About Radon Levels in McHenry County

The average national indoor radon level is 1.3 pCi/L. (FAQ: What is a picocurie?)

The average indoor radon levels of McHenry County, as determined by radon test results from Air Chek, is 5.3 pCi/L

    Results under 2 pCi/L

    Results between 2 and 3.9 pCi/L

    Results 4 pCi/L and above

Additional information about radon levels in McHenry County may be available through this website.

State Radon Officer

Radon Resources

• County Health Department