I was stationed at Takhli 1967-68 with the KC-135 tankers as an aircraft electrician. I remember seeing the empty drums on the flight line that were used to hold up umbrellas for the guards. I believe they were the empty chemical drums. I now have MG, myastheneis gravis, a muscle disease, since 2016. I don't know if it is related to AO but since reading this thread of comments I will have to check it out.