Exposure to mild stressors over extended periods of time enhances the robustness of the organism against that stressor (eg: vaccination, mild stressor here is t

Exposure to mild stressors over extended periods of time enhances the robustness of the organism against that stressor (eg: vaccination, mild stressor here is the weakened disease agent). It's called Hormesis in general, and Radiation hormesis in your specific case - http://en.wikipedia.org/wiki/Radiation_hormesis http://en.wikipedia.org/wiki/Radiation_hormesis