Radon is odorless, colorless, and tasteless; it is an inert noble gas. Radon is a naturally-occurring, carcinogenic, radioactive gas produced by the decay of radium in the soil. Radon gas exposure is the greatest single source of natural, ionizing, background radiation, only surpassed by medical radiation.
Generally, the air inside your home is is lower-pressure than outdoor air. Inside your home, warm air rises and must be replaced with air from outside. Your house can draw up to 20% of the air inside your house from the soil below it.
Cracks, gaps, joints, and cavities in basement floors, walls, and around service openings like water pipes, drains, electric junction boxes, and sump pump pits, allow soil gas to enter the building through the loose, disturbed gravel and soil surrounding your home’s construction.
The conditions necessary for radon in soil gas to enter your home are present through common construction methods, including filling excavation for basements and crawlspaces with loose earth and gravel, allowing the gas to pas through into a home through cracks and gaps in the foundation—even through the hollow cores of block walls.
As radon gas is trapped in your house and builds up inside the lower levels, it will rise with warm air into living spaces. As air is moved throughout your house by fans or heating or air conditioning system, the concentration of radon gas may be little different in the upper levels than in the basement.
As the radon gas inside your house undergoes radioactive decay, it releases ionizing radiation, and airborne radioactive decay products.
How do I lower the radon in my home?
It is impractical and impossible for a homeowner to prevent radon from entering the home through caulking and sealing visible cracks. The only recommended method of remediation is through soil depressurization by a licensed radon remediation professional.
The EPA recommends that every home be tested for radon. Changes to your home such as additions, remodeling, or even a new roof or siding can change the level of radon inside your home.