Is Greene County, MO a radon risk area?

Greene County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Nationally, Greene County ranks higher in radon potential than 64% of rated counties (the 64th percentile).

Where Greene County sits nationally

About 307,942 people live in Greene County, Missouri, spread over 675.329 square miles. Population density there runs about 456 people per square mile. Rank 75 by population within its EPA zone puts Greene County at the 93rd percentile among zone peers. Geologically, Greene County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Zone vs. an actual test

Greene County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Greene County — testing is the only way to know an individual home's actual level.

Next steps for a home in Greene County

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 Missouri'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

Greene County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.