Caddo Parish, LA: EPA's radon zone, explained

Caddo Parish is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Caddo Parish in the 29th percentile nationally for radon potential — higher than 29% of the counties EPA has rated.

How Caddo Parish compares

Caddo Parish, Louisiana is home to about 224,893 people across 879.535 square miles. Population density there runs about 256 people per square mile. By population, Caddo Parish is the 115th largest of every county sharing its EPA zone — the 89th percentile by population within that zone. EPA's geology-based Region 6 groups Caddo Parish with 502 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Caddo Parish

Caddo Parish'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 rating means Caddo Parish's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Testing and mitigation in Caddo Parish

For a Caddo Parish 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 Louisiana's state radon program

For Caddo Parish, an ongoing number beats a one-time test - a Airthings radon monitor tracks Caddo Parish's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Caddo Parish'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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.