Radon in Water

Many people are familiar with radon in indoor air, but radon in water is another potential hazard in the home. The risk for cancer is increased when the body is exposed to radon. Fortunately, there are ways to detect and remove this dangerous gas.

Radon is a radioactive gas that has no odor, taste or color. It occurs when uranium in the ground breaks down and dissolves into the water supply. This is a natural process that can expose people to radon in water that we drink and the air we breathe.

There are three main ways that radon enters the home. It can seep up from the soil and through cracks in foundations, be released from building materials such as granite and from groundwater obtained from drilled or artesian wells that contain radon in water.

While most well water contains radon in water, bedrock wells have the highest concentrations of radon in water. Water from the surface such as reservoirs and lakes see most of their radon released into the air before it reaches the water supplier and then the home.

Most health hazards come from breathing in radon rather than from radon in water. It can be released into the air from the water by activities that agitate water such as showering, laundering, cooking and dishwashing.

Radon in water may increase the risk of stomach cancer and cancer of internal organs. This risk is less than the risk of lung cancer from breathing in radon, especially in confined areas such as basements and attics. There is a clear link between large concentrations of radon in water and lung cancer. In fact, only cigarette smoking causes more lung cancer deaths.

While less than 1 percent of radon released into the air comes from drinking water, it still contributes to an increased risk of lung cancer when individuals are exposed over a lifetime. The EPA estimates that cancer caused by radon in water accounts for about 168 cancer deaths per year.

The highest levels of radon in water in the United States are found in Iowa and the Appalachian Mountain areas, especially southeastern Pennsylvania. Granite rocks from the Canadian Shield were ground into the soil by glaciers, releasing radon.
 
Radon can dissolve in water when it flows through granitic gravel and sand formations or through granite. Landfills containing uranium tailings have been known to increase exposure to radon in water.

Testing for radon in water is relatively inexpensive. For around $25-$50 a water test kit can be purchased. The Safe Drinking Water Hotline provides information about radon in water.

Radon in water levels should be no higher than 4,000. This level will release about 0.4 of radon into the air. Some states require radon in water levels to be 300 with about 0.03 of that contributing to radon in the air. Most scientific and health organization concur that there is no level of radon that can truly be considered “safe” so mitigation of radon from the water supply is always good practice.

There are two main ways to reduce radon in water; they include granular activated charcoal and aeration treatment. Granular activated charcoal involves filtering water through a charcoal bed, and aeration involves mixing water with air or spraying the water so that the radon is vented to the outdoors
Radon in water can pose a health risk to individuals yet there are ways to detect and reduce these risks. Contacting a state certification officer and obtaining radon in water tests will put your mind at ease as you take proactive measures to protect yourself and your family from this cancer causing radioactive gas.