A while ago a story was published in a solid surface trade publication about the use of granite countertops and the release of Radon gas. This produced a myth that granite countertops are dangerous. It was quickly discovered that the author of the story worked for a company making laminate countertops. They were trying to scare people away from buying granite.
Once again this is being raised, this time by BuildCleanTM, a Houston-based group that claims to be a “pending not-for-profit organization that educates consumers and the building industry about safe, healthy and environmentally friendly materials.” The organization appears to be funded by Silestone and Cambria, two companies that manufacture synthetic stone countertops. If you visit the BuildClean site at www.BuildClean.org you will see that the organization appears to be narrowly focused on stone countertops and nothing else.
Here are some facts. Some rock contains small amounts of radioactive material. As they decay to a more stable state, they give off radiation (alpha, beta or gamma). Granite and sedimentary rocks and weathering products like clay minerals are all potassium rich. Potassium has a radio-isotope that emits radiation. When potassium decays, one of the bi-products is radon gas, which itself is radioactive.
But there is no danger from granite countertops. Remember your food was grown in clay rich soils or your meat once ate grass that was grown in such soils. Also, many people live in granite areas without any ill-effects.
A university researcher on the geochemistry of radioactive elements for nearly 20 years at Penn State University and the Colorado School of Mines stated,
“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 slabs”
Above granite image courtesy of Zoonie.
May 24th, 2008 at 8:42 pm
This article is complete hooyey. The Marble Institute, the one that paid for the article quoted above, about the air tight house out of granite, has started using an article from another scientist that refutes everything they have said the past 14 years!
There new paid for scientists says that one stone had almost 300 times more Radon emission than some of the others.
This subject, and the accompanying TV report is all over the internet. What your article is conviently leaving out was that there is a Houston Physicist that says that some granite countertops are indeed dangerous.
This article needs to be pulled for it’s attempt to mislead the public.
May 29th, 2008 at 8:23 am
[...] blog. His post is worth checking out for a more detailed discussion on the matter. You can see it HERE. Share this article Posted by Marc on Thursday, May 29th, 2008 [...]
May 29th, 2008 at 2:25 pm
“When potassium decays, one of the bi-products is radon gas, which itself is radioactive.”
this statement is incorrect. only the Uranium series produces the long-lived
radon. the Thorium series produces the short-lived radon (a.k.a.
Thoron). the EPA considers the longer-lived radon the dangerous one.
anything quarried from the earth contains some amounts of the 40-K, U ore, and
232-Th series.
“Potassium has a radio-isotope that emits radiation. ”
correct. that is 40-K. however, of the studies i’ve done following the measurement of the gamma spectra from natural stones, the 40-K series is not the predominant
source of radiation. the U ore is.
finally, i agree that it is generally true that most stones are very weakly radioactive.
i have however, measured stones for which the radiation is two orders of magnitude about the background rate of ~0.04 mrem/hr. so, it is certainly not
generally true that all stones are very weakly radioactive.
most are yes. but not all.
best regards,
bill
May 29th, 2008 at 4:56 pm
This “author” is Hulligar, who runs a stone restoration website called the NSRA. Hulligar is cutting and pasting this all over the internet. Trying to affect the Google ranking so people don’t find the real story.
Let’s take his arguements apart.
To start off, Build Clean is a non profit 501 corp, not a pending one. Get the small facts straight if you want others to believe you on the big ones.
Secondly, Silestone does help fund this effort, because they themselves want to get to the bottom of the issue. Why? Because Silestone sells millions of dollars of natural granite through their Sensa stone line. They are being proactive, wanting to know if their products can get them sued on down the line.
Thirdly, Build Clean has been in existence for a few months, little time to branch out from granite’s radiation issues. I am a cabinet maker, and can’t wait till they get on the Chinese plywwoods that stink and make your eyes burn. Everyone say it together, FEMA trailers…..
Okay, the little piddly stuff is out of the way. Let’s look at old Hulligar’s main point, that the radiation comes only from the potassium content.
Wrong……
Three common sources of radiation in granite, Potassium 40, Thorium, and Uranium.
The Potassium decays by Beta emission into Calcium or Argon, neither is much risk. The calcium does lead to etching in granite countertops, but is of no known health risks. The Beta radiation from the Potassium 40 can be stopped with a 1/8″ thick steel shield. It will travel quite a ways in a home, so it is not risk free.
Potassium does not decay into Radon. Does this guy know his science or is he attempting to mislead?
The other two souces, Thoruim and Uranium are what Hulligar is desparate to keep quiet. Thorium is classified as a carcinogen based on its chemical qualities, ignoring the radiation.
Thoruim decays by both Alpha and Beta, 20 steps in the decay chain with the atom changing into different elements as it decays down, toxic heavy metals for the most parts, Polonium, lead, Plutonium (yes, that Plutonium), Uranium, Thallium, and Lead. So besides the 20 different radiation particles emitted, it is mostly toxic on a chemical level as well.
Thorium,if aerosolized or present in dust form, it can lead to increased risk of cancers of the lungs, pancreas, and blood.
See where I am going with this, Hulligar?
May 29th, 2008 at 5:19 pm
Now, the Uranium is the true source of the Radon gas. Uranium goes through 14 decays, 8 Alpha, and 6 Beta. One of these steps is Thorium 234, another is Thorium 230, different than the Thorim 232 that I spoke of above. As it decays, many of the same elements appear in addition to protacinium, radium, and Radon.
And Radon itself is not, I repeat, not a hazard! It is what it decays into, the Polonium (think Georgian president that was poisoned), Bismuth, and Lead. In additon to the toxic qualities, since Radon is a gas, it can be breathed in where the decay can deposit radioactive particles inside your body. Think of a Radon atom as a little hand grenade that eventually goes off, causing some damage, while turning into another hand grenade, and so on and so on till it becomes lead…… Yeah, lead in your lungs..
And his expert from Colorado? The guy was retired and did an article for the Marble Institute for a few bucks, not published, no peer review, which is the standard for trustworthy scientific studies or articles.
So, do some research, google some of what this guy claims, then make up your own mind.
Hulligar, you are plain wrong, dude.
May 30th, 2008 at 3:38 pm
Opps, looks like I was wrong on the author. Some of this copy was lifted from Hulligars posts though.
My bad, still the info is completely wrong.
July 24th, 2008 at 8:56 am
http://www.nytimes.com/2008/07/24/garden/24granite.html?no_interstitial
New York Times just released an article today which has proof that you fail.
July 30th, 2008 at 9:36 am
Thanks everyone for your responses - even those who think we’re full of it.
Here’s a link to the EPA site with more information about the issue of radiation as found in household materials, and in the environment in general:
http://www.epa.gov/radon/pubs/citguide.html
From this article, it can be surmised that radon gas is naturally occurring, emanating from the soil and is present in water too. If you have concerns about it, the article outlines a few tips on how to detect and filter radon gas in your home or office.
We hope the information is helpful.
Cheers!
Rob.