39%tests ≥ 4 pCi/L
295tests on record
3.1median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Coles County

ResultShareEPA guidance
Below 2 pCi/L31%Below EPA's levels
2 to 4 pCi/L31%Consider fixing
4 pCi/L or more39%EPA recommends fixing

What the data shows

Where Coles County sits among Illinois's 102 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017
0%20%40%60%80%

How Coles County compares

Coles County ranks 4 of 7 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Shelby County57%Moultrie County48%Douglas County43%Coles County39%Edgar County38%Clark County22%Cumberland County22%Illinois 43%
Data table
AreaTests ≥ 4 pCi/LTests
Shelby County57%113
Moultrie County48%69
Douglas County43%234
Coles County39%295
Edgar County38%116
Clark County22%77
Cumberland County22%55
Illinois (102 counties)43%108,909

Same source as Coles County.

What it means for your home

About 1 in 3 results in Coles County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

Prefer a digital monitor? See Airthings radon monitors, or enter code radonbycounty-10OFF at their discount store for 10% off.

Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

About this data

Source: Radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 295. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us