Now there's a phrase that gives one confidence in what comes next.
Between the crazies on the right like Coulter and the crazies on the left like the anti-vaccine crew at Huffington Post, it's no wonder the public is confused. Who needs evidence when folks just know they are correct?
There is actually reputable (but still controversial) data to indicate that low levels of radiation can be protective:
a) Epidemiological data indicating that people who live in areas with naturally high levels of background radiation get less cancer. E.g. Modern X-ray docs in Britain may suffer less cancer than doctors who practice other specialties. But all of the epi data is at least somewhat open to interpretation as is normally the problem with epi data.
b) Repeatable experiments with animals says that if you know you are going to be getting a lethal dose of radiation tomorrow you'd be wise to get a sublethal dose today - because it is protective. (I don't remember the exact numbers but something like - they irradiated 1/2 of a pop of mice with 1/4 the lethal dose, then the next day irradiated all the mice with lethal doses. A meaningful percentage the pre-irradiated mice survived but none of the others.)