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. Any home may have
a radon problem. This means new and
old homes, well-sealed and drafty
homes, and homes with or without basements.
Radon can enter the home through cracks
in solid floors, walls, construction
joints, gaps in suspended floors and
around service pipes, wall cavities
and the well water supply.
The two main methods used for radon testing involves the use of a "passive" device such as an activated charcoal test kit which collects radon gas atoms for counting in a laboratory, or an alpha track device which uses a small strip of special plastic that is marked when hit by radon's alpha particles. The other main method is the use of an "active" device called a CRM (continuous radon monitor). The latter is for short term testing, usually 2 days, during real estate transactions or other reasons for the need for immediate results. The main purpose of the passive method testing is for a radon "screening measurement" to determine if there is a potential radon problem in the home and the need for additional long term testing.