Original Ohio-focused radon content — geological deep dives, real estate transaction playbooks, regulatory explainers, contractor verification guides, and seasonal awareness articles. Each article cross-references authoritative sources (EPA, ALA, AARST, Ohio DEP/HHS) and is regularly updated to reflect current standards.
Using radon tests reported to the CDC (2008–2017), here’s how Ohio counties compare — the highest-radon counties, the lowest, and why a below-average county still isn’t a safe one.
Ohio's cold continental winters and uranium-bearing Devonian shale make the November–March heating season the most accurate window to test your home for radon.
Ohio Rev. Code § 5302.30 requires sellers of residential property (1-4 unit dwellings) to provide buyers with the state-prescribed Residential Property Disclosure Form. Section 6 of that form specifically addresses radon — and how a seller completes it can determine whether testing or mitigation becomes a contingency, a price reduction, or a deal-breaker. Here's a plain-English walkthrough for both sides of the transaction.
The Glacial Boundary — running roughly diagonally from Cincinnati to Northeast Ohio — divides Ohio into two distinct radon geologies. North and west: glacial till from Wisconsinan-era glaciation. East and southeast: the unglaciated Appalachian Plateau with exposed bedrock. Both regions are EPA Zone 1, but the radon source and mitigation strategy are different.
The Devonian-age Ohio Shale formation is one of the most uranium-rich rock units in the eastern United States. It underlies most of Northeast Ohio — from Cleveland to Youngstown — and is a major driver of the region's elevated indoor radon levels. Learn how Ohio Shale forms radon, which counties are most affected, and what mitigation contractors do differently when the bedrock is Ohio Shale.
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