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Radon Levels in Saline County, Missouri

EPA puts Saline County in Zone 2, its middle radon zone, and only 3 radon tests from it are on file with CDC (2023). 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

    49.1%

    18.5 pts above MO

    Saline
    49.1%
    Missouri
    30.6%

    55 tests, 2008 to 2017

  • Median result

    3.7pCi/L

    Below action level

    Saline
    3.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    55

    53rd of 72 by tests

    Saline
    55
    St. Louis
    17,747

    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 Missouri

    4 of 72

    Top quarter

    Saline
    49.1%
    Atchison
    69.9%

    By share, of 72 with 30+ tests

Read a result for Saline County

Starts at Saline County's median, 3.7 pCi/L

3.7pCi/L

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

EPA’s reading of 3.7 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Saline County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Saline County, At a glance

Saline County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Saline 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 Saline County, 2023

Share of reported tests at or above 4 pCi/L, by year, Saline County
Share of reported tests at or above 4 pCi/L, by year, Saline County
YearShare of reported tests at or above 4 pCi/L
201450.0%
201540.0%
201675.0%
2017100.0%
201833.3%
2019100.0%
202150.0%
202250.0%
202366.7%

2023: 66.7%. Across these years the share ran from 33.3% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 3 tests were reported to CDC for Saline County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Saline County, Compared

Saline County radon figures, compared

Calculated by Radon411

In Saline County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (27 of 55) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 13.4 points higher. Across 115 Missouri counties pooled together, 30.6% of tests reached that level, so Saline County runs 18.5 points above its state.

The newest figure, in 2023, counts only 3 tests (66.7% at or above 4 pCi/L), too few to compare, so this reading uses the 55-test figure.

Of 4 neighbours with a figure, none reported a larger share at or above 4 pCi/L; the spread is 37.9% (Pettis County) to 46.7% (Lafayette County). By share, Saline County is 4th of 72 Missouri counties with 30 or more tests for the same period.

Half the tests came in under 3.7 pCi/L and half over it; the single highest reached 20.4 pCi/L. Below the action level, 17 tests (30.9%) came in under 2 pCi/L, against 41.2% statewide, and 11 tests (20.0%) fell between 2 and 4, against 28.1% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 49.1% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential.

The busiest year on file was 2014, with 8 tests reported; the quietest, 2021, had 2.

Saline County against Missouri, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Saline County
Saline County5549.1%3.7 pCi/LThis county
Missouri, pooled115 counties, pooled58,52530.6%Not pooled−18.5 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−13.4 points
Atchison Countyhighest in the state10369.9%5.6 pCi/L+20.8 points
Vernon Countylowest in the state348.8%0.9 pCi/L−40.3 points
Lafayette County, MOborders it18446.7%3.5 pCi/L−2.4 points
Howard County, MOborders it6243.5%3.5 pCi/L−5.6 points
Cooper County, MOborders it9041.1%2.6 pCi/L−8.0 points
Pettis County, MOborders it13237.9%2.8 pCi/L−11.2 points
Carroll County, MOborders it1833.3%2.7 pCi/L−15.8 points
Chariton County, MOborders it1513.3%1.7 pCi/L−35.8 points
Where Saline County's reported results fell, 2008 to 2017, laboratory, beside Missouri and the United States
ResultSaline County testsSaline County shareMissouri shareU.S. shareAgainst Missouri
Under 2 pCi/L1730.9%41.2%39.6%−10.3 points
2 to 4 pCi/L1120.0%28.1%24.7%−8.1 points
4 pCi/L and above2749.1%30.6%35.7%+18.5 points
Saline County ranked among the 72 Missouri counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Atchison County1 of 7210369.9%5.6 pCi/L
Andrew County2 of 7215860.8%4.9 pCi/L
Buchanan County3 of 7257552.9%4.2 pCi/L
Saline County4 of 725549.1%3.7 pCi/L
Lafayette County5 of 7218446.7%3.5 pCi/L
Howell County6 of 7213845.7%3.5 pCi/L
Cass County7 of 7298845.5%3.5 pCi/L
Howard County8 of 726243.5%3.5 pCi/L
Marion County9 of 7228241.8%3.2 pCi/L
Barry County10 of 725541.8%3.1 pCi/L
Jefferson County11 of 722,65241.6%3.1 pCi/L
Saline County radon tests by year, against Missouri's pooled share
YearTestsAt or above 4 pCi/LMedianHighestMissouri, pooledChange from the row before
2023366.7%6.5 pCi/L7.1 pCi/L35.7%+16.7 points
2022450.0%6.8 pCi/L16.5 pCi/L40.8%Level
2021250.0%3.6 pCi/L6.8 pCi/L31.8%−50.0 points
20192100.0%9.4 pCi/L14.1 pCi/L33.5%+66.7 points
2018333.3%3.4 pCi/L16.4 pCi/L42.1%−66.7 points
20173100.0%6.4 pCi/L20.4 pCi/L37.0%+25.0 points
2016475.0%5.3 pCi/L12.0 pCi/L29.8%+35.0 points
2015540.0%1.4 pCi/L7.5 pCi/L27.6%−10.0 points
2014850.0%2.9 pCi/L16.8 pCi/L34.4%First on file

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

Saline County, Geology

The ground under Saline County

Predicted

USGS's geologic map puts all of Saline County's mapped land in one class: moderate radon potential. The map puts 94.3% of Saline County in the area it calls Osage Plains and 4.4% in Dissected Till Plains, with one smaller area beside them. USGS gives both a radon index of 11, in the moderate band (9 to 11).

USGS's geologic areas under Saline County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Osage PlainsOrdovician dolomite, sandstone, limestone, and shale.Moderate1194.3%
Dissected Till PlainsTill-covered Pennsylvanian sandstone, shale, and limestone.Moderate114.4%
Salem PlateauOrdovician dolomite, sandstone, limestone, and shale.Moderate111.3%

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

Saline County beside the ground around it

Across Missouri 8.2% of the land is rated high; none of Saline County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Carroll County comes nearest at 100%.

Share of land by USGS radon potential: Saline County, the 6 counties bordering it and Missouri
AreaEPA zoneLow potentialModerate potentialHigh potential
Saline CountyZone 2None100%None
Carroll CountyZone 2None100%None
Chariton CountyZone 2None100%None
Pettis CountyZone 2None100%None
Howard CountyZone 2None100%None
Cooper CountyZone 2None100%None
Lafayette CountyZone 2None100%None
Missouri115 counties, pooled by land areaVaries5.8%86.0%8.2%

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

Local help

Saline County, Local resources

Radon testing and mitigation in Saline County

What Missouri's program says
Phone
573-751-6102
Email
radon@health.mo.gov

What it means

Saline County, Questions

Questions about radon in Saline County

Are radon levels high in Saline County?

In 2023, 66.7% of the radon tests reported to CDC for Saline County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.5 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 30.6%.

Which counties border Saline County?

Saline County borders 6 counties: Carroll County, Chariton County, Pettis County, Howard County, Cooper County and Lafayette County.

Products

Saline County, Products

Testing a home in Saline County

In Saline County, 49.1% of 55 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.6% pooled across Missouri. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Saline County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Saline County homes, compared

Explore

Saline County, Bordering counties

Counties bordering Saline County

Calculated by Radon411

Saline County, Cities and towns

Cities and towns in Saline County

Saline County's population has barely moved since 2020: 23,265 residents on July 1, 2025 against 23,334 then, by the Census Bureau's estimates. That works out to 31 people per square mile of land. Marshall alone is home to 13,766 of them, 59.2% of the total. Reported testing is thin here: 55 tests over 2008 to 2017, or 2.4 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.

From Marshall to Grand Pass, CDC publishes no figure by town: each reads Saline County's.

The cities and towns in Saline County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Marshall13,766−0.1%59.2%
Slater1,824−0.7%7.8%
Sweet Springs1,323+0.1%5.7%
Blackburnextends beyond Saline County225−0.4%Counted whole
Emmaextends beyond Saline County201+2.6%Counted whole
Malta Bend190−0.5%0.8%
Gilliam182+1.7%0.8%
Nelson149−0.7%0.6%
Miami143−0.7%0.6%
Mount Leonard65Level0.3%
Arrow Rock57Level0.2%
Grand Pass50Level0.2%

12 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). A place that extends beyond Saline County is counted whole, so it has no share.

Saline County, Homes

Homes in Saline County

Saline County is a place of houses on their own lots: 77% of its 9,833 homes are detached single-family houses, against 70% across Missouri. The homes are older than Missouri's as a whole: half were built before 1970 (1978 for Missouri), and 36% date from before 1960. 71% of occupied homes are lived in by their owner (Missouri: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Saline County, Missouri, 2019 to 2023
HomesSaline CountyMissouri
Housing units9,8332,809,501
Detached houses77%70%
In buildings of 5 or more6%13%
Mobile homes7%5%
Built before 196036%28%
Built since 200013%21%
Middle year built19701978
Owner-occupied71%68%

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