Radon in Philadelphia County, Pennsylvania
Philadelphia County, Pennsylvania, is in EPA radon Zone 3: predicted average indoor radon screening level less than 2 pCi/L (low potential). Radon laboratories reported 8,973 building tests here for 2008 to 2017: median 1.5 pCi/L, with 12.4% at or above EPA's 4 pCi/L action level (Pennsylvania 41.1%, US 36.5%). Pennsylvania state records have 193,339 test results on file for the county, median 1.5 pCi/L, 10.9% at or above 4 pCi/L.
Radon test results in Philadelphia County
| Test results | Period | Tests | Typical result | 4 pCi/L or more |
|---|---|---|---|---|
| Radon testing laboratories | 2008-2017 | 8,973 | median 1.5 pCi/L | 12.4% |
| Pennsylvania state records, every reported test | 1986 to 2026-07 | 193,339 | median 1.5 pCi/L | 10.9% |
| Pennsylvania, all counties (labs) | 2008-2017 | 173,284 | n/a | 41.1% |
| United States (labs) | 2008-2017 | 1,408,802 | n/a | 36.5% |
Test results describe buildings whose owners chose to test and whose results reached the lab or agency, not a random sample; small counts swing widely. State and US shares are computed from county counts and percents. The laboratory data comes from national radon testing laboratories and supplements EPA's zone map.
Radon levels by ZIP code in Philadelphia County
Pennsylvania state results for the ZIP codes with 10 or more tests reported in Philadelphia County, 1986 to 2026-07.
| ZIP code | Tests | Median | 4 pCi/L or more |
|---|---|---|---|
| 18966 | 10 | 2.4 pCi/L | 10% |
| 19002 | 25 | 2.1 pCi/L | 32% |
| 19004 | 28 | 2.2 pCi/L | 3.6% |
| 19019 | 115 | 1.1 pCi/L | 6.1% |
| 19020 | 31 | 2.0 pCi/L | 22.6% |
| 19035 | 16 | 3.8 pCi/L | 50% |
| 19038 | 35 | 3.1 pCi/L | 37.1% |
| 19046 | 13 | 4.2 pCi/L | 69.2% |
| 19082 | 22 | 2.3 pCi/L | 22.7% |
| 19092 | 152 | 0.9 pCi/L | 2.6% |
| 19101 | 212 | 1.5 pCi/L | 9.9% |
| 19102 | 388 | 0.9 pCi/L | 5.9% |
| 19103 | 3,418 | 1.1 pCi/L | 3.7% |
| 19104 | 2,993 | 1.6 pCi/L | 12.1% |
| 19105 | 21 | 1.3 pCi/L | 9.5% |
| 19106 | 2,638 | 1.2 pCi/L | 5.8% |
| 19107 | 1,385 | 1.0 pCi/L | 4.4% |
| 19108 | 24 | 1.4 pCi/L | 8.3% |
| 19110 | 49 | 0.7 pCi/L | 8.2% |
| 19111 | 7,124 | 1.7 pCi/L | 14.4% |
| 19112 | 72 | 0.5 pCi/L | 0% |
| 19114 | 3,776 | 1.1 pCi/L | 6.4% |
| 19115 | 4,161 | 1.9 pCi/L | 21.6% |
| 19116 | 3,965 | 1.6 pCi/L | 15.1% |
| 19118 | 5,928 | 2.4 pCi/L | 29.3% |
| 19119 | 9,169 | 2.0 pCi/L | 18.9% |
| 19120 | 3,432 | 1.2 pCi/L | 4.9% |
| 19121 | 3,758 | 1.5 pCi/L | 11.1% |
| 19122 | 2,489 | 1.4 pCi/L | 7.7% |
| 19123 | 2,933 | 1.6 pCi/L | 10.8% |
| 19124 | 3,263 | 1.7 pCi/L | 22.5% |
| 19125 | 8,201 | 1.7 pCi/L | 9.8% |
| 19126 | 1,792 | 1.5 pCi/L | 9% |
| 19127 | 3,302 | 2.1 pCi/L | 17.2% |
| 19128 | 15,089 | 1.9 pCi/L | 19.7% |
| 19129 | 3,546 | 1.7 pCi/L | 14.2% |
| 19130 | 7,627 | 1.5 pCi/L | 9.2% |
| 19131 | 3,692 | 1.2 pCi/L | 9.2% |
| 19132 | 1,076 | 1.6 pCi/L | 11.1% |
| 19133 | 640 | 1.6 pCi/L | 13.6% |
| 19134 | 3,595 | 1.5 pCi/L | 9.2% |
| 19135 | 2,326 | 1.4 pCi/L | 6.5% |
| 19136 | 2,604 | 1.3 pCi/L | 6.5% |
| 19137 | 779 | 1.8 pCi/L | 16.3% |
| 19138 | 2,444 | 1.3 pCi/L | 3.7% |
| 19139 | 2,667 | 1.4 pCi/L | 6.8% |
| 19140 | 1,366 | 1.4 pCi/L | 5.7% |
| 19141 | 1,647 | 1.3 pCi/L | 6.4% |
| 19142 | 1,297 | 1.1 pCi/L | 1.7% |
| 19143 | 5,642 | 1.5 pCi/L | 6.2% |
| 19144 | 4,912 | 1.8 pCi/L | 14% |
| 19145 | 6,499 | 1.3 pCi/L | 4.2% |
| 19146 | 13,029 | 1.6 pCi/L | 7.4% |
| 19147 | 12,244 | 1.5 pCi/L | 5.5% |
| 19148 | 8,401 | 1.4 pCi/L | 3.9% |
| 19149 | 2,222 | 1.2 pCi/L | 5.6% |
| 19150 | 3,008 | 1.3 pCi/L | 7.8% |
| 19151 | 4,564 | 1.7 pCi/L | 13.8% |
| 19152 | 2,693 | 1.4 pCi/L | 6.1% |
| 19153 | 855 | 0.7 pCi/L | 0.8% |
| 19154 | 3,778 | 1.1 pCi/L | 3.4% |
| 19155 | 14 | 1.9 pCi/L | 7.1% |
| 19428 | 26 | 3.4 pCi/L | 46.2% |
Radon in nearby counties
| County | EPA zone | Lab tests | 4 pCi/L or more |
|---|---|---|---|
| Delaware County, PA | Zone 1 | 8,601 | 21% |
| Camden County, NJ | Zone 2 | n/a | n/a |
| Montgomery County, PA | Zone 1 | 14,749 | 27.2% |
| Gloucester County, NJ | Zone 2 | n/a | n/a |
| Bucks County, PA | Zone 1 | 9,078 | 27.5% |
| Burlington County, NJ | Zone 2 | n/a | n/a |
The six counties with the nearest centers.
What to do about radon in Philadelphia County
Test the building. EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, and says there is no known safe level of exposure. The state environmental protection agency runs the state's radon program.
Buying here? The Environmental Records Report lists this county's radon zone and test results with the flood zone, mapped faults, power lines and federal contamination records near the address.
HeritageDeed searches title in Philadelphia County: Order a Philadelphia title search, owner of record, deeds, mortgages and liens, $49 per report.
Radon in Philadelphia County: questions
What is the radon level in Philadelphia County?
The median of the 8,973 laboratory tests reported for Philadelphia County (2008 to 2017) was 1.5 pCi/L, and 12.4% of them were at or above 4 pCi/L. Pennsylvania's 193,339 state results have a median of 1.5 pCi/L. These are results of tested buildings; a single home can be far above or below them.
Is Philadelphia County in radon Zone 1?
No. EPA's 1993 map puts Philadelphia County in Zone 3 (predicted average indoor radon screening level less than 2 pCi/L (low potential)). EPA says homes in every zone can have high radon and should be tested.
How does radon in Philadelphia County compare with Pennsylvania?
12.4% of laboratory tests in Philadelphia County were at or above 4 pCi/L for 2008 to 2017, against 41.1% across Pennsylvania (173,284 tests) and 36.5% nationally. 49 of Pennsylvania's 67 counties are in Zone 1.
Should I test for radon in Philadelphia County?
Yes. EPA recommends testing every home whatever its zone: "This map should not be used to determine if individual homes need to be tested." Fix the home at 4 pCi/L or more and consider a fix between 2 and 4 pCi/L; EPA says there is no known safe level of radon exposure.
More for Philadelphia County
- Philadelphia title searchOwner of record, deeds, mortgages and liens from the official Philadelphia County records, $49 per report.
- Philadelphia property history lookupFree timeline of what has been recorded against any Philadelphia property: deeds, sale prices, mortgages and releases by year, from official county records.
- Philadelphia property fraud alertThe recording office's own alert service for Philadelphia, and free nightly monitoring of a property's official records: new recorded documents, owner changes and tax sale lists.
- Philadelphia building violations and permitsFree lookup of open violations, condemned or unsafe cases and building permits for any Philadelphia address. The report adds them to the title search.
- Philadelphia property tax appealAppeal deadlines from the official calendar, the free filing route, and an evidence pack with assessment history and comparable sales.
- Recently sold in PhiladelphiaSales of the last 90 published days from the official records: address, date and price, by ZIP code, refreshed nightly.
- Philadelphia zoning lookupThe zoning district, overlays and special districts of a Philadelphia address, from the city's own zoning data.
- Pennsylvania LLC lookupDepartment of State record with the officers listed (initials) and the Philadelphia properties assessed to it.
- Pennsylvania title insurance calculatorTIRBOP Sale Rate owner's policy, simultaneous loan policy and the Homeowner's Policy option.
- Philadelphia closing cost calculatorThe 4.578% realty transfer tax split, title premiums and the seller's net proceeds.
- Philadelphia loan limitsThis year's FHFA conforming, FHA and VA county loan limits for 1 to 4 unit homes, from FHFA's and HUD's official files.
- Philadelphia fair market rentHUD Fair Market Rents for studios to 4 bedrooms, the voucher payment standard range and the change from last year.
- Philadelphia property tax rateEffective property tax rate from Census survey data: median taxes paid against median home value, ranked in the state.
- Environmental records reportSuperfund, hazardous waste, leaking tank and brownfield sites near any Philadelphia address, with distances and a site map. A records search, not a Phase I.
- Superfund sites in PennsylvaniaEvery EPA Superfund site in Pennsylvania with its status, county and a map, refreshed nightly from federal records.
- USDA eligibility map: PennsylvaniaHow much of each Pennsylvania county is in a USDA-eligible rural area, the towns mapped ineligible, and a free address check.
- Opportunity zones in PennsylvaniaEvery designated Opportunity Zone tract in Pennsylvania by county, from the IRS list, and the tracts eligible for the 2027 round.
- Census tract lookupThe census tract of any Philadelphia address with its FFIEC income level and HUD Qualified Census Tract and DDA status.
Other free hazard lookups
- Fault lines near an addressUSGS-mapped earthquake faults within 5 miles, their age and slip rate, and the USGS seismic hazard value.
- Power lines near an addressHigh-voltage transmission lines within 1 mile from federal maps, with voltage and distance.
- Flood zone lookupThe FEMA flood zone mapped at any US address. Not an official flood zone determination.
- Superfund sites near an addressThe nearest EPA Superfund (NPL) sites and their status.
All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).
Radon in every Pennsylvania county · Radon map of every state
Data compiled 2026-10-20. County FIPS 42101. County-level screening information, not a radon measurement of any building.