These several times more likely figures are quite moot as well . The point is that the 2 nd leading cause of lung cancer is still a far shot away from the number one leading cause smoking . You ' re also missing the point that literally every single person on this planet encounters radon , whereas not everyone smokes , so of course smokers are more likely to develop lung cancer . And there is no such thing as a smoker without radon exposure . Shit , smoking even increases your radon exposure thanks to the tobacco plant ' s amazing ability to retain alpha particles , then we smoke it and now it ' s directly in our lungs with tons of other crap . Would I get a radon mitigation system installed ? Technically yes , but it would really just be an exhaust fan . Radon monitoring ? Sure , even though it ' s probably never going to build up past equilibrium without some sort of catastrophic event happening which would probably prompt me to get the hell out anyway . Look , I never said that radon doesn ' t cause lung cancer . But I ' m skeptical about the numbers and the lack of mentioning genetic factors anywhere in the number of lung cancer cases per year . But hey , what the hell do I know ? I ' m just a smoker who used to work in the nuclear industry .