During the Vietnam war, approximately 20 million gallons of herbicides, including about 10.5 million gallons of dioxin-contaminated Agent Orange, were sprayed in South Vietnam to deprive the Viet Cong of food as well as jungle cover. The 30-40 Fairchild C-123 aircraft used in this operation were subsequently returned to the United States and reassigned, without proper decontamination, to Air Force Reserve units for use in transport and aeromedical operations. Between 1972 and 1981, as many as 2,100 reservists trained and worked on both the contaminated as well as other uncontaminated C-123s.

In May 2011, I was contacted by retired Air Force Reserve Major Wes Carter, who for ten years flew C-123s out of Westover AF base, Massachusetts. He was concerned about what seemed to be an unusually high rate of cancers and other illnesses among his crewmates, and wanted to know about the significance of their exposure to dioxin residues contained within contaminated C-123s. Wes presented to me a variety of documents obtained through Freedom of Information requests, including laboratory results from tests performed on a few of the aircraft in 1979, 1994 and 2009. These sparse data suggested to me that, even 9, 24 and 39 years after last use in Vietnam, the C-123s were still heavily contaminated with herbicide residues and dioxins. I reported my opinion to the secretaries of the Air Force and Veterans Affairs (VA) that the reservists, more likely than not, were significantly and excessively exposed to dioxins during their service. Other scientists independently provided similar opinions based on the data.

So began a four-year struggle by Maj. Carter to obtain coverage for those he served with under the Agent Orange Exposure Act of 1992. The VA position was that, since reservists had not set “boots on the ground” in Vietnam, they were not eligible for coverage. The VA also stated that “even though residual Agent Orange may be detected in C-123 aircraft by laboratory techniques years after Agent Orange use, any residual [dioxin] in the aircraft would have solidified and be unable to enter the human body in any significant amount” (emphasis added). Similarly, the Air Force position was that any potential Agent Orange exposures on C-123s after Vietnam were “unlikely to have caused harm.”

The rather interesting interpretation by the VA of scientific principles related to chemical behavior in the environment, stated above, compelled several scientists, including myself, to publish a paper that analyzed the sparse data to estimate likely dioxin exposures using established scientific principles of chemistry. Publication of this paper compelled the VA in 2014 to contract with the Institute of Medicine (IOM) to study the issue. In the end, the IOMs conclusions agreed with our determinations.

This week, the VA, prodded by politicians, including Sen. Jeff Merkley (D-Ore.) and Sen. Richard Burr (R-N.C.), announced a change in policy and will now extend Agent Orange exposure coverage to the AF Reserve veterans. Sometimes it takes awhile, but the scientific truth often prevails. And thanks to you, Major Carter, for your hard work on behalf of those who served our country.