Radon is a tasteless, colorless and odorless gas that is a decay product of uranium and occurs naturally in soil and rock. Radon gas has been identified as the second leading cause of lung cancer, second only to cigarette smoking, and it is estimated to be responsible for 15,000 deaths annually. Radon breaks down into components called radon progeny, sometimes called "radon daughters," which emit high-energy alpha particles. These emissions raise the risk of lung cancer.
Radon problems have been identified in every state. The U.S. Environmental Protection Agency (EPA) estimates that nearly 1 out of every 4 homes in Pennsylvania has indoor radon levels at or above the EPA's recommended action guideline level of four picocuries per liter of air (pCi/L) on a yearly average. Radon can be a problem in schools and work places, too.
HOW DOES RADON GET INDOORS?
Radium, which releases radon, is common in the earth's crust. Soils and rocks containing high levels of uranium, such as granite, phosphate, shale and pitchblende are natural sources of radon.
High levels of radon in the soil are primarily responsible for radon problems. The radon gas percolates up through porous soils under the home or building and enters through gaps and cracks in the foundation or in the insulation and through pipes, sumps, drains, walls or other openings.
Water is another possible pathway for bringing radon into the home. Water, when in contact with rock containing uranium, absorbs the radon gas. The radon is then carried into the home and released into the air in household dishwashers, faucets, showers, or washing machines.
Water-related radon problems usually involve deep private wells rather than community water supplies.
In some unusual situations, radon may be released from home construction materials such as stone used to build fireplaces or solar heating storage systems.
Radon is not a problem outdoors because it is quickly diluted to low levels by outdoor air.
Today's technology can reduce indoor radon levels to below 4 pCi/L; in most cases, to 2pCi/L or less.
A variety of methods are used to reduce indoor radon levels, from sealing cracks in floors and walls to changing the flow of air into the home. Simple systems, known as sub-slab depressurization, use pipes and fans to remove radon gas from beneath the concrete floor and foundation before it can enter the home. Radon is vented above the roof, where it safely disperses.
Other methods may also work in your home. The right system depends on the design of your home and other factors.
Lowering high radon levels requires technical knowledge and special skills. You should use a contractor who is trained to fix radon problems. The EPA Radon Contractor proficiency (RCP) Program tests these contractors. A trained RCP contractor can study the radon problem in your home and help you choose the right treatment method.
Check with your local American Lung Association or state radon office for names of EPA- qualified or state-certified radon contractors in your area. As when hiring a contractor for any other home repair, you may want to get more than one estimate.
The cost of making repairs to reduce radon depends on how your home was built and the extent of the radon problem. Most homes can be fixed for about the same cost as other common home repairs.
Today, homes can be built to reduce the amount of radon coming in by using radon-resistant construction features. Radon-resistant construction features usually keep radon levels in new homes below 2 pCi/L.
HELPFUL RADON LINKS:
DEP of Pennsylvania- Radon Division
LungUSA- What is Radon?
EPA- Indoor Environments
National Radon Profienency Program- Radon Gas