(HealthDay News) -- Radon, an invisible radioactive gas that seeps into homes through foundation cracks, causes 100 times more deaths than carbon monoxide poisoning, says the U.S. Environmental Protection Agency.
To heighten awareness of that potential danger, the agency has designated January as National Radon Action Month.
Radon is the second leading cause of lung cancer behind smoking, and about 20,000 people in the United States will die this year due to breathing too much radon without even knowing it, the EPA said.
"It's remarkably easy to protect our loved ones by testing for radon and building new homes with radon-resistant features that allow everyone to breathe freely and safely," EPA Deputy Administrator Marcus Peacock said in a prepared statement.
As part of the National Radon Action Month, the EPA has released public service announcements about how people can protect themselves against radon, which is emitted by underground sources of uranium and can reach harmful levels if trapped indoors.
About one in 15 homes in the United States have a high radon level, the EPA said.
The first step in protection is to check your house with an easy-to-use radon test kit. If high levels of radon are detected, a venting system can be installed by a contractor. During construction of new homes, it's easy to include radon-resistant features and home buyers should ask for these, said the EPA, which also recommended that new home buyers ask their builder to test for radon gas before they move in.
Over the past 20 years, radon preventive actions have saved about 6,000 lives, according to the EPA, which wants to double that number over the next five years.
The American Lung Association has more about radon.