Radon: Pennsylvania's Invisible Problem

What radon actually is

Radon is a naturally occurring radioactive gas produced as uranium in soil and rock breaks down. It works up through the ground and finds the openings every house has at its base: foundation cracks, the gap around a sump pit, floor drains, slab penetrations, bare crawlspace dirt. Once inside it can concentrate — most of all in basements and lower levels, and most of all in a house that's been tightened up against drafts.

The EPA and the U.S. Surgeon General identify radon as a leading cause of lung cancer among people who have never smoked, and the risk is considerably higher for smokers, because the two exposures compound. No symptoms, no smell, nothing to notice. Testing is the only way to know what's in your house — that's the whole reason this page exists.

Why Pennsylvania keeps coming up

Pennsylvania sits over geology that produces unusually high readings, and the state routinely ranks near the top nationally for average indoor radon. The famous formation is the Reading Prong, in the eastern part of the state, where PA's radon problem was first identified in the 1980s — but elevated results turn up across Pennsylvania, Allegheny County very much included.

Western Pennsylvania has its own reasons to pay attention. The housing stock here is basement-heavy and old — block, stone, and poured walls with decades of settlement cracks give soil gas plenty of ways in. Put that basement into a hillside and you have more below-grade wall against soil than a flat-lot ranch does.

The part people get wrong: radon varies house to house, sometimes sharply between neighbors on the same street. A neighbor's low result tells you nothing useful about yours — and neither does your own reading from twelve years ago, if there's been foundation work or a new heating system since.

Testing, plainly

• Short-term kit (a few days). The cheapest option, sold at hardware stores and often discounted or free through state and county programs. A good first screen.
• Long-term kit (90 days or more). Radon swings with season and weather; a long-term test gives a much better picture of the annual average you actually live in.
• A certified tester. Worth it during a real estate transaction, or any time you want a documented result from someone with no stake in it.

A few rules separate a real result from a wasted kit. Test the lowest level you actually live in — the finished basement if you use it, the first floor if it's storage. Follow the kit's closed-house instructions exactly. Keep the detector away from drafts, doors, bathrooms, and kitchens, and mail it back promptly.

Reading the number: the EPA's action level is commonly cited as 4 picocuries per liter, and at or above it the recommendation is to fix the house. The honest caveat is that no level is definitionally “safe” — reduction is generally worthwhile below that line too. Guidance gets updated, so check current EPA guidance rather than a number you half-remember. Retest after mitigation, every couple of years afterward, and after major foundation work or a new HVAC system.

If the number comes back high

This is the part that surprises people: mitigation is routine. The standard fix is sub-slab depressurization — a contractor cores through the basement slab, runs a pipe from underneath it up and out of the house, and puts a continuously running fan in line so soil gas is pulled from below and vented above the roofline instead of drifting into your living space. Most installations are a day's work, and a simple gauge on the pipe lets you confirm at a glance that it's still running.

• Use a certified mitigator. Pennsylvania certifies radon testing and mitigation contractors, and the Department of Environmental Protection maintains the list — search “PA DEP radon certified contractors.”
• Retest afterward. A system that was installed is not the same as a system that worked.
• Sealing cracks alone is not a fix. Sealing helps a real system perform better. By itself it rarely moves the number much.
• Leave the fan on. It's designed to run continuously on a modest amount of electricity. Switching it off to save a few dollars defeats the installation.

Buying, selling, renting

Radon testing shows up routinely in this region's real estate transactions, usually during the inspection period. Two things are worth knowing. First, an existing mitigation system is a selling point, not a stigma — it means the question was asked and answered. Keep the install date, contractor, and post-mitigation result in your house file; our paper trail guide covers what that file should hold. Second, Pennsylvania has radon-related disclosure requirements in real estate transactions, and obligations can apply to landlords as well. Specifics change and vary by situation — confirm current requirements with your own attorney or agent, not a guide page.

What not to do

• Don't panic. Radon risk builds over years of exposure. A high reading is a maintenance item with a deadline, not a reason to leave the house tonight.
• Don't ignore it either. The most common outcome of a high result is nothing at all — the report goes in a drawer and life continues. That's the real failure mode here.
• Don't let anyone sell you a whole-basement waterproofing job as “radon mitigation.” Different problems, different fixes. If you have water, fix the water — our basement water guide starts at the roof and works down. Neither job substitutes for the other.
• Don't skip testing because of a county map. Maps show regional tendencies. Kits show your house.

The whole exercise is a few days and a stamp. Very few things that matter about a house are that cheap to rule out.