Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Iosco County, Michigan
EPA puts Iosco County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 7.7% of 156 (2008 to 2017, laboratory totals) reached 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
7.7%
19.2 pts below MI
- Iosco
- 7.7%
- Michigan
- 26.9%
156 tests, 2008 to 2017
Median result
0.7pCi/L
Below action level
- Iosco
- 0.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
156
73rd of 82 by tests
- Iosco
- 156
- Oakland
- 16,224
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in Michigan
77 of 82
Lowest quarter
- Iosco
- 7.7%
- Lenawee
- 56.7%
By share, of 82 with 30+ tests
Read a result for Iosco County
Starts at Iosco County's median, 0.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.7 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Iosco County's median reported result, 2008 to 2017.
The data
Iosco County, At a glance
Iosco County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Iosco County, 2008 to 2017, laboratory
Under 2 pCi/L: 81%2 to 4 pCi/L: 11%4 pCi/L and above: 8%
Of 156 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 126 | 80.8% |
| 2 to 4 pCi/L | 18 | 11.5% |
| 4 pCi/L and above | 12 | 7.7% |
What these figures count
These are the 156 tests reported to CDC for Iosco 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).
Iosco County, Compared
Iosco County radon figures, compared
Calculated by Radon411Iosco County reports fewer high tests than Michigan overall. 7.7% of its 156 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 19.2 points below the 26.9% pooled from 83 Michigan counties.
Ordered from highest share down, it comes 77th of 82 Michigan counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Iosco County sits 28.0 points below it.
Next door, the shares run from 8.9% in Arenac County to 20.5% in Alcona County. Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 7.7% share point the same way here.
Half the tests came in under 0.7 pCi/L and half over it; the single highest reached 10.1 pCi/L. The rest split 80.8% under 2 pCi/L and 11.5% from 2 to 4 (Michigan: 46.4% and 26.7%).
CDC's ten-year totals for Iosco County went from 158 tests (2005 to 2014) to 156 (2008 to 2017), the share going from 5.1% to 7.7%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Iosco County, State data
Michigan's own radon test data
MeasuredWhat Michigan's own agencies publish about radon tests in Iosco 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 Iosco County
Michigan EGLE publishes its figures by ZIP code, not by county. These are the 9 ZIP codes that lie wholly or partly in Iosco County, each with the state's own figures for it. Period: About 10 years to 2026-05-15.
| ZIP code | What the state reports |
|---|---|
| 48730 | 0% greater than 4 pCi/L, median 0.3 pCi/L, 16 tests |
| 48737 | 2 tests, figures not shown |
| 48738 | 4 tests, figures not shown |
| 48739 | 38% greater than 4 pCi/L, median 2.1 pCi/L, 8 tests |
| 48745 | 2 tests, figures not shown |
| 48748 | 14% greater than 4 pCi/L, median 0.3 pCi/L, 7 tests |
| 48750 | 0% greater than 4 pCi/L, median 0.3 pCi/L, 11 tests |
| 48763 | 6% greater than 4 pCi/L, median 0.3 pCi/L, 16 tests |
| 48770 | 3 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.
Iosco County, Geology
The ground under Iosco County
PredictedUSGS's geologic map puts all of Iosco County's mapped land in one class: low radon potential. The map puts 56.7% of Iosco County in the area it calls Glacial Lakes and 42.9% in North-Central Michigan Basin. USGS gives the first a radon index of 7 and the second 8, both in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Glacial Lakes | Silt and clay glacial lake deposits. | Low | 7 | 56.7% |
| North-Central Michigan Basin | Sandy and silty glacial deposits derived from sandstones, gray shales, limestones, and dolomites. | Low | 8 | 42.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Iosco County beside the ground around it
Across Michigan 9.6% of the land is rated high; none of Iosco County's is. Of the 4 counties that border it, 2 have more moderate-potential ground, Alcona County the most at 69.4%.
The map rates the ground, not the air in any home.
Local help
Iosco County, Local resources
Radon testing and mitigation in Iosco 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.
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
Iosco County, Questions
Questions about radon in Iosco County
Are radon levels high in Iosco County?
Over the 2008 to 2017 laboratory totals, 7.7% of the radon tests reported to CDC for Iosco County, Michigan were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.7 pCi/L. Of 82 Michigan counties with 30 or more tests for the same period, 76 reported a higher share; pooled, the state comes to 26.9%.
Which counties border Iosco County?
Iosco County borders 4 counties: Alcona County, Arenac County, Ogemaw County and Oscoda County.
Products
Iosco County, Products
Testing a home in Iosco County
In Iosco County, 7.7% of 156 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 26.9% pooled across Michigan. 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 Iosco 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
MonitorX-Sense
XR0A-SR battery digital radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Iosco County, Bordering counties
Counties bordering Iosco County
Calculated by Radon411- Radon levels in Alcona CountyEPA zone 2
20.5%at or above 4 pCi/L
Median 1.7 pCi/L · 185 tests · 12.8 points above Iosco County
- Radon levels in Oscoda CountyEPA zone 3
18.5%at or above 4 pCi/L
Median 2.1 pCi/L · 54 tests · 10.8 points above Iosco County
- Radon levels in Ogemaw CountyEPA zone 3
15.0%at or above 4 pCi/L
Median 2.0 pCi/L · 120 tests · 7.3 points above Iosco County
- Radon levels in Arenac CountyEPA zone 3
8.9%at or above 4 pCi/L
Median 0.7 pCi/L · 79 tests · 1.2 points above Iosco County
Iosco County, Cities and towns
Cities and towns in Iosco County
Iosco County's population has barely moved since 2020: 25,266 residents on July 1, 2025 against 25,189 then, by the Census Bureau's estimates. That works out to 46 people per square mile of land. No town dominates: East Tawas, the largest, has 2,662 residents, 10.5% of the total. Together its 3 incorporated places hold 19.4% of those residents; the other 80.6% live outside any of them. Reported testing is thin here: 156 tests over 2008 to 2017, or 6.2 for every 1,000 residents (2025 estimate), where Michigan as a whole comes to 11.3.
From East Tawas to Whittemore, CDC publishes no figure by town: each reads Iosco County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| East Tawas | 2,662 | +0.1% | 10.5% |
| Tawas City | 1,830 | +0.2% | 7.2% |
| Whittemore | 419 | +0.7% | 1.7% |
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).
Iosco County, Homes
Homes in Iosco County
Iosco County is a place of houses on their own lots: 82% of its 19,978 homes are detached single-family houses, against 72% across Michigan. Half of its homes were built before 1972, close to Michigan's 1972: 29% date from before 1960 and 11% from 2000 or later. Owners live in 83% of the occupied homes (Michigan: 73%), so for most households a test and a fix are their own to order.
| Homes | Iosco County | Michigan |
|---|---|---|
| Housing units | 19,978 | 4,599,683 |
| Detached houses | 82% | 72% |
| In buildings of 5 or more | 6% | 13% |
| Mobile homes | 8% | 5% |
| Built before 1960 | 29% | 36% |
| Built since 2000 | 11% | 15% |
| Middle year built | 1972 | 1972 |
| Owner-occupied | 83% | 73% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.