OTHER RADON SOURCES IN THE HOME
Radon in Water
The radon in your water supply poses an inhalation risk and an ingestion risk. Research has shown that your risk of lung cancer from breathing radon in the air is much greater than your risk of stomach cancer from swallowing water with radon in it. Most of your risk from radon in water comes from radon released into the air when you use water for showering and other household purposes.
Radon in your home's water is not usually a problem when the water source is surface water. A radon problem is more likely when the source is groundwater (e.g., a private well or a public water supply system that uses groundwater). If you're concerned that radon might be entering your home through the water and your water comes from a public water supply, contact your water supplier.
If you've tested your private well and have found a radon problem, it can be fixed. Your water supply can be treated in two ways. Point-of-entry treatment can effectively remove radon from the water before it enters your home. Point-of-use treatment devices remove radon from your water at the tap, but do not treat other sources of water in the home, such as the shower, toilet, washing machine, or hose. Point-of-use treatment devices are not effective in reducing the risk from breathing radon released into the air from the non-treated sources in your home. For more information on radon in drinking water, see http://www.epa.gov/radon/rnwater.html.
Radon in Granite Countertops and Flooring
There is some concern about the possibility of granite kitchen countertops and flooring materials emitting radon. EPA has compiled a list of common concerns about indoor air quality. For more information please review http://www.epa.gov/rpdweb00/tenorm/granite-countertops.html.