How Does Radon Get Into Your Home?
Radon is a radioactive gas. It comes from the natural decay of uranium that
is found in nearly all soils. It typically moves up through the ground to the
air above and into your home through cracks and other holes in the foundation.
Your home traps radon inside, where it can build up.
Radon levels in homes can fluctuate. Levels can be affected by a
number of factors, including weather, soil moisture, and air pressure.
Differences in the air pressure inside the home compared to air pressure outside
of the home can create a vacuum, called an air pressure differential, which
draws radon into the home. Normal activities such as using the furnace, the
bathroom fan, a whole house fan, or the clothes dryer will pull air into the
house which contributes to air pressure differentials. Because of this
fluctuation, it is best to test your home in the winter months, when radon
levels typically are higher.
Nearly 1 out of every 15 homes in the U.S. is estimated to have elevated
radon levels. Elevated levels of radon gas have been found in homes throughout
California. While radon problems may be more common in some areas, any home may
have a problem. You cannot predict which homes will have high radon levels. Two
identical homes on the same street can have different radon levels. The only way
to know a building's radon level is to test.
Radon has been
found in all types of homes,
well sealed homes
homes with basements
homes built on slabs
homes with crawl spaces
Radon and Building Materials
Some natural building materials, such as granite, stone and some concrete
products, can give off very small amounts of radon. However, building materials
rarely cause radon problems by themselves. Radon gas in soils is the primary
source of radon in homes. If your home has natural building products, including
granite countertops, it will generally not contribute a significant amount of
radon to the air in your home. If you still wish to test your granite
countertops or other material, there are specific granite test kits you can
purchase from test kit manufacturers. Handheld meters are not recommended. To reduce your radon risk you should first
test the air in your home to determine the radon level.
Any home may have a radon problem. The only way
to know is to test.