According to "What’s Lurking in Your Countertop?" (http://www.nytimes.com/2008/07/24/garden/24granite.html?_r=1&ref=health
), a recent article in the New York Times, one company sells 900 different kinds of granite, and "with increased sales volume and variety, there have been more reports of 'hot' or potentially hazardous countertops, particularly among the more exotic and striated varieties from Brazil and Namibia." You can get a Geiger counter or a home radon inspection kit (though I've read that these are not accurate). I would recommend hiring a licensed home inspector to do a radon check on the countertop in question -- and while they're at it, they should do a full test on your entire house). According to Accurate Inspections (http://accurateinspections.com/radon.htm
), "Radon levels less than 4 pCi/L still pose a risk, and in many cases, may be reduced." The New York Times article also writes that "The E.P.A. recommends taking action if radon gas levels in the home exceeds 4 picocuries per liter of air (a measure of radioactive emission); about the same risk for cancer as smoking a half a pack of cigarettes per day." I have read of instances where granite countertops are registering up to 9 picocuries. I guess that's like smoking more than a full pack of cigarettes! Scary!