Is Greene County, MS a radon risk area?

EPA places Greene County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Greene County in the 9th percentile nationally for radon potential — higher than 9% of the counties EPA has rated.

How Greene County compares

About 13,675 people live in Greene County, Mississippi, spread over 712.738 square miles. That works out to roughly 19 people per square mile. Rank 738 by population within its EPA zone puts Greene County at the 28th percentile among zone peers. Geologically, Greene 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

Greene County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Greene County testing above the action level often enough that skipping a test isn't the safe assumption.

If Greene County tests above the action level

Nothing about Greene 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 Mississippi's state radon program

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

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.