Radon doesn’t have a smell. It doesn’t stain a wall or make you cough, and it doesn’t trip an alarm unless you’ve set out to measure it. It’s also something the U.S. Environmental Protection Agency (EPA) ranks as a leading cause of lung cancer. That combination is why it’s worth understanding, especially if you’re buying a house.
Here are four things every homeowner should know.
1. Radon comes from the ground under your house
Radon is a radioactive gas that forms naturally when uranium in soil and rock breaks down. There’s a little in the outdoor air everywhere, where it spreads out and does no harm. The trouble starts when it seeps into a house and builds up.
It gets in through cracks in the slab or foundation, gaps around pipes, openings in the floor and the bare soil of a crawl space. Houses tend to pull soil gas in on their own, especially when the air inside is warmer than the air outside, the same way a chimney draws.
Radon levels vary from region to region, but they also vary from house to house, even between next-door neighbors. Old or new, slab or crawl space, drafty or tight, any home can have a radon problem. Your neighbor’s test result doesn’t tell you much about yours.
2. Long-term exposure raises your lung cancer risk
According to the EPA, radon is the second leading cause of lung cancer in the United States after smoking, and the leading cause among people who have never smoked. The risk comes from breathing elevated levels day after day for years, and it’s much higher for smokers, since the two risks compound each other.
There are no early warning signs. Nobody feels radon, which is exactly why testing matters.
3. Testing is the only way to know
Radon is measured in picocuries per liter of air, written pCi/L. The EPA recommends fixing your home if the level is 4 pCi/L or higher, and suggests considering a fix between 2 and 4 pCi/L, since there’s no level that’s known to be completely safe.
There are two basic kinds of tests.
- Short-term tests run from two to 90 days. They’re quick, and they’re what’s used in most home sales, usually for at least 48 hours with windows and doors kept closed except for normal coming and going.
- Long-term tests run more than 90 days. Radon levels rise and fall with the weather and the seasons, so a long-term test gives you a better idea of your year-round average.
A homeowner can pick up a short-term kit at the hardware store, and it’s a fine place to start if you follow the directions closely. For a real estate deal, a professional test with a continuous monitor is the better choice, because it records readings hour by hour and gives everyone a result they can trust.
We offer radon testing on its own or with a home inspection, and you can find the price on our inspection pricing page.
4. High radon levels can be fixed
A high test result isn’t a reason to walk away from a house. Radon mitigation is a well-established fix, and most systems work the same basic way. A pipe and a quiet fan pull radon from under the slab, or from under a sealed plastic sheet in a crawl space, and vent it above the roofline before it can get inside.
Sealing cracks and openings helps, but on its own it usually isn’t enough to bring levels down. Mitigation systems are installed by radon mitigation contractors, and once yours is in, test again to make sure it’s working and keep retesting every couple of years.
A note on well water
If your home is on a private well, radon can also be in the water and get released into the air when you shower, wash dishes or do laundry. Most of the risk still comes from radon in the air, but if you’re on a well, it’s worth testing your water separately.
Buying a house? Test during due diligence
The best time to find out is before you close, while there’s still room to negotiate a mitigation system into the deal. Ask about adding a radon test when you schedule your inspection, or contact us with any questions.
