Is Fannin County, TX a radon risk area?

EPA places Fannin 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. Fannin County sits at the 20th percentile nationally for radon potential — above 20 of every 100 rated counties.

How Fannin County compares

About 38,650 people live in Fannin County, Texas, spread over 877.939 square miles. Averaged across its land area, Fannin County runs about 44 people per square mile. Rank 413 by population within its EPA zone puts Fannin County at the 60th percentile among zone peers. Fannin County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Fannin County

Fannin County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Fannin County testing above the action level often enough that skipping a test isn't the safe assumption.

If Fannin County tests above the action level

Nothing about Fannin 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 Texas's state radon program

Fannin County's test kit answers today; a Airthings radon monitor keeps answering for Fannin 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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.