Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Madison County, Arkansas
EPA puts Madison County in Zone 3, its lowest radon zone, and only 6 radon tests from it are 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
Highest bordering
31.0%
Benton County
- Benton
- 31.0%
- Washington
- 14.3%
2 of 7 neighbours have 30+ tests, 2007 to 2016
Nearest county
14.3%
Washington County, 28 miles
- Washington
- 14.3%
- Arkansas
- 22.7%
Share at 4+ pCi/L, 56 tests, 2007 to 2016
Ground above low
36.4%
15.1 pts above Arkansas
- Madison
- 36.4%
- Arkansas
- 21.3%
Share of land USGS rates moderate or high potential
Tests reported
6
Too few for a share
- Madison
- 6
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Madison County
Starts at EPA's action level
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
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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.
The data
Madison County, At a glance
Madison County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 64% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Madison County, 2008 to 2017, laboratory
CDC holds 6 reported tests for Madison County over the 2008 to 2017 laboratory totals, with a median of 1.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Madison County beside the counties around it is how this page reads it.
What these figures count
Only 6 tests were reported to CDC for Madison 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).
Madison County, Compared
Madison County radon figures, compared
Calculated by Radon411CDC's largest figure for Madison County rests on 6 tests over the 2008 to 2017 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 16.7 points and no rank or comparison is drawn from it. Results reached as high as 4.4 pCi/L, with a middle value of 1.2 pCi/L.
Of the counties bordering it, 2 have a figure over the 2007 to 2016 laboratory totals: Benton County reported the largest share at or above 4 pCi/L, 31.0%, and Washington County the smallest, 14.3%. Farther out, Garland County (104 miles away) at 45.8%, Saline County (111 miles away) at 31.9% and Pulaski County (117 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 Madison County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 64% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Madison County, Geology
The ground under Madison County
PredictedUSGS's geologic map splits Madison County: 63.6% of its land is low radon potential and 36.4% moderate. The map puts 63.6% of Madison County in the area it calls Boston Mountains and 32.2% in Springfield Plateau, with one smaller area beside them. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Boston Mountains | Mississippian and Pennsylvanian sandstones and shales. | Low | 8 | 63.6% |
| Springfield Plateau | Mississippian limestone, shale, and sandstone. | Moderate | 9 | 32.2% |
| Salem Plateau | Ordovician dolomite. | Moderate | 9 | 4.2% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Madison County beside the ground around it
Madison County has more moderate-potential ground than Arkansas as a whole: 36.4% of its land against 21.3%. Of the 7 counties that border it, 4 have more moderate-potential ground, Benton County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Madison County, Local resources
Radon testing and mitigation in Madison County
- Arkansas's radon programArkansas Department of HealthArkansas's radon program answers questions about testing, mitigation and the rules in Arkansas.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- See the Arkansas directoryNo professionals are listed in Arkansas yet. The state program can point you to registered testers and mitigators.
What Arkansas's program says
- Phone
- 501-661-2621
- ADH.EPI.Radon@arkansas.gov
What it means
Madison County, Questions
Questions about radon in Madison County
Are radon levels high in Madison County?
Over the 2008 to 2017 laboratory totals, 16.7% of the radon tests reported to CDC for Madison County, Arkansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.2 pCi/L. Of the counties bordering it, 2 have a figure over the 2007 to 2016 laboratory totals: Benton County reported the largest share at or above 4 pCi/L, 31.0%, and Washington County the smallest, 14.3%.
Which counties border Madison County?
Madison County borders 7 counties: Carroll County, Newton County, Washington County, Benton County, Johnson County, Franklin County and Crawford County.
Products
Madison County, Products
Testing a home in Madison County
No CDC figure names Madison County; the nearest county with one, Washington County (28 miles away), reported 14.3% 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. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Madison County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Monitor
RadonPro Wi-Fi radon monitor with a built-in Geiger counter
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Madison County, Bordering counties
Counties bordering Madison County
Calculated by Radon411- Radon levels in Johnson CountyEPA zone 3
66.7%at or above 4 pCi/L
Median 9.7 pCi/L · 3 tests
- Radon levels in Carroll CountyEPA zone 2
31.6%at or above 4 pCi/L
Median 2.0 pCi/L · 19 tests
- Radon levels in Benton CountyEPA zone 2
31.0%at or above 4 pCi/L
Median 1.8 pCi/L · 145 tests
- Radon levels in Washington CountyEPA zone 3
14.3%at or above 4 pCi/L
Median 2.2 pCi/L · 56 tests
- Radon levels in Crawford CountyEPA zone 3
12.5%at or above 4 pCi/L
Median 0.7 pCi/L · 8 tests
- Radon levels in Newton CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 3.0 pCi/L · 1 test
- Radon levels in Franklin CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
Madison County, Cities and towns
Cities and towns in Madison County
Madison County is growing: the Census Bureau puts it at 18,410 residents on July 1, 2025, up 11.2% from 16,555 in 2020. That works out to 22 people per square mile of land. No town dominates: Huntsville, the largest, has 3,576 residents, 19.4% of the total. Together its 3 incorporated places hold 20.6% of those residents; the other 79.4% live outside any of them. Testing is reported here more often than across the state: CDC's 6 reported tests for 2008 to 2017 come to 0.3 for every 1,000 residents (2025 estimate), against 0.2 for Arkansas.
From Huntsville to Hindsville, CDC publishes no figure by town: each reads Madison County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Huntsville | 3,576 | +23.9% | 19.4% |
| St. Paul | 126 | +21.2% | 0.7% |
| Hindsville | 95 | +10.5% | 0.5% |
3 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).
Madison County, Homes
Homes in Madison County
Madison County is a place of houses on their own lots: 78% of its 7,699 homes are detached single-family houses, against 70% across Arkansas. Half of its homes were built before 1990, close to Arkansas' 1987: 17% date from before 1960 and 31% from 2000 or later. Owners live in 79% of the occupied homes (Arkansas: 66%), so for most households a test and a fix are their own to order.
| Homes | Madison County | Arkansas |
|---|---|---|
| Housing units | 7,699 | 1,382,664 |
| Detached houses | 78% | 70% |
| In buildings of 5 or more | 2% | 10% |
| Mobile homes | 18% | 11% |
| Built before 1960 | 17% | 14% |
| Built since 2000 | 31% | 28% |
| Middle year built | 1990 | 1987 |
| Owner-occupied | 79% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.