Is Mississippi County, AR a radon risk area?

Mississippi County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally that's the 20th percentile for radon potential — Mississippi County outranks 20% of every county EPA has rated.

How Mississippi County compares

About 38,095 people live in Mississippi County, Arkansas, spread over 902.093 square miles. Population density there runs about 42 people per square mile. Rank 419 by population within its EPA zone puts Mississippi County at the 59th percentile among zone peers. Mississippi County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

A Zone 3 county like Mississippi County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Don't read Zone 3 as a pass for Mississippi County — EPA's guidance to test every home makes no exception for counties predicted low.

If Mississippi County tests above the action level

Nothing about Mississippi 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 Arkansas's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Mississippi County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.