Percentage of Homes, listed by County, that Exceed Radon Levels of 4.0 pCi/L:
Cook: 25.50%
DuPage: 39.50%
Kane: 43.60%
Kendall: 45.90%
Lake: 30.90%
Will: 41.10%
DeKalb: 34%
(Data compiled by the Illinois Emergency Management Agency's Department of Nuclear Safety)
Please note that this data is not an indication of a particular house's potential to have elevated levels of radon. Radon is a house-by-house issue, and radon levels seasonally and diurnally fluctuate. Close to half of all Illinois homes test out elevated for radon gas! Our highest reading was 180 pCi/L!