Andrew County, MO: EPA's radon zone, explained

EPA's own radon map rates Andrew County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. That puts Andrew County in the 81st percentile nationally for radon potential — higher than 81% of the counties EPA has rated.

Andrew County by the numbers

Andrew County, Missouri is home to about 18,091 people across 432.634 square miles. Population density there runs about 42 people per square mile. By population, Andrew County is the 599th largest of every county sharing its EPA zone — the 44th percentile by population within that zone. EPA's geology-based Region 7 groups Andrew County with 411 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Andrew County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. Some Andrew County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

Next steps for a home in Andrew County

For a Andrew 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 Missouri's state radon program

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

Where Andrew County's figures come from

Andrew County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Andrew County carries, the zone explainer covers what it does and doesn't tell you about any one house.