Large areas of South Vietnam are covered in thick tropical vegetation ranging from dense forests, to tall elephant grass, to clinging vines troops called “wait-a-minute” vines (so named because anyone caught in them usually shouted “Wait a minute” as he fought to free himself). Such thick plant life offered countless places for Viet Cong forces to build sanctuaries, to hide, and to set up ambushes. To eliminate this cover, the U.S. military used herbicides in a defoliation-and-crop-destruction campaign code-named “Operation Ranch Hand.”
While some herbicides were dispensed by riverboats, trucks, and men with individual sprayers, most were deployed by specially rigged helicopters or airplanes. The defoliants were named after the color of the stripes on their shipping containers. The active ingredient in all the herbicides was a poisonous substance called 2-, 3-, 7-, 8-tetrachlorodibenzo-para-dioxin (TCDD). The first used in South Vietnam were Agent Purple and Agent Pink. Later they were replaced with three others, one of which was Agent Orange.
Large tracts of land, particularly around base camps and other military installations, were laid barren of all plant life through the use of these herbicides. This made it much easier for American troops and aircraft to spot enemy movement. Ultimately approximately six million acres were sprayed by defoliants, destroying roughly ten percent of South Vietnam’s forests. When Operation Ranch Hand concluded in 1970, approximately nineteen million gallons of herbicide had been used.
The defoliant campaign became controversial because of its impact on plants, animals, citizens, and soldiers, particularly the men who handled the herbicides. Over the years, health problems in people exposed to the herbicides, including respiratory problems, persistent skin rashes, some forms of skin cancer, and birth defects in their children, were widely reported. Numerous studies were conducted to track these complaints. The August 2003 issue of the Journal of Occupational and Environmental Medicine, which released the results of a 2002 study conducted in Bien Hoa City, reported high levels of dioxins in food and residents more than thirty years after the defoliant campaign had ended. Eventually chemical companies that manufactured the herbicides agreed to establish a trust fund of $180 million that would be distributed to veterans who suffered health problems or died as a result of exposure to the herbicides.