McNairy County, TN: EPA's radon zone, explained

EPA's own radon map rates McNairy County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Rank it against the rest of the country and McNairy County lands in the 49th percentile for radon potential.

How McNairy County compares

McNairy County, Tennessee is home to about 26,103 people across 562.845 square miles. Population density there runs about 46 people per square mile. By population, McNairy County is the 534th largest of every county sharing its EPA zone — the 48th percentile by population within that zone. EPA's geology-based Region 4 groups McNairy County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

EPA's Zone 2 rating for McNairy County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. A county-wide moderate average, like McNairy County's, can still hide a specific house well above or below it — testing is what actually answers the question.

If McNairy County tests above the action level

For a McNairy 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 Tennessee's state radon program

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

McNairy County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone McNairy County carries, the zone explainer covers what it does and doesn't tell you about any one house.