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 Douglas County, Nevada
EPA puts Douglas County in Zone 1, its highest radon zone, and 37.0% of its 1,617 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
37.0%
14.2 pts above NV
- Douglas
- 37.0%
- Nevada
- 22.8%
1,617 tests, 2008 to 2017
Median result
3.1pCi/L
Below action level
- Douglas
- 3.1 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,617
3rd of 11 by tests
- Douglas
- 1,617
- Washoe
- 5,046
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 Nevada
4 of 11
Middle half
- Douglas
- 37.0%
- Carson City
- 40.6%
By share, of 11 with 30+ tests
Read a result for Douglas County
Starts at Douglas County's median, 3.1 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.1 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. Douglas County's median reported result, 2008 to 2017.
The data
Douglas County, At a glance
Douglas County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Douglas County in
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Douglas County, 2008 to 2017, laboratory
Under 2 pCi/L: 30%2 to 4 pCi/L: 33%4 pCi/L and above: 37%
Of 1,617 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 485 | 30.0% |
| 2 to 4 pCi/L | 534 | 33.0% |
| 4 pCi/L and above | 598 | 37.0% |
What these figures count
These are the 1,617 tests reported to CDC for Douglas 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).
Douglas County, Compared
Douglas County radon figures, compared
Calculated by Radon411In Douglas County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (598 of 1,617) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 1.3 points higher. Across 16 Nevada counties pooled together, 22.8% of tests reached that level, so Douglas County runs 14.2 points above its state.
Of 4 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 7.4% (Placer County, CA) to 40.6% (Carson City). By share, Douglas County is 4th of 11 Nevada counties with 30 or more tests for the same period.
Half the tests came in under 3.1 pCi/L and half over it; the single highest reached 58.0 pCi/L. Below the action level, 485 tests (30.0%) came in under 2 pCi/L, against 52.5% statewide, and 534 tests (33.0%) fell between 2 and 4, against 24.8% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 37.0% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential.
CDC's ten-year totals for Douglas County went from 1,552 tests (2005 to 2014) to 1,617 (2008 to 2017), the share going from 36.6% to 37.0%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Douglas County, State data
Nevada's own radon test data
MeasuredWhat Nevada's own agencies publish about radon tests in Douglas County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What the Nevada Radon Education Program reports for the ZIP codes in Douglas County
The Nevada Radon Education Program publishes its figures by ZIP code, not by county. These are the 8 ZIP codes that lie wholly or partly in Douglas County, each with the state's own figures for it. Period: 1989-2015.
| ZIP code | What the state reports |
|---|---|
| 89410 | average 4.0 pCi/L |
| 89413 | average 8.7 pCi/L |
| 89423 | average 3.2 pCi/L |
| 89444 | average 4.5 pCi/L |
| 89448 | average 7.1 pCi/L |
| 89449 | average 9.0 pCi/L |
| 89460 | average 6.3 pCi/L |
| 89705 | average 2.9 pCi/L |
- NBMG says the results are based on independently tested homes, not scientific sampling.
- The service publishes an average for each ZIP code but no count of tests.
- Site specific testing is the only way to determine local radon concentrations.
- A ZIP code that crosses the county line is listed whole; its figures cover all of it.
Measured: Nevada Radon Education Program data, 1989-2015.
Douglas County, Geology
The ground under Douglas County
PredictedUSGS's geologic map puts all of Douglas County's mapped land in one class: moderate radon potential. The map puts 79.3% of Douglas County in the area it calls Sierra Nevada and 20.6% in Great Basin. USGS gives the first a radon index of 9 and the second 11, both in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Sierra Nevada | Northern Sierra Nevada is underlain primarily by Paleozoic and Mesozoic metamorphic rocks. Granitic rocks predominate in the southern Sierrra Nevada , with lesser Mesozoic metamorphic rocks. | Moderate | 9 | 79.3% |
| Great Basin | Sandstone, shale, limestone, mafic volcanic rocks. | Moderate | 11 | 20.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Douglas County beside the ground around it
Across Nevada 17.3% of the land is rated high; none of Douglas County's is. Of the 6 counties that border it, 1 has more high-potential ground, Lyon County the most at 13.5%.
The map rates the ground, not the air in any home.
Local help
Douglas County, Local resources
Radon testing and mitigation in Douglas County
- Nevada Radon Education ProgramNevada Radon Education Program, run by University Of Nevada, Reno, offers free or discounted test kits, and answers questions about testing and mitigation in Nevada.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The program offers literature, maps, educational presentations and low-cost radon test kits.
- Compare kits
- Professionals in Nevada20 professionals are listed in Nevada.
What Nevada's program says
- chrisk@unr.edu
What it means
Douglas County, Questions
Questions about radon in Douglas County
Are radon levels high in Douglas County?
Over the 2008 to 2017 laboratory totals, 37.0% of the radon tests reported to CDC for Douglas County, Nevada were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.1 pCi/L. Of 11 Nevada counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 22.8%.
Which counties border Douglas County?
Douglas County borders 6 counties: Alpine County, CA, Carson City, NV, Lyon County, NV, El Dorado County, CA, Placer County, CA and Mono County, CA.
Products
Douglas County, Products
Testing a home in Douglas County
In Douglas County, 37.0% of 1,617 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.8% pooled across Nevada. In Zone 1 the year-round level in Douglas 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
MonitorAEGTEST
HOUND-3786 rechargeable radon monitor with a 3.5-inch color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
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
Douglas County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Douglas County
Explore
Douglas County, Bordering counties
Counties bordering Douglas County
Calculated by Radon411- Radon levels in Alpine County, CAEPA zone 2
63.2%at or above 4 pCi/L
Median 4.5 pCi/L · 19 tests · 26.2 points above Douglas County
- Radon levels in Mono County, CAEPA zone 2
50.0%at or above 4 pCi/L
Median 4.6 pCi/L · 20 tests · 13.0 points above Douglas County
- Radon levels in Carson City, NVEPA zone 1
40.6%at or above 4 pCi/L
Median 3.3 pCi/L · 731 tests · 3.6 points above Douglas County
- Radon levels in Lyon County, NVEPA zone 1
30.4%at or above 4 pCi/L
Median 2.6 pCi/L · 303 tests · 6.6 points below Douglas County
- Radon levels in El Dorado County, CAEPA zone 2
30.3%at or above 4 pCi/L
Median 1.6 pCi/L · 274 tests · 6.7 points below Douglas County
- Radon levels in Placer County, CAEPA zone 2
7.4%at or above 4 pCi/L
Median 1.1 pCi/L · 283 tests · 29.6 points below Douglas County
Douglas County, Residents
Who lives in Douglas County
The Census Bureau estimates 50,111 residents in Douglas County for July 1, 2025, 586 more than in 2020 (+1.2%). That works out to 71 people per square mile of land. Testing is reported here more often than across the state: CDC's 1,617 reported tests for 2008 to 2017 come to 32.3 for every 1,000 residents (2025 estimate), against 3.3 for Nevada.
Census lists no incorporated place in Douglas County: every home in it reads the county's figures.
Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Douglas County, Homes
Homes in Douglas County
Douglas County is a place of houses on their own lots: 77% of its 24,599 homes are detached single-family houses, against 60% across Nevada. Half of its homes were built before 1990, close to Nevada's 1996: 3% date from before 1960 and 27% from 2000 or later. Owners live in 78% of the occupied homes (Nevada: 59%), so for most households a test and a fix are their own to order.
| Homes | Douglas County | Nevada |
|---|---|---|
| Housing units | 24,599 | 1,307,338 |
| Detached houses | 77% | 60% |
| In buildings of 5 or more | 5% | 22% |
| Mobile homes | 7% | 6% |
| Built before 1960 | 3% | 5% |
| Built since 2000 | 27% | 40% |
| Middle year built | 1990 | 1996 |
| Owner-occupied | 78% | 59% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.