During U.S. involvement in the Vietnam War (1961-1971), a series of herbicides were used as a warfare tactic to destroy the dense jungles of the Vietnamese landscape and crop supplies.1 The most well-known of these herbicides was Agent Orange. While Agent Orange did accomplish its mission of destroying the Vietnamese environment, it also had detrimental effects on humans who came into contact with the gas. The herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was first synthesized by Robert Pokorny in 1941 during his time working for an agriculture company.1 In 1957, it was discovered that during the synthesis of 2,4,5-T, an intermediate molecule, 2,4,5-trichlorophenolate, undergoes an undesired reaction with itself, contaminating the desired product with the toxic dioxin, tetrachlorodibenzo-p-dioxin (TCDD). Contamination levels ranged from 0.5-47 parts per million (ppm), which is much higher than the United State’s current regulation of 0.1ppm.1 The term “Agent Orange” refers to the entire dioxin-containing herbicide. Despite the impacts of Agent Orange in Vietnam, the United States has focused little on the toxic effects on the Vietnamese community itself.
The consequences of Agent Orange exposure are numerous and pernicious including an increased risk for cancer, miscarriages, and other diseases. However, the effect of dioxin as a teratogen, a substance that alters the health of a fetus while in utero, is particularly harmful. Studies have shown that exposure to TCDD through air, food, or soil leads to higher percentages of birth defects, most notably spina bifida, cleft lip and palate, neural tube defects, heart disease, and stillbirths.2 Within Vietnam, towns that were exposed to higher concentrations of Agent Orange have greater birth defects compared to towns with less exposure.2 Particularly, a recent study, found that in 2020 children from southern Vietnam had a higher prevalence of congenital heart disease (CDH) compared to children from northern Vietnam.3 This pattern is consistent with deployment sites of Agent Orange during the war.
The difficult process and high temperatures required to break down TCDD, has resulted in little clearance of the toxin from the environment. In fact, current levels of dioxin in Vietnamese soils are approximately equal to TCDD contamination levels in Agent Orange during the Vietnam war.3 One cause of these high contamination levels is that TCDD sprayed in river beds and mountains migrates to agricultural lowlands of Vietnam, polluting produce.3 The community’s continual exposure to the toxic chemical via indirect sources, such as local food, perpetuates the effects of the teratogen.3 Despite these consequences, little research has been conducted to analyze the effects of TCDD on the Vietnamese community.
An investigation conducted by Kiem N. Truong and Khuong V. Dinh collected studies published over the last 50 years that analyzed the effects of Agent Orange. They found that only 20% of those studies were with regards to Vietnamese communities and 15% were dedicated to TCDD’s impacts on local environment and wildlife.4 Of the few studies conducted, research has shown that the effects of TCDD are widely felt across Vietnam. During the war, 1,679,734 hectares of southern Vietnam were sprayed with a TCDD contaminated herbicide at least once, and over 700,000 hectares were sprayed over 4 times.3 This contamination is thought to have directly affected over 4.8 million people at the time.3
Over the 61 years since Agent Orange’s first use, the dioxin has not only left a mark on US veterans and their families, but continues to affect the Vietnamese population and environment. However, to the present day, the repercussions of Agent Orange on these groups have been disproportionately studied. Throughout history TCDD has caused harm on both fronts and, as it is still physically present in the soil of Vietnam, most likely will continue to do so for the foreseeable future. As the increased number of birth defects and persistent contamination of the Vietnamese soil over the past six decades indicate, TCDD’s potential to do harm is ever present.3