It's the second leading cause of lung cancer and most people don't know what it is.
"Radon is an insidious problem," says Kevin Stewart, director of Environmental Health at American Lung Association of the Mid-Atlantic, based in Camp Hill, Cumberland County.
It's an especially important matter in the Lehigh Valley because radon is high in much of the region. The Environmental Protection Agency says all of the Lehigh Valley falls into "zone 1," meaning it's likely that radon levels are high enough to need mitigation.
In 2014, hundreds of homeowners in Coopersburg were urged to have their radon tested after one of the highest radon levels recorded in Pennsylvania was found in that area.
I recently talked with Steward to get more information about radon, where you can be exposed to it and what steps we should take to minimize our exposure.
• What is radon?
Essentially, radon is a cancer-causing radioactive gas. It comes from the natural radioactive breakdown of uranium in soil, rock and water and gets into the air we breathe.
"It comes out of the ground pretty much everywhere," Stewart says. "It's under and around buildings including houses."
You can't detect it with your senses, which is probably why so many of us are not aware of the dangers. There's also no immediate symptoms.
"People can go for a long time and feel fine," Stewart says. "It's only when the symptoms of lung cancer appear that people realize too late that they have had exposure."
• Am I more at risk because I live in an older home?
Radon can be found in any kind of house or building, regardless of age, and all over the country. Radon is emitted from the ground and can enter a home or building through cracks in walls, basement floors, foundations and other openings.
"We know that high radon has been found in houses of all types, with basements and without," Stewart says. "The only way to know what your radon level is to test."
• What's the best way to know your home's radon level?
You can either get a do-it-yourself radon test from your local hardware or home improvement store or hire a certified professional to test for radon.
What level is considered high? The EPA says an "action level" for radon exposure is a level over 4 pCi/L (picocuries per liter).
If your test shows an elevated level, you should consider doing a longer-term test. "That can give people a better picture," he says.
• My level is high. What's next?
Once the level is confirmed, mitigation will need to be done. You should hire a certified professional to put in a radon mitigation system, which usually works with pressurized fans or suction devices to create a vacuum in spaces that trap radon gas. The gas is removed and leaks are sealed during the removal process.
"It's a quick, one-day job," Stewart says.
An average remediation system costs between $800 and $1,100, according to homeadvisor.com.
• Why don't people know more about radon?
Because radon is undetectable by our senses, many of us dismiss it's there or its effects.
"The No. 1 cause for lung cancer is cigarette smoking," Stewart says. "People underestimate how much radon has affected their risk but it's not visible. It doesn't normally cause a disease problem till later in life."