Listed for: Testing
Verified:Illinois state license
Call Aether Radon Solutions LLC at (872) 305-1517No website listed
Locations and reports
Radon in Chicago, Illinois
Chicago lies in 2 counties, in EPA Zone 2; 98.9% of it is in Cook County, where 19.4% of 26,937 reported tests (2017) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so the only way to know your home's level is to test it.
Data checked By Radon411Methodology
Share at 4+ pCi/L
19.4%
14.3 pts below IL
- Cook
- 19.4%
- Illinois
- 33.7%
Cook, 67th of 70 in IL, 2017
Median result
1.9pCi/L
Below action level
- Cook
- 1.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of Cook's tests, 2017
Highest county
33.7%
DuPage
- DuPage
- 33.7%
- Cook
- 19.4%
2 counties, 2 with 30+ tests, 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
Cook; DuPage Zone 2
Tests reported
26,937
In Cook
- Cook
- 26,937
- DuPage
- 19,401
Reported to CDC before any fix, 2017
Read a result for Chicago
Starts at Cook County's median, 1.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.9 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Cook County's median reported result, 2017.
The data
Chicago, What is published
What is published for Chicago
Information:
Every figure for Chicago is a county's
Radon data is published by county, not by city, and Chicago reaches into 2 counties: Cook County and DuPage County. Each has its own EPA zone and its own CDC test figures, set side by side below and each labelled with its county. Only a test tells you about one home.
Chicago covers 228 square miles of land: 98.9% of it lies in Cook County and 1.1% in DuPage County. Its 2,731,585 residents live 11,995 to the square mile.
Chicago, Counties
Chicago's counties, side by side
MeasuredEach county's own EPA zone and its own published CDC figures for 2017, the newest period any of them has. A county without a figure for that period is shown without one, never with a figure from another year.
- Cook County
- EPA zone
- Zone 2: Moderate predicted potential
- At or above 4 pCi/L
- 19.4%
- Median result
- 1.9 pCi/L
- Tests reported
- 26,937 tests
- Annual years on file
- 4
- DuPage County
- EPA zone
- Zone 2: Moderate predicted potential
- At or above 4 pCi/L
- 33.7%
- Median result
- 2.7 pCi/L
- Tests reported
- 19,401 tests
- Annual years on file
- 4
| County | EPA zone | Reported tests at or above 4 pCi/L | Median reported result | Tests reported | Annual years on file |
|---|---|---|---|---|---|
| Cook County | Zone 2: Moderate predicted potential | 19.4% | 1.9 pCi/L | 26,937 tests | 4 |
| DuPage County | Zone 2: Moderate predicted potential | 33.7% | 2.7 pCi/L | 19,401 tests | 4 |
Chicago spans 2 counties, each with its own EPA zone and its own CDC figure: Cook County (Zone 2, 19.4% of 26,937 tests) and DuPage County (Zone 2, 33.7% of 19,401 tests).
Cook County ranks 67th of 70 Illinois counties with 30 or more tests for that period, 14.3 points below the 33.7% pooled across Illinois's counties, 12.3 points below the national pool of 31.7%. Of the city's other county, DuPage County reported 33.7%.
Measured from the middle of Chicago, the nearest counties with a CDC figure for 2017 are Will County (31 miles, 40.0% of 10,776 tests), Lake County (37 miles, 27.4% of 13,050 tests) and Kane County (39 miles, 36.6% of 8,682 tests). Across the 8 nearest, the share at or above 4 pCi/L runs from 27.4% to 41.1%; the farthest of them, DeKalb County, is 56 miles away at 41.1%.
The directory lists 19 businesses with an address in Chicago, 19 for testing and 1 for mitigation. Illinois's other cities with a page of their own: Rockford, Naperville, Springfield and Glenview.
Against Illinois and its other counties
Shares of tests people chose to run and report, by county (2017); the state's is its counties' counts added up, calculated by Radon411. Only a test measures a home.
The counties around Chicago
By distance from the middle of Chicago; counties with 30 or more tests.
The median reported pre-mitigation result for 2017 was 1.9 pCi/L in Cook County and 2.7 pCi/L in DuPage County.
Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2017.
Chicago, Geology
The ground under Chicago
PredictedUSGS's geologic map puts all of Chicago's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Wheaton Morainal Country, to which USGS gives a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Wheaton Morainal Country | Glacial lake deposits and clay-rich glacial till. | Moderate | 11 | 99.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Chicago beside its counties and Illinois
Cook County as a whole has 3.2% of its land rated high; none of that ground lies under Chicago. Across Illinois 64.5% of the land is rated high; none of Chicago's is.
The map rates the ground, not the air in any home.
Chicago, Homes
Homes in Chicago
Chicago has 1,268,199 homes, and many share a building: 42% are in buildings of five or more, 26% are detached houses, against 40% across Cook County. The homes are older than Cook County's as a whole: half were built before 1952 (1961 for Cook County), and 59% date from before 1960. Most occupied homes here are rented: owners live in 46% (Cook County: 58%). A tenant can run a test; a fix is the landlord's to make.
| Homes | Chicago | Cook County | Illinois |
|---|---|---|---|
| Housing units | 1,268,199 | 2,270,349 | 5,443,501 |
| Detached houses | 26% | 40% | 58% |
| In buildings of 5 or more | 42% | 34% | 22% |
| Mobile homes | under 1% | 1% | 2% |
| Built before 1960 | 59% | 49% | 38% |
| Built since 2000 | 14% | 12% | 16% |
| Middle year built | 1952 | 1961 | 1970 |
| Owner-occupied | 46% | 58% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.
Local help
Chicago, Professionals
Radon professionals listed in Chicago
Businesses whose listed city is Chicago, from the state registries and listings in the Radon411 directory, with the same business and certification status the directory shows.
Radon professionals listed in Chicago: 1 of 6
19 listings with Chicago as the city. See radon mitigation and testing in Chicago, or all radon professionals in Illinois.
Chicago, Local resources
Local resources for Chicago
Who to ask in Illinois: its radon program, test kits and professionals.
- IEMA-OHS Radon ProgramRun by Illinois Emergency Management Agency and Office of Homeland Security, phone (800) 325-1245.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- Professionals in Illinois19 listings cover Chicago.
The program's own words on licensing and disclosure are on the Illinois page.
What it means
Chicago, Questions
Questions about radon in Chicago
What radon zone is Chicago in?
Both counties Chicago reaches into (Cook County and DuPage County) are in Zone 2, the map's middle class: a predicted county average of 2 to 4 pCi/L. EPA zones counties, not cities, so that is the zone for every part of Chicago.
What are radon levels in Chicago?
Most tests near Chicago come back under EPA's action level, but not all: 19.4% of Cook County's 26,937 tests for 2017 were at or above 4 pCi/L. The median reported result was 1.9 pCi/L. DuPage County reported 33.7% of 19,401 tests; the counties are kept apart.
Should I test my home in Chicago?
Yes. In Cook County, about one reported test in 5 reached 4 pCi/L. That is below Illinois' pooled 33.7%, and still not a reason to skip it, and ranks Cook County 67th of the 70 Illinois counties with 30 or more tests. The number for one house comes only from testing it. How to test a home.
What ground is Chicago built on, as far as radon goes?
USGS's geologic map puts all of Chicago on one named area, "Wheaton Morainal Country", rated moderate for radon potential, radon index 11.
Is radon higher in the counties around Chicago?
Higher, in every direction measured: all 8 of the nearest counties with a figure report a larger share of high tests than Cook County's 19.4%, up to DeKalb County (41.1%, 56 miles off).
Who tests for or fixes radon in Chicago?
Chicago is the address of 19 businesses in Radon411's directory, 19 listed for testing and 1 for mitigation. Each entry names the public list it came from. Radon professionals in Chicago.
The answers use the published figures of Cook County and DuPage County, the counties Chicago lies in.
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