Veterans who worked on Agent Orange–contaminated aircraft after the Vietnam War were exposed to potentially hazardous levels of the toxic herbicide, according to a new study released Friday by the Institute of Medicine.
The findings of the report challenge the position of the U.S. Department of Veterans Affairs, which has long downplayed the likelihood of postwar exposure to Agent Orange on the contaminated planes and the risk of long-term health effects from it.
The report could prove significant for veterans who have fought for years to get compensation from the Air Force and Veterans Affairs for Agent Orange–related ailments, although the report’s authors could not make any policy determinations based on their findings.
From 1962 to 1971, the U.S. Air Force waged herbicidal warfare in Vietnam under the auspices of Operation Ranch Hand. C-123 aircraft sprayed about 11 million gallons of a defoliating chemical cocktail known as Agent Orange over the forests of southern Vietnam to eliminate vegetation providing cover for Viet Cong fighters.
Agent Orange is made up of two herbicides, 2,4,5-T and 2,4-D, but it is dioxin, a breakdown product produced during the manufacture of 2,4,5-T, that is responsible for the health effects associated with Agent Orange exposure. Dioxin is a carcinogen that has been linked to leukemia as well as cancers of the larynx, lung and prostate.
In 1972 the aircraft were decommissioned and returned to the United States, deployed for medical evacuation and cargo missions, but they were never decontaminated or tested for the herbicides. About 1,500 Air Force reservists worked on the planes from 1972 to 1982. Many are now seeking compensation for ailments that they claim are the result of Agent Orange exposure. Only one, Paul Bailey, has been successful.
Agent Orange was considered harmless to people at the time of the war, but as returning veterans began reporting health problems they attributed to Agent Orange exposure, research began to link dioxins to serious problems, including cancer, Parkinson’s disease and birth defects in children.
“In the 1960s there were a number of chemicals that we thought were safer than they turned out to be,” said Linda McCauley, a member of the report’s scientific committee and a professor at Emory University’s department of environmental health. “PCBs and dioxin and DDT and a lot of organophosphate pesticides. So in that era there was just a greater acceptance of the use of chemicals than we have today.”
“We will say to [the veterans] that their question about could they have been exposed to this chemical has been answered, from the viewpoint of an expert committee, that they could have been exposed,” she said, adding that the researchers were not tasked with researching the health effects of the exposure.
In 1991, the Agent Orange Act paved the way for veterans who were exposed to Agent Orange during active service in Vietnam to receive health benefits for dioxin-related ailments.
But the provisions of the act applied only to those who served in Vietnam from Jan. 9, 1962, to May 7, 1975. Air Force reservists who flew or worked on the contaminated aircraft in the United States from 1972 to 1982 have fought for years to gain to access the same benefits and compensation.
The Institute of Medicine, an independent nonprofit organization and the medical wing of the National Academy of Science, began work on its report earlier this year, at the request of the Department of Veterans Affairs. The institute was tasked with judging the plausibility of claims that Air Force reservists who worked on C-123s were exposed to dangerous levels of Agent Orange residue.
For the study, the volunteer committee looked at samples taken from the exterior and interior surfaces of C-123 aircraft from 1979 to 2009 — 24 samples from three aircraft — as well as documents covering everything from historical records and personal testimonies to published research. All the aircraft, with one exception, have been destroyed since the last samples were taken.
The study was limited by a dearth of information and sampling data, as well as the long delay between the time of exposure and the collection of data — close to two decades in some cases. Because dioxins degrade over time, the data likely underestimate exposure experienced by reservists.
Despite the limitations, the committee found that reservists were exposed to levels of dioxin that fell well within or above what is considered safe and acceptable.
“Detection of TCDD [dioxins] so long after the Air Force reservists worked in the aircraft means that the levels at the time of their exposure would have been at least as high as the taken measurements and quite possibly considerably higher,” committee chairman Robert Herrick, a senior lecturer at the Harvard School of Public Health, said in a statement.
The VA website states that the likelihood of exposure to dioxins on the contaminated planes was “extremely low” and the risk of long-term health effects “minimal,” denying benefits to Air Force reservists who applied for assistance under the Agent Orange Act. VA policy requires veterans to prove that they were exposed to Agent Orange during the course of their service.
In 2012 the Air Force conducted a study of the risks associated with dioxin exposure from the planes and found that “potential exposures to Agent Orange in C-123 planes used after the Vietnam War were unlikely to have put aircrew or passengers at risk for future health problems.” However, the report also concluded that “there was not enough information and data to conclude how much individual persons would have been exposed to Agent Orange.”
The Institute of Medicine committee’s opinion differs greatly from the Air Force’s and VA’s on dioxin and how it behaves in a closed space, said McCauley. The Air Force and VA have based their analysis on the assumption that the chemical in its dry, solid form on the surfaces of the aircraft didn’t pose the same threat to crews as the mists of liquid Agent Orange that veterans were exposed to during the war.
That’s a view that’s no longer accepted science, said the committee.
“When you paint something on a wall,’ she explained, “you may think that substance is there and it stays there. But there’s a category of chemicals which change from a solid or liquid to a gas at a very, very slow rate.” That category includes dioxins.
Dr. Ralph Erikson, director of the VA’s pre-9/11 era environmental health program, said the report was very well received by the VA, but could not comment on the policy implications of the report. A working group will now review the findings of the study and report back to the Department’s senior policy makers.
It’s not yet clear how the findings affect the postwar crews of the C-123s.
“If you report to a group that there has been no exposure, they can either believe you or not,” said McCauley. “If you report that they were exposed, it doesn't necessarily answer all the questions for the veterans, but it's the only thing we can answer for them.”