Is Dyer County, TN a radon risk area?

EPA's own radon map rates Dyer County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Rank it against the rest of the country and Dyer County lands in the 19th percentile for radon potential.

How Dyer County compares

About 36,403 people live in Dyer County, Tennessee, spread over 512.351 square miles. Averaged across its land area, Dyer County runs about 71 people per square mile. Rank 432 by population within its EPA zone puts Dyer County at the 58th percentile among zone peers. Dyer County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Dyer County

Dyer 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. A Zone 3 label describes Dyer County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Dyer County tests above the action level

Nothing about Dyer 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

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

The methodology guide shows exactly which EPA and Census sources feed Dyer County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.