W.J. Llope's Granite Radiation F.A.Q. Area

After the Houston KHOU story, the N.Y. Times story, and the Houston Chronicle story, I have been flooded with e-mails (by now over 1000). I have answered every one so far - but I cannot continue to do this and keep my head above water.

So, I've collected the most common questions and my responses here. The information below covers about 95% of the questions that I've received to date.

If you're new to the subject, you might want to read all of these topics in order. There is some overlap in the different responses, and the information that you're looking for might be under a topic other than the one you might have expected from the question heading.

I hope that you find this helpful. Please excuse the inevitable spelling errors.... Take care, Bill

  • I have stone called "[insert name]" - is it dangerous?
  • I heard from the Houston Chronicle article that some of the worst stones are from Brazil and Namibia. Are all stones from these countries dangerous?
  • What about marbles or engineered stones?
  • What are the potential health risks here?
  • Are the radon emanation rates and radiation emanation rates correlated at all?
  • How do I test, or where can I find a professional tester, for the radon?
  • Am I supposed to put the radon test kit(s) under a bowl?
  • If there is not a significant radon emanation rate, does that mean there is no radiation at all?
  • How can I measure the radiation rate from my stone?
  • I have a portable radiation survey instrument - how should I operate it?
  • My meter can read the radiation rate in CPM or uR/hr - which numbers should I record?
  • My stone was measured with a geiger counter, and it is only a small factor about background - so it's safe right?
  • I have not purchased the stone yet - how can I test it beforehand?
  • Is there any sort of database on the radiation rate from different stones?
  • I need a sense of scale - other household items (some pottery, bananas, smoke detectors etc.) are radioactive too.
  • Does sealing the stone regularly (if suggested by the manufacturer) reduce the radon or the radiation, if there?
  • Some groups claim that this is all just a "myth" that is meant to scare consumers away from granite - what do you say to that?
  • Radon has a half-life of about 4 days. Most of the gamma radiation comes from radionuclides that have half-lives of some days or hours. Once the stone is quarried, don't the radon and radiation emission rates die off rather quickly?
  • What research are you actually doing here?
  • You said in your May 2008 PDF writeup that there are over 1000 different commercial granites out there. How can your results possibly represent all of these stones?
  • You must know what stone trade names are more commonly "hot" - why don't you list their trade names on your site?
  • You're just concentrating on the radiation now, not the radon. Everyone seems to be talking about the radon. Why are you ignoring the radon?
  • You're not a geologist - why should I believe a word of what you're saying?


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