Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Iron County, Missouri
EPA puts Iron County in Zone 1, its highest radon zone, and only 3 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
41.1%
St. Francois County
- St. Francois
- 41.1%
- Crawford
- 14.7%
3 of 7 neighbours have 30+ tests, 2008 to 2017
Nearest county
41.1%
St. Francois County, 24 miles
- St. Francois
- 41.1%
- Missouri
- 30.6%
Share at 4+ pCi/L, 146 tests, 2008 to 2017
Ground above low
100.0%
5.8 pts above Missouri
- Iron
- 100.0%
- Missouri
- 94.2%
Share of land USGS rates moderate or high potential
Tests reported
14
Too few for a share
- Iron
- 14
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Read a result for Iron 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
Iron County, At a glance
Iron County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Iron County in
USGS geologic potential: High across 85% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Iron County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2015 | 50.0% |
| 2016 | 0.0% |
| 2019 | 0.0% |
| 2021 | 0.0% |
| 2022 | 33.3% |
2022: 33.3%. Across these years the share ran from 0.0% to 50.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for Iron County over 2022, 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: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).
Iron County, Compared
Iron County radon figures, compared
Calculated by Radon411CDC's largest figure for Iron County rests on 14 tests over the 2008 to 2017 laboratory totals, 7 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 26.1 pCi/L, with a middle value of 3.5 pCi/L.
Of the counties bordering it, 3 have a figure over the 2008 to 2017 laboratory totals: St. Francois County reported the largest share at or above 4 pCi/L, 41.1%, and Crawford County the smallest, 14.7%, with Washington County at 26.3% between. Farther out, Ste. Genevieve County (39 miles away) at 31.1%, Jefferson County (50 miles away) at 41.6% and Perry County (53 miles away) at 37.8% 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 Iron County in Zone 1, the map's highest label: a predicted county average above 4 pCi/L. USGS geology rates 85% of the county's land high radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Iron County, Geology
The ground under Iron County
PredictedMost of the ground under Iron County is one class on USGS's geologic map: 85.3% of its land is high radon potential, with 14.7% moderate. The map puts 85.3% of Iron County in the area it calls St. Francois Mountains and 14.7% in Salem Plateau. USGS gives the first a radon index of 13, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| St. Francois Mountains | Granitic and volcanic rocks. Some soils have high uranium concentrations. | High | 13 | 85.3% |
| Salem Plateau | Ordovician dolomite, sandstone, limestone, and shale. | Moderate | 11 | 14.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Iron County beside the ground around it
Iron County has more high-potential ground than Missouri as a whole: 85.3% of its land against 8.2%. Of the 7 counties that border it, none has as large a share of high-potential ground; Madison County comes nearest at 68.2%.
The map rates the ground, not the air in any home.
Local help
Iron County, Local resources
Radon testing and mitigation in Iron County
- Missouri Radon ProgramMissouri Radon Program, run by Missouri Department of Health and Senior Services, offers free or discounted test kits, and answers questions about testing and mitigation in Missouri.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Missouri residents (limit one per household).
- Compare kits
- Professionals in Missouri27 professionals are listed in Missouri.
What Missouri's program says
- Phone
- 573-751-6102
- radon@health.mo.gov
What it means
Iron County, Questions
Questions about radon in Iron County
Are radon levels high in Iron County?
In 2022, 33.3% of the radon tests reported to CDC for Iron County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of the counties bordering it, 3 have a figure over the 2008 to 2017 laboratory totals: St. Francois County reported the largest share at or above 4 pCi/L, 41.1%, and Crawford County the smallest, 14.7%, with Washington County at 26.3% between.
Which counties border Iron County?
Iron County borders 7 counties: Madison County, Reynolds County, St. Francois County, Wayne County, Washington County, Dent County and Crawford County.
Products
Iron County, Products
Testing a home in Iron County
No CDC figure names Iron County; the nearest county with one, St. Francois County (24 miles away), reported 41.1% 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 1 the year-round level in Iron 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
Monitor
RM-63Pro rechargeable radon monitor with a touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Iron County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Iron County
Explore
Iron County, Bordering counties
Counties bordering Iron County
Calculated by Radon411- Radon levels in St. Francois CountyEPA zone 2
41.1%at or above 4 pCi/L
Median 2.9 pCi/L · 146 tests
- Radon levels in Madison CountyEPA zone 2
39.1%at or above 4 pCi/L
Median 3.5 pCi/L · 23 tests
- Radon levels in Dent CountyEPA zone 2
35.7%at or above 4 pCi/L
Median 3.0 pCi/L · 14 tests
- Radon levels in Reynolds CountyEPA zone 2
33.3%at or above 4 pCi/L
Median 2.2 pCi/L · 3 tests
- Radon levels in Washington CountyEPA zone 2
26.3%at or above 4 pCi/L
Median 1.5 pCi/L · 38 tests
- Radon levels in Wayne CountyEPA zone 2
23.5%at or above 4 pCi/L
Median 1.9 pCi/L · 17 tests
- Radon levels in Crawford CountyEPA zone 2
14.7%at or above 4 pCi/L
Median 1.5 pCi/L · 34 tests
Iron County, Cities and towns
Cities and towns in Iron County
About 9,318 people live in Iron County by the Census Bureau's estimate for July 1, 2025, 194 fewer than in 2020 (−2.0%). That works out to 17 people per square mile of land. No town dominates: Ironton, the largest, has 1,408 residents, 15.1% of the total. Together its 6 incorporated places hold 40.0% of those residents; the other 60.0% live outside any of them. Reported testing is thin here: 14 tests over 2008 to 2017, or 1.5 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Ironton to Des Arc, CDC publishes no figure by town: each reads Iron County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Ironton | 1,408 | −2.9% | 15.1% |
| Pilot Knob | 701 | +3.4% | 7.5% |
| Viburnum | 652 | −2.2% | 7.0% |
| Arcadia | 605 | −3.0% | 6.5% |
| Annapolis | 239 | −2.8% | 2.6% |
| Des Arc | 121 | −2.4% | 1.3% |
6 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).
Iron County, Homes
Homes in Iron County
Iron County is a place of houses on their own lots: 78% of its 4,704 homes are detached single-family houses, against 70% across Missouri. Half of its homes were built before 1975, close to Missouri's 1978: 28% date from before 1960 and 12% from 2000 or later. Owners live in 76% of the occupied homes (Missouri: 68%), so for most households a test and a fix are their own to order.
| Homes | Iron County | Missouri |
|---|---|---|
| Housing units | 4,704 | 2,809,501 |
| Detached houses | 78% | 70% |
| In buildings of 5 or more | 2% | 13% |
| Mobile homes | 12% | 5% |
| Built before 1960 | 28% | 28% |
| Built since 2000 | 12% | 21% |
| Middle year built | 1975 | 1978 |
| Owner-occupied | 76% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.