How Radon Gets Into Homes

Drawing of house.

Radon can enter and collect inside almost any home or other building through dirt floors, hollow block walls, cracks in the foundation floor and walls, sump pumps, openings around floor drains, joints and foundation openings for pipes, sewers and other utility connections. Radon can also enter homes through water supplies obtained from wells or from small water systems utilizing groundwater. Once inside, the gas can become trapped and pose a health risk.

While radon problems may be more common in certain areas of the country, any home in any state may be affected including:

  • new homes
  • old homes
  • well sealed homes
  • drafty homes
  • homes with basements
  • homes built on slabs
  • homes with crawl spaces

Nearly one out of every 15 homes in the U.S. is estimated to have a high concentration at or above the EPA Action Level of 4 pCi/l. You cannot predict which homes will have high radon levels. Two identical homes next to each other can have different radon levels, depending on numerous variables, including how the home was constructed and lifestyle factors. The only way to know a building’s radon level is to test.

Adapted with permission of University of Nevada Cooperative Extension from the Nevada Radon Education Program website.