Radon
What is radon? When should I take action?
Radon is a naturally occurring radioactive gas that you can't see, taste, or smell. It is produced by the breakdown of uranium in soil, rock, and water. Radon is measured in picocuries per liter (pC il L) of air. EPA recommends that action be taken to reduce radon levels if the annual average is 4 pCi/L or higher.
Where is radon found?
All rocks contain some uranium, although most contain just a small amount. Certain types of rock, including granites, dark shales, light-colored volcanic rocks, sedimentary rocks containing phosphate, and metamorphic rocks derived from these rocks, have higher than average uranium contents. The radon gas from the soil can enter a home or building through dirt Ooors, hollow-block walls, cracks in the foundation Ooor and walls, and openings around floor drains, pipes, and sump pumps.
Radon is more concentrated in the lower levels of the home (that is, basements, ground Ooors, and first floors) . Radon problems have been identified in every state. The U.S, Environmental Protection Agency (EPA) estimates that one in 15 homes in the United States has an elevated radon level (4 pCi/L or more). You can't know if you have a radon problem unless you test.
