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

EPA places Bradley County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally that's the 95th percentile for radon potential — Bradley County outranks 95% of every county EPA has rated.

How Bradley County compares

Bradley County, Tennessee is home to about 113,782 people across 328.762 square miles. That works out to roughly 346 people per square mile. By population, Bradley County is the 172nd largest of every county sharing its EPA zone — the 84th percentile by population within that zone. EPA's geology-based Region 4 groups Bradley County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Bradley County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. That doesn't mean every Bradley County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Next steps for a home in Bradley County

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Bradley County carries, the zone explainer covers what it does and doesn't tell you about any one house.