De Soto Parish, LA: EPA's radon zone, explained

EPA places De Soto Parish 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. That puts De Soto Parish in the 17th percentile nationally for radon potential — higher than 17% of the counties EPA has rated.

Where De Soto Parish sits nationally

De Soto Parish, Louisiana is home to about 27,274 people across 876.45 square miles. Population density there runs about 31 people per square mile. By population, De Soto Parish is the 513th largest of every county sharing its EPA zone — the 50th percentile by population within that zone. De Soto Parish falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, De Soto Parish's Zone 3 prediction is the low end of the scale. A Zone 3 label describes De Soto Parish's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Testing and mitigation in De Soto Parish

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

Where De Soto 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.