Is Harlan County, KY a radon risk area?

EPA places Harlan County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Harlan County in the 48th percentile nationally for radon potential — higher than 48% of the counties EPA has rated.

Where Harlan County sits nationally

About 25,052 people live in Harlan County, Kentucky, spread over 465.83 square miles. Population density there runs about 54 people per square mile. Rank 553 by population within its EPA zone puts Harlan County at the 46th percentile among zone peers. Harlan 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 Harlan County

Harlan County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Harlan County's Zone 2 rating sits in the middle nationally; EPA's guidance is unchanged by that — test every home regardless of its zone.

If Harlan County tests above the action level

Nothing about Harlan 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 Kentucky's state radon program

Harlan County's test kit answers today; a Airthings radon monitor keeps answering for Harlan County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Harlan County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.