Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Coos County, Oregon
EPA puts Coos County in Zone 3, its lowest radon zone, and only 5 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
19.3%
2.5 pts above OR
- Coos
- 19.3%
- Oregon
- 16.8%
88 tests, 2020
Median result
1.3pCi/L
Below action level
- Coos
- 1.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2020
Tests reported
88
14th of 20 by tests
- Coos
- 88
- Multnomah
- 1,753
Reported to CDC before any fix, 2020
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in Oregon
8 of 20
Middle half
- Coos
- 19.3%
- Union
- 35.3%
By share, of 20 with 30+ tests
Read a result for Coos County
Starts at Coos County's median, 1.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.3 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. Coos County's median reported result, 2020.
The data
Coos County, At a glance
Coos County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 99% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Coos County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 14.3% |
| 2015 | 25.0% |
| 2016 | 14.3% |
| 2017 | 16.7% |
| 2018 | 4.5% |
| 2019 | 7.7% |
| 2020 | 19.3% |
| 2021 | 17.4% |
| 2022 | 88.9% |
| 2023 | 20.0% |
2023: 20.0%. Across these years the share ran from 4.5% to 88.9%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 5 tests were reported to CDC for Coos County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Coos County, Compared
Coos County radon figures, compared
Calculated by Radon411Coos County's 88 reported tests in 2020 had a middle value of 1.3 pCi/L and a maximum of 24.2 pCi/L, and 19.3% reached 4 pCi/L. Oregon as a whole (33 Oregon counties, pooled) comes to 16.8%: 2.5 points lower than here.
The newest figure, in 2023, counts only 5 tests (20.0% at or above 4 pCi/L), too few to compare, so this reading uses the 88-test figure.
Among its state's counties it ranks 8th of 20 Oregon counties with 30 or more tests for the same period. Statewide for the same period, Union County reported the highest share (35.3%) and Wasco County the lowest (2.6%).
Below the action level, 54 tests (61.4%) came in under 2 pCi/L, against 62.8% statewide, and 17 tests (19.3%) fell between 2 and 4, against 20.4% statewide. The busiest year on file was 2020, with 88 tests reported; the quietest, 2015, had 4.
EPA's 1993 zone map puts Coos County in Zone 3, a predicted county average under 2 pCi/L. USGS geology rates 99% of the county's land low radon potential.
Douglas County, the one bordering county with a figure for the same period, reported 12.7%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Coos County, Geology
The ground under Coos County
PredictedUSGS's geologic map puts all of Coos County's mapped land in one class: low radon potential. The map puts 86.3% of Coos County in the area it calls Coast Range and 12.5% in Klamath Mountains. USGS gives both a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Coast Range | Northern Coast Range is marine sedimentary rocks and Tertiary mafic volcanic rocks. Southern Coast Range is Tertiary estuarine and marine sedimentary rocks, feldspathic and micaceous. | Low | 7 | 86.3% |
| Klamath Mountains | Triassic to Jurassic metamorphic, volcanic, and sedimentary rocks with some Cretaceous intrusive igneous rocks. | Low | 7 | 12.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Coos County beside the ground around it
Across Oregon 62.3% of the land is rated moderate; none of Coos County's is. None of the 2 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Coos County, Local resources
Radon testing and mitigation in Coos County
- Oregon Radon Awareness ProgramOregon Radon Awareness Program, run by Oregon Health Authority, offers free or discounted test kits, and answers questions about testing and mitigation in Oregon.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Oregon Radon Awareness Program provides a FREE short-term radon test kit to those living in areas of Oregon where little radon testing has been done.
- Compare kits
- Professionals in Oregon38 professionals are listed in Oregon.
What Oregon's program says
- Radon.program@dhsoha.state.or.us
What it means
Coos County, Questions
Questions about radon in Coos County
Are radon levels high in Coos County?
In 2023, 20.0% of the radon tests reported to CDC for Coos County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.7 pCi/L. Of 20 Oregon counties with 30 or more tests for the same period, 7 reported a higher share; pooled, the state comes to 16.8%.
Which counties border Coos County?
Coos County borders 2 counties: Curry County and Douglas County.
Products
Coos County, Products
Testing a home in Coos County
In Coos County, 19.3% of 88 tests reported to CDC in 2020 reached 4 pCi/L, against 16.8% pooled across Oregon. 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 Coos County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-3699 radon monitor with a 2.1-inch touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
First reading: Within 1 hour
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Coos County, Bordering counties
Counties bordering Coos County
Calculated by Radon411- Radon levels in Douglas CountyEPA zone 3
12.7%at or above 4 pCi/L
Median 1.2 pCi/L · 220 tests · 6.6 points below Coos County
- Radon levels in Curry CountyEPA zone 3
5.3%at or above 4 pCi/L
Median 0.9 pCi/L · 19 tests · 14.0 points below Coos County
Coos County, Cities and towns
Cities and towns in Coos County
About 63,992 people live in Coos County by the Census Bureau's estimate for July 1, 2025, 990 fewer than in 2020 (−1.5%). That works out to 40 people per square mile of land. Its largest town, Coos Bay, has 15,686 residents, 24.5% of the total. Together its 7 incorporated places hold 59.3% of those residents; the other 40.7% live outside any of them. CDC's 88 reported tests for 2020 work out to 1.4 per 1,000 residents (2025 estimate), close to Oregon's 1.3.
From Coos Bay to Powers, CDC publishes no figure by town: each reads Coos County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Coos Bay | 15,686 | −1.9% | 24.5% |
| North Bend | 9,966 | −3.3% | 15.6% |
| Coquille | 3,943 | −1.7% | 6.2% |
| Bandon | 3,297 | −1.2% | 5.2% |
| Myrtle Point | 2,462 | −0.9% | 3.8% |
| Lakeside | 1,863 | −2.3% | 2.9% |
| Powers | 702 | −1.7% | 1.1% |
7 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).
Coos County, Homes
Homes in Coos County
Of Coos County's 31,698 homes, 68% are detached houses, against 63% across Oregon; 15% are mobile homes. Half of its homes were built before 1973, close to Oregon's 1980: 32% date from before 1960 and 15% from 2000 or later. 71% of occupied homes are lived in by their owner (Oregon: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Coos County | Oregon |
|---|---|---|
| Housing units | 31,698 | 1,838,631 |
| Detached houses | 68% | 63% |
| In buildings of 5 or more | 8% | 17% |
| Mobile homes | 15% | 8% |
| Built before 1960 | 32% | 23% |
| Built since 2000 | 15% | 24% |
| Middle year built | 1973 | 1980 |
| Owner-occupied | 71% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.