Granite countertops stir debate over radon emissions
By Valerie Christopher
Granite countertops have been a red-hot product for several years, so when news reports recently revisited the topic that sometimes granite can truly be "hot," as in radioactive, Josh Crouch of Atlanta took offense. Granite is his livelihood and he says the criticism is misguided.
"They're making a mountain out of a molehill," says Crouch, president of Atlanta Intown Granite. "If I believed it was harmful, I wouldn't have granite in my home - on my kitchen countertops, bathroom and columns. How could I possibly sleep at night knowing that I am selling a product that's potentially life-threatening?"
The issue Crouch is referring to is whether some granite countertops emit dangerous levels of radiation, especially radon, a radioactive gas released from the normal decay of uranium in rocks and soil. Experts agree that most granite emits some radon, but the Environmental Protection Agency says the amount typically is not near 4 picocuries per liter, the level at which it recommends mitigation. Regardless, the agency recommends all homeowners test for radon, the second-leading cause of lung cancer.
Rice University physicist William Llope says he found potentially dangerous levels of radiation in 60 tested samples of retail granite. Llope says that potentially the most dangerous aspect of granite is not radon, or beta, radiation, but direct, or gamma, radiation.
"Only the admixture of uranium ore results in both direct radiation and the long-lived radon that the EPA warns about," he writes on his website, wjllope.rice.edu. "Natural stone can also contain Potassium-40 and Thorium-232, and these radionuclides and their progeny produce (gamma) radiation that could also potentially be a whole-body health risk."
In an interview with Angie's List Magazine, Llope said direct radiation is hard to mitigate.
"If you are in a kitchen with a hot countertop, you are getting a dose," Llope says. "The only mitigation would be to cover the countertop with 6 inches of lead, or to never go in the kitchen."
Alison and Stephen Hersch, of Atlanta, say they've read the reports about radiation in granite countertops, but bought them anyway.
"We haven't thought a thing about it. We're enjoying our granite," Alison says. "We're not alarmist people. I believe newspapers have to sell papers. It doesn't mean I won't get a radon test someday. If I have it, I will have (the radon) removed."
Two years ago, Coby and Daine Pearson bought granite kitchen countertops and say they couldn't be happier. "My countertop isn't going out of my kitchen," Coby says. Originally from Europe, she says "Americans have a tendency to overreact about things."
Llope, who says he will release his full findings once they are accepted by a peer-reviewed journal, offers the following advice in the meantime:
*Don't assume your granite countertops are excessively radioactive. Most aren't.
*If you are worried about it, get them tested for both radon and radiation. Interpreting the results can be tricky (many professionals make mistakes), so discuss them with other experts.
Llope also says sealants won't stop radiation.
"These gammas can happily travel through several inches of lead," he says. "So a thin layer of some sealant is irrelevant to the radiation rate."