Thursday, June 26, 2008

Does Granite Release Radon? By ANN PORTER


Does Granite Release Radon?

Posted June 25, 2008

Recently, a video has circulated online that has created widespread consumer confusion and concern about radiation levels occurring in granite used for residential countertops.

The report from Houston area not-for-profit BuildCleanis raising fears about the dangers of granite countertops, and its preliminary results show that while most granite countertops in the study contain very little to no radon at all, the countertops that do contain radon have levels that are frighteningly high.

It has been reported that two major contributors of BuildClean are manufacturers of engineered stone. One of those contributing manufacturers is said to have a marketing executive on the board of directors. Is this a marketing ploy to switch consumers away from granite and toward engineered stone? I am not sure.

The Marble Institute of America (MIA) conducted a four-month study of thirteen of the most popular granites used for kitchen countertops in the United States during 2007 to refute claims that granite is harmful to consumers.

The MIA 's most recent testing was conducted by L.L. Chyi, a PhD and professor of Geochemistry and Environmental Geology at Akron University, Akron, OH.

Granite and most natural components found in building material, allows vapors to pass through them that might contain trace amounts of radon. However, for a compact rock with no internal porosity and fractures, like a polished granite countertop, only radium atoms in the very surface layer of countertop have a chance to generate radon atoms that escape quickly into the air of the nearby environment.

The MIA report did show their Crema Bordeaux sample tested higher (292 times) than the others. The testing methodology was designed to measure the amount of radon which each granite type would add to the interior of a 2,000 square foot, normally ventilated home with 8 ft ceilings. The results show that Crema Bordeaux would contribute a concentration component of less than 0.28 pCi/L, or less than 7% of the EPA's recommended actionable level of 4.0 pCi/L.

According to the Solid Surface Alliance Blog, Crema Bordeaux is one of the lower level Bordeauxs. They claim Juparana Bordeaux, shortened to Bordeaux, is one of the stones that must be tested prior to purchase.

They say rarely do you see a Bordeaux below 50 uR/hr Gamma and that a level of 25 uR/hr Gamma would cause alarm with local officials.

They also claim the EPA, changed their position in May and now suggest homes with granite have radon testing done. I could not find anything about countertops on the EPA website but in general they say all homes should be tested for Radon.

So from what may be perceived on the surface as another "going green" ad campaign, seems to be a different slant on the ongoing battle of the engineered stone manufacturers against natural stone.

Ann Porter, CKD, is a 15-year veteran of kitchen and bath design who is owner-founder of Kitchen Studio of Naples, Inc., providing customer-specialized service. See her portfolio and contact her at or at 597-4543.

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