I have been done with radiation since Nov. '05. The mucus and sinus problems have plagued me since then. No one will tell me for sure if it's caused by the radiation, but I know I did not have these problems before (some sinus, some bronchitis, but not to this extent). I have full-blown upper respiratory infections at least three times a year or more now with coughs that linger for weeks. You just can't tell me it's not a long-term side effect. One of the nurses during treatment said that cold air, dust and smoke would always bother me and boy, was he right. I cannot stand certain smells now, any type of floral air freshener, etc. I have a handicapped sticker for my vehicle for use in the winter because the cold air just burns my throat up and might cause a coughing fit.
I could go on and on, but I think your concerns are valid.