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 Smyth County, Virginia
EPA puts Smyth County in Zone 1, its highest radon zone, and high results are common there: 61.0% of the 123 radon tests reported to CDC (2008 to 2017, laboratory totals) came back 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
61.0%
30.6 pts above VA
- Smyth
- 61.0%
- Virginia
- 30.4%
123 tests, 2008 to 2017
Median result
5.5pCi/L
Action level reached
- Smyth
- 5.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
123
53rd of 84 by tests
- Smyth
- 123
- Fairfax
- 8,657
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 Virginia
4 of 84
Top quarter
- Smyth
- 61.0%
- Russell
- 67.3%
By share, of 84 with 30+ tests
Read a result for Smyth County
Starts at Smyth County's median, 5.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 5.5 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Smyth County's median reported result, 2008 to 2017.
The data
Smyth County, At a glance
Smyth County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Smyth County in
USGS geologic potential: High across 95% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Smyth County, 2008 to 2017, laboratory
Under 2 pCi/L: 17%2 to 4 pCi/L: 22%4 pCi/L and above: 61%
Of 123 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 21 | 17.1% |
| 2 to 4 pCi/L | 27 | 22.0% |
| 4 pCi/L and above | 75 | 61.0% |
What these figures count
These are the 123 tests reported to CDC for Smyth 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).
Smyth County, Compared
Smyth County radon figures, compared
Calculated by Radon411More than half: 61.0% of the 123 radon tests reported to CDC for Smyth County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 4th of 84 Virginia counties with 30 or more tests for the same period. That is 30.6 points above the 30.4% pooled from 131 Virginia counties.
The median result, 5.5 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 53.5 pCi/L. The rest split 17.1% under 2 pCi/L and 22.0% from 2 to 4 (Virginia: 44.7% and 24.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 61.0% share point the same way here.
2 of its 5 bordering counties with figures ran higher, led by Russell County at 67.3%; Tazewell County reported 40.3%. Statewide for the same period, Russell County reported the highest share (67.3%) and Norfolk city the lowest (2.7%).
CDC's ten-year totals for Smyth County went from 122 tests (2005 to 2014) to 123 (2008 to 2017), the share going from 64.8% to 61.0%.
Nationally, every county with a figure for the same period pools to 35.7%; Smyth County sits 25.3 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Smyth County, Geology
The ground under Smyth County
PredictedMost of the ground under Smyth County is one class on USGS's geologic map: 94.7% of its land is high radon potential, with 5.3% moderate. The map puts 94.7% of Smyth County in the area it calls Valley and Ridge and 5.3% in Blue Ridge. USGS gives the first a radon index of 15, in the high band (12 to 17), and the second 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Valley and Ridge | Cambrian dolomite, limestone, shale, and sandstone, Silurian-Ordovician limestone, dolomite, shale, and sandstone, Mississippian-Devonian sandstone, shale, limestone, gypsum, and coal. | High | 15 | 94.7% |
| Blue Ridge | Granite, pegmatite, monazite, schist, and gneiss. | Moderate | 10 | 5.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Smyth County beside the ground around it
Smyth County has more high-potential ground than Virginia as a whole: 94.7% of its land against 47.9%. Of the 6 counties that border it, 3 have more high-potential ground, Bland County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Smyth County, Local resources
Radon testing and mitigation in Smyth County
- VDH Radon ProgramVDH Radon Program answers questions about testing, mitigation and the rules in Virginia.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 Virginia2 professionals are listed in Virginia.
What Virginia's program says
- Phone
- (804) 864-8161
- Radon@vdh.virginia.gov
- Licensing of radon professionals
The Code of Virginia requires that Radon testers and mitigators be currently certified by either the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).
What it means
Smyth County, Questions
Questions about radon in Smyth County
Are radon levels high in Smyth County?
Over the 2008 to 2017 laboratory totals, 61.0% of the radon tests reported to CDC for Smyth County, Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.5 pCi/L. Of 84 Virginia counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 30.4%.
Which counties border Smyth County?
Smyth County borders 6 counties: Grayson County, Tazewell County, Wythe County, Washington County, Bland County and Russell County.
Products
Smyth County, Products
Testing a home in Smyth County
In Smyth County, 61.0% of 123 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.4% pooled across Virginia. In Zone 1 the year-round level in Smyth 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
RadonPro Wi-Fi radon monitor with a built-in Geiger counter
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 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
Smyth County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Smyth County
Explore
Smyth County, Bordering counties
Counties bordering Smyth County
Calculated by Radon411- Radon levels in Russell CountyEPA zone 1
67.3%at or above 4 pCi/L
Median 6.7 pCi/L · 49 tests · 6.3 points above Smyth County
- Radon levels in Wythe CountyEPA zone 1
65.5%at or above 4 pCi/L
Median 6.0 pCi/L · 119 tests · 4.5 points above Smyth County
- Radon levels in Washington CountyEPA zone 1
58.1%at or above 4 pCi/L
Median 4.8 pCi/L · 384 tests · 2.9 points below Smyth County
- Radon levels in Bland CountyEPA zone 1
46.2%at or above 4 pCi/L
Median 2.6 pCi/L · 13 tests · 14.8 points below Smyth County
- Radon levels in Grayson CountyEPA zone 2
44.7%at or above 4 pCi/L
Median 3.8 pCi/L · 47 tests · 16.3 points below Smyth County
- Radon levels in Tazewell CountyEPA zone 1
40.3%at or above 4 pCi/L
Median 2.8 pCi/L · 372 tests · 20.7 points below Smyth County
Smyth County, Cities and towns
Cities and towns in Smyth County
About 28,882 people live in Smyth County by the Census Bureau's estimate for July 1, 2025, 898 fewer than in 2020 (−3.0%). That works out to 64 people per square mile of land. No town dominates: Marion, the largest, has 5,555 residents, 19.2% of the total. CDC's 123 reported tests for 2008 to 2017 work out to 4.3 per 1,000 residents (2025 estimate), close to Virginia's 6.0.
From Marion to Chilhowie, CDC publishes no figure by town: each reads Smyth County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Marion | 5,555 | −3.4% | 19.2% |
| Saltvilleextends beyond Smyth County | 1,760 | −3.2% | Counted whole |
| Chilhowie | 1,599 | −3.3% | 5.5% |
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). A place that extends beyond Smyth County is counted whole, so it has no share.
Smyth County, Homes
Homes in Smyth County
Of Smyth County's 15,080 homes, 71% are detached houses, against 61% across Virginia; 18% are mobile homes. The homes are older than Virginia's as a whole: half were built before 1974 (1984 for Virginia), and 29% date from before 1960. 71% of occupied homes are lived in by their owner (Virginia: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Smyth County | Virginia |
|---|---|---|
| Housing units | 15,080 | 3,654,784 |
| Detached houses | 71% | 61% |
| In buildings of 5 or more | 5% | 19% |
| Mobile homes | 18% | 4% |
| Built before 1960 | 29% | 19% |
| Built since 2000 | 12% | 25% |
| Middle year built | 1974 | 1984 |
| Owner-occupied | 71% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.