What EPA's radon map says about Mason County

EPA's own radon map rates Mason County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Rank it against the rest of the country and Mason County lands in the 44th percentile for radon potential.

Mason County by the numbers

About 16,956 people live in Mason County, Kentucky, spread over 240.127 square miles. That works out to roughly 71 people per square mile. Among counties sharing Mason County's EPA zone, it outranks 35% of them by population. Geologically, Mason County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

What this actually means for a house in Mason County

Mason County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. Nothing about a Zone 2 label lowers the case for testing in Mason County — EPA recommends it in every zone, moderate included.

Next steps for a home in Mason County

Mitigation cost doesn't depend on Mason County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Kentucky's state radon program

Mason County's test kit answers today; a Airthings radon monitor keeps answering for Mason County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.