Fight over Radon in Granite Countertops Heats Up
The Marble Institute of America better get ready for another round of fighting because the issue of radon in granite countertops is back. For the past decade, the MIA has been trying, with much success, to squash the rumor that granite countertops have the potential to add dangerous amounts of radon in the home. A new study being conducted by Houston area not-for-profit BuildClean is raising old fears about the dangers of granite countertops, and its preliminary results show that while most granite countertops in the study contain very little to no radon at all, the countertops that do contain radon have levels that are frighteningly high. While consumers can be secure in the fact that the vast majority of granite is perfectly safe, a small percentage is still in question, and no independent scientific study exists to assuage consumer fears.
The first issue of Solid Surface in 1995 explored the possibility that granite countertops may pose a health risk. Soon, the MIA issued their response, which attacked the credibility of the science involved in the study as well as the fact that the advertisers in the journal included companies that competed with granite countertop manufacturers. But one phrase in the response, a highlighted phrase no less, is troubling: “…actual levels of radon gas emmissions are so low as to be insignificant and generally represent no threat.” As a father, I don’t want to be assured that there is “generally” no threat to my family. I want to know there is no threat. And after BuildClean* found that 3 of 95 granite countertops contained harmful amounts of radon, would the MIA consider such a small number to be “generally” no threat? I’m sure the owners of those three countertops are not reassured.
(*Correction: BuildClean did not find that 3 of 95 countertops contained harmful amounts of radon. Rather, the results are from a study by Dr. William Llope, a Rice University Physicist, who is not associated with either BuildClean or the MIA. His comments can be found on the third page of comments below.)
Look around for information on radon in granite and you will find many sites telling you the “truth” or uncovering “myths” about radon. Since many of the statistics cited are the same, it’s clear that much of the information comes from the MIA response linked above or from an updated (though with the same references) MIA PDF. My personal favorite was a site titled “Ask an Expert - 9 Myths about Granite” where they claim that “No one today takes credit for starting the rumor, and certainly no one supports it.” No one? They then make the claim that granite actually has healing properties. Most troubling is the fact that, as experts, they don’t seem to know that “lose” is spelled with only one “o.” The most common argument you’ll find, that radon occurs naturally, really needs to be taken out of their playbook. Just because it’s on the periodic table of the elements doesn’t mean I want it in my house. I’m talking to you, Californium.
In late 2007, the MIA scuffled with Home Safety Systems, which sells radon detectors. Like the fight over the original journal article, this seems to be another example of competing companies arguing science, which doesn’t sit right with me. The current BuildClean study is funded in part by Silestone and Cambria, two competitors of granite countertops. (Ironically, Silestone is a sponsor of the “Ask the Experts” article above - their logo is at the bottom of the page.)
So how do we start trusting that granite is safe? An independent study done by the EPA would be a good start. Leave corporate interests out of it. And don’t give us general findings - tell us exactly what was found. Since radon is found naturally in some parts of the earth, the MIA needs to admit that there is a possibility that some granite will contain radon, and then show how they are making sure such slabs do not make their way into our homes. Are granite countertops screened for radon before reaching the consumer? (Maybe the folks over at Home Safety Systems can help the MIA out with that.) Otherwise, without solid assurances, it won’t be long until consumers reject granite outright.
For information on green alternatives to granite, try Green Counter Culture.
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 without scientific proof, that natural stone could be a major contributor of radon in a household.
The allusion that seems to be made, that natural stone installed in your home is dangerous to your health is raised repeatedly on the website and 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.
Here are some facts about Radon:
WHERE DOES RADON COME FROM?
“Radon comes from the natural radioactive decay of radium and uranium found in the soil beneath the house. The amount of radon in the soil depends on complex soil chemistry, which varies from one house to the next. Radon levels in the soil range from a few hundred to several thousands of pCi/L. The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, and the suction within the house”.
HOW DOES RADON GET INTO THE HOUSE?
“Houses act like large chimneys. As the air in the house warms, it rises to leak out the attic openings and around the upper floor windows. This creates a small suction at the lowest level of the house, pulling the radon out of the soil and into the house.( Just as natural stone filters radon emission as mentioned before.) You can test this on a cold day by opening a top floor window an inch. You will notice warm air from the house rushing out that opening; yet, if you open a basement window an inch, you will feel the cold outside air rushing in. This suction is what pulls the radon out of the soil and into the house. You might think caulking the cracks and the openings in the basement floor will stop the radon from entering the house. However, scientific studies show, it only takes enough unsealed cracks or pin holes in the caulking to equal a hole 1/2″ in diameter to let all the radon in. It is unlikely that caulking the accessible cracks and joints will permanently seal the openings radon needs to enter the house. The radon levels will still likely remain unchanged.
Fortunately, there are other extremely effective means of keeping radon out of your home. Throughout the country, several million people have already tested for radon. Some houses tested as high as 2,000-3,000 pCi/L; yet, there hasn’t been one house that could not mitigate to an acceptable level. The difference in reference to natural stone is that one the stone slab is removed from the source and exposed to the atmosphere the radon is vented in the same way ventilation of a house mitigates the radon emissions in the soil.
Levels of radiation from granite products, which technically are measurable, are in fact, small fractional values of established thresholds for environmental safety. The truth of the matter is that granite is a safe product. It’s been used for thousands of years and the relationship between granite and radon has been studied for years and years. How safe is granite? There have been mathematical models developed that show that one could live in an all-granite home or building, including sleeping on granite, for an entire year and still be within very safe levels of exposure.
Calculations show that, if an average countertop, traps an average uranium concentration of four ppm (parts per million), the concentration of radon that is given off by the countertop into the household air would be 270,000 times less than the level of radon in the outside air. The maximum contact level that you would receive over one year if you were to sit on a countertop all of the time would be about one quarter of the annual radiation from all sources. If you were just a few inches away from the granite (such as when doing the dishes), the dose would be too low to measure.
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.”
In a more recent study that was conducted by L. L. Chyi, a Ph.D. and professor of Geochemistry and Environmental Geology at The University of Akron, Akron, Ohio. Dr. Chyi studied 13 of the most popular granites used throughout the United States as determined by an industry-wide survey. Due to their popularity these 13 granites, are believed to represent up to 85% of the granite countertop market in recent years. The granite types are as follows:
1. New Venetian Gold, Brazil; medium grained, yellow-beige gneiss with many dark red garnets
2. Uba Tuba, Brazil; A medium- to coarse grained, olive-green granite
3. Santa Cecilia, Brazil; A coarse-grained, yellow-grey gneiss with up to pie-sized, red garnets
4. Tropic Brown, Saudi Arabia; medium-grained, brown granite
5. Absolute Black, India; black basalt
6. Tan Brown, India; A black-brown igneous rock with big, shapeless, brown-red feldspar crystals
7. Giallo Ornamental, Brazil; coarse-grained, brown-yellow granulite with some brown-red garnets
8. Crema Bordeaux, Brazil; Juparana Crema Bordeaux (Brunello). A coarse- to very coarse-grained, pink to red granite with areas of quartz, alkali feldspar and quite a lot of ore
9. Baltic Brown, Finland; brown-black granite
10. Giallo Veneziano, Brazil; medium- to coarse-grained, ochre-yellow to golden-brown, also light pink, gneiss
11. Dakota Mahogany, USA; medium- to coarse-grained, brown-red granite
12. China Black, China, a fine-grained plutonic rock
13. Yellow Star, China, a medium-grained yellow to pink granite
The testing methodology was designed to measure the amount of radon which each granite type would add to the interior of a 2,000 square foot, normally ventilated home with 8 ft ceilings. The results show that Crema Bordeaux (the most active in terms of radon emissions) would contribute a concentration component of less than 0.28 pCi/L, or less than 7% of the EPA’s recommended actionable level of 4.0 pCi/L. This radon amount is well below a level which might cause health concerns. Tropic Brown and Baltic Brown, second and third in radon emanation based upon Dr. Chyi’s testing, amounted to only 1% of this action level. The other granites tested added almost immeasurable amounts of radon to the house. Radon atoms in pore spaces and fractures are of minimal concern in the case of granite countertops
Dr. Chyi’s test results show that the granites that are currently found in the United States’ market place are insignificant contributors to radon levels in the home. “Based on the testing results and EPA standards, we can conclude that the most popular granites used as countertop surfaces pose no health threat to homeowners. If proper resealing is applied once a year or at other frequencies determined by the industry, the radon emanation can be further reduced”.
Daniel J. Steck, Ph.D. also ran a test on interior radon and granite, and this is what he had to say.
“The average radionuclide contents of your building material samples are similar to other average granite samples and other common earth-derived building materials such as brick and soil. Thus, the amount of gamma radiation emitted from similar masses of these building materials will be approximately the same;
There is little sample-to-sample variation in the radon family radionuclide concentrations; the radon flux is somewhat larger for the counter-top squares than for the smaller samples. This indicates that the effective diffusion length is only on the order of the thickness of the counter-top samples, i.e. several centimeters. Thus, material thicker than 5 cm (2″) most likely will not emit more than the counter-top samples.
While we feel that health safety is a great concern especially in our homes, for an industry to attempt to gain financially by “scare tactics” or under the auspices of “Eco friendly” is reprehensible. We urge the consumer to not be taken in by these alarmist tactics.
http://www.nsraweb.com
@ Huligar:
Branding something as alarmist just because people have a concern is pretty irresponsible in itself. It’s already been clearly stated (and restated)in this article and comments that the discussion concerns a very small number of products, and that most are safe.
But if you really want to bring the green community on board, instead of name-calling, why not join us and call for some responsible data? It sounds like the companies in question are too embroiled in competing with each other to provide an unbiased answer. Bring in a neutral 3rd party to appease everyone and record some reliable facts (as opposed to misleading the public).
It sounds like Christina has begun to do some of this, and has uncovered a legitimate concern. Instead of burying it or blowing it out of proportion, let’s get some real data, isolate the problem, and adjust product accordingly to provide customers (source of business and generally a group who does not want to discover a company tried to ignore a potential problem) with a safe, reliable product. That is, after all, the best way to gain customers, keep their business, and spread a good reputation for your company.
Thank you for commenting everyone and for engaging in this discussion.
Huligar, rather than cutting and pasting a response to the issue as a whole, please leave your own comments, responses to issues mentioned in the original article or comments, and links to the studies themselves. Much of what was in your comment was already linked in the original article.
I am interested in presenting both sides of this issue, but there is something very disingenuous about titling that particular article “Radon in Granite Causes Cancer.” The same article is found elsewhere titled “Genuine concern of the effects of radon emissions in residential homes” with a sub heading of “scientific proof that natural stone could be a major contributer to radon in a household.” It doesn’t take a rocket surgeon to see that someone is trying to flood search engine results with links that take people to only one side of the story.
My follow up to my first post about the Niagara Gold & finding a hot spot.
I have discovered that the Niagara Gold did not come from Italy but was only processed in Italy. It was quarried in Namibia & exported in block form to Italy where it was cut & polished into slabs & then exported to America & elsewhere.
Namibia is the 5th largest producer of uranium & new mines are being developed as the price of uranium increases (as with other energy sources). A new mine developed by Forsys Metals by 2009 will produce 7% of the world’s yellow cake uranium. Google Namibia uranium mine & you’ll see what I’m talking about.
This would explain why we found radioactivity in the slab of Niagara Gold (& why we found another, more to come later). It seems that some granite companies in an effort to sell high priced exotics to keep up with increasing demand for unique exotics, is willing to sell any stone deemed attractive without testing for uranium levels.
If a stone importer is exploring potential stone sources within a nation with many uranium sources, shouldn’t they have to do an analysis of the uranium content of the stones they would like to sell? Shouldn’t they provide uranium content information to the consumer? The uranium mining companies have to do radiation research to provide to the local community. What about the very stone that sits in your kitchen that your family is exposed to every day?
We have a supplier of granite slabs & he has been extremely cooperative & helpful in so many ways. He is buying testing equipment & will be ensuring that every slab that goes out to a fabricator is safe. He has even received support & assistance from the quarries in Brazil where he buys his material from. We actually went through his warehouse full of granite & found very little to be concerned with. We did find one slab of Four Seasons that tested high & as soon as he saw our results he cancelled the bundle that he had on order.
This would be the time for other companies to come forward & ensure the safety of their material as a competitive advantage if not for the concern for the customer & fabricators’ health.
We have a granite tile countertop, and I had no idea that it could contain radon.
Thanks for the clarification, Christina. I’m glad your supplier is being proactive on the issue. That’s got to be reassuring for his customers.
Wow, I won’t hate on my cheap Formica anymore :/
Jennifer, it’s probably doubtful that your granite tile countertop emits radon or radioactivity. 1st of all its probably one of the pretty common granites that are sold everywhere. And 2nd we tested granite tiles at Home Depot & there was no activity from the scintillators whatsoever. So I probably wouldn’t worry about it if I were you. But if you’re at all concerned you can get a radon test kit from your state for maybe $25.
Certain granite importers are exploring & quarrying exotic granites in areas not previously explored. They are doing this so that they can command a hefty premium for their granite because other companies offering that exotic granite are so few in number. That’s why they are taking chances with new quarry sites. Just my theory. It seems it may be a problem afflicting the wealthy or those investing heavily into their kitchens.
On the issue of Formica. The laminate companies are coming out with new patterns that do a good job resembling granite. When you order a laminate top & you want to ensure clean indoor air after its installed, ask for a formaldehyde free substrate. Many panel manufacturers now offer this. Columbia has what they call Purebond which is soybean based.
Talk about another issue that the US is far behind. We still allow unregulated levels of formaldehyde in wood products. Not even the Chinese allow this.
@ Joel Bittle
That post is my comment, as for it been posted else where, look at the author, we are one and the same “Huligar”
@ MichelleBennett
We do respect the most people want to save our planet. But profiting off the fears of others is not cool. The ES guys would have you believe “if you gave granite you will you but yourself at risk oh cancer.”
If you want to talk green, lets looking to the by product of ES and how damaging that is for the environment.
My intent is not to point a finger, but to help other see both sides of the coin.