Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Baltimore city, Maryland
EPA puts Baltimore city in Zone 2, its middle radon zone, and most reported tests there come back low, though 7.9% of 1,148 (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
7.9%
16.0 pts below MD
- Baltimore city
- 7.9%
- Maryland
- 23.9%
1,148 tests, 2008 to 2017
Median result
0.8pCi/L
Below action level
- Baltimore city
- 0.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,148
11th of 19 by tests
- Baltimore city
- 1,148
- Montgomery
- 10,969
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Maryland
18 of 19
Lowest quarter
- Baltimore city
- 7.9%
- Washington
- 56.0%
By share, of 19 with 30+ tests
Read a result for Baltimore city
Starts at Baltimore city's median, 0.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.8 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. Baltimore city's median reported result, 2008 to 2017.
The data
Baltimore city, At a glance
Baltimore city at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Baltimore city is a
USGS geologic potential: Moderate across 55% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Baltimore city, 2008 to 2017, laboratory
Under 2 pCi/L: 79%2 to 4 pCi/L: 13%4 pCi/L and above: 8%
Of 1,148 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 907 | 79.0% |
| 2 to 4 pCi/L | 150 | 13.1% |
| 4 pCi/L and above | 91 | 7.9% |
What these figures count
These are the 1,148 tests reported to CDC for Baltimore city 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).
Baltimore city, Compared
Baltimore city radon figures, compared
Calculated by Radon411Baltimore city reports fewer high tests than Maryland overall. 7.9% of its 1,148 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 16.0 points below the 23.9% pooled from 24 Maryland counties.
Ordered from highest share down, it comes 18th of 19 Maryland counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Baltimore city sits 27.8 points below it.
Next door, the shares run from 17.4% in Anne Arundel County to 19.1% in Baltimore County. The reported tests do not follow EPA's Zone 2 label for Baltimore city (predicted average between 2 and 4 pCi/L): 7.9% of them reached 4 pCi/L, fewer than that label suggests.
Half the tests came in under 0.8 pCi/L and half over it; the single highest reached 40.8 pCi/L. The rest split 79.0% under 2 pCi/L and 13.1% from 2 to 4 (Maryland: 56.6% and 19.5%).
CDC's ten-year totals for Baltimore city went from 934 tests (2005 to 2014) to 1,148 (2008 to 2017), the share going from 7.8% to 7.9%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Baltimore city, Geology
The ground under Baltimore city
PredictedUSGS's geologic map splits Baltimore city: 55.3% of its land is moderate radon potential and 36.7% high. The map puts 55.3% of Baltimore city in the area it calls Western Shore and 36.7% in Eastern Piedmont. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Western Shore | Cretaceous, Quaternary, minor Tertiary gravel, sand, silt, clay. | Moderate | 10 | 55.3% |
| Eastern Piedmont | Precambrian igneous and metamorphic rocks (schist and gneiss). | High | 12 | 36.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Baltimore city beside the ground around it
On high-potential ground Baltimore city is close to Maryland as a whole: 36.7% of its land against 36.7%. Of the 2 counties that border it, 1 has more high-potential ground, Baltimore County the most at 81.1%.
The map rates the ground, not the air in any home.
Local help
Baltimore city, Local resources
Radon testing and mitigation in Baltimore city
- Maryland's radon programMaryland Department of HealthMaryland's radon program offers free or discounted test kits, and answers questions about testing and mitigation in Maryland.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Maryland residents may be eligible for a free radon test kit.
- Compare kits
- Professionals in Maryland5 professionals are listed in Maryland.
What Maryland's program says
- Phone
- 1-866-703-3266
What it means
Baltimore city, Questions
Questions about radon in Baltimore city
Are radon levels high in Baltimore city?
Over the 2008 to 2017 laboratory totals, 7.9% of the radon tests reported to CDC for Baltimore city, Maryland were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.8 pCi/L. Of 19 Maryland counties with 30 or more tests for the same period, 17 reported a higher share; pooled, the state comes to 23.9%.
Which counties border Baltimore city?
Baltimore city borders 2 counties: Baltimore County and Anne Arundel County.
Products
Baltimore city, Products
Testing a home in Baltimore city
In Baltimore city, 7.9% of 1,148 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 23.9% pooled across Maryland. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Baltimore city; a long-term test tells the year-round average.
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
MonitorAranet
Radon One battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Baltimore city, Bordering counties
Counties bordering Baltimore city
Calculated by Radon411- Radon levels in Baltimore CountyEPA zone 1
19.1%at or above 4 pCi/L
Median 1.4 pCi/L · 7,706 tests · 11.2 points above Baltimore city
- Radon levels in Anne Arundel CountyEPA zone 2
17.4%at or above 4 pCi/L
Median 1.4 pCi/L · 4,088 tests · 9.5 points above Baltimore city
Baltimore city, Cities and towns
Cities and towns in Baltimore city
About 569,997 people live in Baltimore city by the Census Bureau's estimate for July 1, 2025, 13,298 fewer than in 2020 (−2.3%). Packed into its land, that is 7,042 people per square mile. Baltimore, its one incorporated place, has 569,997 residents, 100.0% of the total. Reported testing is thin here: 1,148 tests over 2008 to 2017, or 2.0 for every 1,000 residents (2025 estimate), where Maryland as a whole comes to 7.7.
Baltimore is the one incorporated place here; CDC publishes no figure by town, so it reads Baltimore city's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Baltimore | 569,997 | −2.3% | 100.0% |
One incorporated place, 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).
Baltimore city, Homes
Homes in Baltimore city
Fewer than six in ten of Baltimore city's 293,631 homes are detached houses (15%, against 51% across Maryland); the rest are attached, in shared buildings or mobile. The homes are older than Maryland's as a whole: half were built before 1948 (1979 for Maryland), and 68% date from before 1960. Most occupied homes here are rented: owners live in 48% (Maryland: 67%). A tenant can run a test; a fix is the landlord's to make.
| Homes | Baltimore city | Maryland |
|---|---|---|
| Housing units | 293,631 | 2,545,532 |
| Detached houses | 15% | 51% |
| In buildings of 5 or more | 25% | 23% |
| Mobile homes | under 1% | 1% |
| Built before 1960 | 68% | 27% |
| Built since 2000 | 9% | 20% |
| Middle year built | 1948 | 1979 |
| Owner-occupied | 48% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.