Granite countertops are increasingly popular in modern kitchens. They’re so popular, in fact, that more than 900 kinds of granite are known to be commercially available in the US residential construction market. Granite sold for countertops in the US comes from at least 63 countries as far flung as Namibia and Brazil.
A report in yesterday’s New York Times (NYT) suggests the possibility that the mineral content of those beautiful granite countertops may include minerals that are naturally radioactive, meaning they emit toxic fumes into the environment as they decay. Mineral content varies from one kind of granite to the next and is often the factor behind the distinctive colors in the stone. Because mineral content varies, so does the level of radioactivity in the stone.
Uranium, thorium, and potassium are just some of the radioactive minerals that might be in a granite countertop. As countertops are used, they emit radon and radiation into the near vicinity. Radon is the #2 leading cause of lung cancer.
Everyone is exposed to radiation every day. It streams down through the air from the far reaches of the cosmos. It seeps up from the center of the earth. Smoke detectors, watches with LED-crystal faces, and the x-rays doctors rely on all emit radiation, too, so it’s impossible to strictly avoid exposure.
Radioactivity is measured in picocuries, with 4 picocurries raising the threat of cancer by about the same degree as smoking half a pack of cigarettes a day. In the NYT report, some of the granite samples tested as high as 100 picocurries.
Radiation tests can be conducted to measure the toxicity of installed granite countertops, floors, and other decorative touches. Even though a counter top is tested and found “hot,” the countertop may still be safe to live with. The danger of radiation is directly related to proximity and length of exposure. The radiation emitted by most countertops isn’t strong enough to cause any harm under normal kitchen use. Where radiation levels are highest, a person would have to remain within inches of the countertop for hours before absorbing a measurable amount of radiation.
Nevertheless, caution is advised in households where smokers or lung-cancer patients are expected to spend time in rooms finished in granite. To minimize harm to children, small children and pregnant women should limit time around granite, too.
Source: NYT