Monday, October 20, 2008
Home should be checked for radon
By Ann Robinson and Annie Schwemmer
All of us face a variety of risks to our health as we go about our daily lives.
Driving in cars, flying in planes and being exposed to environmental pollutants all pose varying degrees of risk. Some risks are unavoidable; others we accept so as to not restrict our lives; and some we might choose to avoid if we only knew better.
Indoor air pollution is one risk that you can do something about.
Last week we talked about waterproofing your home using air barriers, vapor barriers and moisture barriers. These waterproofing systems essentially make your home's building envelope air tight — which is a great thing for energy efficiency (keeping your home the temperature you want it to be without too much strain on your HVAC systems).
But tight homes can pose a problem for indoor air quality. Just as they trap the heat in the winter, tight homes can also trap pollutants in the air your family is breathing.
One of the most dangerous indoor air pollutants is radon.
Radon is a gas you can't see, smell or taste. Radon is estimated to cause many thousands of deaths each year because when you breathe air containing radon, you can get lung cancer. In fact, it is the second-leading cause of lung cancer next to smoking.
Radon is a radioactive gas that comes from the natural decay of uranium 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.
According to the EPA, nearly one out of 15 homes in the United States is estimated to have elevated radon levels. Radon from soil gas is the main cause, but sometimes radon enters the home through well water. In a small number of homes, the building materials can give off radon, too. However, building materials rarely cause radon problems by themselves.
Because there is no way to detect radon with the human senses, you should test your home for elevated levels.
The quickest way to do that is with short-term tests. Short-term tests remain in your home for two days to 90 days, depending on the device. "Charcoal canisters," "alpha track," "electret ion chamber," "continuous monitors" and "charcoal liquid scintillation" detectors are most commonly used for short-term testing.
Because radon levels tend to vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level. If you need results quickly, however, a short-term test followed by a second short-term test may be used to decide whether to fix your home.
If you want to perform the radon test yourself, you can order a test kit from www.radon.utah.gov. Also, professional radon inspectors can be found in your local listings and online. The National Environmental Health Association provides a list of radon inspectors who are certified through the National Radon Proficiency Program.
There are several proven methods to reduce radon in your home, but the one primarily used is a vent pipe system and fan, which pulls radon from beneath the house and vents it to the outside. This system (known as a soil suction radon reduction system) does not require major changes to your home, but sealing foundation cracks and other openings makes this kind of system more effective and cost-efficient. Similar systems can also be installed in houses with crawl spaces. Radon contractors can use other methods that may also work in your home. The right system depends on the design of your home and other factors.
It costs about $1,200 for a contractor to fix a radon problem, although this can range from about $800 to about $2,500. The cost is much less if a passive system was installed during construction.
If you are planning any major structural renovation, such as converting an unfinished basement area into living space, it is especially important to test the area for radon before you begin the renovation. If your test results indicate a radon problem, radon-resistant techniques can be inexpensively included as part of the renovation. Because major renovations can change the level of radon in any home, always test again after the work is completed. As always, we welcome your home architect design questions at firstname.lastname@example.org.