Vietnam chemical warfare’s secret toxic legacies: Agent Blue

For over 50 years US news about chemical warfare during the American Vietnam War has been dominated by the story of Agent Orange and its devastating impacts.

During the Vietnam War period, however, another diabolical concoction called Agent Blue was also used extensively in Vietnam. This arsenic-based herbicide was used to kill rice and the public knew little about its use.

In fact, the first news reference to this chemical weapon was a simple letter to the editor sent by Arthur H. Westing in 1971 and published by the New York Times under the headline “‘Agent Blue’ in Vietnam.”

This blip of attention to tactical herbicide Agent Blue wasn’t followed up until 44 years later, when Loana Hoylman published an article, “Today’s Blue Arsenic in the Environment,” in a 2014 issue of Veteran magazine, published by Vietnam Veterans of America.

Finally, in 2020 Kenneth R. Olson (one of the authors of the article you are reading now) and Larry Cihacek published the first refereed journal article on the topic, “The Fate of Agent Blue, the Arsenic Based Herbicide, Used in South Vietnam during the Vietnam War,” in the Open Journal of Soil Science.

Using new primary source data, the 2020 article reconstructed the paper trail of those “Made in America” chemical weapons, and developed an updated chemical research framework.

International news media started paying attention. Mike Tharp, a member of the Merry Band of Retirees, our group of military veterans working on this issue, wrote articles that Asia Times published. Mike died last year, probably from his exposure to dioxin TCDD and/or arsenic while stationed at Bien Hoa Air Force base in Vietnam during the Vietnam War.

The question remains: How can this secret use of Agent Blue to