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Radon Levels in Crawford County, Illinois

EPA puts Crawford County in Zone 2, its middle radon zone, and only 21 radon tests from it are on file with CDC (2017). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    19.3%

    23.8 pts below IL

    Crawford
    19.3%
    Illinois
    43.1%

    181 tests, 2008 to 2017

  • Median result

    1.8pCi/L

    Below action level

    Crawford
    1.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    181

    58th of 93 by tests

    Crawford
    181
    Cook
    14,199

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Illinois

    86 of 93

    Lowest quarter

    Crawford
    19.3%
    Stark
    80.5%

    By share, of 93 with 30+ tests

Read a result for Crawford County

Starts at Crawford County's median, 1.8 pCi/L

1.8pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 1.8 pCi/L

Below 2 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Crawford County's median reported result, 2008 to 2017.

Interpret this reading

The data

Crawford County, At a glance

Crawford County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Crawford County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Crawford County, 2017

Share of reported tests at or above 4 pCi/L, by year, Crawford County
Share of reported tests at or above 4 pCi/L, by year, Crawford County
YearShare of reported tests at or above 4 pCi/L
201441.7%
2015100.0%
20170.0%

2017: 0.0%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 21 tests were reported to CDC for Crawford County over 2017, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2017. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Crawford County, Compared

Crawford County radon figures, compared

Calculated by Radon411

Crawford County's 181 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.8 pCi/L and a maximum of 17.2 pCi/L, and 19.3% reached 4 pCi/L. Illinois as a whole (102 Illinois counties, pooled) comes to 43.1%: 23.8 points higher than here.

The newest figure, in 2017, counts only 21 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 181-test figure.

Among its state's counties it ranks 86th of 93 Illinois counties with 30 or more tests for the same period. Statewide for the same period, Stark County reported the highest share (80.5%) and Williamson County the lowest (13.3%).

Below the action level, 99 tests (54.7%) came in under 2 pCi/L, against 31.6% statewide, and 47 tests (26.0%) fell between 2 and 4, against 25.3% statewide. The busiest year on file was 2014, with 72 tests reported; the quietest, 2015, had 3.

EPA's 1993 zone map puts Crawford County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Next door, the shares run from 18.8% in Lawrence County to 43.1% in Knox County, IN, with Richland County and Lawrence County below Crawford County.

CDC also counts 8 tests taken after mitigation in Crawford County for the same period: tests in homes where a fix was already in.

Crawford County against Illinois, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Crawford County
Crawford County18119.3%1.8 pCi/LThis county
Illinois, pooled102 counties, pooled108,90943.1%Not pooled+23.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+16.4 points
Stark Countyhighest in the state8780.5%7.4 pCi/L+61.2 points
Williamson Countylowest in the state60113.3%1.3 pCi/L−6.0 points
Sullivan County, INborders it1346.2%3.1 pCi/L+26.9 points
Knox County, INborders it5843.1%3.4 pCi/L+23.8 points
Jasper County, ILborders it7623.7%1.9 pCi/L+4.4 points
Clark County, ILborders it7722.1%2.0 pCi/L+2.8 points
Richland County, ILborders it14818.9%1.8 pCi/L−0.4 points
Lawrence County, ILborders it4818.8%1.8 pCi/L−0.5 points
Where Crawford County's reported results fell, 2008 to 2017, laboratory, beside Illinois and the United States
ResultCrawford County testsCrawford County shareIllinois shareU.S. shareAgainst Illinois
Under 2 pCi/L9954.7%31.6%39.6%+23.1 points
2 to 4 pCi/L4726.0%25.3%24.7%+0.7 points
4 pCi/L and above3519.3%43.1%35.7%−23.8 points
Crawford County ranked among the 93 Illinois counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Cumberland County81 of 935521.8%1.8 pCi/L
Saline County82 of 938220.7%1.7 pCi/L
Marion County83 of 9336420.6%1.7 pCi/L
Cook County84 of 9314,19920.2%1.8 pCi/L
Franklin County85 of 9319919.6%1.8 pCi/L
Crawford County86 of 9318119.3%1.8 pCi/L
Richland County87 of 9314818.9%1.8 pCi/L
Lawrence County88 of 934818.8%1.8 pCi/L
Massac County89 of 933315.2%1.9 pCi/L
Wayne County90 of 938615.1%1.4 pCi/L
Clay County91 of 936814.7%1.1 pCi/L
Crawford County radon tests by year, against Illinois' pooled share
YearTestsAt or above 4 pCi/LMedianHighestIllinois, pooledChange from the row before
2017210.0%2.3 pCi/L3.2 pCi/L33.7%−100.0 points
20153100.0%5.2 pCi/L5.2 pCi/L36.6%+58.3 points
20147241.7%3.1 pCi/L5.7 pCi/L37.8%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Crawford County, Geology

The ground under Crawford County

Predicted

USGS's geologic map puts all of Crawford County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Southern Central Lowland Province, to which USGS gives a radon index of 9, in the moderate band (9 to 11).

USGS's geologic areas under Crawford County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Southern Central Lowland ProvinceIllinoian glacial deposits, sandstone, and gray shale.Moderate999.8%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Crawford County beside the ground around it

Across Illinois 64.5% of the land is rated high; none of Crawford County's is. Of the 6 counties that border it, 1 has more high-potential ground, Clark County the most at 3.5%.

Share of land by USGS radon potential: Crawford County, the 6 counties bordering it and Illinois
AreaEPA zoneLow potentialModerate potentialHigh potential
Crawford CountyZone 2None100%None
Sullivan County, INZone 2None100%None
Clark CountyZone 2None96.5%3.5%
Jasper CountyZone 2None100%None
Lawrence CountyZone 2None100%None
Richland CountyZone 2None100%None
Knox County, INZone 2None100%None
Illinois102 counties, pooled by land areaVaries0.9%34.5%64.5%

The map rates the ground, not the air in any home.

Local help

Crawford County, Local resources

Radon testing and mitigation in Crawford County

What Illinois's program says
Phone
(800) 325-1245
Licensing of radon professionals
The Agency also licenses and regulates the individuals who provide radon measurement and mitigation to the public.
Disclosure when a home is sold or rented
Illinois Radon Awareness Act - This is the legislation that requires the seller to provide to the buyer of any interest in residential real property the IEMA-OHS pamphlet entitled "Radon Testing Guidelines for Real Estate Transactions" and the Illinois Disclosure of Information on Radon Hazards.

What it means

Crawford County, Questions

Questions about radon in Crawford County

Are radon levels high in Crawford County?

In 2017, 0.0% of the radon tests reported to CDC for Crawford County, Illinois were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.3 pCi/L. Of 93 Illinois counties with 30 or more tests for the same period, 85 reported a higher share; pooled, the state comes to 43.1%.

Which counties border Crawford County?

Crawford County borders 6 counties: Sullivan County, IN, Clark County, IL, Jasper County, IL, Lawrence County, IL, Richland County, IL and Knox County, IN.

Products

Crawford County, Products

Testing a home in Crawford County

In Crawford County, 19.3% of 181 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.1% pooled across Illinois. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Crawford County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Crawford County homes, compared

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Crawford County, Bordering counties

Counties bordering Crawford County

Calculated by Radon411

Crawford County, Cities and towns

Cities and towns in Crawford County

Crawford County's population has barely moved since 2020: 18,648 residents on July 1, 2025 against 18,631 then, by the Census Bureau's estimates. That works out to 42 people per square mile of land. Its largest town, Robinson, has 7,283 residents, 39.1% of the total. Together its 6 incorporated places hold 57.6% of those residents; the other 42.4% live outside any of them. CDC's 181 reported tests for 2008 to 2017 work out to 9.7 per 1,000 residents (2025 estimate), close to Illinois' 8.6.

From Robinson to Stoy, CDC publishes no figure by town: each reads Crawford County's.

The cities and towns in Crawford County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Robinson7,283+2.0%39.1%
Oblong1,352−1.2%7.3%
Palestine1,210−1.6%6.5%
Hutsonville469−1.5%2.5%
Flat Rock322−1.2%1.7%
Stoy105−0.9%0.6%

6 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Crawford County, Homes

Homes in Crawford County

Crawford County is a place of houses on their own lots: 83% of its 8,461 homes are detached single-family houses, against 58% across Illinois. Half of its homes were built before 1965, close to Illinois' 1970: 45% date from before 1960 and 13% from 2000 or later. Owners live in 80% of the occupied homes (Illinois: 67%), so for most households a test and a fix are their own to order.

Homes in Crawford County, Illinois, 2019 to 2023
HomesCrawford CountyIllinois
Housing units8,4615,443,501
Detached houses83%58%
In buildings of 5 or more3%22%
Mobile homes9%2%
Built before 196045%38%
Built since 200013%16%
Middle year built19651970
Owner-occupied80%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.