Many counties in central Ohio have average indoor radon levels greater tahn the EPA action level of 4.0 pCi/L. Averages recorded in Franklin county are 6.0 to 8.0 pCi/L, and Licking county is over 8.0 pCi/L.

Any home can have elevated radon levels, and even homes next to each other can have different levels of indoor radon due to construction and geographic difference. Every home should be tested, old or new, and even if it already has a radon remediation system in place.

Average indoor radon concentrations by ZIP Code

Indoor radon levels in Columbus and surrounding ZIP codes average higher than the EPA recommended action level of 4.0 pCi/L.

ZIP Code City> Number of Tests Average
43215 Columbus 319 6.32 pCi/L
43212 Columbus 391 6.44 pCi/L
43221 Columbus 1,100 8.97 pCi/L
43220 Columbus 1,135 7.79 pCi/L
43017 Dublin 1,977 10.5 pCi/L
43026 Hilliard 1,076 9.04 pCi/L

Source: Average indoor radon concentrations by Ohio ZIP Code

Nearly one out of every 15 homes in the US is estimated to have a radon level of 4 pCi/L or more. You cannot predict radon levels inside a house based on state, local, or neighborhood radon measurements. Testing is the only way to know if you or your family are at risk from radon.

Radon is a naturally-occurring gas produced by the natural, radioactive breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon can be found all over the country. According to US Geological Service maps, Ohio has relatively high concentrations of uranium due to glacial deposits and shale. As this dissolved uranium content in rocks and soils undergoes radioactive decay, it produces new radionuclides including thorium, radium, and radon gas.

Radon is ubiquitous, usually in small amounts, in rock and soil and can be carried in water and air. Some rock types have the potential to produce higher than average amounts of radon gas.


You can get an idea as to how concerned you should be about radon in your house by learning about the geology of your home site and its radon potential. If your house is in an area with a high potential for radon, then chances are that your house may have an indoor radon problem. However, the way a house is built can increase the risk, so even in areas of low radon potential, some houses can have unhealthy radon levels.

All homes should be tested for elevated levels of radon, regardless of EPA zone designation.

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. You can call 614-782-1705 or click the button below to schedule a radon test at your home.

Written by Warren Watkins

Warren Watkins is a Software Quality Assurance Director.

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