. Subsequently thousands of troops and refugees were dusted to protect against typhus and other diseases. The results were dramatic, preventing any outbreak of typhus in these populations. In contrast thousands of cases of typhus occurred among soldiers in other theaters of the war and among persons in prison camps. Millions of people had been victims of typhus in previous wars.

There is no evidence of any fatal poisoning, or other adverse reaction, in humans from DDT in spite of such widespread and intimate application.  In fact all recorded attempts at suicide where DDT was used failed. Workers at the Montrose Chemical Company absorbed 400 times as much DDT as the average American, but not a single case of cancer was reported.[1]

Virtually everyone who lived in that era, and indeed since, has demonstrable residues of DDT in the body fat tissues. Elimination from these stores is slow. The biologic half-life of DDT in cattle is 335 days. During the 1960s when DDT was widely used, levels of 5 ppm were found in human fat tissue. By the late 1960s, after the reduction in the application of DDT and the eventual ban, these levels were down to 2 ppm. By 1982 only trace levels were found in human adipose tissue.[2]

In spite of this evidence of widespread exposure and long-term storage, no adverse health effects have ever evolved. DDT was reported to cause liver tumors in laboratory animals (rats and mice) as early as 1947. Then a nationwide hysteria followed the publication of Rachel Carson’s book, Silent Spring in 1962, in which she labeled DDT a dangerous chemical that might be causing cancer in humans. Experience and scientific studies have proven her wrong.  Carson, who was a vegetarian, blamed DDT for her own breast cancer.  She was wrong again. Carson resorted to the distortion of facts in her book in a campaign to condemn DDT.[3]

Many others took part in this conspiracy. In EPA testimony that was published in Science, Dr. Samuel Epstein reported that mice that were fed DDT developed cancer. He withheld the fact that the mice that were not fed DDT developed more cancers than those fed DDT (83 versus 68 in the DDT fed mice). In reality, long-term studies of large numbers of people have demonstrated no evidence that DDT caused cancer or otherwise shortened the lives of people exposed to it.[4] Extensive use of this pesticide worldwide ever since that time has failed to demonstrate any significant adverse effects in humans. DDT remains the safest and most effective pesticide ever developed.

Fish are very sensitive to the toxicity of DDT, as they are to most chemicals including soaps and detergents, and to temperature and pH. People who have tropical fish tanks are well aware of this sensitivity. Behavioral changes were among the most obvious evidence of accumulation of DDT in fish. Widespread publicity was given to claims in the 1960s that the survival of certain species of wild birds was threatened through the thinning of their eggshells. This was blamed on DDT. In reality, bird populations increased significantly after DDT was introduced.[5] It was later learned that studies that were done to prove eggshell thinning were fraudulent. The study birds were deliberately malnourished and calcium was withheld, conditions known to produce eggshell thinning.

When Bitman repeated this experiment (Nature 1969, 224:44; Science in 1970; and Poultry Science 1971, 50:657-659) with appropriate calcium in the bird’s diet there was no thinning of eggshells. Subsequent studies have also suggested that other industrial chemicals such as polychlorinated biphenyls (PCBs), which have been widely used in electrical transformers, may have played a part in the observed eggshell thinning.[6] Furthermore the bald eagle had been on the verge of extinction in the 1920s long before DDT. Eagles were shot for bounties and for their feathers. An epidemic of Newcastle Disease (avian influenza) during this period also decimated some bird populations.

DDT, as well as chlordane, PCBs and PBBs, are all stored in the fatty tissues of fish and most animals including humans. The environmental zealots claimed that the higher up the food chain that these stores of chemicals were consumed, the greater would become the concentration stored in fat. They again turned to fraudulent studies to prove their claims, selecting only tissue samples that they knew would produce the desired result.  In reality honest studies disproved their biomagnification claims.

On June 14, 1972 William Ruckelhaus, Administrator of the EPA, as a result of political pressure from environmental extremists, made a one man decision to ban the use of DDT in United States, a move that was illegal. He took this action ignoring 8,300 pages of testimony and the findings of the hearing examiner and most scientists and in the absence of any honest substantiating science. He subsequently refused to comply with requests made under the Freedom of Information Act and defied the National Environmental Policy Act by refusing to file an Environmental Impact Statement on the disastrous consequences of his decision. After he left the EPA Ruckelhaus affixed his name to letters soliciting membership in the Environmental Defense Fund, the organization that led the fight to ban DDT.[7]

The pesticides that replaced DDT, such as dieldrin and aldrin, are far more toxic, and have been responsible for many deaths.  Because of the low cost of DDT and the absence of equally effective substitutes with low toxicity, it continued to be used internationally.  When huts were sprayed with DDT only 3 percent as many mosquitoes entered as compared with the most widely used alternative.[8] This effectiveness lasted for six months or more, a feature not matched by alternative pesticides that cost three times as much.

Great pressure has been exerted on those countries to discontinue its use.  In some countries such as Sri Lanka, spraying programs that had virtually eliminated malaria were terminated. As a consequence the number of cases of malaria in that country rose to 2.5 million in 1968 and 1969.[9] More than 100,000 people died as a result of malaria epidemics in Swaziland and Madagascar in the mid-1980s after house spraying with DDT was stopped. Since the early 1970s the UN and the WHO have blackmailed developing countries, through the withholding of financial aid, to force them to discontinue the use of DDT. The result has been an upsurge in the number of cases of malaria. The South African government has reported that the annual number of deaths from malaria there have risen from 20,000 to 350,000 since the ban on DDT. Malaria currently kills about two million people each year, and the number is rising.

DDT was used in Ethiopia in 1991 to control a major epidemic of louse-borne relapsing fever among the hundreds of thousands of soldiers in refugee camps.[10] As had been the case in World War II, it was highly effective in controlling the human body louse that transmits the Borrelia recurrentis of relapsing fever. Millions of lives have been saved by the control of mosquitoes, flies and lice that transmit such diseases as malaria, yellow fever, dengue fever, filariasis and plague.  Many residents of West Africa were spared the ravages of river blindness (onchocerciasis) when DDT killed the insect vector (black fly) carrying the filaria for this disease. All of this progress is now threatened by UN politicians who are either totally ignorant of the facts or dedicated to population reduction.





This article is extracted from Donald E. Waite, Environmental Health Hazards: Recognition and Avoidance, Chapter XIV, “Hazards of Pesticides and Herbicides,” Columbus, OH: Environmental Health Consultants, 2002. Dr. Waite is emeritus professor of public health at Michigan State University, a consultant on environmental and public health, author of Your Environment, Your Health and You, and one of the world’s foremost authorities on chemicals, health and the environment. Reprinted with permission of the author.


[1] Arch Environmental Health, 15:766-775 (1967).

[2] Klassen CD, Amdur MO, Doull JD. Casarett and Doull’s Toxicology, 5th edition, McGraw-Hill, Columbus, OH (1996).

[3] Rachel Carson quoted Albert Schweitzer as saying, “Man has lost the capacity to foresee and forestall.  He will end by destroying the earth.”  Carson made it appear that he was referring to pesticides, and DDT in particular.  She knew that he was referring to nuclear weapons and atomic warfare.  In fact, in his autobiography he wrote “How much labor and waste of time these wicked insects do cause us … but a ray of hope, in the use of DDT, is now held out to us.” (p. 262)

[4] Austin H, Keil JE, Cole P.  A prospective follow-up study of cancer mortality in relation to serum DDT.  American Journal of Public Health, 79(1):43 (1989). See also Key T, Reeves G. Organochlorines in the environment and breast cancer.  British Medical Journal, 308:1520-1521 (1994).

[5] Bird counts in 1960 (after DDT) vs. 1941 yielded 12 times more robins, 21 times more cowbirds, 38 times more blackbirds and 131 times more grackles. Diseases of birds carried by mosquitos were eliminated, and food supply and protective cover were increased by DDT.

[6] Edwards, JG. “DDT effects on bird abundance and reproduction,” in Lehr JH (ed) Rational Readings on Environmental Concerns. New York: Van Nostrand Reinhold, 195-216 (1992).

[7] Lee Ray D, Guzzo L., Trashing the Planet. Regnery Gateway, Washington, DC (1990).

[8] Research by Dr. Don Roberts, Uniformed Services University of Health Sciences.

[9] Green, MB, Pesticides: Boon or Bane? Boulder, CO: Westview Press, 1976.

[10] Sundnes K, Haimanot A., “Epidemic of louse-borne relapsing fever in Ethiopia,” The Lancet, 342:1213-1215 (1993).