Direct answer
Yes. Hamilton County and most of Greater Cincinnati sit in EPA Radon Zone 1, the highest-risk classification. Radon is the second leading cause of lung cancer in the US, responsible for about 21,000 deaths annually.
Cincinnati’s underlying limestone and shale geology releases radon as it decays. Roughly 1 in 3 homes tested in Hamilton County exceeds the EPA action level of 4.0 pCi/L.
Authoritative sources
Cincinnati and surrounding counties sit in EPA Radon Zone 1, the highest-risk classification.
EPA recommends mitigation above 4.0 pCi/L and consideration of mitigation between 2.0 and 4.0 pCi/L.
Ohio Radon Program guidance on testing, mitigation, and contractor licensure.
Related questions
We connect Greater Cincinnati homeowners with NRPP-credentialed radon mitigators in our partner network. Mon-Sat 8am-7pm.
