The data is actually a bit old. It was from when they established the FAA reccomendations. I would assume that if done again the data would show even more film-safeness (if that is a word) with the newer equipment. Unfortunately I've lost my ties to the scanner manufacturers otherwise I'd ask them... but I think you might be correct about lower dosage levels. I know when I was working those issues the focus was on post-processing techniques to eliminate the need to "re-zap" items yet get better discrimination of contraband. At one time the manufacturers all had their specs online so I suppose with a little effort that could be verified rather easily.