During the Vietnam War, United States aircraft sprayed more than 20 million gallons of herbicides, including dioxin-contaminated Agent Orange, on the country’s rain forests, wetlands, and croplands. Agent Orange defoliated the thick jungle vegetation concealing Viet Cong fighters and destroyed a portion of the country’s food crops, but it was primarily the dioxin contaminant that harmed so many Vietnamese and U.S. military personnel. A new article from the University of Illinois and Iowa State University documents the environmental legacy of Agent Orange in Vietnam, including hotspots where dioxin continues to enter the food supply.
“Existing Agent Orange and dioxin research is primarily medical in nature, focusing on the details of human exposure primarily through skin contact and long-term health effects on U.S. soldiers,” says Ken Olson, professor emeritus in the Department of Natural Resources and Environmental Sciences at U of I and co-author on the article. “In this paper, we examine the short and long-term environmental effects on the Vietnamese natural resource base and how persistence of dioxin continues to affect soils, water, sediment, fish, aquatic species, the food supply, and Vietnamese health.”
Olson and co-author Lois Wright Morton of Iowa State University explain that Agent Orange was a combination of two herbicides, 2,4-D and 2,4,5-T, neither of which persist longer than a few days or weeks in the environment when exposed to sunlight. However, during production of Agent Orange, a toxic byproduct formed: dioxin TCDD, the most toxic of the dioxin family of chemicals. Once dioxin TCDD gets into the environment, Olson and Wright Morton say, it can stick around for decades or even centuries. That’s what happened in the Vietnam landscape.
Read more at University of Illinois College of Agricultural, Consumer and Environmental Sciences
Image: US aircraft sprayed 20 million gallons of herbicides across Vietnam during the Vietnam War. Dioxin, a contaminant in Agent Orange, persists today. (Credit: Photo by US Army Flight Operations Specialist 4 John Crivello in 1969)