I disagree with the radon LLE. There is lots of proof (Access to Energy, February 2002 list some)that moderate exposure to radon (such as that found in residential basements) will result in a negative LLE. The radon risk here is based on the linear no-threshold extrapolation of high radiation exposure data back to low levels. There is lots of proof that shows a mild benefit to low radon exposure, much the same way that low levels of sunlight help the body process vitamin E. It is theorized that low levels of radiation, like that from radon, forces the body to be on alert for mutated cells.