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Radon Levels in Sullivan County, Missouri

Zone 2Moderate predicted potential648 square miles · 5 bordering counties

What this means for you

  • Your area: EPA rates Sullivan County Zone 2, the middle of its three radon zones. That is a prediction for the whole county, and homes with elevated levels occur in all three zones.
  • Local tests: Of 1 radon tests reported to CDC for Sullivan County (2022), 0.0% were at or above 4 pCi/L, EPA's action level.
  • Your home: The only way to know your home’s level is to test it.

pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.

In 2022, 0.0% of the radon tests reported to CDC for Sullivan County, Missouri came back at or above the EPA action level of 4 pCi/L, and the median result was 1.4 pCi/L. EPA's Map of Radon Zones places the county in Zone 2, moderate predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

EPA predicts an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³) across the county as a whole.

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

USGS geologic potential: Moderate across 100% of the county's land area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Sullivan County, 2022

Tests reported
1
At or above 4 pCi/L
0.0%
Median result
1.4 pCi/L
Reported results by concentration band, Sullivan County, 2022
Under 2 pCi/L: 100%2 to 4 pCi/L: 0%4 pCi/L and above: 0%

Of 1 pre-mitigation tests reported to CDC, not homes in this area. CDC publishes the share in each band, not a count per band, so the per-band counts in the table are calculated by Radon411 and rounded to add up to the published total.

Reported results by concentration band, Sullivan County, 2022: data table
Result bandTests Calculated by Radon411Share Measured
Under 2 pCi/L1100.0%
2 to 4 pCi/L00.0%
4 pCi/L and above00.0%

Distribution of tested buildings, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

Measured: CDC tracking data. Figure above: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).

Sullivan County, In figures

Sullivan County in figures

What the published data says about Sullivan County, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places Sullivan County in Zone 2, moderate predicted potential, as it does 96 other counties of Missouri's 115.

      Of the 5 bordering counties, EPA places Adair County, Grundy County, Linn County, Mercer County and Putnam County in Zone 2.

  • Reported tests

    Measured

    CDC has annual figures for Sullivan County for 3 years, 2014 to 2022. In 2022, 0.0% of 1 reported tests were at or above 4 pCi/L.

    Across those years the share ranged from 0.0% (2022) to 100.0% (2014). Few tests in a year can move it a long way.

  • Local record

    Missouri's radon program is the Missouri Radon Program, run by Missouri Department of Health and Senior Services; its contacts are under Local resources.

    The county's largest incorporated places are Milan, Green City and Browning; the figures here cover them as part of the county.

Sullivan County, Reported testing

Reported testing over time

Measured
Reported radon test results by year, Sullivan County, pCi/LLogarithmic scale: each step up the axis multiplies the level, so the median and the single highest result can share one chart. The darker gridline is EPA's action level, 4 pCi/L.
Median reported resultHighest reported result

No figures are published for 2016 to 2021. The axis keeps the space for the missing years and the line is not drawn across it.

Reported radon test results by year, Sullivan County, pCi/L: data table
YearMedian reported resultHighest reported resultShare of tests at or above 4 pCi/L
201439.5 pCi/L39.5 pCi/L100.0%
20150.7 pCi/L1.2 pCi/L0.0%
20221.4 pCi/L1.4 pCi/L0.0%

What these figures count

Every percentage here is a share of radon tests reported to CDC for Sullivan County in 2022. It is not a share of homes in Sullivan County, and it is not a random sample: it counts only the tests people chose to run and that were reported.

The shares and the median are calculated from pre-mitigation tests (1 for 2022).

Sullivan County, Comparison

How Sullivan County compares

Measured

Sullivan County's own published CDC figures beside those of the counties that border it, for the same period.

Share of reported tests at or above 4 pCi/L

Measured

2022, highest first. Each county’s own published CDC figure.

  1. Putnam CountyMO1 test100.0%
  2. Linn CountyMO5 tests40.0%
  3. Adair CountyMO10 tests30.0%
  4. Sullivan CountyThis page1 test0.0%

Median reported result

Measured

2022, highest first. Each county’s own published CDC figure.

  1. Putnam CountyMO1 test9.3 pCi/L
  2. Adair CountyMO10 tests2.4 pCi/L
  3. Sullivan CountyThis page1 test1.4 pCi/L
  4. Linn CountyMO5 tests1.1 pCi/L

Each figure is that county’s own published CDC figure for 2022, counting radon tests reported to CDC, not homes. Sullivan County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2022: Grundy County, MO; Mercer County, MO. Every Missouri county’s own figure is in the Missouri county table.

CDC publishes this figure only for counties here, so there is no state or national number to compare Sullivan County, Missouri with.

Sullivan County, Bordering counties

Counties bordering Sullivan County

Calculated by Radon411

5 counties share a boundary with Sullivan County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.

Sullivan County, Local resources

Local resources in Missouri

Who to ask in Missouri: the state's radon program, test kits and professionals.

Missouri Radon Program

Missouri Department of Health and Senior Services

Missouri’s radon program answers questions about testing, mitigation and the rules where you live.

Phone
573-751-6102
Email
radon@health.mo.gov
Visit the program's page(opens in a new tab)

Test kits

The program says: Free radon test kits are available for Missouri residents (limit one per household).

Radon professionals

6 professionals are listed in Missouri.

Professionals in Missouri

Sullivan County, Cities and towns

Cities and towns in Sullivan County

The radon figures on this page are for Sullivan County as a whole. They do not differ by city or town.

  • Milan
  • Green City
  • Browning (part)
  • Greencastle
  • Newtown
  • Humphreys
  • Harris
  • Pollock
  • Osgood

9 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county.

Sullivan County, Questions

Questions about radon in Sullivan County

Common questions8 questions, answered from the figures above

Who does radon mitigation in Sullivan County?

No listed mitigator names Sullivan County as a service area yet; the Missouri directory lists 6 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Missouri requires one.

How radon mitigation worksWhat mitigation costsMitigators in Missouri

Are radon levels high in Sullivan County?

In 2022, 0.0% of the radon tests reported to CDC for Sullivan County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.4 pCi/L. That is a share of reported tests, not of homes. EPA places Sullivan County in Zone 2, moderate predicted potential, a predicted average indoor screening level 2 to 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

What a radon level meansRadon in Missouri

How do I get a radon test in Sullivan County?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No certified tester listed on Radon411 names Sullivan County as a service area yet. The Missouri radon program is the place to ask about certified testers and any test kit offer it runs.

How to test a homeTest kits comparedFree and low-cost kits by stateMissouri radon program

What EPA radon zone is Sullivan County in?

EPA places Sullivan County, Missouri in Zone 2, which EPA describes as moderate predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in Sullivan County?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border Sullivan County?

Sullivan County borders 5 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

What these figures mean if you own, buy, sell or rent

The reported-test figures on this page describe Sullivan County, Missouri in 2022. They describe tests other people carried out in other buildings, and none of them measures yours.

  • If you own your home

    Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.

    How to test a home
  • If you are buying

    Ask for past results and any system's post-mitigation test, and test during the sale.

    Buying a house: radon guide
  • If you are selling

    Testing before you list puts the timing in your hands; disclosure rules differ by state.

    Selling a house: radon guide
  • If you rent, or rent out a home

    A tenant can test; a fix is the owner's to make, and duties differ by state.

    Radon in rental homes

How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.

Sullivan County, Products

Testing and mitigation products

Whatever the figures for Sullivan County show, only a test tells you about one home.

Sullivan County / Next steps

What to do next

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.