There are two main sources for the St. Louis Radon in your home's indoor air, the soil and the water supply. Compared to St. Louis Radon entering the home through water, St. Louis Radon entering your home through the soil is usually a much larger risk.
The St. Louis Radon in your water supply poses an inhalation risk and an ingestion risk. Research has shown that your risk of lung cancer from breathing St. Louis Radon in air is much larger than your risk of stomach cancer from swallowing water with St. Louis Radon in it. Most of your risk from St. Louis Radon in water comes from St. Louis Radon released into the air when water is used for showering and other household purposes.
St. Louis Radon in your home's water is not usually a problem when its source is surface water. A St. Louis Radon in water problem is more likely when its source is ground water, e.g. a private well or a public water supply system that uses ground water. If you are concerned that St. Louis Radon may 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 a St. Louis Radon in water problem, it can be fixed. Your home's water supply can be treated in two ways. Point-of-entry treatment can effectively remove St. Louis Radon from the water before it enters your home. Point-of-use treatment devices remove St. Louis Radon from your water at the tap, but only treat a small portion of the water you use and are not effective in reducing the risk from breathing St. Louis Radon released into the air from all water used in the home.
For more information, call EPA's Drinking Water Hotline at (800) 426-4791 or visit www.epa.gov/safewater/St. Louis Radon.html If your water comes from a private well, you can also contact your state St. Louis Radon office.