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 Cecil County, Maryland
EPA puts Cecil County in Zone 2, its middle radon zone, and 24.9% of its 1,071 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
24.9%
1.0 pts above MD
- Cecil
- 24.9%
- Maryland
- 23.9%
1,071 tests, 2008 to 2017
Median result
1.9pCi/L
Below action level
- Cecil
- 1.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,071
12th of 19 by tests
- Cecil
- 1,071
- 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
9 of 19
Middle half
- Cecil
- 24.9%
- Washington
- 56.0%
By share, of 19 with 30+ tests
Read a result for Cecil County
Starts at Cecil County's median, 1.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.9 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. Cecil County's median reported result, 2008 to 2017.
The data
Cecil County, At a glance
Cecil County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Cecil County is a
USGS geologic potential: High across 38% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Cecil County, 2008 to 2017, laboratory
Under 2 pCi/L: 52%2 to 4 pCi/L: 23%4 pCi/L and above: 25%
Of 1,071 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 554 | 51.7% |
| 2 to 4 pCi/L | 250 | 23.3% |
| 4 pCi/L and above | 267 | 24.9% |
What these figures count
These are the 1,071 tests reported to CDC for Cecil 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).
Cecil County, Compared
Cecil County radon figures, compared
Calculated by Radon411Cecil County's 1,071 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.9 pCi/L and a maximum of 134.7 pCi/L, and 24.9% reached 4 pCi/L. Maryland as a whole (24 Maryland counties, pooled) comes to 23.9%: 1.0 points lower than here.
Among its state's counties it ranks 9th of 19 Maryland counties with 30 or more tests for the same period. Statewide for the same period, Washington County reported the highest share (56.0%) and Wicomico County the lowest (0.0%).
Below the action level, 554 tests (51.7%) came in under 2 pCi/L, against 56.6% statewide, and 250 tests (23.3%) fell between 2 and 4, against 19.5% statewide. CDC's ten-year totals for Cecil County went from 1,073 tests (2005 to 2014) to 1,071 (2008 to 2017), the share going from 21.6% to 24.9%.
EPA's 1993 zone map puts Cecil County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 38% of the county's land high radon potential.
Next door, the shares run from 17.0% in New Castle County, DE to 55.1% in Lancaster County, PA, with Harford County and New Castle County, DE below Cecil County.
CDC also counts 87 tests taken after mitigation in Cecil County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Cecil County, Geology
The ground under Cecil County
PredictedNo class of ground holds half of Cecil County on USGS's geologic map: 38.0% of its land is high radon potential, 35.4% moderate and 20.0% low. The map puts 38.0% of Cecil County in the area it calls Eastern Piedmont and 35.4% in Western Shore, with one smaller area beside them. USGS gives the first a radon index of 12, 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 |
|---|---|---|---|---|
| Eastern Piedmont | Precambrian igneous and metamorphic rocks (schist and gneiss). | High | 12 | 38.0% |
| Western Shore | Cretaceous, Quaternary, minor Tertiary gravel, sand, silt, clay. | Moderate | 10 | 35.4% |
| Eastern Shore | Quaternary coastal sand, silt. | Low | 7 | 20.0% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Cecil County beside the ground around it
On high-potential ground Cecil County is close to Maryland as a whole: 38.0% of its land against 36.7%. Of the 5 counties that border it, 3 have more high-potential ground, Lancaster County, PA the most at 100%.
The map rates the ground, not the air in any home.
Local help
Cecil County, Local resources
Radon testing and mitigation in Cecil County
- 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
Cecil County, Questions
Questions about radon in Cecil County
Are radon levels high in Cecil County?
Over the 2008 to 2017 laboratory totals, 24.9% of the radon tests reported to CDC for Cecil County, Maryland were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of 19 Maryland counties with 30 or more tests for the same period, 8 reported a higher share; pooled, the state comes to 23.9%.
Which counties border Cecil County?
Cecil County borders 5 counties: New Castle County, DE, Harford County, MD, Kent County, MD, Chester County, PA and Lancaster County, PA.
Products
Cecil County, Products
Testing a home in Cecil County
In Cecil County, 24.9% of 1,071 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 Cecil County; 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
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
Cecil County, Bordering counties
Counties bordering Cecil County
Calculated by Radon411- Radon levels in Lancaster County, PAEPA zone 1
55.1%at or above 4 pCi/L
Median 4.8 pCi/L · 11,194 tests · 30.2 points above Cecil County
- Radon levels in Kent County, MDEPA zone 3
52.6%at or above 4 pCi/L
Median 4.4 pCi/L · 57 tests · 27.7 points above Cecil County
- Radon levels in Chester County, PAEPA zone 1
29.3%at or above 4 pCi/L
Median 2.2 pCi/L · 12,912 tests · 4.4 points above Cecil County
- Radon levels in Harford County, MDEPA zone 1
22.6%at or above 4 pCi/L
Median 1.7 pCi/L · 5,283 tests · 2.3 points below Cecil County
- Radon levels in New Castle County, DEEPA zone 2
17.0%at or above 4 pCi/L
Median 1.8 pCi/L · 10,247 tests · 7.9 points below Cecil County
Cecil County, Cities and towns
Cities and towns in Cecil County
The Census Bureau estimates 107,131 residents in Cecil County for July 1, 2025, 3,333 more than in 2020 (+3.2%). That works out to 309 people per square mile of land. No town dominates: Elkton, the largest, has 16,670 residents, 15.6% of the total. Together its 8 incorporated places hold 29.8% of those residents; the other 70.2% live outside any of them. CDC's 1,071 reported tests for 2008 to 2017 work out to 10.0 per 1,000 residents (2025 estimate), close to Maryland's 7.7.
From Elkton to Port Deposit, CDC publishes no figure by town: each reads Cecil County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Elkton | 16,670 | +5.5% | 15.6% |
| Perryville | 4,592 | +2.7% | 4.3% |
| North East | 4,237 | +2.9% | 4.0% |
| Rising Sun | 2,761 | +0.4% | 2.6% |
| Charlestown | 1,553 | +2.8% | 1.4% |
| Chesapeake City | 749 | +2.3% | 0.7% |
| Cecilton | 691 | +2.8% | 0.6% |
| Port Deposit | 633 | +2.9% | 0.6% |
8 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).
Cecil County, Homes
Homes in Cecil County
Of Cecil County's 44,159 homes, 72% are detached houses, against 51% across Maryland; 9% are in buildings of five or more homes. Much of Cecil County is recent building: 29% of its homes have gone up since 2000 and the middle year built is 1987, against 1979 for Maryland. Owners live in 75% of the occupied homes (Maryland: 67%), so for most households a test and a fix are their own to order.
| Homes | Cecil County | Maryland |
|---|---|---|
| Housing units | 44,159 | 2,545,532 |
| Detached houses | 72% | 51% |
| In buildings of 5 or more | 9% | 23% |
| Mobile homes | 5% | 1% |
| Built before 1960 | 20% | 27% |
| Built since 2000 | 29% | 20% |
| Middle year built | 1987 | 1979 |
| Owner-occupied | 75% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.