Radon in Pennsylvania

Pennsylvania has an elevated radon risk

The Pennsylvania Department of Environmental Protection is direct about this: approximately 40% of homes tested in Pennsylvania have radon levels above the EPA's action guideline of 4 pCi/L, and DEP describes Pennsylvania as having "one of the most serious radon problems in the United States." That's a statewide figure describing homes that have been tested — it says nothing about any specific property, including yours.

The EPA maintains a radon zone map that groups counties by general radon potential, and is explicit about its limits: "This map should not be used to determine if individual homes need to be tested. No matter where you live, test your home for radon." A county or state-level statistic can tell you radon is a genuine regional concern. It can't tell you your number. See how to test your own home.

Sources: Pennsylvania DEP, "Radon in the Home" (pa.gov/agencies/dep/programs-and-services/radiation-protection/radon-division/radon-in-the-home). U.S. EPA, "EPA Map of Radon Zones and Supplemental Information" (epa.gov/radon/epa-map-radon-zones-and-supplemental-information).

If your own test has already come back above that guideline, the useful thing isn't the statewide statistic — it's the sequence that follows. See what to do when a home tests at or above 4 pCi/L.

Buying or selling a home in Pennsylvania

Pennsylvania's Real Estate Seller Disclosure Law requires a seller to disclose known material defects to a buyer before an agreement of sale is signed. The underlying statute itself uses a general category — "presence of hazardous substances" — but the state's official Seller Property Disclosure Statement, which implements that requirement, is more specific: it directly asks sellers whether they're aware of hazardous substances on the property "including, but not limited to, asbestos, polychlorinated byphenyls (PCBs), radon, lead paint, urea-formaldehyde foam insulation (UFFI), etc.," and separately asks whether the property has been tested for any hazardous substances. Pennsylvania DEP guidance states that radon test results must be disclosed when a tested home is sold. Pennsylvania does not require a seller to test for radon before listing — if no test has been done, there's no result to disclose.

This is general information, not legal advice, and real estate disclosure obligations can be fact-specific. A real estate agent or attorney is the right source for how this applies to a specific transaction. What's more directly useful here: if you're buying or selling, the EPA recommends hiring a qualified, professional tester rather than relying on a DIY kit for a transaction.

Sources: 68 Pa.C.S. § 7304(b)(14), Real Estate Seller Disclosure Law ("presence of hazardous substances"). 49 Pa. Code § 35.335a, Seller Property Disclosure Statement (radon named specifically within the hazardous-substances question). Pennsylvania DEP, Citizen's Guide to Radon, "Radon and Home Sales" section: "If your home has been tested for radon, the test results must be disclosed when the home is sold."