Are radon levels below 4 pCi/l safe?
Other environmental exposures are regulated to reduce the lifetime risk of cancer to one in 100,000. The EPA lists Radon risk exposure to 4.0 pCi/L for a lifetime (18 hours per day) to cause 7 additional lung cancers in a thousand non-smokers or 62 additional lung cancers in 1000 smokers. The risk is considered linear which means even 2 pCi/L for a lifetime would cause 3 additional cancers in a 1000 non-smokers. Fortunately, most of us are not exposed for a lifetime; however, we would get a similar risk if we were exposed to four times as much for a quarter of a lifetime or 16 pCi/L in your bedroom for 17 years.
