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Radon Levels in Marion County, Arkansas

EPA puts Marion County in Zone 2, its middle radon zone, and only 1 radon test from it is on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Highest bordering

    34.7%

    Taney County

    Taney
    34.7%

    1 of 5 neighbours have 30+ tests, 2007 to 2016

  • Nearest county

    31.0%

    Benton County, 88 miles

    Benton
    31.0%
    Arkansas
    22.7%

    Share at 4+ pCi/L, 145 tests, 2007 to 2016

  • Ground above low

    100.0%

    78.7 pts above Arkansas

    Marion
    100.0%
    Arkansas
    21.3%

    Share of land USGS rates moderate or high potential

  • Tests reported

    2

    Too few for a share

    Marion
    2
    Needed
    30

    2006 to 2015, 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 Marion 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

Marion County, At a glance

Marion County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Marion 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 Marion County, 2008 to 2017, laboratory

CDC holds 1 reported test for Marion County over the 2008 to 2017 laboratory totals, a result of 0.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Marion County beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Marion County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Marion County, Compared

Marion County radon figures, compared

Calculated by Radon411

CDC's largest figure for Marion County rests on 2 tests over the 2006 to 2015 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 50.0 points and no rank or comparison is drawn from it. Results reached as high as 0.1 pCi/L, with a middle value of 0.1 pCi/L.

Taney County, MO, the one bordering county with a figure over the 2007 to 2016 laboratory totals, reported 34.7% of its tests at or above 4 pCi/L. Farther out, Benton County (88 miles away) at 31.0%, Washington County (88 miles away) at 14.3% and Pulaski County (105 miles away) at 6.8% have figures too. Pooled across 60 Arkansas counties, 22.7% of reported tests reached that level; across every county in the country with a figure, 35.8%.

Statewide for the same period, Garland County reported the highest share (45.8%) and Pulaski County the lowest (6.8%). EPA's 1993 map puts Marion 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.

Arkansas, the United States and the counties around Marion County, 2007 to 2016, laboratory
AreaTestsAt or above 4 pCi/LMedian
Arkansas, pooled60 counties, pooled68722.7%Not pooled
United States, pooled2,666 counties, pooled1,939,02535.8%Not pooled
Garland Countyhighest in the state4845.8%2.9 pCi/L
Pulaski Countylowest in the state1036.8%0.9 pCi/L
Baxter County, ARborders it2065.0%5.3 pCi/L
Searcy County, ARborders it450.0%3.5 pCi/L
Boone County, ARborders it2334.8%3.3 pCi/L
Taney County, MOborders it14434.7%2.8 pCi/L
Ozark County, MOborders it825.0%0.4 pCi/L
The nearest Arkansas counties to Marion County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Benton County88 mi14531.0%1.8 pCi/L
Washington County88 mi5614.3%2.2 pCi/L
Pulaski County105 mi1036.8%0.9 pCi/L
Saline County112 mi4731.9%2.2 pCi/L
Garland County120 mi4845.8%2.9 pCi/L
Marion County ten-year laboratory totals, against Arkansas' pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestArkansas, pooledChange from the row before
2008 to 201710.0%0.1 pCi/L0.1 pCi/L23.2%Level
2007 to 201610.0%0.1 pCi/L0.1 pCi/L22.7%Level
2006 to 201520.0%0.1 pCi/L0.1 pCi/L22.5%Level
2005 to 201410.0%0.1 pCi/L0.1 pCi/L24.3%First on file

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

Marion County, Geology

The ground under Marion County

Predicted

USGS's geologic map puts all of Marion County's mapped land in one class: moderate radon potential. The map puts 80.1% of Marion County in the area it calls Salem Plateau and 19.7% in Springfield Plateau. USGS gives both a radon index of 9, in the moderate band (9 to 11).

USGS's geologic areas under Marion County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Salem PlateauOrdovician dolomite.Moderate980.1%
Springfield PlateauMississippian limestone, shale, and sandstone.Moderate919.7%

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

Marion County beside the ground around it

Marion County has more moderate-potential ground than Arkansas as a whole: 100% of its land against 21.3%. Of the 5 counties that border it, none has as large a share of moderate-potential ground; Baxter County comes nearest at 100%.

Share of land by USGS radon potential: Marion County, the 5 counties bordering it and Arkansas
AreaEPA zoneLow potentialModerate potentialHigh potential
Marion CountyZone 2None100%None
Boone CountyZone 25.2%94.8%None
Baxter CountyZone 2None100%None
Searcy CountyZone 226.5%73.5%None
Ozark County, MOZone 2None100%None
Taney County, MOZone 2None100%None
Arkansas75 counties, pooled by land areaVaries78.7%21.3%None

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

Local help

Marion County, Local resources

Radon testing and mitigation in Marion County

What Arkansas's program says
Phone
501-661-2621
Email
ADH.EPI.Radon@arkansas.gov

What it means

Marion County, Questions

Questions about radon in Marion County

Are radon levels high in Marion County?

Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Marion County, Arkansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.1 pCi/L. Taney County, MO, the one bordering county with a figure over the 2007 to 2016 laboratory totals, reported 34.7% of its tests at or above 4 pCi/L.

Which counties border Marion County?

Marion County borders 5 counties: Boone County, AR, Baxter County, AR, Searcy County, AR, Ozark County, MO and Taney County, MO.

Products

Marion County, Products

Testing a home in Marion County

No CDC figure names Marion County; the nearest county with one, Benton County (88 miles away), reported 31.0% of its tests at or above 4 pCi/L over the 2007 to 2016 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 Marion County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Marion County homes, compared

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Marion County, Bordering counties

Counties bordering Marion County

Calculated by Radon411

Marion County, Cities and towns

Cities and towns in Marion County

The Census Bureau estimates 17,593 residents in Marion County for July 1, 2025, 726 more than in 2020 (+4.3%). That works out to 29 people per square mile of land. No town dominates: Bull Shoals, the largest, has 1,888 residents, 10.7% of the total. Together its 5 incorporated places hold 28.4% of those residents; the other 71.6% live outside any of them. Reported testing is thin here: 2 tests over 2006 to 2015, or 0.1 for every 1,000 residents (2025 estimate), where Arkansas as a whole comes to 0.2.

From Bull Shoals to Pyatt, CDC publishes no figure by town: each reads Marion County's.

The cities and towns in Marion County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Bull Shoals1,888−3.5%10.7%
Flippin1,290−4.2%7.3%
Yellville1,095−6.6%6.2%
Summit526−3.3%3.0%
Pyatt192+7.9%1.1%

5 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).

Marion County, Homes

Homes in Marion County

Marion County is a place of houses on their own lots: 77% of its 9,623 homes are detached single-family houses, against 70% across Arkansas. Half of its homes were built before 1985, close to Arkansas' 1987: 13% date from before 1960 and 22% from 2000 or later. Owners live in 83% of the occupied homes (Arkansas: 66%), so for most households a test and a fix are their own to order.

Homes in Marion County, Arkansas, 2019 to 2023
HomesMarion CountyArkansas
Housing units9,6231,382,664
Detached houses77%70%
In buildings of 5 or more2%10%
Mobile homes18%11%
Built before 196013%14%
Built since 200022%28%
Middle year built19851987
Owner-occupied83%66%

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