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Radon Levels in Fulton County, Illinois

EPA puts Fulton County in Zone 1, its highest radon zone, and high results are common there: 64.6% of the 144 radon tests reported to CDC (2017) came back at or above 4 pCi/L. 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

    64.6%

    30.9 pts above IL

    Fulton
    64.6%
    Illinois
    33.7%

    144 tests, 2017

  • Median result

    5.8pCi/L

    Action level reached

    Fulton
    5.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2017

  • Tests reported

    144

    45th of 70 by tests

    Fulton
    144
    Cook
    26,937

    Reported to CDC before any fix, 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Illinois

    4 of 70

    Top quarter

    Fulton
    64.6%
    Stark
    69.2%

    By share, of 70 with 30+ tests

Read a result for Fulton County

Starts at Fulton County's median, 5.8 pCi/L

5.8pCi/L

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

EPA’s reading of 5.8 pCi/L

At or above 4 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 at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Fulton County's median reported result, 2017.

Interpret this readingWhat a fix costs

The data

Fulton County, At a glance

Fulton County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Fulton County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

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

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Fulton County, 2017

Share of reported tests at or above 4 pCi/L, by year, Fulton County
Share of reported tests at or above 4 pCi/L, by year, Fulton County
YearShare of reported tests at or above 4 pCi/L
201457.6%
201550.0%
201764.6%

2017: 64.6%. Across these years the share ran from 50.0% to 64.6%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 144 tests reported to CDC for Fulton County over 2017, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not 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

Fulton County, Compared

Fulton County radon figures, compared

Calculated by Radon411

More than half: 64.6% of the 144 radon tests reported to CDC for Fulton County in 2017 read at least 4 pCi/L. That places it 4th of 70 Illinois counties with 30 or more tests for the same period. That is 30.9 points above the 33.7% pooled from 93 Illinois counties.

The median result, 5.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 35.4 pCi/L. The rest split 16.7% under 2 pCi/L and 18.8% from 2 to 4 (Illinois: 37.7% and 28.6%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 64.6% share point the same way here.

No bordering county with a figure for the same period reported a higher share; the closest is Knox County at 56.6%, the lowest Mason County at 21.4%. Statewide for the same period, Stark County reported the highest share (69.2%) and Williamson County the lowest (8.4%).

The busiest year on file was 2014, with 198 tests reported; the quietest, 2015, had 120.

Over 3 years of annual figures the share rose 7.0 points, from 57.6% in 2014 to 64.6% in 2017; its peak was 64.6% in 2017. Nationally, every county with a figure for the same period pools to 31.7%; Fulton County sits 32.9 points above it.

Share of reported tests at or above 4 pCi/L by year, Fulton County against Illinois2014 to 2017, years with 30 or more tests: Fulton County 57.6% to 64.6%, the state's pooled share 33.7% in 2017.
Fulton CountyIllinois, pooled
Share of reported tests at or above 4 pCi/L by year, Fulton County against Illinois: data table
YearTestsFulton County, at or above 4 pCi/LIllinois, pooled
201419857.6%37.8%
201512050.0%36.6%
201714464.6%33.7%
Fulton County against Illinois, the United States and nearby counties, 2017
AreaTestsAt or above 4 pCi/LMedianDifference from Fulton County
Fulton County14464.6%5.8 pCi/LThis county
Illinois, pooled93 counties, pooled138,00633.7%Not pooled−30.9 points
United States, pooled937 counties, pooled528,06231.7%Not pooled−32.9 points
Stark Countyhighest in the state3969.2%5.8 pCi/L+4.6 points
Williamson Countylowest in the state2498.4%0.9 pCi/L−56.2 points
Knox County, ILborders it24956.6%4.7 pCi/L−8.0 points
McDonough County, ILborders it21055.7%4.3 pCi/L−8.9 points
Warren County, ILborders it4250.0%3.6 pCi/L−14.6 points
Tazewell County, ILborders it2,72446.4%3.6 pCi/L−18.2 points
Peoria County, ILborders it3,81640.2%3.1 pCi/L−24.4 points
Mason County, ILborders it4221.4%2.8 pCi/L−43.2 points
Where Fulton County's reported results fell, 2017, beside Illinois and the United States
ResultFulton County testsFulton County shareIllinois shareU.S. shareAgainst Illinois
Under 2 pCi/L2416.7%37.7%43.5%−21.0 points
2 to 4 pCi/L2718.8%28.6%24.8%−9.8 points
4 pCi/L and above9364.6%33.7%31.7%+30.9 points
Fulton County ranked among the 70 Illinois counties with 30 or more tests, by share at or above 4 pCi/L, 2017
CountyRankTestsAt or above 4 pCi/LMedian
Stark County1 of 703969.2%5.8 pCi/L
Mercer County2 of 706668.2%5.5 pCi/L
Morgan County3 of 7038166.9%6.5 pCi/L
Fulton County4 of 7014464.6%5.8 pCi/L
Carroll County5 of 7021062.9%5.5 pCi/L
Livingston County6 of 7034561.7%5.3 pCi/L
Bureau County7 of 7033358.6%5.1 pCi/L
Stephenson County8 of 7051957.2%4.8 pCi/L
De Witt County9 of 7012657.1%5.2 pCi/L
Ford County9 of 704257.1%4.0 pCi/L
Knox County11 of 7024956.6%4.7 pCi/L
Fulton County radon tests by year, against Illinois' pooled share
YearTestsAt or above 4 pCi/LMedianHighestIllinois, pooledChange from the row before
201714464.6%5.8 pCi/L35.4 pCi/L33.7%+14.6 points
201512050.0%4.0 pCi/L18.6 pCi/L36.6%−7.6 points
201419857.6%4.6 pCi/L30.4 pCi/L37.8%First on file

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

Fulton County, Geology

The ground under Fulton County

Predicted

USGS's geologic map puts all of Fulton County's mapped land in one class: high radon potential. All of it lies in the area the map calls Galesburg Plain, to which USGS gives a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under Fulton County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Galesburg PlainIllinoian glacial deposits and loess over Paleozoic sedimentary rocks.High13100%

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

Fulton County beside the ground around it

Fulton County has more high-potential ground than Illinois as a whole: 100% of its land against 64.5%. Of the 7 counties that border it, none has as large a share of high-potential ground; Knox County comes nearest at 100%.

Share of land by USGS radon potential: Fulton County, the 7 counties bordering it and Illinois
AreaEPA zoneLow potentialModerate potentialHigh potential
Fulton CountyZone 1NoneNone100%
Mason CountyZone 1NoneNone100%
Knox CountyZone 1NoneNone100%
McDonough CountyZone 1NoneNone100%
Peoria CountyZone 1NoneNone100%
Tazewell CountyZone 1NoneNone100%
Schuyler CountyZone 1NoneNone100%
Warren CountyZone 1NoneNone100%
Illinois102 counties, pooled by land areaVaries0.9%34.5%64.5%

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

Local help

Fulton County, Local resources

Radon testing and mitigation in Fulton 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

Fulton County, Questions

Questions about radon in Fulton County

Are radon levels high in Fulton County?

In 2017, 64.6% of the radon tests reported to CDC for Fulton County, Illinois were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.8 pCi/L. Of 70 Illinois counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 33.7%.

Which counties border Fulton County?

Fulton County borders 7 counties: Mason County, Knox County, McDonough County, Peoria County, Tazewell County, Schuyler County and Warren County.

Products

Fulton County, Products

Testing a home in Fulton County

In Fulton County, 64.6% of 144 tests reported to CDC in 2017 reached 4 pCi/L, against 33.7% pooled across Illinois. In Zone 1 the year-round level in Fulton County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Fulton County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Fulton County

Explore

Fulton County, Bordering counties

Counties bordering Fulton County

Calculated by Radon411

Fulton County, Cities and towns

Cities and towns in Fulton County

About 32,901 people live in Fulton County by the Census Bureau's estimate for July 1, 2025, 661 fewer than in 2020 (−2.0%). That works out to 38 people per square mile of land. Its largest town, Canton, has 13,297 residents, 40.4% of the total. Reported testing is thin here: 144 tests over 2017, or 4.4 for every 1,000 residents (2025 estimate), where Illinois as a whole comes to 10.9.

From Canton to Ellisville, CDC publishes no figure by town: each reads Fulton County's.

The 12 largest cities and towns in Fulton County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Canton13,297−0.4%40.4%
Farmingtonextends beyond Fulton County2,298−4.0%Counted whole
Lewistown1,962−4.0%6.0%
Cuba1,131−4.0%3.4%
Astoria882−4.0%2.7%
Avonextends beyond Fulton County672−4.1%Counted whole
Vermont557−2.5%1.7%
St. David505−4.2%1.5%
Ipava418−4.3%1.3%
Fairview410−3.3%1.2%
London Millsextends beyond Fulton County342−2.3%Counted whole
Table Grove329−4.4%1.0%
  • Dunfermline
  • Smithfield
  • Bryant
  • Norris
  • Banner
  • Marietta
  • Liverpool
  • Ellisville

20 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Fulton County is counted whole, so it has no share.

Fulton County, Homes

Homes in Fulton County

Fulton County is a place of houses on their own lots: 87% of its 15,883 homes are detached single-family houses, against 58% across Illinois. The homes are older than Illinois' as a whole: half were built before 1959 (1970 for Illinois), and 51% date from before 1960. Owners live in 78% of the occupied homes (Illinois: 67%), so for most households a test and a fix are their own to order.

Homes in Fulton County, Illinois, 2019 to 2023
HomesFulton CountyIllinois
Housing units15,8835,443,501
Detached houses87%58%
In buildings of 5 or more4%22%
Mobile homes3%2%
Built before 196051%38%
Built since 20009%16%
Middle year built19591970
Owner-occupied78%67%

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