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Quite a few questions were asked about the recent events and how they would affect fabricators of natural stone, including my shop. I’ll try to address the questions.

“Just curious, do you have a written policy that requires testing, and specifies what level of radon you will accept from a supplier?”

One thing , we aren’t measureing for Radon yet, just radiation.

First the easy answer, what level. 25 uR/hr over background radiation, about three to four times background levels. We prefer much lower, say 12 to 13 including background (6 to 7 uR/hr). Anything over 25 uR/hr we consider a hazard to our workers.

We are cutting up far, far, hotter material for the scientists. One of the few accepted reasons for exposure is to further the public good, providing some benefit for the risk. A prettier granite countertop does not meet that standard in our view. Our workers are fully informed, and we take extrodinary care in handling and cutting the hotter material.

Since we are a small company, no formal written policy has been set down, but on our website we mention the testing requirement, in red letters no less. In our granite countertop quotes, we have a clause requiring the slabs be tested for radiation prior to us accepting the granite job. Easily done with a small meter.

Radon is another issue, not possible unless we had possesion of the slab for a few days. And, we have yet to purchase the Radon meters, all of our focus has been on radiation. There is a relationship between radiation and Radon since the radiation is a measurable by product of the decay. So despite the lack of portable and fast Radon testing, simply rejecting the slab based upon high radiation levels will solve the problem. Or so we think…..

Some studies say that Radon production in a stone is about that of the radiation emission, measure the radiation and you have an approximate amount of Radon being produced. Other studies have found less Radon versus radiation, but I have yet to see a study that said a little radiation was present when a lot of Radon was produced. So we are pretty certain, and we state that there is some risk despite choosing low level radiation stone, and that the measurement of radiation is not an exact science at the hand held meter level.

One Radon company has developed a method of direct Radon measurements, IF you have a sizeable sample of the exact slab. The problem is the variation of the slabs, you never really know if that small chunk knocked off the corner of the slab is the same as the majority of the slab. Costs $175, takes a couple of weeks including shipping time.

We will start testing for Radon very soon, still researching the subject. Luckily, this testing effort has me connected to some of the top Radon scientists in the field. I’m getting some of the best samples to them found so far, so I can usually get a dumb question answered

“Because most of the information out there right now is funded by groups with a financial interest in the outcome, many people are skeptical of the results. “

Not so much a question as a statement that needs addressed. To start with, Silestone sells about as much granite as many companies, so they have potential liability as well as potential gain no matter which way this goes. From an inside view, with some access to info that few will see, I see this as an huge risk for Silestone and one taken only because they are unsure of their own potential liabilities. I really think they are attempting to jump start the conversation as well as the testing of all natural stone and quartz.

The only testing that Build Clean has an actual hand in is the 300 home testing effort, done by state certified Radon technicians using a protocol developed by the meter’s manufacturer and vetted by a PhD withexpertise in the field. The conclusions will be written by an expert as well.

Would it be better if someone else did this? Of course, but first the need to test has to be shown. Plenty of scientific studies on granite emitting Radon, but no one has done an in home study. Think of this as a way to prove the need, not as the last word on the subject. Who else will pay for this besides an interested party that stood to gain one way or the other? Since when did the funder of a study cause the study to lose status and credibility? This study is not designed for publication, it is just a fact finding mission.

And, there have been no results given so far, can’t be till the study is finished. If and when the study provides evidence of real world Radon emission from granite, then it will be time to do this again, at 10 times the cost so that it can be peer reviewed and published in a scientific journal.

“I’m suggesting to the developer/General Contractor that they develop a spec requiring that the slabs be tested and pass. As a fabricator, I think you would want to require the same thing of the slab yard. From what I understand, the testing is relatively inexpensive, and it would be a condition of your continued business. I’d require a letter from the slab yard with the results of the test on it, then it’s their liability.”

First thing is that there will never be zero risk with either Radon or radiation unless there is zero Radon and radiation. I can think of only a few granites that will provide zero radiation or Radon. No matter what you do or what you have people sign, Dr. Chiodo said the children and any visitors or future homeowners will have every right to sue since they didn’t or legally couldn’t sign your disclosure/release form. Dr. Chiodo is a top Toxic Tort lawyer as well as being a doctor. He knows both health risks and the law.

These are great ideas and I support it being done. Just understand that you can’t pass on your liability, only a judge or jury can do that. Stay in this business if you have good insurance that covers this risk specifically and always test for at least radiation before you buy a slab or accept one from a consumer for fabrication. Own your own meter, have it callibrated every year, check it against your check source often, and keep records of any testing results. CYA as you have never done before. Understand that despite your every effort, you will be a party to any lawsuit if something should slip through, or someone frivolously claims harm from your low level granite countertop.

If you search online for information on granite and Radiation, you will run into a piece posted by the NSRA, National Stone Restoration Alliance, in hundreds of places. The author, one Jo Huligar, challenged me to a debate on the issues, actually went to a lot of trouble to get me to register at his forum. As always, they couldn’t defend their positions, but some of their members were open minded.

Here is what they were spreading as facts, with some of my comments in bold.

Quote:
“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.
Of course, Build Clean has dozens of studies quoted on their website and has a host of scientists researching the issues

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. Actually, one of the sponsors sells as much natural stone, their Sensa line, as any other granite company in the United States. And, if I were contributing a lot of money to a testing effort, I’d want a seat on the board as well to see that my money was well spent.
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. Sure, no doubt there is a marketing angle to this, few companies will spend a millon dollars unless it benefits their bottom line. As long as the science is valid, it matters little who organizes the effort. Any studies resulting from this will be published after peer review, making them as objective as you can get.

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. Actually, there can be thousands per part per million, while 80 parts per million is enough for commercial nuclear fuel processing. When quarried if a large cluster of biotite is exposed the result initially would be a radon reading. Wrong, the Uranium is mixed into the stone itself in various quanities in various spots. 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. Wrong, since the Radon comes from the decay of the Uranium itself as it passes through the decay chain, it is going to be present for millions of years.
We do endorse Radon testing but to allude that natural stone is a main contributor seems ludicrous. A straw man argument, no one has ever said that Radon from granite was the main contributor. There are cases of that happening, but for the most part, granite just contributes Radon to the normal occuring Radon, raises the level.
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. Sure it is vented, right into your home. This info on soil based Radon is just confusing the issues, we can ventilate the slab or crawl space for soil based Radon, but what can we do once the source is installed, at great cost, inside the home?

Levels of radiation from granite products, which technically are measurable, are in fact, small fractional values of established thresholds for environmental safety. No, that is an outright lie. The current theory of radiation protection is ALARA, As Low As Reasonably Achievable, in other words, there is no threshold below which radiation is considered harmless. There are standards set that compare the cost of limiting the amount of radiation you are exposed to, but regardless of how low, current science says that there is a small risk attached to that exposure.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. Ah, Langmuir is quoted again. This guy was a geologist, not a radiation expert, hired by the MIA to write an article for them. No publication, no explanation of how he figured the dose/risk in his examples, and the guy was retired when he wrote it.
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. Wrong, even the MIA’s latest article blows this out of the water. Their highest reading in the study, Crema Bordeaux, contributed .28 pCi/L using their suspect calculations. Out side air is usually .4 pCi/L, or 30% higher than the Crema Bordeaux. And as we will show later in this article, even the latest MIA test was flawed, the Crema Bordeaux emission should have been triple or quadruple what they claimed. So Langmuir was off by a factor of 900 times!.
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. Sure, some granites, the low level ones, would emitt small amounts like this. Some much larger amounts. Sure your normal average radiation exposure is 360 mR/yr, but one quarter of that would be 90 mR/yr. The experts, including govt experts, say that 100 mR/yr is the maximum you should be exposed to over your regular 360 mR/yr. So even Langmuir admits that you are only 10% away with an average granite top.

But, I found a Crema Bordeaux this weekend that measured 8.5 mR./hr using our LENi Geiger counter. At that rate, 12 hours of using the granite countertop puts you at the 100 mR limit for additional radiaton. A years worth of radiation, at 2 hours per day, would be 6,205 mR for the year, 62 times the allowed additional radiation.

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. Wrong, as a few minutes online searching will prove. Again either complete ignorance or a complete lie. The Alpha radiation won’t reach more than two inches, but the Beta can travel from a few feet to 18 feet depending upon energy levels. It will only penetrate one centimeter into flesh (3/4″). Still that is enough according to Dr Chiodo to cause sterility, even birth defects if you stand close to a sink or cooktop rail while you use the kitchen.

Gamma radiation is entirely different. It goes right through you. When I trained one of our vendors to use the meters to test their granite slabs, I had each one lean against an A frame of granite after measureing that exact spot, then hold the meter up to their chest where they could see it. All of them would bolt when they saw that the Gamma was only a little less than on contact, the Gamma blasted right through their body. Gamma radiation can travel from tens of feet to hundreds of feet in the air, but some Gamma we receive came from distant galaxies.

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.
Oh, this one is rich, complety off the wall stupid. Here are some quotes that will allow us to compare what Langmuir said to what others say.

Now all that math proves one thing, that Langmuir’s calculation of .85 decays per year is way, way off. How much? Well using the above example of 2.4 ppm Uranium and a 2,000 square foot house, we got 83,827 decays per second. So we need to figure seconds in a year and then multiply. 31,536,000 seconds in a year x 83,827 dps = 2,640,550,000,000 decays per year from 2.4 ppm granite. He only missed it by 3 trillion times….. Is there any wonder the MIA is famous for using junk science in their marketing efforts?

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. What he said in the previous three sentences is if the granite has movement,veining, or grain, the Radon release will increase, but mesh back and resining will allow these weakened granites to market anyway. He addressed this in his last sentence, but he forgot about the back and worked edges of the stone not being resined.

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.” Well, the bottom isn’t sealed and according to the lates news in Radon research, the bottom gives off a lot more Radon than the top polished surface. Even the MIA says in their technical pages that there is no way to completely seal a natural stone surface, in fact, they say to attempt to do so is to invite spalling and damage of the surface. Resining is very common these days, most granites are resined, so that alone invalidates Langmuir’s statements.

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. That is a lie, .28 pCi/L will have an excess cancer rate of 4.75 people per 10,000 people exposed. Crema Bordeaux is one of the lowest level Bordeauxs, but the average Crema Bordeaux still gives off around .5 mR/hr, four to five times less than Juparana Bordeaux. But we have found Crema Bordeaux up to 5100 cpm or 8.51.4 mR/hr so using their own example, this .28 could become1.12 pCi/L if a hotter than average slab gets into a home.
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. No, as they decay it raises the general radiation levels of the granite countertop, you are almost better off letting it into the home.

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”. But, many in the granite industry claim that most granites don’t need sealing and the back is never sealed in any way. Nor are Beta or Gamma radiation stopped by sealing.

Now, there are other gaping holes in Chyi’s estimates. One flaw was the amount of granite included in the calculation. They tested small samples, then extrapolated the results into 13 linear feet of granite countertop or 26 square feet. As a fabricator of all types of countertops, including granite, I can tell you that 13 linear feet of tops is small, very small, for a 2,000 foot home. Sixty five to seventy five square feet is more likely to be found in a home of that size. Increasing the size of the top increases the amount of Radon in their calculation, figure 2.5 times higher at least. That would put you at .675 pCi/L which will have a cancer rate of 1.175 per thousand people exposed. Even the .27 pCi/L will have an excess cancer rate of 4.75 people per 10,000 people exposed. Were we talking about toys, food, paint, or water bottles, there would not be a debate, the product would be yanked off the market.

Lastly, the report made mention of six air changes per hour, possible in some months of the year in the better climates of our country, but try that in Houston in the summer, Milwaukee in the winter, or Oklahoma for 10 months of the year and you will have some very high utility bills. Modern air tight homes have difficulty getting a fireplace to work properly, the air changes are minimal at best. This red herring of six air changes per hour was thrown in after the conclusions, but is an excellent example of non scientific thought. I would bet money that it wasn’t Chyi that wrote the paragraph. Even Huligar admits that in his NY home, the windows are rarely open, just the door opening and closing which allows very little air exchange.

Dr Chyi went on to quote a twenty year old study done by Dr. Steck, where a number of American mined granite products were tested for Radon emission, all of which tested at low levels. While Dr. Steck’s results were perfectly good science and 100% accurate for the samples he studied, those results have absolutely no bearing on the sometimes highly radioactive granite materials currently being imported into the US.

Dr. Steck had saved a few of the samples, one of which served all this time as a trivet for his kitchen countertop! He retested the sample with his newer methods and equipment, and got simular results to the original study. However, the samples that we provided him in June tested from 50 to 100 times higher than the original samples.

Dr. Chyi went on to say:

“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.” Again, it looks like Chyi is speaking about tile samples and he is speaking only of the Radon. The Gamma radiation will be affected by the mass of thicker materials, I’ve seen it myself in our testing. Another point is that unlike these uniform samples, granite will be higher or lower on every square inch. ”

Editors note: The following paragraph is from Dr. Chyi’s MIA study. Dr. Steck saw it and was very concerned that it might be construed as being his words, so we edited the above paragraphs and added this note to make sure that no one missunderstands. We even removed the Dr. Steck quote that Dr. Chyi used in his study to remove any confusion on who said what. I believe it is safe to say that despite Dr. Steck being quoted, he might not agree with Dr. Chyi’s conclusions on the motivations of those interested in studying these issues and having standards implemented on the industry

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. ”

This may well be a marketing effort, but it is backed by real scientific studies and more are on the way. The quartz industry will bury the stone industry if testing existing material inventory is not done, if the existing countertops are not tested and removed if found dangerous, and if the industry doesn’t start testing at the quarry, the distributor and at the fabrication shop.

Now, let’s look at what was left out of Huligar’s article. Looking at the MIA study will reveal other flaws. The first paragraph is just a puff piece, not a single supported statement in it.
To start off, the stones they tested supposedly represented 95% of granite types most sold. Okay, let’s say I buy that. What about the other 5%? Remember I say that from 3 to 15% are of concern. And I don’t check a lot of Uba Tuba, Santa Cecilia, or really any of the stones in their report. So they are basically testing safe stones, about what I would expect from the MIA.
Note that they tested mostly 2 cm instead of 3 cm, but they did include one 3 cm, Dakota Mahogany. This is a big no no in science. Everything has to be exactly the same or the results can not be trusted. This point alone would have meant the study would have to be redone if it were being considered for publication.

And finally, look at the disclaimer at the end. It basically says not to rely upon the study, in contrast to a real scientific study that strives to be taken as gospel.