What levels of radon are safe?
Unknown. Studies of the effects of radon in homes have produced mixed results. Some studies indicate a positive association, others don’t. These are very difficult studies to do well because smoking-related lung cancer is such a large component of the total lung cancer rate and because it is very difficult to reconstruct the lifetime dose from radon decay products for any individual. It is virtually impossible to avoid exposure to radon concentrations below 1 pCi/L because outdoor air is generally contains radon concentrations from 0.1 to 1 pCi/L.
