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Radon is a naturally occurring radioactive gas that enters buildings from the surrounding soil. It is colorless, odorless, and tasteless. Elevated levels of radon have been found in homes in every county in Ohio.

Increased radon levels increase the risk of lung cancer in humans. Radon is the primary cause of lung cancer among nonsmokers in the United States. Radon is second only to tobacco smoking as the leading cause of lung cancer.

Ohio's Commitment to Radon Action

In recognition of the potential health hazards associated with elevated levels of radon, and in acknowledgement of how simple and inexpensive nature of radon testing is to implement, Gov. John R. Kasich has designated January as "Radon Action Month."  

Radon Questions and Answers for Household Members

Should I test my home for radon?

Yes. Testing is the only way to find out how much radon is in your home. ODH estimates that one-half of Ohio homes have radon levels above the Environmental Protection Agency’s recommended action level of 4 picoCuries/liter (4 pCi/l) of air.

How much radon in a home is safe?

Any amount of radon carries some risk, even at or below the recommended action level. The risk of lung cancer increases with higher radon levels. Because it isn’t possible to reduce radon to zero, the best approach is to lower levels as much as possible.


ODH Indoor Radon Program

Environmental Protection Agency

Ohio Radon Information System


Page updated: 1/8/2018