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

EPA places Rankin County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Rank it against the rest of the country and Rankin County lands in the 28th percentile for radon potential.

How Rankin County compares

Rankin County, Mississippi is home to about 160,573 people across 775.501 square miles. Population density there runs about 207 people per square mile. By population, Rankin County is the 159th largest of every county sharing its EPA zone — the 85th percentile by population within that zone. EPA's geology-based Region 4 groups Rankin County with 735 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Rankin County

A Zone 3 county like Rankin County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 label describes Rankin County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Next steps for a home in Rankin County

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

Where Rankin County's figures come from

Rankin County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.