Is Saline County, MO a radon risk area?

EPA places Saline County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Saline County ranks higher in radon potential than 48% of rated counties (the 48th percentile).

Saline County by the numbers

About 23,325 people live in Saline County, Missouri, spread over 755.51 square miles. Averaged across its land area, Saline County runs about 31 people per square mile. Rank 574 by population within its EPA zone puts Saline County at the 44th percentile among zone peers. Saline County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Saline County

Saline 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 county-wide moderate average, like Saline County's, can still hide a specific house well above or below it — testing is what actually answers the question.

If Saline County tests above the action level

Nothing about Saline 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

Saline County's test kit answers today; a Airthings radon monitor keeps answering for Saline 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 Saline County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.