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Tag: Chemical Sealant In what seems to be a genuine concern of the effects of radon emissions in residential homes. A certain website from a non-profit organization out of Houston has made it a point to imply withoutThe allusion that seems to be made, that natural stone installed in your home is dangerous to your health is raised repeatedly on the websiteand in a recent local Houston TV news program.It's interesting to note that the two major contributors of this non-profit organization are manufacturers of engineered stone. One of those contributing manufacturers has a marketing executive on the board of directors of this particular organization.From what may be perceived on the surface as perhaps another 'going green' ad campaign, seems to be a different slant on the ongoing battle of the engineered stone manufacturers against natural stone.Keep in mind that granite as does most natural components found in building material, allows vapors to pass through them that might contain trace amounts of radon. There are very small amounts of uranium found in trace minerals such as biotite in some natural stones. When quarried if a large cluster of biotite is exposed the result initially would be a radon reading. However, once a piece of granite or natural stone exposed to a large amount of uranium rich mineral in the ground is removed from the source and exposed to the air, the radon vapor transmission would weaken drastically and then dissipate. Simply put, think of natural stone as a very dense sponge that allows water, air and yes radon to pass through the stone. Once the stone is removed from the source of radon (the earth) the stone has no radon to filter through it.We do endorse Radon testing but to allude that natural stone is a main contributor seems ludicrous.To Quote Donald Langmuir, PhD, Professor Emeritus of Geochemistry, Colorado School of Mines, & President, Hydrochem Systems Corp.'To show how laughable are the concerns of radon emitted from natural stone, the typical granite countertop in our example will release 7.4 x 10 -7 pCi/L of air. This corresponds to 2.7 x 10 -8 atom decays per second (dps). This represents 0.85 decays per year. In other words, less than one atom of radon is produced by the countertop in one year. This is hardly worth getting excited about. I would suggest that a good way to reduce our exposure to the radon present in outdoor air would be to build an air-tight house out of granite countertops! There are certain properties of rocks that can increase their radon emanation efficiency, or in other words increase the release of radon from a given weight of rock. These are rock properties that maximize the exposure of internal or external rock surfaces to water or air, allowing any radon gas to escape. The author of 'Granite and Radon' argues that such properties, which include rock porosity, fissuring and mylonitization, will increase radon releases. This is probably true, however, a granite with such properties would be too brittle to make into a countertop, and too open to take a polish, and so would not be marketable as a countertop - unless the rock pores were first filled with a chemical sealant. Such sealing would also eliminate any possible radon release problems.'
 2008-05-23 09:40:57