Short answer: the median radon test in Warren County was 4.4 pCi/L (CDC, lab tests 2008 to 2017). That means at least half of the tested buildings were at or above EPA’s action level of 4 pCi/L.
How Warren County compares
Warren County’s median of 4.4 pCi/L ranks #24 of 67 Pennsylvania counties with CDC data. The middle Pennsylvania county median is 3.8 pCi/L, so Warren County is above the state’s typical county. EPA puts the county in Zone 2, moderate potential on EPA’s map (predicted average indoor level 2 to 4 pCi/L).
These numbers come from tests homeowners and buyers chose to run, not a random survey. They show local risk; they cannot predict the level in your house.
Certified radon mitigation pros based in Warren County
Each listing below appears on Pennsylvania DEP’s certified mitigation list dated September 1, 2026. We show the city on file and the DEP certification number so you can confirm it.
Matthew Shaw
Certified individual based in Pittsfield, PA
PA DEP certified mitigationCertification #3193
Radon in counties next to Warren
| County | Median pCi/L | EPA zone |
|---|---|---|
| Cattaraugus, NY | 3.0 | Zone 1 (high) |
| Chautauqua, NY | 2.5 | Zone 1 (high) |
| Crawford, PA | 2.7 | Zone 2 (moderate) |
| Elk, PA | 3.9 | Zone 2 (moderate) |
| Erie, PA | 2.6 | Zone 2 (moderate) |
| Forest, PA | 3.6 | Zone 2 (moderate) |
| McKean, PA | 1.6 | Zone 2 (moderate) |
| Venango, PA | 3.8 | Zone 1 (high) |
What to do in Warren County
- Test your home. EPA recommends testing every home below the third floor, whatever the county average.
- Fix it at 4 pCi/L or higher. EPA also suggests considering a fix between 2 and 4 pCi/L.
- Use a certified pro. In Pennsylvania, radon mitigation for pay requires DEP certification. Check the number against the state list before you sign.
- Retest after the system is installed.
Sources
- County median radon levels and test counts: CDC Environmental Public Health Tracking Network, radon tests from labs, 10-year period 2008 to 2017 (ephtracking.cdc.gov).
- Radon zones: U.S. EPA Map of Radon Zones (epa.gov/radon).
- Certified mitigation firms and individuals: Pennsylvania DEP list of certified radon mitigation firms dated September 1, 2026 (PDF), checked October 24, 2026.
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