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Radon Levels in Marshall County, Indiana

Zone 1Highest predicted potential450 square miles · 6 bordering counties

What this means for you

  • Your area: EPA rates Marshall County Zone 1, the highest 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 383 radon tests reported to CDC for Marshall County (2008 to 2017), 39.7% 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.

Over the 2008 to 2017 laboratory totals, 39.7% of the radon tests reported to CDC for Marshall County, Indiana came back at or above the EPA action level of 4 pCi/L, and the median result was 3.2 pCi/L. EPA's Map of Radon Zones places the county in Zone 1, highest predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA predicts an average indoor of greater than 4 pCi/L (greater than 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: Low across 87% of the county's land area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Marshall County, 2008 to 2017, laboratory

Tests reported
383
At or above 4 pCi/L
39.7%
Median result
3.2 pCi/L
Reported results by concentration band, Marshall County, 2008 to 2017, laboratory
Under 2 pCi/L: 30%2 to 4 pCi/L: 31%4 pCi/L and above: 40%

Of 383 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, Marshall County, 2008 to 2017, laboratory: data table
Result bandTests Calculated by Radon411Share Measured
Under 2 pCi/L11429.8%
2 to 4 pCi/L11730.5%
4 pCi/L and above15239.7%

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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

Marshall County, In figures

Marshall County in figures

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

    • Predicted

      Predicted

      EPA places Marshall County in Zone 1, highest predicted potential, as it does 56 other counties of Indiana's 92.

      Of the 6 bordering counties, EPA places Elkhart County, Fulton County, Kosciusko County and St. Joseph County in Zone 1 and Pulaski County and Starke County in Zone 2.

  • Reported tests

    Measured

    CDC publishes no annual figure for Marshall County; its figure is a laboratory total for 2008 to 2017: 39.7% of 383 reported tests were at or above 4 pCi/L.

  • Local record

    Indiana's radon program and its page are under Local resources.

    The county's largest incorporated places are Plymouth, Bremen and Argos; the figures here cover them as part of the county.

Marshall County, Comparison

How Marshall County compares

Measured

Marshall 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

2008 to 2017, laboratory, highest first. Each county’s own published CDC figure.

  1. Kosciusko CountyIN1,248 tests50.6%
  2. Elkhart CountyIN2,856 tests46.4%
  3. Fulton CountyIN97 tests46.4%
  4. Marshall CountyThis page383 tests39.7%
  5. Pulaski CountyIN22 tests31.8%
  6. St. Joseph CountyIN7,346 tests29.3%
  7. Starke CountyIN24 tests4.2%

Median reported result

Measured

2008 to 2017, laboratory, highest first. Each county’s own published CDC figure.

  1. Kosciusko CountyIN1,248 tests4.0 pCi/L
  2. Elkhart CountyIN2,856 tests3.7 pCi/L
  3. Fulton CountyIN97 tests3.3 pCi/L
  4. Marshall CountyThis page383 tests3.2 pCi/L
  5. St. Joseph CountyIN7,346 tests2.7 pCi/L
  6. Pulaski CountyIN22 tests2.3 pCi/L
  7. Starke CountyIN24 tests1.6 pCi/L

Each figure is that county’s own published CDC figure for 2008 to 2017, laboratory, counting radon tests reported to CDC, not homes. Marshall 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. Every Indiana county’s own figure is in the Indiana county table.

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

Marshall County, Bordering counties

Counties bordering Marshall County

Calculated by Radon411

6 counties share a boundary with Marshall 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.

Marshall County, Local resources

Local resources in Indiana

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

Indiana's radon program

Indiana Department of Health

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

Phone
1-800-272-9723
Licensing of radon professionals
According to the Indiana Radon Rule, 410 IAC 5.1, everyone who is serving Indiana by doing radon testing, analysis and mitigation (radon reduction) in residential structures must be certified by the Indiana State Department of Health.
Visit the program's page(opens in a new tab)

Test kits

The program says: To purchase a low-cost radon short term or long term test kit, please visit the American Lung Association

Radon professionals

6 professionals are listed in Indiana.

Professionals in Indiana

Marshall County, Cities and towns

Cities and towns in Marshall County

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

  • Plymouth
  • Bremen
  • Argos
  • Bourbon
  • Culver
  • La Paz

6 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.

Marshall County, Questions

Questions about radon in Marshall County

Common questions8 questions, answered from the figures above

Are radon levels high in Marshall County?

In 2017, 39.7% of the radon tests reported to CDC for Marshall County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.2 pCi/L. That is a share of reported tests, not of homes. EPA places Marshall County in Zone 1, highest predicted potential, a predicted average indoor screening level greater than 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 Indiana

How do I get a radon test in Marshall 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 Marshall County as a service area yet. The Indiana 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 stateIndiana radon program

Who does radon mitigation in Marshall County?

No listed mitigator names Marshall County as a service area yet; the Indiana 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 Indiana requires one.

How radon mitigation worksWhat mitigation costsMitigators in Indiana

What EPA radon zone is Marshall County in?

EPA places Marshall County, Indiana in Zone 1, which EPA describes as highest 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 Marshall 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 Marshall County?

Marshall County borders 6 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 Marshall County, Indiana in 2017. 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.

Marshall County, Products

Testing and mitigation products

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

Marshall 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.