Lamar County, MS radon potential

Lamar County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Lamar County in the 24th percentile nationally for radon potential — higher than 24% of the counties EPA has rated.

Where Lamar County sits nationally

Lamar County, Mississippi is home to about 66,734 people across 496.57 square miles. Population density there runs about 134 people per square mile. Within its own EPA zone, Lamar County is bigger by population than 73% of the counties that share it. EPA's geology-based Region 4 groups Lamar County with 735 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Lamar County

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Lamar County's Zone 3 prediction is the low end of the scale. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Lamar County testing above the action level often enough that skipping a test isn't the safe assumption.

Next steps for a home in Lamar County

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Mississippi's state radon program

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

Where Lamar County's figures come from

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