Do Granite Countertops Emit Radon? (And Other Radon FAQs)
People love granite countertops, though some 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? Here are some frequently asked questions about radon and the risks associated with granite.
Why is radon a possibility with granite?
Like all rocks, granite may contain naturally-occurring radioactive elements like radium, uranium and thorium. Some pieces of granite may 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).
Are the levels of radon in granite countertops harmful?
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 agrees. “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,” Emery says.
A greater risk of radon exposure comes from the radon originating in soil beneath a home’s foundation and radon in well water, says Hanson
OK, so the risk from granite is ‘minuscule.’ But, how common is radon in U.S. homes overall?
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 makes its way up from the ground and into your home through cracks and other holes and gaps in the foundation.
What is a safe versus unsafe radon level?
All houses have some level of radon. The national 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 install a mitigation system to help lower levels. Testing is the only way to know what level of radon your home has.
What does a radon test involve?
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 representatives that manage 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, as it requires 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.
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.
How expensive is radon mitigation?
If a home contains a high level of radon, 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.
What safeguards should I take if I build a new home?
Be sure a builder uses radon-resistant new construction, says the EPA, which involves sealing openings, cracks and crevices in a concrete foundation and walls to help prevent radon and other soil gases from entering. Installing a vent pipe from the gravel layer through the home and roof may also help vent away gases. If the house’s water supply comes from a well, filter systems can be installed, says Emery. Do not rely on geology maps indicating radon zones, which may be outdated — get a radon test done, 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.
What if I still have a problem?
The EPA offers an extensive list of information sources. You can also contact the Radon Hotline run by Kansas State University by calling 1-800-SOS-Radon (767-7236).
No matter if you’re installing new granite countertops in your kitchen or looking to buy a new home, testing for radon is a simple way to help confirm the levels in your home are safe.
Originally published on January 1, 2017.