Cargo and luggage scanners are very powerful and will wreck film. I know this from painful personal experience. Carry on scanners in first world counties won't. I know this from paranoid personal experience, as in I could detect no b+f increase, after no less than six scans on film 100-1600 iso. Now you could insist that the carry on scanner does something, and I couldn't argue that, but I couldn't find it with my densitometer, and I'm pretty anal about negs.