If A Little X-Ray Is Good For You, Is More Better?

A recent airport visit and and article on an online medical service, prompted me to recall a superb lecture at an American Society of Hematology Annual Meeting several years ago and the nagging question with which I left the hall.  The subject was the biologic effect of radiation and the speaker scientist guided his audience through the intricacies of cellular responses to radiation, making the point that cellular repair systems spring into action within 10 seconds of exposure and may remain activated. And then he said something disconcerting, to the effect that he had been impressed with the interest of certain officials involved in the American defense system, in upping the exposure of Americans to radiation with the expectation that this exposure would augment their bodies' "resistance" to further radiation. The idea struck me as bizarre, since I and generations of physicians had been taught that there is no safe dose of radiation, and that with each increase in exposure, the frequency of mutations (with increased risk of cancer) increases.  But then at the airport was this machine, supposedly in the interest of preventing terrorism,  radiating a portion of the population . . .      Oh really?

Added April 6, 2011: Drugs for treatment of radiation exposure.