Agent Orange

Agent Orange is the code name for a powerful herbicide that the U.S. military regularly used as a defoliant and chemical weapon during the Vietnam War. Agent Orange was a 1:1 mix of 2,4,-D (2,4, dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5 trichlorophenoxyacetic acid). U.S. armed forces employed Agent Orange, originally developed as a weed killer in the 1940s, to destroy forest canopies that hid Viet Cong and North Vietnamese units from U.S. air power and to secure outlying base areas.

Agent Orange was colorless, as were several other chemical defoliants developed for use during the conflict. The color coding came from identifying bands or stripes used on the 55-gallon drums in which manufacturers shipped the product. In addition to Agent Orange, the military used lesser amounts of Agent White, Agent Blue, Agent Purple, Agent Pink, and Agent Green.

Both the topography of Vietnam and enemy dispositions called for the use of herbicides. The U.S. military divided Vietnam into four zones of operations. The III Corps area, the area around Saigon from the South China Sea to the Cambodian border, experienced the most spraying; Viet Cong units regularly threatened Saigon. The I Corps area, along the 17th parallel separating northern and southern Vietnam and the border with Laos, was second in the quantity of Agent Orange applied, while II Corps in the central highlands and IV Corps in the Mekong Delta were third and fourth, respectively. The goal was to secure broad zones around Saigon and to limit North Vietnamese infiltration. Additionally, troops sprayed around perimeters of bases to keep the concertina wire and approaches free of vegetation and along riverbanks to help the riverine Navy hold down casualties from hidden fire on shore.

Agent Orange and Agent White were used mainly to destroy the forests of South Vietnam, while Agent Blue was used to destroy grain crops, thus denying food and supplies to the enemy. As a military weapon, these chemical agents were used in concentrations 20- to 40-times greater than normal for agricultural herbicidal uses. All told, the U.S. military sprayed 19 million gallons, or 72 million liters, of herbicides over South Vietnam from 1962 to 1971, with the [Page 21]heaviest applications coinciding with the period of heaviest U.S. offensive activity, 1967 to 1969.

Overall military benefits of this herbicide spraying, code-named Operation Ranch Hand, are difficult to determine precisely, but it does not seem to have accomplished much. The spraying evidently did not materially impede the infiltration of men and matériel from North to South Vietnam; nor did it seem to limit the maneuverability of communist units in the South. It also apparently did not limit attacks against outlying U.S. bases, especially Special Forces and forward fire bases.

However, the long-term negative health effects on American combat veterans and Vietnamese civilians have been severe and continuing. Agent Orange contains dioxin (2,3,7,8-tetrachlorodibenzo-paradioxin). Mammals react individually and differently to dioxin exposure, and it is difficult to generalize the effect of prolonged exposure to high concentrations of dioxin for any population. Nonetheless, the long-term record seems clear. Sudden infant death syndrome (SIDS) has been four times more likely to kill children of veterans exposed to Agent Orange than children of parents from the general, nonexposed population; this statistic reflects dioxin's impact on the human immune system. The National Academy of Sciences (NAS) has found an association between these herbicides and spina bifida in Vietnam veterans’ children, too. The Veterans Administration and the NAS have also found a high rate of adult-onset diabetes among Vietnam veterans who participated in spraying operations.

...