10 July 2011

Proper Interpretation of C-123K Dioxin Testing Results

ALL of the multiple Air Force tests agree that the C-123 fleet was in some degree contaminated with dioxin remaining from the Vietnam War Agent Orange spray operations. We agree with that as well. In 1996 AMARC had the stored fleet tested for dioxin...all aircraft were reported contaminated! The Air Force's official conclusion is that most of the fleet was contaminated, and the service also concludes officially that confusion about the C-123s which apparently were not spray aircraft but which might have been forced the final conclusion that the entire fleet must be viewed as dioxin contaminated. It doesn't matter which tail numbers we flew...the Air Force in 2010 decided they all have to be considered dioxin contaminated!

What we need to bring to everyone's attention is the natural degrading over time of dioxin...its half-life. In the human body dioxin tends to accumulate in body fat and doesn't want to leave...half-life in humans is 6.7 to 132 years. That means testing for our own body fat accumulation of dioxin, to which we were exposed between 1972-1982, must take that degrading into consideration. A modest indication of dioxin contamination in a test today is a fraction of what that test would have revealed decades ago!

Another perspective: the half-life of dioxin in the environment on surfaces can be nine to fifteen years. All the Air Force tests reflect contemporary levels of toxicity in their lab reports of swipe tests done on the stored C-123K/UC-123K airplanes. Some reports cite the "very low" to "sub-detectable" results. But the first of these tests (that we've found) dates from 1993, 21 years after the last spray missions and twelve years after we last flew the aircraft before the fleet was retired to the Boneyard. Tests done by AFMC of the 18 remaining aircraft in some cases indicate presence of dioxin but note that the levels were low enough to allow limited worker exposure during the final shredding and smelting process...but we aircrews were exposed to at least double and perhaps triple the toxicity during our years on the Provider! 

This means we cannot accept as-is the testing results from 1993 or any other year as indicative of sub-hazardous levels of dioxin contamination because, first, any level of dioxin contamination is unsafe and second, the levels would have been between 200% and 300% higher if done during the years of our flying. For those tests to be relative to us, they must include adjustment for the half-life of dioxin plus the atmospheric exposure aircrews underwent. While dioxin is not an aerosol, it can be inhaled when carried on dust-born particles. And do you remember how dirty our planes got, especially during deployments??

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