The fact that Coulter is hawking this dog-eared theory (which has had a LOT of money thrown at it by the pro-nuclear lobby and nuclear industry) comes as no surprise. Here's a woman who seems to have a pathological hunger for self-immolation and would shill for a penny.
Whenever I listen to Coulter (along with all the other American shock jocks) I'm reminded of the truckload of self-important sophists in Plato's dialogues who, when confronted with the reason of good natured Socrates, resort to mind-boggling fictions meant to leave their opponent not knowing which way is up. Bill O'Reilly is no Socrates - but I'm sure the old Greek would have approved of his performance in that exchange.
Of course, the theory of "Radiation Hornesis" is a joke. It has almost no support in the scientific community and even the various nuclear regulatory bodies (who are notorious for setting "safe" radiation limits well above those considered so by physicians just so that people can actually work at atomic facilities) think it's a crock of shit. The idea that "Radon gas is good for smokers" is absolutely crazy. Smokers ALREADY receive significantly higher doses of radiation than non-smokers. Indeed, it's the REASON they develop cancer. It's a little-known fact that the tobacco plant functions as a natural receptacle for the radioactive element Polonium (which cannot do any serious harm outside the body as human skin acts as a secure barrier, but once inside in begins wreaking havoc with cell replication leading to tumors) and it remains tightly bound to the leaves throughout the manufacturing process (the tobacco companies have been trying to neutralise it without success for decades).
Wow, I never thought I'd see O'Reilly being the voice of reason.