Central Ohio has relatively high natural concentrations of uranium from glacial deposits and shale, which during radioactive decay, produces radium and radon.
The EPA’s current radon action level is four picocuries of radon per liter of air (4 pCi/L). Most counties in central Ohio have high potential for radon, with predicted average indoor greater than the EPA action level. According to one study cited by Ohio Department of Natural Resources Department of Geological Survey, 38% of Ohio’s 88 counties had average indoor radon levels above 4.0 pCi/L, but Licking County’s average was above 8.0 pCi/L. Seven Ohio counties—Carroll, Fairfield, Franklin, Harrison, Knox, Pickaway, and Ross—had average indoor Radon concentrations between 6 and 8 pCi/L.
The amount of radon in the soil depends on soil chemistry, which varies from one house to the next. Radon levels in the soil range from a few hundred to several thousands of pCi/L in air. The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, and the suction within the house.
Many Ohio counties have elevated average indoor radon levels
Average indoor radon concentrations by ZIP Code
Indoor radon levels in Grove City and surrounding ZIP codes average higher than the EPA recommended action level.
| ZIP Code | City> | Number of Tests | Average |
|---|---|---|---|
| 43123 | Grove City | 647 | 7.73 pCi/L |
| 43137 | Lockbourne | 20 | 7.45 pCi/L |
| 43204 | Columbus | 299 | 5.95 pCi/L |
| 43207 | Columbus | 210 | 12.05 pCi/L |
| 43223 | Columbus | 103 | 5.92 pCi/L |
| 43119 | Galloway | 212 | 7.68 pCi/L |
Average radon readings by Ohio county
Usually, the air pressure in homes and buildings is lower than the pressure outside in the soil around or underneath the foundation–that pressure difference will create suction. As warm air rises and escapes through vents, windows, gaps, and cracks, the air in the building must be replaced. A house can get between five and 20% of its air from the basement; causing soil gas, including radon, to enter the home through the gravel and loose fill around the house’s lowest level.
The EPA recommends that homeowners consider fixing their homes when the radon level is between 2 and 4 pCi/L; since there is significant risk even at levels below 4 pCi/L, and there is no known safe level of radon exposure.
EPA interactive radon zone map
The EPA recommends that every home be tested for radon. Changes to your home such as additions, remodeling, or even a new roof or siding can change the level of radon inside your home. Click the button below to schedule a radon test at your home.
