Jeanne
Mager Stellman PhD, and Steven
D. Stellman PhD, MPHAuthor
affiliations, information, and correspondence details
Accepted: March 13, 2018 Published Online: May 09, 2018
Between 1961 and 1971, US and Republic of Vietnam forces sprayed more than 20.2 million gallons of military herbicides to defoliate forests and mangroves in what was then South Vietnam to deny cover to enemy troops and make bombing targets more visible. Relatively small quantities (2%) were used for defoliation of military base perimeters; 9% of the total was used to destroy “unfriendly” crops as a means of reducing enemy food supplies. The herbicides were also used in the United States, but at application rates at least an order of magnitude lower and with somewhat differing formulations.
The military herbicides were nicknamed in accordance with the colored stripes on their 55-gallon drums. Agent Orange was a mixture of butoxyethanol esters of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Agent Blue, which consisted of dimethylarsinic acid (salt of cacodylic acid), was used primarily for crop destruction. Agent White was a mixture of 2,4-D and picloram. The herbicides that contained 2,4,5-T were contaminated with dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD]). The extent and implications of the TCDD content were not widely known or appreciated until well into the 1970s, when 2,4,5-T was banned from most US domestic uses owing to evidence of its teratogenicity.
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