Is Shelby County, AL a radon risk area?

EPA's own radon map rates Shelby County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Shelby County in the 63rd percentile nationally for radon potential — higher than 63% of the counties EPA has rated.

How Shelby County compares

About 235,969 people live in Shelby County, Alabama, spread over 785.455 square miles. That works out to roughly 300 people per square mile. Rank 101 by population within its EPA zone puts Shelby County at the 90th percentile among zone peers. Geologically, Shelby 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

EPA's Zone 2 rating for Shelby County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Middle-of-the-pack doesn't mean risk-free for any one Shelby County address — a moderate county average still leaves individual homes to test either side of it.

If Shelby County tests above the action level

Nothing about Shelby 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 Alabama's state radon program

Shelby County's test kit answers today; a Airthings radon monitor keeps answering for Shelby 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 Shelby County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.