Rock Island County, IL Radon Zone Data

Is Rock Island County, IL a radon risk area?

EPA places Rock Island County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Rock Island County ranks higher in radon potential than 96% of rated counties (the 96th percentile).

Where Rock Island County sits nationally

About 142,731 people live in Rock Island County, Illinois, spread over 427.497 square miles. Population density there runs about 334 people per square mile. Rank 141 by population within its EPA zone puts Rock Island County at the 87th percentile among zone peers. Rock Island County falls in EPA Radon Region 5, one of 524 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Rock Island County

Rock Island County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Rock Island County specifically.

Testing and mitigation in Rock Island County

Nothing about Rock Island 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 Illinois's state radon program

Rock Island County's test kit answers today; a Airthings radon monitor keeps answering for Rock Island 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

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.