Radon in Granite: Understanding Risks and Mitigation

The demand for natural stones such as granite, marble, and limestone in home decor has grown substantially in recent years. Consumers have made granite the most popular stone for kitchen counter-tops. However, several studies in the past few years have shed light on an alarming fact. Some granite slabs used in consumer homes emit higher than average levels of radon and radiation causing some concern as to the consequential health effects. Radon exposure is the second leading cause of lung cancer next to cigarettes. In the studies done so far, most granite on the market contain negligible amounts of radon. However, two exotic granites have been designated as possibly having high levels of radon emission.

Brazilian Granite

• Brazilian granite is known for its rich dark colored variations and its beautiful golden and blue variations. Some suspect that Brazilian granite mines may contain high concentrations of uranium ore. High uranium concentrations increase the likelihood of taking granite samples which emit higher than normal levels of radon and radioactive material. Early preliminary reports suggest Brazilian granite, most notably the striated variation have unusually high levels of radon emission. Popular striated versions include Giallo Vicenza, Blue Coffee, Bordeaux, Cinza Prata and many others.

Namibian Granite

• Namibian granite is best known for its Tropical Sun variation. Other names for this yellow hued granite include Spitzkop, Giallo Africa, Spitzkoppe, and Namibia yellow. The granite shown emitting high levels of emissions were also more striated. Namibia blue is also extremely veined and striated. Namibia blue exists in limited available quantities. Another type of Namibian granite, Bianco Rhino, may also emit higher radon levels. Preliminary studies also suggest that these exotic granites may possess uranium ores in higher amounts resulting in increased radon emission.

Other Granite variations

• Geologists still know very little about which granite types specifically emit the highest levels of radon. With over 2700 granite varieties it may be tough to identify granite with high radon emissions. However, a radon inspector or detector kit can easily identify if the slab of a particular granite type emits high levels of radon. Hiring a radon inspector can cost several hundred dollars. Radon kits can also differentiate between normal radon levels and unusually high levels in granite. Some stones contain above average levels of Uranium nuclei that radioactively decays into Radium, the source of the dangerous and unstable gas Radon. Breathing in radon exposes biological tissues directly to radioactive elements and can increase the chances of developing lung cancer. So far, scientists know very little about which countertops emit highest amounts of radon and many granite manufacturers or distributors deny any negative allegations. Aside from avoiding the exotic Brazilian varieties, have all granite slabs tested prior to in home installation.