Radon in granite counter tops?

On occasion, I have been asked about the possibility of radon being emitted from granite counter tops. Up until recently, I wasn't sure myself. It made sense, but I wanted to know more. So I took a Radon measurement and testing course and learned many interesting things about where it comes from, what it is and the hazard it presents to us. The following is taken from Health Canada's site regarding the question regarding radon in granite counters.

Q. What about radon and radioactivity in granite counter tops?

Radon is produced from the natural decay of uranium found in rock. Granite used to produce commercial products, such as counter tops, can contain varying amounts of uranium. Some granites could contain more natural uranium than others, and thus possibly show higher than expected radiation or radon levels, however, in the vast majority of cases, these levels are not expected to be significant. Health Canada completed a study in February 2010 of 33 types of granite commonly purchased in Canada and none were found to have significant levels of radon.

At this time, Health Canada expects that the main source of radon in a house will be soil gas (containing radon formed by the decay of uranium found in rock under the house) which is drawn inside naturally by differences in pressure between the indoor environment and the outside. Our recommendation is that you reduce your radon risk by first testing the air in your house to determine the radon level.

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Thanks for reading this article,
Darren
http://www.nookncranny.ca/