Hancock County, MS: EPA's radon zone, explained

Hancock County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Hancock County sits at the 21st percentile nationally for radon potential — above 21 of every 100 rated counties.

Hancock County by the numbers

Hancock County, Mississippi is home to about 46,492 people across 473.966 square miles. Population density there runs about 98 people per square mile. By population, Hancock County is the 364th largest of every county sharing its EPA zone — the 65th percentile by population within that zone. Geologically, Hancock County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

At Zone 3, Hancock County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Don't read Zone 3 as a pass for Hancock County — EPA's guidance to test every home makes no exception for counties predicted low.

Next steps for a home in Hancock County

For a Hancock County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Mississippi's state radon program

For Hancock County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Hancock County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

Where Hancock County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Hancock County carries, the zone explainer covers what it does and doesn't tell you about any one house.