United States Sprays Agent Orange in Vietnam

The U.S. Army used the defoliant Agent Orange during the Vietnam War to thin the jungles in which the Viet Cong were hiding. Thousands of U.S. soldiers and unknown numbers of Vietnamese were exposed to dioxin, a highly toxic contaminant in the defoliant.

Summary of Event

The involvement of U.S. military forces in the war between North Vietnam and South Vietnam presented the troops with problems U.S. soldiers had seldom experienced. Most of the war was fought in jungles, and the combat strategies that had been used in most preceding U.S. conflicts were not effective. U.S. forces were largely unaccustomed to fighting against enemies hidden in the underbrush of thick jungles. In addition to providing secure hiding places for the enemy, the jungle provided North Vietnamese soldiers and members of the Viet Cong with adequate food supplies, so they did not have to rely on deliveries. Agent Orange
Vietnam War (1959-1975);Agent Orange
[kw]United States Sprays Agent Orange in Vietnam (Jan. 12, 1962-1971)
[kw]Agent Orange in Vietnam, United States Sprays (Jan. 12, 1962-1971)
[kw]Vietnam, United States Sprays Agent Orange in (Jan. 12, 1962-1971)
Agent Orange
Vietnam War (1959-1975);Agent Orange
[g]Southeast Asia;Jan. 12, 1962-1971: United States Sprays Agent Orange in Vietnam[07190]
[g]Vietnam;Jan. 12, 1962-1971: United States Sprays Agent Orange in Vietnam[07190]
[c]Wars, uprisings, and civil unrest;Jan. 12, 1962-1971: United States Sprays Agent Orange in Vietnam[07190]
[c]Vietnam War;Jan. 12, 1962-1971: United States Sprays Agent Orange in Vietnam[07190]
[c]Atrocities and war crimes;Jan. 12, 1962-1971: United States Sprays Agent Orange in Vietnam[07190]
Kennedy, John F.
[p]Kennedy, John F.;Vietnam War
Bunker, Ellsworth
Reutershan, Paul

In 1961, U.S. Army personnel at Fort Detrick were asked to determine the feasibility of using herbicides as defoliants in Vietnam. At that time, U.S. assistance to South Vietnam consisted only of sending “military advisers,” economic aid, and some logistic support. In December, 1961, President John F. Kennedy authorized the use of herbicides, and on January 12, 1962, the first herbicides were sprayed from U.S. Air Force planes. The herbicides—which were used only in South Vietnam—were delivered with the full cooperation and at the request of the South Vietnamese government. By the time the first U.S. combat troops arrived in Vietnam in April, 1965, the defoliation program was well under way.

From 1962 to 1971, several different combinations of herbicides were sprayed on the jungles of Vietnam. They were identified by the colored band on the barrels in which the defoliants arrived and given names such as Agent Purple, Agent White, and so on. More than 19 million gallons of herbicide were sprayed over 3.6 million acres of jungle. The substance commonly called Agent Orange—because it was shipped in barrels with orange bands—accounted for approximately 11.2 million gallons of the defoliant sprayed. Agent Orange is a fifty-fifty mixture of two herbicides: 2,4-dichlorophenoxyacetic acid 2,4-dichlorophenoxyacetic acid[two four dichlorophenoxyacetic acid] (2,4-D) and 2,4,5-trichlorophenoxyacetic acid 2,4,5-trichlorophenoxyacetic acid[two four five trichlorophenoxyacetic acid] (2,4,5-T).

Agent Orange was sprayed over jungles by U.S. Air Force planes and helicopters. Soldiers also sprayed herbicides on the ground to defoliate the perimeters of base camps and fire bases. The spraying was done from trucks or by soldiers carrying tanks of the herbicides. Navy riverboats sprayed along riverbanks. It was not uncommon for other American soldiers or Vietnamese civilians to be present as spraying took place. Australian military forces serving in Vietnam were also exposed to herbicides that were being sprayed.

Although 2,4-D and 2,4,5-T were not considered to have serious effects on animals except in large quantities, it was later found that the herbicides used in Vietnam were contaminated with 2,3,7,8-tetrachlorodibenzo-paradioxin, commonly known as dioxin Dioxin . Dioxin is a highly toxic by-product of the manufacture of 2,4,5-T. It is estimated that 368 pounds of dioxin was sprayed in Vietnam over a six-year period.

In March, 1964, the Federation of American Scientists Federation of American Scientists expressed concern about the use of defoliants, and in June, 1964, the American Association for the Advancement of Science American Association for the Advancement of Science (AAAS) called for an investigation into herbicide spraying. The AAAS continued to pursue the issue of herbicide spraying, and in December, 1968, announced participation in the study. As the clamor of scientists persisted, the Department of Defense Department of Defense, U.S. commissioned the Midwest Research Institute in Kansas City to begin a study to assess the ecological effects of extensive or repeated herbicide use. The study was based on the analysis of fifteen hundred papers, but no field studies in Vietnam were included.

In April, 1970, the Departments of Health, Education, and Welfare, the Interior, and Agriculture announced an immediate suspension of the use of 2,4,5-T around homes, ponds, lakes, farms, and food crops. At that time, the Department of Defense suspended the use of Agent Orange in all military operations in Vietnam. The debate about the use of herbicides was quelled by the cessation of the spraying. The respite was short-lived, however, as the American soldiers returned to their homes.

Accidents Workplace hazards
Labor;workplace hazards
Hazardous materials at chemical plants during the 1950’s, 1960’s, and 1970’s exposed nearly one thousand men to varying concentrations of dioxin and other pesticides Pesticides . The exact exposure concentrations of the various substances is unknown; however, the effects of exposure include skin manifestations and systemic effects such as digestive disorders, liver toxicity, muscular aches and pains, cardiovascular disorders, neurological effects, and psychiatric effects.

While literature regarding toxicity of dioxin to humans was limited, there was extensive information regarding its highly toxic effects on animals. Like many other poisons, dioxin has a toxic effect on the liver in animals. Damage to the liver results in an excessive production of certain liver enzymes necessary for normal health and a decrease in the production of certain other liver enzymes. In addition to provoking liver damage, dioxin poisoning caused impairment of animal immune systems and led to decrease in the number of blood platelets. Platelets are necessary for the integrity of the clotting system of the bloodstream. Exposed animals also demonstrated reproductive effects, including cleft palates, spontaneous abortions, stillbirths, and infertility.

Prior to the spraying of herbicides in Vietnam, few people had been exposed to pure dioxin. The only case reported in the scientific literature was the case of a laboratory technician who had been exposed while drying crystals of the substance in 1955. For nearly twenty years, he suffered from chloracne, a skin disease that can affect various parts of the body, but he was able to continue his work. Also, in the 1970’s dioxin was applied directly onto the skin of prison volunteers. As a result, they, too, suffered from severe chloracne, which lasted from four to seven months.

In 1977, Vietnam veterans Veterans;disabilities
Vietnam War (1959-1975);veterans sought treatment for several different health problems that they believed were the result of exposure to Agent Orange. The government asserted that the veterans’ health problems were unrelated to Agent Orange, but the media brought the story to the attention of the American public.

The concerns about dioxins were compounded by two other events. In July, 1976, an explosion in a chemical plant in Seveso, Italy, released dioxin into the atmosphere in the form of a dense white cloud of gas. The solid particles and water droplets fell to the earth in a residential district surrounding the chemical plant. The Italian government evacuated the immediate area and took measurements of dioxin in the vegetation, soil, and water in the areas of contamination. Significant quantities of dioxin were deposited around the plant.

The second event that focused attention on dioxin occured in Missouri. A chemical plant there produced dioxin in large quantities as a by-product of the manufacture of hexachlorophene. The waste that was left behind was the responsibility of a private contractor, who mixed the dioxin-containing waste with waste oil in a large storage tank. The mixture was then sprayed on dirt roads, parking lots, and horse arenas to control dust. Residents of Missouri became aware of the problems when sixty-two horses died in one stable and the daughter of the owner of the stable became ill.

The problem became national news when, in December, 1982, the residents of Times Beach, Missouri, were encouraged not to return to their homes following a flood because of the high levels of dioxin in the soil. The residents had been evacuated because of floodwater; when the waters receded, the soil was tested and was found to contain high levels of the pesticide. The media focused attention on these events and on the possible effects the Vietnam spraying might have had on the veterans who had served there.


The effects of Agent Orange on soldiers continue to be debated, but little correlation between Agent Orange exposure and diseases other than chloracne has been proven. The long interval between exposure to a carcinogen and the development of cancer makes establishment of a causal link particularly difficult. On the other hand, a Red Cross study has shown that, among Vietnamese veterans of the war, those who fought in South Vietnam and were therefore likely exposed to Agent Orange are five times as likely to have children with serious birth defects than are those veterans who remained in North Vietnam throughout the war. The lack of controls for other possible contributing factors, again, makes this evidence damning but not conclusive.

At least thirty-five thousand Vietnam veterans have filed claims with the Veterans Administration for disabilities allegedly caused by exposure to Agent Orange, but the Veterans Administration and the defoliant manufacturers deny any connection between the medical disorders and Agent Orange. Various studies have led to conflicting and inconclusive results. In 1984, the defoliant manufacturers agreed to a $180 million settlement with nearly nine thousand Vietnam veterans, without, however, admitting any guilt or connection between the disorders and exposure to the herbicide. The legal battles are expected to continue, as Vietnam veterans age and their incidence of age-related diseases such as cancer increases.

Similarly, little is known about the effects of Agent Orange on the Vietnamese citizens who were exposed. The damage to the environment, however, was excessive; more than one-third of South Vietnam’s extensive mangrove forests were destroyed. Estimates suggest that a century will pass before the jungles of Vietnam recover from the effects of Agent Orange. Agent Orange
Vietnam War (1959-1975);Agent Orange

Further Reading

  • Environmental Agents Service, U.S. Department of Veterans Affairs. Agent Orange: Information for Veterans Who Served in Vietnam—General Information. Washington, D.C.: Author, 2003. This Veterans Administration source provides an official U.S. perspective on the effects of Agent Orange upon veterans.
  • Gough, Michael. Dioxin, Agent Orange: The Facts. New York: Plenum Press, 1986. Analyzes the facts surrounding the dioxin contamination in Vietnam and in the United States. Examines the dioxin incidents and the future implications of the use of herbicides.
  • Harnly, Caroline D. Agent Orange and Vietnam: An Annotated Bibliography. Metuchen, N.J.: Scarecrow Press, 1988. A thorough bibliography that includes chapters on ethical and political issues, the effect of Agent Orange on Vietnam’s ecology, the health effects and societal costs of exposure of the Vietnamese, the disposal of leftover Agent Orange, and the effect of Agent Orange on Vietnam veterans.
  • Schuck, Peter H. Agent Orange on Trial: Mass Toxic Disasters in the Courts. Cambridge, Mass.: Belknap Press of Harvard University Press, 1988. Evaluates the legal aspects of Agent Orange use. Includes recommendations for handling such litigation in the future. Although the material is covered in depth, it is written in an easy and informative style.
  • Whiteside, Thomas. The Pendulum and the Toxic Cloud: The Course of Dioxin Contamination. New Haven, Conn.: Yale University Press, 1977. Stresses the need for further study of dioxin. Whiteside makes a strong case for governmental regulation of toxic substances.
  • Wilcox, Fred. Waiting for an Army to Die: The Tragedy of Agent Orange. New York: Random House, 1983. Examines the effect that the spraying of Agent Orange has had on Vietnam veterans. Wilcox is particularly concerned with the effects of spraying on individuals rather than on the environment.
  • Young, A. L., and G. M. Reggiani, eds. Agent Orange and Its Associated Dioxin: Assessment of a Controversy. Amsterdam: Elsevier, 1988. Looks at all aspects of Agent Orange use in Vietnam; includes works by many experts in the field of medicine, ecology, and the military. Confronts controversial issues and attempts to make unbiased judgments.

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