Is Henry County, TN a radon risk area?
EPA places Henry 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. Nationally that's the 18th percentile for radon potential — Henry County outranks 18% of every county EPA has rated.
Where Henry County sits nationally
About 32,883 people live in Henry County, Tennessee, spread over 561.902 square miles. Averaged across its land area, Henry County runs about 59 people per square mile. Rank 459 by population within its EPA zone puts Henry County at the 56th percentile among zone peers. Geologically, Henry County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.
What this actually means for a house in Henry County
At Zone 3, Henry County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Even at Zone 3, Henry County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.
Testing and mitigation in Henry County
Nothing about Henry 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 Tennessee's state radon program
Henry County's test kit answers today; a Airthings radon monitor keeps answering for Henry 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
Henry County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Henry County carries, the zone explainer covers what it does and doesn't tell you about any one house.