Is Duval County, FL a radon risk area?

Duval County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Duval County in the 32nd percentile nationally for radon potential — higher than 32% of the counties EPA has rated.

Duval County by the numbers

About 1,055,159 people live in Duval County, Florida, spread over 762.687 square miles. Population density there runs about 1,383 people per square mile. Rank 24 by population within its EPA zone puts Duval County at the 98th percentile among zone peers. Geologically, Duval County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

A Zone 3 county like Duval County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Don't read Zone 3 as a pass for Duval County — EPA's guidance to test every home makes no exception for counties predicted low.

Next steps for a home in Duval County

Nothing about Duval 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 Florida's state radon program

Duval County's test kit answers today; a Airthings radon monitor keeps answering for Duval 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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.