Clay County, MS: EPA's radon zone, explained

EPA's own radon map rates Clay County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally, Clay County ranks higher in radon potential than 45% of rated counties (the 45th percentile).

How Clay County compares

Clay County, Mississippi is home to about 18,213 people across 410.011 square miles. Averaged across its land area, Clay County runs about 44 people per square mile. By population, Clay County is the 657th largest of every county sharing its EPA zone — the 36th percentile by population within that zone. Clay County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Clay County

EPA's Zone 2 rating for Clay County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Middle-of-the-pack doesn't mean risk-free for any one Clay County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Clay County

For a Clay 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 Mississippi's state radon program

For Clay County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Clay 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 Clay County's figures come from

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