Jan 15, 2014 by Pauline Hammerbeck

"People love their granite countertops, though some now consider them too commonplace and prefer newer choices like quartz or quartzite. But theres another reason some segue from granite. They worry that it will emit radon, a colorless, odorless radioactive gas that comes from the natural breakdown of rocks and natural stones.

....

"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 contain more of these elements than others. These radioactive elements are solids, but, over time, they decay into radon, a colorless, odorless, radioactive gas, the EPA says.

"Are the levels of radon in granite countertops harmful?
Because granite isnt very porous (compared to other porous stones like sandstone) and because large quantities of it arent typically used in most single-family homes, the radon isnt likely to escape in a significant enough quantity to cause problems, says Hanson. Moreover, kitchens and bathrooms and other rooms that might contain granite are usually well ventilated, which lessens risks, he says.

"Emery 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 its 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.""

Here is a link that might be useful: Allstate.com Blog