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Radon Levels in Dent County, Missouri

EPA puts Dent County in Zone 2, its middle radon zone, and only 4 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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  • Highest bordering

    19.3%

    Texas County

    Texas
    19.3%
    Crawford
    14.7%

    3 of 6 neighbours have 30+ tests, 2008 to 2017

  • Nearest county

    14.7%

    Phelps County, 24 miles

    Phelps
    14.7%
    Missouri
    30.6%

    Share at 4+ pCi/L, 204 tests, 2008 to 2017

  • Ground above low

    100.0%

    5.8 pts above Missouri

    Dent
    100.0%
    Missouri
    94.2%

    Share of land USGS rates moderate or high potential

  • Tests reported

    14

    Too few for a share

    Dent
    14
    Needed
    30

    2008 to 2017, laboratory

  • 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

Read a result for Dent County

Starts at EPA's action level

4.0pCi/L

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

EPA’s reading of 4.0 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.

Interpret this readingWhat a fix costs

The data

Dent County, At a glance

Dent County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Dent 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 Dent County, 2023

Share of reported tests at or above 4 pCi/L, by year, Dent County
Share of reported tests at or above 4 pCi/L, by year, Dent County
YearShare of reported tests at or above 4 pCi/L
20140.0%
20150.0%
20160.0%
2017100.0%
20180.0%
2020100.0%
20210.0%
202225.0%
202350.0%

2023: 50.0%. 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 4 tests were reported to CDC for Dent 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

Dent County, Compared

Dent County radon figures, compared

Calculated by Radon411

CDC's largest figure for Dent County rests on 14 tests over the 2008 to 2017 laboratory totals, 5 of them at or above 4 pCi/L, so each test moves its share by 7.1 points and no rank or comparison is drawn from it. Results reached as high as 6.6 pCi/L, with a middle value of 3.0 pCi/L.

Of the counties bordering it, 3 have a figure over the 2008 to 2017 laboratory totals: Texas County reported the largest share at or above 4 pCi/L, 19.3%, and Crawford County the smallest, 14.7%, with Phelps County at 14.7% between. Farther out, Pulaski County (41 miles away) at 18.7%, Washington County (42 miles away) at 26.3% and Gasconade County (58 miles away) at 31.8% have figures too. Pooled across 115 Missouri counties, 30.6% of reported tests reached that level; across every county in the country with a figure, 35.7%.

Statewide for the same period, Atchison County reported the highest share (69.9%) and Vernon County the lowest (8.8%). EPA's 1993 map puts Dent County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Missouri, the United States and the counties around Dent County, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedian
Missouri, pooled115 counties, pooled58,52530.6%Not pooled
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled
Atchison Countyhighest in the state10369.9%5.6 pCi/L
Vernon Countylowest in the state348.8%0.9 pCi/L
Iron County, MOborders it1450.0%3.5 pCi/L
Reynolds County, MOborders it333.3%2.2 pCi/L
Shannon County, MOborders it1926.3%1.3 pCi/L
Texas County, MOborders it5719.3%1.3 pCi/L
Phelps County, MOborders it20414.7%1.5 pCi/L
Crawford County, MOborders it3414.7%1.5 pCi/L
The nearest Missouri counties to Dent County with 30 or more tests, 2008 to 2017, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Phelps County24 mi20414.7%1.5 pCi/L
Crawford County28 mi3414.7%1.5 pCi/L
Texas County32 mi5719.3%1.3 pCi/L
Pulaski County41 mi10718.7%1.3 pCi/L
Washington County42 mi3826.3%1.5 pCi/L
Gasconade County58 mi4431.8%2.3 pCi/L
St. Francois County58 mi14641.1%2.9 pCi/L
Laclede County59 mi4637.0%2.3 pCi/L
Dent County radon tests by year, against Missouri's pooled share
YearTestsAt or above 4 pCi/LMedianHighestMissouri, pooledChange from the row before
2023450.0%4.3 pCi/L6.3 pCi/L35.7%+25.0 points
20221225.0%1.3 pCi/L14.7 pCi/L40.8%+25.0 points
202110.0%2.0 pCi/L2.0 pCi/L31.8%−100.0 points
20201100.0%5.5 pCi/L5.5 pCi/L33.2%+100.0 points
201820.0%1.6 pCi/L1.8 pCi/L42.1%−100.0 points
20172100.0%5.3 pCi/L5.5 pCi/L37.0%+100.0 points
201610.0%1.1 pCi/L1.1 pCi/L29.8%Level
201510.0%2.9 pCi/L2.9 pCi/L27.6%Level
201410.0%3.2 pCi/L3.2 pCi/L34.4%First on file

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

Dent County, Geology

The ground under Dent County

Predicted

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

USGS's geologic areas under Dent County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Salem PlateauOrdovician dolomite, sandstone, limestone, and shale.Moderate11100%

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

Dent County beside the ground around it

Across Missouri 8.2% of the land is rated high; none of Dent County's is. Of the 6 counties that border it, 2 have more high-potential ground, Iron County the most at 85.3%.

Share of land by USGS radon potential: Dent County, the 6 counties bordering it and Missouri
AreaEPA zoneLow potentialModerate potentialHigh potential
Dent CountyZone 2None100%None
Phelps CountyZone 2None100%None
Crawford CountyZone 2None100%None
Texas CountyZone 2None100%None
Shannon CountyZone 2None100%None
Reynolds CountyZone 2None85.5%14.5%
Iron CountyZone 1None14.7%85.3%
Missouri115 counties, pooled by land areaVaries5.8%86.0%8.2%

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

Local help

Dent County, Local resources

Radon testing and mitigation in Dent County

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

What it means

Dent County, Questions

Questions about radon in Dent County

Are radon levels high in Dent County?

In 2023, 50.0% of the radon tests reported to CDC for Dent County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.3 pCi/L. Of the counties bordering it, 3 have a figure over the 2008 to 2017 laboratory totals: Texas County reported the largest share at or above 4 pCi/L, 19.3%, and Crawford County the smallest, 14.7%, with Phelps County at 14.7% between.

Which counties border Dent County?

Dent County borders 6 counties: Phelps County, Crawford County, Texas County, Shannon County, Reynolds County and Iron County.

Products

Dent County, Products

Testing a home in Dent County

No CDC figure names Dent County; the nearest county with one, Phelps County (24 miles away), reported 14.7% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Dent County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Dent County homes, compared

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Dent County, Bordering counties

Counties bordering Dent County

Calculated by Radon411

Dent County, Cities and towns

Cities and towns in Dent County

The Census Bureau estimates 14,584 residents in Dent County for July 1, 2025, 192 more than in 2020 (+1.3%). That works out to 19 people per square mile of land. Its largest town, Salem, has 4,674 residents, 32.0% of the total. Reported testing is thin here: 14 tests over 2008 to 2017, or 1.0 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.

From Salem to Bunker, CDC publishes no figure by town: each reads Dent County's.

The cities and towns in Dent County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Salem4,674+0.8%32.0%
Bunkerextends beyond Dent County297−0.7%Counted whole

2 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 Dent County is counted whole, so it has no share.

Dent County, Homes

Homes in Dent County

Of Dent County's 6,834 homes, 70% are detached houses, against 70% across Missouri; 18% are mobile homes. Half of its homes were built before 1979, close to Missouri's 1978: 21% date from before 1960 and 22% from 2000 or later. Owners live in 77% of the occupied homes (Missouri: 68%), so for most households a test and a fix are their own to order.

Homes in Dent County, Missouri, 2019 to 2023
HomesDent CountyMissouri
Housing units6,8342,809,501
Detached houses70%70%
In buildings of 5 or more2%13%
Mobile homes18%5%
Built before 196021%28%
Built since 200022%21%
Middle year built19791978
Owner-occupied77%68%

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