Hi toeknee (by the way, that's very cute!) -
I don't know if this will give you a more narrow list of results than you've already seen or not. But I went to Google and typed in: copd "agent orange"
(yes, that's a space after copd, and you need the "s around agent orange)
I haven't really sifted through it all yet, but at first glance it looks to me like there just might be some good information amongst the results. If nothing else, maybe at least some good places to jump off from (so to speak). Good luck -- and good luck to your friend (God bless him/her). Please tell him/her that their service was, and still is, appreciated by many.
God bless.
Take care...Shiney
I am sorry to report that my search did not find any references that link Agent Orange to COPD.