SHORTLY before Lynn Sugarman of Teaneck, N.J., bought her summer home in Lake George, N.Y., two years ago, a routine inspection revealed it had elevated levels of radon, a radioactive gas that can cause lung cancer. So she called a radon measurement and mitigation technician to find the source. “He went from room to room,” said Dr. Sugarman, a pediatrician. But he stopped in his tracks in the kitchen, which had richly grained cream, brown and burgundy granite countertops. His Geiger counter indicated that the granite was emitting radiation at levels 10 times higher than those he had measured elsewhere in the house. “My first thought was, my pregnant daughter was coming for the weekend,” Dr. Sugarman said. When the technician told her to keep her daughter several feet from the countertops just to be safe, she said, “I had them ripped out that very day,” and sent to the state Department of Health for analysis. The granite, it turned out, contained high levels of uranium, which is not only radioactive but releases radon gas as it decays. “The health risk to me and my family was probably small,” Dr. Sugarman said, “but I felt it was an unnecessary risk.” As the popularity of granite countertops has grown in the last decade so have the types of granite available. For example, one source, Graniteland (graniteland.com) offers more than 900 kinds of granite from 63 countries. 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. “It's not that all granite is dangerous,” said Stanley Liebert, the quality assurance director at CMT Laboratories in Clifton Park, N.Y., who took radiation measurements at Dr. Sugarman's house. “But I've seen a few that might heat up your Cheerios a little.” Allegations that granite countertops may emit dangerous levels of radon and radiation have been raised periodically over the past decade, mostly by makers and distributors of competing countertop materials. The Marble Institute of America has said such claims are “ludicrous” because although granite is known to contain uranium and other radioactive materials like thorium and potassium, the amounts in countertops are not enough to pose a health threat. Indeed, health physicists and radiation experts agree that most granite countertops emit radiation and radon at extremely low levels. They say these emissions are insignificant compared with so-called background radiation that is constantly raining down from outer space or seeping up from the earth's crust, not to mention emanating from manmade sources like X-rays, luminous watches and smoke detectors. But with increasing regularity in recent months, the US Environmental Protection Agency (EPA) has been receiving calls from radon inspectors as well as from concerned homeowners about granite countertops with radiation measurements several times above background levels. 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. In Dr. Sugarman's kitchen, the readings were 100 picocuries per liter. In her basement, where radon readings are expected to be higher because the gas usually seeps into homes from decaying uranium underground, the readings were 6 picocuries per liter. The average person is subjected to radiation from natural and manmade sources at an annual level of 360 millirem (a measure of energy absorbed by the body), according to government agencies like the EPA and the Nuclear Regulatory Commission US . The limit of additional exposure set by the commission for people living near nuclear reactors is 100 millirem per year. To put this in perspective, passengers get 3 millirem of cosmic radiation on a flight from New York to Los Angeles. A “hot” granite countertop like Dr. Sugarman's might add a fraction of a millirem per hour and that is if you were a few inches from it or touching it the entire time. Nevertheless, there is no known safe level of radon or radiation and scientists agree that any exposure increases your health risk.” A granite countertop that emits an extremely high level of radiation, as a small number of commercially available samples have in recent tests, could conceivably expose body parts that were in close proximity to it for two hours a day to a localized dose of 100 millirem over just a few months. Radon is the second leading cause of lung cancer after smoking and is considered especially dangerous to smokers, whose lungs are already compromised. Children and developing fetuses are vulnerable to radiation, which can cause other forms of cancer. David J. Brenner, director of the Center for Radiological Research at Columbia University in New York, said the cancer risk from granite countertops, even those emitting radiation above background levels, is “on the order of one in a million.” Being struck by lightning is more likely. Nonetheless, Dr. Brenner said, “It makes sense. If you can choose another counter that doesn't elevate your risk, however slightly, why wouldn't you?” __
