There is a fancy term for it (begins with H) but there is a scientific viewpoint that low doses of radiation are beneficial. Low doses can stop cancers from forming. There was one expert who was hounded out of the public spotlight for making such a claim within the past 5 years. It appears to be true, but very politically incorrect to claim that radiation is a health tonic in low doses.
Reminds me of one of my favorite movies, Repo Man:
http://www.youtube.com/watch?v=qljXevEW2W0
Seriously, I have a book by Gilfillin where he describes an experiment where they exposed a roomful of lab animals to one RAD per day.
Outlived the Control Group.