Which Granites Have High Radon Emissions?

The highest radon emissions from granite are found in the reds, browns and earthy colors. Black generally emits the lowest. Within the range of colors, other factors determine the amount of radon escaping into the surrounding air. "Granite is a natural product, no way to know which sample or slab will have more uranium, thus more radon emission than the other." (http://solidsurfacealliance.org/blog/2008/06/06/safe-granites/)

Source of radon

• Radon is a health hazard

  Radon is produced by the natural process of uranium decaying, thereby releasing the odorless, colorless and tasteless gas into the surrounding air. It is present throughout the world.

  Scientists are unable to pinpoint the amount of radon emitted by any specific type of granite, as the measurement varies from slab to slab.

How radon is measured

• Radon is measured in picocuries per liter of air (pci/l). The EPA (Environmental Protection Agency) recommends people take action to ventilate an area when the level reaches 4 pci/l. They also caution that as little as 2 pci/l may be a health risk. The organization "Build Clean" (http://buildclean.org/?id=249) quotes The New York Times as saying, "4 picocuries is about the same risk for cancer as smoking a pack of cigarettes per day."

  Homeowners can measure radon with inexpensive equipment starting under $20.00 as of April 2010. If the results are 2 pci/l or more, professional testing is a recommended option.

The dangers of radon

• Granite - stylish and easy to clean

  As radon gas dissipates, it leaves particulate in the air. This is inhaled and deposited in the lungs where, over time, it can pose a growing risk of lung cancer.

  According to The Marble Institute of America, "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."

  The public's interest in radon and granite has come to the forefront because of the increased popularity of granite and similar natural materials in home decoration.

Mitigatiion of radon gas

• If the level of radon in a home is too high, mitigation is quite simple. Air circulation via fans and opening windows is the immediate, short-term solution. Long-term is also easy to accomplish but is likely to be more costly. Because radon rises, it is best to focus the strongest ventilation at the lowest point of the house. It seldom reaches dangerous levels above the third floor.

  Energy efficient housing has complicated the radon problem. Sealing a house to conserve energy also seals in the gas, requiring more sophisticated venting. At this point it is wise to consult engineering advice either in person or print.

Summary

• Sitting on a stone park bench will probably have no effect on your health

  The person wanting to use granite will have to weigh the importance of fashion over health. Both are compatible in moderation. If it is to be used outdoors, the effect is negligible.