Dung Manh H, T Kido, R Okamoto, S XianLiang, LT Anh, S Supratman, S Maruzeni, M Nishijo, H Nakagawa, S Honma, T Nakano, T Takasuga, DD Nhu, NN Hung, LK Son. 2014. Serum dioxin levels in Vietnamese men more than 40 years after herbicide spraying. Environmental Science and Technology. Link.
Synopsis by EHN Staff
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| Defoliant was sprayed by aircraft during the Vietnam War. |
Vietnamese men living near a former U.S. military base where Agent Orange was stored and sprayed more than 40 years ago remain highly contaminated with dioxins, according to a new study.
Vietnamese men living near a former U.S. military base where Agent Orange was stored and sprayed more than 40 years ago remain highly contaminated with dioxins, according to a new study.
While health problems among herbicide-exposed U.S. veterans of the Vietnam War have been well-documented, little is known about men living in Vietnam, according to the scientists who conducted the study, which was published in Environmental Science & Technology.
“This is one of a few studies to examine the individual serum dioxin levels in Vietnamese men who experienced herbicide spraying at any time during the Vietnam War,” the authors wrote.
Researchers from several universities in Japan and Vietnam tested the blood of 97 men, ages 55 to 80, who lived in 2010 near the former Phu Cat base, and compared it to 85 men who resided in an unsprayed area of northern Vietnam. The toxic equivalency factor (which measures the toxicity of dioxins and dioxin-like compounds) was 2.5 times higher in the men near the base. For the most toxic dioxin, known as TCDD, the levels found in their blood were 1.7 times higher.
“Our findings suggested that people living close to the former U.S. air bases might have been exposed to both Agent Orange and other sources of dioxin-like compounds,” the scientists wrote.
From 1961 to 1971 about 10 percent of South Vietnam was sprayed with various defoliants. The most infamous was Agent Orange, a mix of herbicides that accidentally contained TCDD, which has been characterized as the most highly toxic substance known to man.
Dioxins are slow to break down, so they persist in people’s bodies and in the environment.
“Public heath prevention and dioxin monitoring programs should focus on people living in the areas surrounding these hotspots,” the scientists wrote.
Exposure to Agent Orange has been linked to prostate cancer, diabetes, Parkinson’s disease, leukemia, skin disorders, heart disease, lung cancer and other health problems in U.S. veterans, according to the U.S. Department of Veterans Affairs.
Previously, elevated dioxins were found in the breast milk and blood of people in Vietnam living near former U.S. air bases and in areas that were heavily sprayed. Exposure has been linked to impaired brain development and growth of infants in sprayed areas.
The new study is unusual because it focused on older Vietnamese men who were likely to have lived in sprayed areas during the war.
For the men now living in the unsprayed area, “the dioxin levels were no different between men who went to the South during the Vietnam War and those who remained in the North,” according to the authors. That could mean the high exposures of the men who live near the air bases came from their environment in the years after the war.
Other than the TCDD, the dioxins and polychlorinated biphenyls, or PCBs, could have come from industries or other pesticide use.
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