Is LaSalle Parish, LA a radon risk area?

EPA places LaSalle 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. Nationally that's the 10th percentile for radon potential — LaSalle Parish outranks 10% of every county EPA has rated.

Where LaSalle Parish sits nationally

About 14,702 people live in LaSalle Parish, Louisiana, spread over 624.854 square miles. Population density there runs about 24 people per square mile. Rank 715 by population within its EPA zone puts LaSalle Parish at the 31st percentile among zone peers. Geologically, LaSalle Parish is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

LaSalle Parish's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. Don't read Zone 3 as a pass for LaSalle Parish — EPA's guidance to test every home makes no exception for counties predicted low.

Testing and mitigation in LaSalle Parish

Nothing about LaSalle Parish'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 Louisiana's state radon program

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