People love their granite countertops, though some now consider them too commonplace and prefer materials such as quartz or quartzite. But there’s another reason some segue from granite. They may worry that it will emit radon, a colorless, odorless radioactive gas that comes from the natural breakdown of rocks and natural stones.
So, are granite countertops a real risk? Since January is Radon Action Month, this is a good time to learn all you can about potential risks of radon in granite and elsewhere in your home. Here are some frequently asked questions about radon.
Like all rocks, granite may contain naturally occurring radioactive elements like radium, uranium and thorium. Some pieces of granite contain more of these elements than others. These radioactive elements are solids, but, over time, they may decay into radon, says the Environmental Protection Agency (EPA).
Because granite isn’t very porous and large quantities of it aren’t typically used in most single-family homes, the radon isn’t likely to escape in a significant enough quantity to potentially cause problems, says Brian Hanson, a specialist with the National Radon Program Services at Kansas State University. Moreover, kitchens, bathrooms and other rooms that might contain granite are usually well ventilated, which may lessen the risks, he says.
Robert Emery, DrPH, vice president of safety, health, environment, and risk management at the University of Texas, Health Science Center concurs, saying, “From published scientific literature, it seems that the amount of radon from granite countertops is minuscule. The decision whether to use it or rip it out if it’s already in a house you buy really becomes a personal decision about what products you bring into your home — similar to whether to use traditional paints or those with only no or low-VOC compounds.”
A greater risk is radon originating in soil beneath a home’s foundation and radon in well water, says Hanson.
The EPA says that approximately one of every 15 homes throughout the country, whether new or old, has elevated radon levels. Radon that originates in the soil is the main cause of radon problems, the EPA says; the gas moves up from the ground and into your home through cracks and other holes and gaps in the foundation.
All houses have some level of radon. The U.S. average for indoor radon levels is 1.3 picocuries per liter (pCi/L), the EPA says. The agency also recommends all homes that test at or above 4 pCi/L be mitigated to lower levels. Testing is the only way to know what level of radon your home has.
The test is simple when it involves measuring your home’s air. According to the EPA, you may purchase a do-it-yourself kit by contacting your state’s radon program, at a home improvement store or through the National Radon Program Services at Kansas State University.
Testing your granite countertops for radon is typically more expensive, requiring more sophisticated equipment and the expertise of a qualified radon mitigation expert, who still may not be able to indicate the percentage of indoor radon attributable to granite. You can find a professional by accessing the American Association of Radon Scientists and Technologists’ website. Testing costs may vary.
Besides concern for your family’s health, you may want to know your radon levels if you plan to sell, since most buyers will want proof of low levels or may request a test.
The cost to mitigate soil may run $1,500, though treating well water is higher — about $2,000 or so, says Hanson. The EPA has some tips on how to find contractors to help fix your home.
Be sure a builder uses radon-resistant new construction, which involves sealing openings, cracks and crevices in a concrete foundation and walls to help prevent radon and other soil gases from entering, and installing a vent pipe from the gravel layer through the home and roof to help vent away gases. If the house uses well water, filter systems can be installed, says Emery. Do not rely on geology maps indicating radon zones, which may be outdated; get a test, he says.
Similarly, the EPA advises that radon zone maps shouldn’t be used to determine whether a home should be tested. Homes with elevated radon levels can be found throughout the country, the agency says, and all homes should be tested, period.
The EPA offers a list of information sources. You can also contact the Radon Hotline run by Kansas State University by calling 1-800-SOS-Radon (767-7236).
Originally published January 15, 2014.