Is Hancock County, OH a radon risk area?

Hancock County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Hancock County sits at the 92nd percentile nationally for radon potential — above 92 of every 100 rated counties.

Hancock County by the numbers

About 75,016 people live in Hancock County, Ohio, spread over 531.324 square miles. That works out to roughly 141 people per square mile. Rank 237 by population within its EPA zone puts Hancock County at the 78th percentile among zone peers. Geologically, Hancock County is grouped into EPA Region 5 alongside 523 other counties that share its rock and soil setting.

What this actually means for a house in Hancock County

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Hancock County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Being in Zone 1 raises the odds Hancock County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Testing and mitigation in Hancock County

Nothing about Hancock County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Ohio's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Hancock County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.