Some times the stone that exhales the most Radon is not the hottest stone, but one that is fairly porus, which both New Venetian Gold and Santa Cecilia usually are quite porous. It would be a good idea to procure an actual sample, say a 3″ x 3″ chunk or larger, and send it to a lab for testing. It isn’t that expensive, $75.00 will get it done, or just buy a Radon test kit from your state Radon office, put the chunk of stone and the opened test kit in a plastic bag tied shut and wait two days, then send it to the lab.

New Ventian Gold usually runs low, we have measured slabs from 144 to 240 cpm (counts per minute with 60 cpm being background radiation). That is 2.4 to 4 times background radiation levels. Of course I would much rather have the 2.4 times background levels than the 4 in my home.

Santa Cecilia runs from 84 cpm to 324 cpm, or 1.4 to 5.4 cpm with background included. So Santa Cecilia would be a better choice if you can find a low level slab.

Remember if you have someone test your slabs, have them take the background radiation levels away from the granite slab yard, the parking lot would be fine. If there is a slab that is border line, have them move it away from the other slabs to see if the radiation coming from the slabs behind the front one are influencing the front slab.

And finally, don’t reject a color or type, reject hot slabs. Low level slabs can be found in most types of granite.

Brent is a great guy, has a lot at stake with his granite business, yet supports the testing effort on granite. Glad you ran into him.

Here is what I know about low dose Radiation. The most conservative (read that as almost dismissive of any concerns) radiation protection organization is the Health Physicist Society (HPS). They are on record stating that normal background radiation (60 counts per minute (CPM)) is responsible for three extra cancer cases per 10,000 people exposed per year.

We were looking at some Santa Cecilia today which read a bit over 180 CPM, or three times background radiation (really twice as much if you strip the background radiation of 60 cpm). So considering the Santa Cecila AND the background radiation, it will triple your risk of radiation damage resulting in cancer, birth defect, even miscarriage. That would be 9 in 10,000 exposed, or .9 extra cancers per thousand people exposed. This would be in adddition to those that will develop cancer from other causes.

It is not a good idea to say any stone is a certain level, but there are some that tend to be lower AS A GROUP than others. Rainforest Green, Absolute Black, Black Galaxy, and Soap Stone (my favorite natural stone) are all very low levels, USUALLY around 50% to 100% of background levels (120 cpm to 90 cpm).

“Does quartz have absolutely no radiation? ”

I have tested Quartz with my equipment and found no appreciable radiation present. I sent new, full, sample boxes of Hanstone, Silestone, Cambria, and some Cesear stone samples to Dr. Llope at Rice University, with no radiation levels of any concern found ( a tiny, tiny bit, far below background levels). I would not hesitate to install Quartz in my home.

” My husband wants to put granite on the island, which is 52 sq feet and we will all be sitting around it quite regularly. If we chose a low radiation granite, is it still going to increase the cancer risk to our family?”

Yes, there will be an increased cancer risk. We have a dose/risk calculator linked to from our website. You input the radiation level of your granite, the amount of time per year you think you will spend sitting at the island or working close to it (say six feet), and the number of years you plan on living in the home. The program will calculate your odds of increased cancer, usually 1 in 300 to 1 in 500, depending on many factors.

” Also, I saw you have one person in TN on your list for testers, do you have any more?”

Right now, just the one, Bob Druecker in Nashville, but sometimes I can find someone on one of the radiation forums once I know where you live. Another idea is to see if there are any Radon testing and mitigation companies locally, some of them are beginning to learn how to measure radiation.

” What to you would be an acceptable reading that you would put it in your house if you had small kids and a pregnant wife?”

I personally would not put granite in my home if I had small children or planned on having any children, why take any risk when a Quartz countertop would work just as well? I would put granite in my home currently as we have no small children, as long as I could keep the levels below around 20 uR/hr (that is micro Roentgen per hour, 20 millionths of a Roentgen).

Using or being near a 20 uR/hr granite top for four hours per day would give you 80 uR per day, and 29,200 uR per year (or 29.2 mR (milli Roentgen)). The govt says that the max anyone should recieve over their normal yearly dose (360 mR per year) is 100 mR with only 25% coming from one source.

“Do you test all your granite? ”

Yes, every square foot of every slab before we buy the slabs. Brent Nance at Pinnacle Countertop Solutions is the only distributor I would buy from without testing, but I would also check it when it came in the shop.

” Do you sell to TN?”

Sorry, no, we don’t sell in TN. I would check the local shops, see which ones attempt to dismiss the issues and which ones are taking them seriously and testing. I would want to see the test with my own eyes, or get them to put the levels in writing as part of the estimate for the job. Or better, get someone independent to test it prior to you paying a deposit on the job.

My questions for you are… is there any granite that has no radiation or is right at background level? Does quartz have absolutely no radiation? Can you recommend a good neutral color (light beige with browns or blacks) that is very low. If I got my granite tested and it was determined to be low… what risk does that carry with it? My husband wants to put granite on the island, which is 52 sq feet and we will all be sitting around it quite regularly. If we chose a low radiation granite, is it still going to increase the cancer risk to our family? Help! I’m quite confused by all this. Also, I saw you have one person in TN on your list for testers, do you have any more? What to you would be an acceptable reading that you would put it in your house if you had small kids and a pregnant wife? Do you test all your granite? Do you sell to TN?

http://www.deadlygranite.com/

Using the Health Physicist Society’s figures, the Gamma gave a risk of 3 in 10,000 of getting a cancer from the exposure. Added to the background radiation, it left 6 in 10,000 risk.

Our advice was to leave the tile in place, as it was a small risk, but that it was not a granite tile that should be installed if one had advance notice of the risk. A Radon test, short term, was recomended if there were any further concern, but with the low level of radiation, there should be little Radon being emitted.

Oklahoma state DEQ office offers the short term Radon tests for $25.00 per test, including postage and lab fees.

Call 630.260.0700 or see us at http://www.RADONRON.com