Radon distribution (pic)

This is total exposure, which, depending on the location, may be dominated by radon or may be dominated by other gamma-ray exposure such as K-40. The high plains tend to get more radon exposure. I have tried to see correlations in the CDC data but the differences in cancer rates due to the difference in exposure (+/- 200 mRem) across the US using linear models is something like 11 cases in 100,000 per year. The normal cancer rate per year is like 400 to 500 per 100,000. The variations around that 400-500 average from place to place and from year to year tends to mask any correlations that could be found. However, I did not try very hard. If one combines data from many states with high exposures and states with lower exposures, one may reduce the statistical error enough to make a general conclusion. To date, I have not seen literature that makes a positive correlation of cancer rates to natural background variations.