Radon Pros in Ohio

Last updated: March 2026

Ohio has one of the most widespread radon problems in the United States. According to EPA mapping, the majority of Ohio's 88 counties are classified as Zone 1, particularly in the northeastern and central regions. Cleveland, Columbus, and Cincinnati metro areas all report significant radon issues, driven by the state's glacial soils and underlying shale bedrock that create strong conditions for radon gas generation and indoor accumulation. Ohio requires radon testers and mitigators to be licensed by the Ohio Department of Health, one of the stronger state regulatory frameworks in the Midwest. Ohio's residential property disclosure form includes a radon section — sellers must disclose known test results to buyers, making it one of the few states with a formal disclosure requirement. In real estate transactions, radon testing is standard practice across most of the state. Ohio's radon profile is notable for the geographic breadth of the problem: unlike states where risk is concentrated in one region, Ohio's glacial geology produces elevated readings across most of the state from the Lake Erie shore south to the Ohio River Valley. The EPA recommends all Ohio homes be tested, and the Ohio Department of Health maintains public resources for locating licensed radon professionals.