In Central Ohio, there are significant natural deposits of uranium found in glacial deposits and shale. As uranium undergoes radioactive decay, it generates radium and radon.

The Environmental Protection Agency (EPA) has set the current radon action level at four picocuries of radon per liter of air (4 pCi/L). In central Ohio, most counties have a high likelihood of radon presence, with indoor radon levels predicted to exceed the EPA action level on average. According to a study cited by the Ohio Department of Natural Resources Department of Geological Survey, 38% of Ohio's 88 counties exhibited average indoor radon levels above 4.0 pCi/L, while Licking County's average surpassed 8.0 pCi/L. Seven Ohio counties—Carroll, Fairfield, Franklin, Harrison, Knox, Pickaway, and Ross—recorded average indoor radon concentrations ranging from 6 to 8 pCi/L.

The concentration of radon in the soil depends on the soil's chemistry, which varies from house to house. Radon levels in the soil can range from a few hundred to several thousands of pCi/L in the air. The amount of radon that enters a house from the soil is influenced by weather conditions, soil porosity, soil moisture, and the suction within the house.