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
Locations and reports
Radon Levels in Cass County, Michigan
EPA puts Cass County in Zone 1, its highest radon zone, and 30.4% of its 572 reported radon tests (2008 to 2017, laboratory totals) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
30.4%
3.5 pts above MI
- Cass
- 30.4%
- Michigan
- 26.9%
572 tests, 2008 to 2017
Median result
2.6pCi/L
Below action level
- Cass
- 2.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
572
43rd of 82 by tests
- Cass
- 572
- Oakland
- 16,224
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Michigan
20 of 82
Top quarter
- Cass
- 30.4%
- Lenawee
- 56.7%
By share, of 82 with 30+ tests
Read a result for Cass County
Starts at Cass County's median, 2.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.6 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Cass County's median reported result, 2008 to 2017.
The data
Cass County, At a glance
Cass County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Cass County in
USGS geologic potential: High across 65% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Cass County, 2008 to 2017, laboratory
Under 2 pCi/L: 41%2 to 4 pCi/L: 29%4 pCi/L and above: 30%
Of 572 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 234 | 40.9% |
| 2 to 4 pCi/L | 164 | 28.7% |
| 4 pCi/L and above | 174 | 30.4% |
What these figures count
These are the 572 tests reported to CDC for Cass County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Cass County, Compared
Cass County radon figures, compared
Calculated by Radon411In Cass County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (174 of 572) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 5.3 points lower. Across 83 Michigan counties pooled together, 26.9% of tests reached that level, so Cass County runs 3.5 points above its state.
Of 6 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 18.0% (Van Buren County) to 46.4% (Elkhart County, IN). By share, Cass County is 20th of 82 Michigan counties with 30 or more tests for the same period.
Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 96.9 pCi/L. Below the action level, 234 tests (40.9%) came in under 2 pCi/L, against 46.4% statewide, and 164 tests (28.7%) fell between 2 and 4, against 26.7% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 30.4% share point the same way here. USGS geology rates 65% of the county's land high radon potential. CDC also counts 31 tests taken after mitigation in Cass County for the same period: tests in homes where a fix was already in.
CDC's ten-year totals for Cass County went from 581 tests (2005 to 2014) to 572 (2008 to 2017), the share going from 25.6% to 30.4%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Cass County, State data
Michigan's own radon test data
MeasuredWhat Michigan's own agencies publish about radon tests in Cass County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Michigan EGLE reports for the ZIP codes in Cass County
Michigan EGLE publishes its figures by ZIP code, not by county. These are the 14 ZIP codes that lie wholly or partly in Cass County, each with the state's own figures for it. Period: About 10 years to 2026-05-15.
| ZIP code | What the state reports |
|---|---|
| 49031 | 32% greater than 4 pCi/L, median 2.9 pCi/L, 22 tests |
| 49042 | 0% greater than 4 pCi/L, median 2.0 pCi/L, 16 tests |
| 49045 | 14% greater than 4 pCi/L, median 2.4 pCi/L, 7 tests |
| 49047 | 21% greater than 4 pCi/L, median 1.6 pCi/L, 38 tests |
| 49061 | 1 tests, figures not shown |
| 49067 | 23% greater than 4 pCi/L, median 2.0 pCi/L, 13 tests |
| 49093 | 34% greater than 4 pCi/L, median 3.0 pCi/L, 73 tests |
| 49095 | 2 tests, figures not shown |
| 49099 | 55% greater than 4 pCi/L, median 4.1 pCi/L, 31 tests |
| 49102 | 4 tests, figures not shown |
| 49111 | 0% greater than 4 pCi/L, median 1.9 pCi/L, 6 tests |
| 49112 | 23% greater than 4 pCi/L, median 2.8 pCi/L, 13 tests |
| 49120 | 32% greater than 4 pCi/L, median 2.6 pCi/L, 82 tests |
| 49130 | 1 tests, figures not shown |
- EGLE's figures cover first-time tests only, from organizations willing to provide data.
- EGLE does not publish figures for a ZIP code with fewer than 5 test results.
- EGLE says the map is not intended to decide whether a home should be tested: all homes should be tested.
- ZIP code boundaries are postal delivery areas, not legal or administrative boundaries.
- A ZIP code that crosses the county line is listed whole; its figures cover all of it.
Measured: Michigan EGLE data, About 10 years to 2026-05-15.
Cass County, Geology
The ground under Cass County
PredictedUSGS's geologic map splits Cass County: 65.5% of its land is high radon potential and 34.5% low. The map puts 64.9% of Cass County in the area it calls Saginaw Lobe Moraine Area and 34.5% in Lake Michigan Lobe Deposits, with one smaller area beside them. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Saginaw Lobe Moraine Area | Glacial deposits derived from Sandstone and shale. | High | 12 | 64.9% |
| Lake Michigan Lobe Deposits | Sandy to clayey glacial deposits and some glacial lake deposits. | Low | 8 | 34.5% |
| Saginaw Lobe | Clayey and loamy glacial deposits. | High | 12 | 0.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Cass County beside the ground around it
Cass County has more high-potential ground than Michigan as a whole: 65.5% of its land against 9.6%. Of the 6 counties that border it, 3 have more high-potential ground, Elkhart County, IN the most at 100%.
The map rates the ground, not the air in any home.
Local help
Cass County, Local resources
Radon testing and mitigation in Cass County
Listed radon businesses with an address in Cass County:
- Michigan Indoor Radon ProgramMichigan Indoor Radon Program, run by Michigan Department of Environment, Great Lakes, and Energy, does not license radon professionals, and answers questions about testing and mitigation in Michigan.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
- Professionals in Michigan69 professionals are listed in Michigan.
Listed radon professionals by town: Edwardsburg
What Michigan's program says
- Phone
- 800-723-6642
- Radon@Michigan.gov
- Licensing of radon professionals
Michigan does not license or regulate radon testing and mitigation contractors.
What it means
Cass County, Questions
Questions about radon in Cass County
Are radon levels high in Cass County?
Over the 2008 to 2017 laboratory totals, 30.4% of the radon tests reported to CDC for Cass County, Michigan were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 82 Michigan counties with 30 or more tests for the same period, 19 reported a higher share; pooled, the state comes to 26.9%.
Which counties border Cass County?
Cass County borders 6 counties: Berrien County, MI, Elkhart County, IN, St. Joseph County, MI, Van Buren County, MI, St. Joseph County, IN and Kalamazoo County, MI.
Products
Cass County, Products
Testing a home in Cass County
In Cass County, 30.4% of 572 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 26.9% pooled across Michigan. In Zone 1 the year-round level in Cass 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
Hello Radon C battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Cass County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Cass County
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Cass County, Bordering counties
Counties bordering Cass County
Calculated by Radon411- Radon levels in Elkhart County, INEPA zone 1
46.4%at or above 4 pCi/L
Median 3.7 pCi/L · 2,856 tests · 16.0 points above Cass County
- Radon levels in St. Joseph County, MIEPA zone 1
34.1%at or above 4 pCi/L
Median 2.9 pCi/L · 1,068 tests · 3.7 points above Cass County
- Radon levels in Kalamazoo County, MIEPA zone 1
33.3%at or above 4 pCi/L
Median 2.8 pCi/L · 4,100 tests · 2.9 points above Cass County
- Radon levels in St. Joseph County, INEPA zone 1
29.3%at or above 4 pCi/L
Median 2.7 pCi/L · 7,346 tests · 1.1 points below Cass County
- Radon levels in Berrien County, MIEPA zone 3
24.2%at or above 4 pCi/L
Median 2.0 pCi/L · 1,192 tests · 6.2 points below Cass County
- Radon levels in Van Buren County, MIEPA zone 3
18.0%at or above 4 pCi/L
Median 1.9 pCi/L · 394 tests · 12.4 points below Cass County
Cass County, Cities and towns
Cities and towns in Cass County
Cass County's population has barely moved since 2020: 51,677 residents on July 1, 2025 against 51,553 then, by the Census Bureau's estimates. That works out to 105 people per square mile of land. Niles, the largest place on its list (11,665 residents in all), extends beyond Cass County, so no share of the total is worked out for it. CDC's 572 reported tests for 2008 to 2017 work out to 11.1 per 1,000 residents (2025 estimate), close to Michigan's 11.3.
From Niles to Vandalia, CDC publishes no figure by town: each reads Cass County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Nilesextends beyond Cass County | 11,665 | −2.5% | Counted whole |
| Dowagiac | 5,725 | −1.2% | 11.1% |
| Cassopolis | 1,707 | −1.4% | 3.3% |
| Edwardsburg | 1,286 | −1.3% | 2.5% |
| Marcellus | 1,045 | −2.6% | 2.0% |
| Vandalia | 327 | −2.4% | 0.6% |
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). A place that extends beyond Cass County is counted whole, so it has no share.
Cass County, Homes
Homes in Cass County
Cass County is a place of houses on their own lots: 84% of its 25,543 homes are detached single-family houses, against 72% across Michigan. Half of its homes were built before 1972, close to Michigan's 1972: 37% date from before 1960 and 19% from 2000 or later. Owners live in 81% of the occupied homes (Michigan: 73%), so for most households a test and a fix are their own to order.
| Homes | Cass County | Michigan |
|---|---|---|
| Housing units | 25,543 | 4,599,683 |
| Detached houses | 84% | 72% |
| In buildings of 5 or more | 4% | 13% |
| Mobile homes | 8% | 5% |
| Built before 1960 | 37% | 36% |
| Built since 2000 | 19% | 15% |
| Middle year built | 1972 | 1972 |
| Owner-occupied | 81% | 73% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.