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  1. #1
    William Levy's Avatar
    William Levy Guest

  2. #2
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    Default Re: High Radon and Radiation from some granite counters

    Granite (and other hard rock) contains uranium. Uranium decays to eventually produce radon which is released from the rock. Therefore granite countertops can certainly be a source of radon in a home.

    However, due to the small volume of granite associated with granite countertops I would suspect the amount of radon released from the granite countertops to be relatively small (if not imperceptible) compared to the amount of radon entering the home from the soil. Certainly you may be able to detect measurable amounts of radon emanating from the surface of the granite countertops but that is not an accurate measurement of the contribution from the granite countertops to the total radon concentration of the home. (That is akin to measuring the undiluted combustion gasses from an appliance and claiming that represents the CO concentration of an appliance after dilution.)

    There must be a source for there to be radon that can enter a home. The source of radon is uranium and uranium is typically found in hard rock (e.g., granite) buried beneath the surface. The larger the source the greater the potential for radon in a home. In other words, everything else being equal, a home with more granite beneath it has a higher propensity to higher levels of radon than a home with less granite beneath it.

    When you compare the volume of granite in the ground beneath a home to the volume of granite found in a granite countertop you see the countertops represent an infinitesimally small source as compared to the granite beneath the home.

    Rather than worry about the radon emanating from granite contertops I think one's energy would be better spent reducing the amount of radon entering the home from the soil and water.

    Last edited by Bruce Breedlove; 07-18-2008 at 03:46 PM.
    "Baseball is like church. Many attend but few understand." Leo Durocher
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    Default Re: High Radon and Radiation from some granite counters

    Michael Thomas
    Paragon Property Services Inc., Chicago IL
    http://paragoninspects.com

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    Default Re: High Radon and Radiation from some granite counters

    Looks like they reached the same conclusion that I did: Residential radon from granite countertops is a non-issue.

    "Baseball is like church. Many attend but few understand." Leo Durocher
    Bruce Breedlove
    www.avaloninspection.com

  5. #5
    William Levy's Avatar
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    Default Re: High Radon and Radiation from some granite counters

    Please take the time to review the recent findings posted Web home: Radiation & Radon from Natural Stone, W.J. Llope by Web Home: Radiation and Radon from Natural Stone
    W.J. Llope
    Rice University, Houston, TX

    and review : solidsurfacealliance.org Blog › Login

    Here is a recent post reply:

    W.J. Llope said,
    June 11, 2008 at 8:06 am
    Hi -
    thanks for the update. but there’s a couple of things here that you might want to correct….
    “Dr. Hans Hensen claims that most of the radiation in granite countertops comes from Potassium 40 ( K 40), in fact most of the radiation comes from Radon and Thorium.”
    from the stones i’ve looked at the Uranium ore is the major player. i see less than
    a 1% contribution from 40-K. the longer-lived Radon (the one people mean
    they say “radon”, half life ~4 days) is in the 238-U series. the 232-Th series also produces a “radon” called “thoron” but that guy has a very short half-life.
    “So there it is, even the EPA says that the radiation risks are unknown…… ”
    not a mistake in your post - just wanted to mention that i intend to change
    this. i have now ~40 samples from 3 stone yards and several private
    individuals that i will investigate with my NaI(Th) spectrometer.
    i intend to publish. Journal of Environmental Radioactivity or something
    like that.
    “Twenty microRems per hour is written as 20uR/hr. ”
    20 uR/hr is 20 micro-Roentgens per hour, not 20 micro-rem/hr.
    the latter (rem) is the unit of absorbed dose. it is the product of the dose
    (in Roentgens) and a “quality factor”. this quality factor accounts for
    the different amount of damage (”biological efficiency”) that different particles can do to human tissue.
    the quality factor for gammas and betas is one, and it’s 20 for alphas.
    in the sense that *external* alpha radiation generally poses little risk
    (typical 1-2 MeV alphas have a range of only 1-2″ in air, and less than
    the thickness of a single piece of paper, and they
    are absorbed in the dead-layer of skin called the epidermis) then it’s not
    heinous to mix mR and mrem. but your geiger counters are measuring
    mR, not mrem, because they do not and cannot know what the particles
    are.
    my gamma spectrometer does though! also, your geiger counters are
    generally underestimating the true fluence, especially for energies above
    1 MeV, due to their known (in)efficiency as a function of the particle and
    energy. this too is something that i can correct for with my NaI setup
    to get the “true” fluence…
    BTW the use of the unit “rem” is not strongly discouraged by NIST, although
    when i undergo my yearly radiation retraining as part of my day job, the
    unit mrem is still used. and it is very common elsewhere.
    “Without going into a lot of detail on this topic, EPA and some State agencies have used an exposure of 20 microR/hour as a remediation action level for entire rooms, homes or buildings.”
    i’d love to have references for that comment!
    cheers,


  6. #6
    William Levy's Avatar
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    Default Re: High Radon and Radiation from some granite counters

    the pdf of the paper Dr Llope is at :



    http://www.khou.com/images/0805/LLOP...dRn_080507.pdf


    William Levy


  7. #7
    Al Gerhart's Avatar
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    Default Re: High Radon and Radiation from some granite counters

    Hello,

    I am the evil genius (Ha!) behind the SSA site on the granite/Radon/radiation issues. A granite fabricator by the way, along with other products we work with.

    Dr. Llope has been a huge help in this effort to prove the existence of significant Radiation emmisions from some granites used as countertop and floor tile. Plenty of Radon experts helping as well, Stan Liebert, Bill Brodhead, of course William Levy has recently joined the effort, or shall I say we have joined him since he has been working on the issue of Radon from building materials for close to two decades.

    Radiation levels are indicitive of Radon emissions, from 20% to 95% depending upon which study you read, which in turn depends on which stones were in the study.

    Dr. Kitto reviewed around 40 samples recently, has sent his study for peer review (Health Physics Journal if I remember right). He found one or two granite top materials that would contribute 1 pCi/L and one that would contribute up to 2 pCi/L. Bill Brodhead is one of his confidants in the effort, and two of the samples I sent Brodhead measured 50 pCi/SF/Hr and 500 pCi/SF/Hr. It would seem that finding these levels has shown the need to revisit the issue with another study. I know that Brodhead recently shipped the samples to Dr. Kitto and I will send Kitto some others as well.

    Dr. Steck, who has done previous work for the MIA (who opposes this effort to prove hot granite) has also received samples far hotter than he has seen in the past.

    Here is the thing, all of us know that we make our decisions based on what we know at the time. New info will always change a reasonable mind. Skepticism is good, but apply that same skepticism to what the MIA is saying. In the end, the results of the tests will prove it one way or the other.

    Liebert has found several cases of hot granite raising Radon levels, and proof will soon be published, including homeowner interveiws. The company that sold the stone, Innovative Stone of Long Island NY, appears to have changed the name of the stone since it has received a bad reputation in the stone industry. A relatively cheap stone, it was popular, but several shops have stopped selling it, including one huge national seller of natural stone and quartz.

    In addition to the Houston TV report case (I sent William a copy of the lab report on that stone, 1,100 times normal Radium content), there are more cases popping up from the Houston in home countertop testing effort. About 200 homes tested so far, 100 more to go before the survey ends.

    Dr. Llope and I stay in touch, and I've already addressed the issues in his post, but I thought it would be a good way to introduce some of the salient points here.

    “Twenty microRems per hour is written as 20uR/hr. "

    Absolutely, the quality factor for internal contamination is a major factor, thus the need to write as Roentgen instead of Rem. However, to avoid confusing readers with no background in the units used, I tend to us Roentgen as interchangable with Rem, which you point out can be interchangable in our limited use.

    For a fabricator, who is subjected to inhaling small quanities of the radioactive dust, ingestion of the radioactive dust from touching the face or not washing their hands before lunch, any manner of pathways into the digestive system, we certainly would write as Roentgens. Then we would also measure the Alpha and Beta radiation, add that to the Gamma for the total exposure to the fabrictor.

    Dr Hans Henson is a shill hired by the MIA. Has a PhD in geology, from Australia, and has been quoted by his friends as being hired to "dirt up" the Quartz industry. While no fan of Quartz (but I do sell it when I have to), I dislike a hired gun lying for a buck. Dr. Hans refused to answer questions posed to him on a consumer forum where he was attacking Dr. Llopes investigation into this issue.

    The EPA is actively investigating the issue. I spoke to the regional head a few weeks ago while in the office of our state Radiation dept. The Radiation dept manager was defending our granite countertop radiation measurements to the EPA regional head, who had been given the task of verifying our reports. Since then, the state Radiation dept has shown to be very interested, including setting an appointment with a homeowner whose granite top had alarming rates of Gamma radiation.

    Our meters were found to be withing accuracy ranges normal for hand held meters, within 25% of the Radiation departments more expensive and more accurate meter. Experts like Dr. Llope predict that even these more accurate and more expensive meters may miss from two to six times more radiation than his very accurate Gamma Spectrometer set up.

    I ordered my Gamma Spectrometer last week, once the learning curve is past, I'll post some results on the SSA blog site.

    If Inspectors begin measuring granite counters, showers, or tile, you will find that existing hand held meters will seldom agree with another, even of the same brand and model. They have different "efficiencies" as Dr. Llope pointed out, so using one to sort high level granite from low level granite is workable, just don't fool yourself into thinking you are getting an accurate reading.

    Depending upon the radiation strength and type, you might read 11% of the radiation or 65% of the radiation and you might over count the Alpha if it is a strong Alpha source.

    For that reason, we are measuring primarily Gamma when surveying granite countertop materials. Our meters are specified at 30% one way or the other, within a range of electron volt levels. Under the range won't be counted, over the range will blast right through the meter without registering.

    No doubt by now readers are realizing that this will not be an exact science with hand held detectors, but the meters are accurate to sort high from low, thus are useful and accurate enough for this use. The "safe" level MUST be low enough to account for the innaccuracies in measuring, luckily every granite tested so far has low level slabs available if the fabricator, vendor, and quarry selling the product will take the care to test. The estimate of problem slabs runs from 3% to 10%, but the Chinese report that from 20% to 30% fail their Class A "safe" standard test.

    The remediation info from the Federal goverment is here

    Incidently, I don't consider myself an expert in Radon emmisson from natural stone, more like a some what educated advocate of the issue. William and the other Radon techs, Dr. Kitto, Dr. Steck and Dr. Llope are far more prepared to answer questions or comments. I do seem to have developed enough experience in measuring radiation from natural stones to be of some use to the experts, that and my access to samples. I can probably answer questions on the radiation issues of granite.

    But, bottom line, heads up, this is a real issue. A huge story on this ought to be published late next week in a national newspaper. I will provide a link as soon as it is printed. It was slated for last week, but when the editors realized the depth and importance of the article, they personally interviewed some of the top sources and then sent photographers to document two of the labs helping out.

    Last edited by Al Gerhart; 07-19-2008 at 05:21 PM.

  8. #8
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    Default Re: High Radon and Radiation from some granite counters

    This kind of reminds me of the aluminum cooking pan scare of years past. The folks that make stainless steel cookware funded a study of aluminum cookware and it correlation with Alzheimer's disease. Guess what? We still have aluminum cookware and they never found a verifiable correlation, but they made a huge dent in aluminum cookware sales by saying that it was possible.

    So, as a home inspector who lives and works in an area with fairly high levels of radon in homes already, what should one do?

    Scott Patterson, ACI
    Spring Hill, TN
    www.traceinspections.com

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    Default Re: High Radon and Radiation from some granite counters

    If you love granite counter tops as I do my advise is to by them and have them installed.

    Quite frankly gentlemen this is like going outside in the unfiltered with out a mask of some kind to filter it.

    Radiation from granite counter tops in a conditioned air home where the doors are opened up off and on all day, Please. Everyone has an opinion but come on now.

    Hey don't drive your car with the window cracked if you are in heavy traffic. Don't eat food off of teflon pans.

    Don't drink the city water with out a massive filtration system.

    We are all going a little to far folks. It is time to scale back and start living life. If life is so horribly dangerous then just stop living. Give your air up to someone else.



    Kidding folks. All of that was just a gross example of over kill.

    Granite counter tops are beautiful, functional, useful items that enhance a home. Is there radiation in granite, yup. Step outside boys, that radiation out there is enough to kill you.


    Hey, I have an idea. It should be mandatory for Radon testing for all home inspectors. Then we can sell more toys than ever and keep updating them so the inspectors can by more of our toys. While we are at it why don't we find several more spooky things with fancy names and funny numbers to test so no one will ever want to live in a home. Hey we could all live in caves. OOOps can't do that to much rock around with radiation in it.

    I have read it all now on granite counter tops.

    My opinion is there is nothing more to it than hundreds of items in our daily life, like cell phones, that are just as bad or far worse than granite.

    Put your toys away on the granite. Start living life.

    Ted Menelly, Castle Home Inspection Services
    www.inspectmycastle.com
    Fort Worth, Keller, Southlake, Plano, Flower Mound, DFW, TX

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    Default Re: High Radon and Radiation from some granite counters

    Funny that the ad right above my post here is for granite countertops.

    rick


    Now its gone

    Last edited by Rick Hurst; 07-20-2008 at 10:58 AM. Reason: ad disappeared

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    Default Re: High Radon and Radiation from some granite counters

    Mr Rick

    How is the week end going. You haven't sucked in any radon from any granite counter tops have you.

    Hey, I mentioned on a different thread about your picture taking in the vehicle. Watch out that you don't wind up parking inside a Denney's or something.

    Ted Menelly, Castle Home Inspection Services
    www.inspectmycastle.com
    Fort Worth, Keller, Southlake, Plano, Flower Mound, DFW, TX

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    Default Re: High Radon and Radiation from some granite counters

    We're been polishing up the granite pacifiers we made for those grandchildren that are coming soon.


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    Default Re: High Radon and Radiation from some granite counters

    Just kidding about all that Radon stuff.

    I have to admit Rick, that was pretty funny about the pacifiers.

    I guess everyone has an opinion and I guess you noticed I always express mine.

    Ted Menelly, Castle Home Inspection Services
    www.inspectmycastle.com
    Fort Worth, Keller, Southlake, Plano, Flower Mound, DFW, TX

  14. #14
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    Default Re: High Radon and Radiation from some granite counters

    This topic makes for great newscopy on a slow news day:

    What’s Lurking in Your Countertop?

    Published: July 24, 2008

    SHORTLY before Lynn Sugarman of Teaneck, N.J., bought her summer home in Lake George, N.Y., two years ago, a routine inspection revealed it had elevated levels of radon, a radioactive gas that can cause lung cancer. So she called a radon measurement and mitigation technician to find the source.

    “He went from room to room,” said Dr. Sugarman, a pediatrician. But he stopped in his tracks in the kitchen, which had richly grained cream, brown and burgundy granite countertops. His Geiger counter indicated that the granite was emitting radiation at levels 10 times higher than those he had measured elsewhere in the house.

    “My first thought was, my pregnant daughter was coming for the weekend,” Dr. Sugarman said. When the technician told her to keep her daughter several feet from the countertops just to be safe, she said, “I had them ripped out that very day,” and sent to the state Department of Health for analysis. The granite, it turned out, contained high levels of uranium, which is not only radioactive but releases radon gas as it decays. “The health risk to me and my family was probably small,” Dr. Sugarman said, “but I felt it was an unnecessary risk.”

    . . .

    Allegations that granite countertops may emit dangerous levels of radon and radiation have been raised periodically over the past decade, mostly by makers and distributors of competing countertop materials. The Marble Institute of America has said such claims are “ludicrous” because although granite is known to contain uranium and other radioactive materials like thorium and potassium, the amounts in countertops are not enough to pose a health threat.

    Indeed, health physicists and radiation experts agree that most granite countertops emit radiation and radon at extremely low levels. They say these emissions are insignificant compared with so-called background radiation that is constantly raining down from outer space or seeping up from the earth’s crust, not to mention emanating from manmade sources like X-rays, luminous watches and smoke detectors.

    . . .

    In Dr. Sugarman’s kitchen, the readings were 100 picocuries per liter. In her basement, where radon readings are expected to be higher because the gas usually seeps into homes from decaying uranium underground, the readings were 6 picocuries per liter.

    . . .

    As for Dr. Sugarman, the contractor of the house she bought in Lake George paid for the removal of her “hot” countertops. She replaced them with another type of granite. “But I had them tested first,” she said.

    . . .

    Hmmm. That's interesting. I wonder if the radon levels in her kitchen dropped to normally-expected levels (~2.5 - pCi/L based on the radon level measured in her basement) after the offending countertops were removed. Sadly, the article does not say. Typical reporting. Hype up a story but don't wrap it up.

    Again the article does not tell us but I wonder if the inspector thought to test the water for radon. This house is described as the lady's "second home" and, if it located in a rural area, it may have a well. As we know, well water can contribute a large portion of the radon in a home. Could the dishwasher have been used before or during the radon test in the kitchen? If so, that could greatly skew the results if there is a large amount of radon in the well water.

    Also, what kind of device was used to measure the radon in the kitchen? If it was a charcoal canister I would not have any faith in those results because charcoal canisters are greatly affected by moisture. (That's why EPA protocols say not to test in a kitchen.)

    On another tangent . . .

    I have advised people about the dangers of disconnected furnace flues and leaking gas valves but I have never advised anyone to "Stay away from the countertops" due to radon.

    I do radon testing but I don't use a Geiger counter. Does anybody here use a Geiger counter for radon testing? I am fairly certain in saying that a Geiger counter is not an EPA-approved radon testing device. I guess it may be somewhat useful in narrowing down the source of radiation (e.g., a sump pit or water in a shower) but one would need to be able to differentiate between different sources of radiation.

    Most Geiger counters detect ionizing radiation (alpha and beta radiation). The radiation that the inspector measured emanating from the countertops may have had nothing whatsoever to do with radon. But it sure makes a great dog and pony show, good enough to scare this lady into immediately tearing out her countertops. And good enough to make the news.

    This whloe things seems eerily similar to the mold scare of a few years ago.

    I prefer facts, not hype.

    "Baseball is like church. Many attend but few understand." Leo Durocher
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  15. #15
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    Default Re: High Radon and Radiation from some granite counters

    When marketing a product, one expects a bit of hype. The idea is to show that the product is the best over the competitor's line of product. That is the trade of advertisers and the history of marketing. Some tactics used to sell can be humorous or as serious as the competition between manufacturers. Marketing tactics that play on fears of the general public can be a very powerful tool.

    In the present day, there's a very popular angle of "green." This is prevalent everywhere in the media. So what happens when you mix a scare tactic under the guise of environmental concern?

    Buildclean found the answer to that question. The premise seems of the nonprofit organization seems to be admirable but the fact that the "awareness campaign" that Buildclean is currently using seems to be curiously slanted. In fact, the target seems to be the natural stone industry.

    When Sara Selber of BuildClean was asked how she got involved in natural stone and radon, she explained how she was approached by the owner of C&C North America, a company that produces two products – granite and a quartz product called Silestone®™.
    "C&C North America then recruited a quartz company called Cambria, after they learned quartz was an issue, she further explained that the two companies hired her to test quartz, granite and other surfaces for radon emission. Both companies are testing their products through BuildClean, and they contracted two labs – one in New York and one in Israel.

    We have looked all over the C&C website but cannot find any mention of natural stone.

    When ask what granites emit radon, Sara Selber said; "Not all granites emit radon or radiation. There are some that clearly do. There are some that absolutely don't. We don't know," she said.

    They're being set up as a non-profit, and they're funded with two large donations.
    The first is $250,000 from the makers of 'Silestone.' They manufacture quartz countertops, which is a direct competitor to granite. Silestone finance records show that they started out in April of 1998 with a an initial investment of $410K, made there first million in 1998, sales in 2002 was over $70M, and sales in 2006 was well over $260M. it is not hard to see that they have the money to invest $250,000 in a new advertising campaign.

    BuildClean is also getting money from Cambria, another quartz manufacturer.
    In fact, Cambria's marketing director is on BuildClean's board of directors.

    When asked about the funding Sara responds: I don't believe the issue is who our founders are. And I'm not going to have that debate." That answer seems to be clear enough.

    In a recent interview Mrs. Selber mentions teaming up with Al Gerhart who has some interest in the granite \radon scare.

    Al Gerhart is a carpenter whohappens to own a website called the Solid Surface Alliance .org. He educated himself, regarding materials he works with that may expose him to harmful elements."

    Upon further review it seems this "personality" is well known for his view of natural stone. All one has to do is look at the website to get the gist of his viewpoint. Coincidentally, there also seems to be a new business venture for Solid Surface Alliance as the website now sells Geiger counters to detect radiation…
    His debates have earned him quite a place online in forums discussing the subject.

    After a certain debate on a well known residential forum, a renowned geoscientist in the industry concluded:
    "Al attempts to hijack debates by choking the system with verbal diarrhea. The problem appears to be that he has a bit of knowledge about some things but not enough sense and understanding of the subjects. In that debate on the Garden Forum he threw in so many fabrications (plain made up lies) that his credibility just plummeted to zero.

    Anyone who operates this way (by including a number of facts to gain an element of credibility in the eyes of a generally uninformed audience, twisting facts deliberately or because of his lack of understanding, and then throwing in a number of lies) does not deserve extended airtime. Many years ago when doing science psychology I still remember my professor giving the advice to his students that you should never engage a nutter in debate. You can never win an argument with such people. I recognized this early in the forum and that is why I would not engage him in "debate".

    One of his major problems is that he does not know what the numbers mean and how they are derived."

    In response to the buildclean tactics, The Marble Institute of America is in the process of doing their own independent study:

    "The Marble Institute of America (MIA) is grateful for the preliminary response from the members to the newly established Truth About Granite Fund. Based on this positive response, it's clear that their colleagues share their commitment to protect consumers from needless fear mongering by establishing standards for the testing of granite so consumers can safely and comfortably enjoy the beauty, durability and practicality of this natural stone."

    When we asked the MIA why Sara Speer Selber consider The Truth About Granite Fund as a draconian move that is being waged against BuildClean(TM), they simple responded:

    "The Truth About Granite Fund was established to help raise funds to develop unbiased, scientific standards for the granite industry, including the testing of granite for radon. No such standards currently exist in the natural stone industry. Previous tests of granite samples have found they are safe. However, the Truth in Granite Fund aims to take advantage of new, advanced scientific instruments that make testing both more practical and more accurate. Our goal is to make sure testing follows consistent protocols, so that future studies are meaningful and based on consistent, approved science – not isolated methodologies or unapproved instruments. Ultimately, our goal is to make sure the granite we sell is safe."

    This latest sales tactic received the attention of an independent group called the Natural Stone Restoration Alliance (NSRA). The NSRA saw Radon testing as an added service that their members could provide to the homeowners along with all their other services for natural stone. Josveek Huligar, one of the lead testers and trainer for the NSRA , invited times Members of the Solid Surface Alliance dot org to discuss and provide proof of this threat to the home owners.

    The Solid Surface Alliance dot org agreed to provide an alleged radiation producing granite sample that they claim to have in their possession to do independent testing. After an initial agreement between the two groups it seems the Solid Surface Alliance dot org has reneged on the delivery of the alleged material. Mr Huligar was disappointed of the outcome. The NSRA than requested the name of the company that Mr. Gerhart claimed to just have rejected over 10k worth of radon producing granite. When the information was not provided, Huligar ask if he could purchase the next slab that Mr. Gerhart rejected. But for some reason Mr. Gerhart could no longer find a sample for testing. Mr. Huligar went on to say: "All we care about at this point. As for whether are not Stone adds a measurable amount of "radon" in a home, Mr. Gerhart had agreed to come to NY and pick out a hot slab that I would place in my own home after testing my home for radon. Once the granite was installed I would test my home again as described by the EPA and have it tested by someone approved by the EPA. Not only would we do the short and long term test, we would also video tape the whole event, the selection, the creation, the install, and than setting up cameras for anyone to view the stone and meters on the net. I was looking forward to do this, but at this time it appears that Mr. Gerhart has no plans on doing as he said which is a big disappointment."

    The NSRA plans to push for this simple test, they feel that the consumers only care about one thing; "whether or not adding granite in your home would significantly change the radon levels in a home". At present, the most prudent consumer should watch the outcome of this debate and make an informed decision, not taken in by a scare tactic by advertisers.

    EPA Confirms That Granite Countertops Pose No Significant Health Risk
    EPA Confirms That Granite Countertops Pose No Significant Health Risk | Story


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    Default Re: High Radon and Radiation from some granite counters

    That's some good info. Welcome to the message board.


    Quote Originally Posted by Huligar View Post
    As for whether are not Stone adds a measurable amount of "radon" in a home, Mr. Gerhart had agreed to come to NY and pick out a hot slab that I would place in my own home after testing my home for radon. Once the granite was installed I would test my home again as described by the EPA and have it tested by someone approved by the EPA. Not only would we do the short and long term test, we would also video tape the whole event, the selection, the creation, the install, and than setting up cameras for anyone to view the stone and meters on the net.

    If he needs a house to test I'll volunteer my house. I could use nice, new granite countertops.

    "Baseball is like church. Many attend but few understand." Leo Durocher
    Bruce Breedlove
    www.avaloninspection.com

  17. #17
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    Default Re: High Radon and Radiation from some granite counters

    Thanks for the welcome Bruce.

    You are a bit far for us to send the slab, plus all the tools to keep track. I do not see this test taking place see that Al Gerhart has choose to leave the debate and spam the web with beliefs. Before you ask why not buy a meter and find a slab on my own, no matter what slab I find, once the testing is done and it shows that the stone did not give off the amount of gas as they claim, they will simple say that we rigged the the testing.

    We are willing to pay for every thing. I all we need them to do is go on record and state that the slab that we install is what they would consider hot. Is this too much to ask?


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    Default Re: High Radon and Radiation from some granite counters

    Whether real or perceived this issue will effect sales of solid stone countertops. Why take any risk with our health.

    I believe that the industry will pay to solve the problem by developing a standard for testing and an EPA, NRSB or NEHA certification process for all stone and marble slabs.

    Too much is at stake for this to remain an uncertainty. The only problem as you can imagine will be the time it takes to complete. The more money lost by the industry, the faster it will be completed.


  19. #19
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    Talking Re: High Radon and Radiation from some granite counters

    My son Jeff and his wife had granite counter tops installed in their kitchen about 5 years ago and all appears dandy. So far the only complaint from my older son is he has been forced to wear a sleep mask at night due to his wife glowing in the dark, which prevents him getting a good night’s sleep.

    Jerry McCarthy
    Building Code/ Construction Consultant

  20. #20
    William Levy's Avatar
    William Levy Guest

    Default Re: High Radon and Radiation from some granite counters

    Not all radon testing devices are affected by moisture, and the charcoal devices mentioned as unsuitable for kitchen areas in most cases have difusion barrier to help keep the moisture, the analytical lab have a weight correction and rejection cut off if the device comes in with excess moisture. We use E-Perm devices that are moisture and air flow independent and with the correct gamma correction can measure directly on a granite surface.

    The measurement of gamma radiation as well as ionizing radiation fall well within the scope of service of a radon inspector. As a NRPP and FL DOH certified radon analytical laboratory have been measuring gamma ralated to radon , radon emanation from building materials and soils for the past 15 years.

    The "hot" granite is not a new issue as is radon from concrete, high radon levels have been showing up in 20+ story buildings all over the US. In Florida we have delt with it since 1990 and 1000,s of apartments , condos, SF Homes, etc have been mitigated as a result.

    We are now testing granite and other composite materials for radon emanation as well as potentially dangerous gamma and alpha radiation. Our results will not be influeced by any trade interested faction. As we have the capability to directly measure the actual radon emanating fraction of any materials' Radium-226, uniuque radon daughter Po214 alpha in a specific energy band.

    Lets see what the results of the Texas radon testing by another group, and other soon to start investigation.

    I welcome the opportunity to apply our concrete surface and soil radon emanation capabilities to the issue at hand : reducing cancer risk

    William Levy
    Radon Measurement Specialist


  21. #21
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    Default Re: High Radon and Radiation from some granite counters

    Quote Originally Posted by William Levy View Post
    Not all radon testing devices are affected by moisture, and the charcoal devices mentioned as unsuitable for kitchen areas in most cases have difusion barrier to help keep the moisture, the analytical lab have a weight correction and rejection cut off if the device comes in with excess moisture. We use E-Perm devices that are moisture and air flow independent and with the correct gamma correction can measure directly on a granite surface.
    William,

    I mentioned charcoal devices only because the high levels of radon measured in the kitchen may not be reliable IF the device used to measure the radon was a charcoal canister and there were high levels of moisture in the kitchen during the measurement period. An E-PERM would be among the best devices to use in a high-moisture environment.

    I have used E-PERMs for several years and am very familiar with them.

    "Baseball is like church. Many attend but few understand." Leo Durocher
    Bruce Breedlove
    www.avaloninspection.com

  22. #22
    William Levy's Avatar
    William Levy Guest

    Default Re: High Radon and Radiation from some granite counters

    Here is a link to a 2008 study it worth looking at and add to the current knowledge base

    http://www.marble-institute.com/indu...-akron2008.pdf



    I will comment relative to the radon risk and source modeling after a bit of additional study time,

    Cheers

    William


  23. #23
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    Smile Re: High Radon and Radiation from some granite counters

    Sorry guys, I only had time to scan this post, not read it entirely. One of the PhD's up in Minnesota did a study on the subject and found only 2 type of granite out of 10 tested had any issues.

    If it is sealed top AND BOTTOM the sealer will prevent most of the radon and alpha from escaping. The experts that I communicate with say that the contribution to home air is negligible.

    But in any case when in doubt test

    Bruce


  24. #24
    Silvia Osante's Avatar
    Silvia Osante Guest

    Default Re: High Radon and Radiation from some granite counters

    The Marble Institute of America wants to reassure the public that granite countertops are safe.
    Research shows granite countertops pose no threat.
    • The U.S. Environmental Protection Agency, Consumer Reports and repeated independent studies have shown granite countertops pose no health hazard.
    • An independent scientific analysis of a variety of studies shows that, accounting for normal airflow in the typical home, radon contributed by granite countertops ranges from 0.01 – 0.02 pCi/L – levels that are 200 to 400 times lower than the EPA guideline of 4 pCi/L.
      • By some measures, the amount of radon emitted bya granite countertop is less than one millionthof that already present in household air from other sources. Many granite countertops do not emit radon at all, and those treated with sealant reduce emissions even further.

    Silvia Osante
    Cohn & Wolfe on behalf of The Marble Institute of America


  25. #25
    Bruce Thomas's Avatar
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    Default Re: High Radon and Radiation from some granite counters

    Silvia,

    Welcome to the board. It's nice to see someone from a PR firm with the ethics to also state who they represent.

    This whole mess was started by a solid surface counter top trade association. From what I have read on the subject the radiation emitted from most granite is of little concern. But buzz words like most and may are typical of the media and PR firms. We can't deal in buzz words in our profession, in fact Crema Bordeaux emits almost 300 times the radiation levels of other types of granite. There is another type that is approx 200 times but the name escapes me.

    Wouldn't it be a better service to the public to inform them that this type of granite has an average level of X and make the information available for each type as tested by an independent lab. In fact the emission varies across the slab and averages have to be used to make sense of the readings. It is true that most (buzz word) granite is perfectly harmless but what if you just spent $20,000 on a kitchen full of Crema Bordeaux.

    Sealing will reduce the emissions but the bottom and unpolished edges should also be sealed as well in my opinion.

    The granite industry has been unfairly targeted but it is up to you to bring the true facts to the public. Truth is the best way to regain trust.

    Bruce


  26. #26
    William Levy's Avatar
    William Levy Guest

    Default Re: High Radon and Radiation from some granite counters

    The Current version EPA position is a bit different and is pasted below or go to : Answer
    >
    Also the "sealing" to stop radon emanation from the material mineral matrix may present a challange...as many of the materials available are semi transparent to radon. The problem of surface sealing is also complicated by the fact that the radon concentration "under" the sealer continues to increase and thus increase the diffusive drive and unless the source material is completely encapusulated the higher radon finds an path to the area of lowest concentation the surrounding air.
    >
    The production of the alpha radiation happens after the radon has departed the matrix surface.
    >
    William


    Question
    What about radon in granite countertops? Answer Does the EPA believe there is a danger of radon gas or associated radiation being emitted from granite countertops?

    Granite is a naturally occurring igneous rock, meaning that it was formed by the cooling of molten rock. It is quarried and processed to produce commercial products such as countertops. It is possible for any granite sample to contain varying concentrations of uranium that can produce radon gas, a source of alpha and beta particles and gamma rays. Some granite used for countertops may contribute variably to indoor radon levels. At this time, however, EPA does not believe sufficient data exist to conclude that the types of granite commonly used in countertops are significantly increasing indoor radon levels. Some granite may emit gamma radiation above typical background levels. While radiation levels are not typically high, measurement of specific samples may reveal higher than expected levels on a case-by-case basis.

    For more information on radiation and countertops Click Here


    What advice does the EPA have about radon for consumers who have granite countertops?
    While natural rocks such as granite may emit radon gas, the levels of radon attributable to such sources are not typically high. EPA believes the principal source of radon in homes is soil gas that is drawn indoors through a natural suction process. To reduce radon risk you should first test the air in your home to determine the radon level. There are many home radon test kits available at the retail level and on-line, starting at about $25.

    If your home has a high radon level, a level of 4 picocuries per liter (pCi/L) of air or more, there are ways to mitigate or reduce the radon level in almost any home. Contact your state radon office (www.epa.gov/iaq/whereyoulive.html) just click on your state, or a professional radon testing and mitigation firm (www.epa.gov/radon/radontest.html) for assistance. A specially-trained and qualified professional may be equipped to test for lesser sources (such as granite or diffusion from drinking water) when evaluating the nature and source of your home's radon problem. The key to reducing risk is to test your home for radon and then make decisions as appropriate.

    Learn more about radon, read the Citizen's Guide at www.epa.gov/radon/pubs/citguide.html.

    Are the levels of radon in granite dangerous to humans or animals?

    While radon levels attributable to granite are not typically high, there are simply too many variables to generalize about the potential health risks inside a particular home that has granite countertops. It is prudent to limit your family's exposure to radon whenever possible. EPA recommends that indoor air have a radon level as far below 4 picocuries per liter (pCi/L) of air as possible. There are easy ways to test the air in your home for radon, and high radon levels can be reduced with proven and inexpensive technology. EPA believes the most significant source of radon risk is soil gas. Regardless of source, all homes should be tested for radon.

    Has EPA done studies on radon in granite countertops?

    We are aware of a few studies that have conducted limited research on radon in granite countertops. EPA will continue to review this research. The U.S. Surgeon General and EPA recommend that all homes be tested for radon in indoor air. It's easy and inexpensive to test homes with do-it-yourself radon test kits that are commonly available at the retail level and on-line.

    Does the EPA have plans to conduct a study on radon in granite countertops?

    EPA will continue to monitor and analyze the evolving research on this issue and will update its recommendations as appropriate.

    end of paste


  27. #27
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    Default Re: High Radon and Radiation from some granite counters

    Quote Originally Posted by William Levy View Post
    The problem of surface sealing is also complicated by the fact that the radon concentration "under" the sealer continues to increase and thus increase the diffusive drive and unless the source material is completely encapusulated the higher radon finds an path to the area of lowest concentation the surrounding air.
    I agree with that but only to a point. The radon concentration "under" the sealer will only build up to a certain point - the point of equilibrium - at which point the new radon that is produced is approximately equal to the old radon that is decaying away.

    This is similar to a vacant house that has been closed up for several months. The radon concentration in the vacant house does not continue to build up to infinity because the older radon is constantly decaying.

    "Baseball is like church. Many attend but few understand." Leo Durocher
    Bruce Breedlove
    www.avaloninspection.com

  28. #28
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    Smile Re: High Radon and Radiation from some granite counters

    This graphic was taken from,
    Short Primer on U238 Radioactive Decay

    There is a lot of additional good information there as well. Take the time to read it.

    As you can see from the chart Radium it the "parent" of radon the elements above and below radon are primarily alpha emitters. That is not to say that there are no other forms of radiation but alpha is the major issue.

    [IMG]file:///C:/DOCUME%7E2/Bruce/LOCALS%7E1/Temp/moz-screenshot.jpg[/IMG]Radon-222

    Half-life : 3.825 days - Emissions: Alpha 5.48MeV - Beta None - Gamma None


    Bruce is correct when he states that equilibrium occurs but it's in about 2 hours not days or months. Therefore the amount of radiation in say 1 square inch of stone will be constant, sealed or not. Depending on the sealant, that is enough to retain the alpha and beta. There is also Gama and the sealant has no effect. If you double the distance from a source you reduce exposure by 4 for Gama.

    My advice to a home owner would be to test the home air. Basement and kitchen (not on the granite counter top) If the levels are above 4 pCi/L, contact an informed mitigator for further advice.

    If the kitchen is high and the basement is acceptable the source MAY be the counter. Before you go to the expense of scraping a perfectly good and beautiful counter top it should be tested to be sure that it is the source. It would also be worth the effort to attempt sealing.

    Breathing air is the issue, if it's acceptable, you are good. If not find the source and fix it.

    Bruce




  29. #29
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    Default Re: High Radon and Radiation from some granite counters

    Quote Originally Posted by Bruce Thomas View Post
    If the kitchen is high and the basement is acceptable the source MAY be the counter. Before you go to the expense of scraping a perfectly good and beautiful counter top it should be tested to be sure that it is the source.
    I made this point on another of the many threads discussing this topic.

    In the kitchen in the NYT article the measured radon concentration was 100 pCi/L while the basement measured 6 pCi/L. The article did not address this but I wondered if the house uses well water. (The house was described as a second home.) If the house uses well water and water was used before or during the measurement period (e.g., dishwasher) a large portion of the measured radon may have been contributed by the water.

    Like you said, before I would recommend ripping out granite countertops I would want to be sure they were the source of the high levels of radon in the kitchen.

    "Baseball is like church. Many attend but few understand." Leo Durocher
    Bruce Breedlove
    www.avaloninspection.com

  30. #30
    Al Gerhart's Avatar
    Al Gerhart Guest

    Default Re: High Radon and Radiation from some granite counters

    Discussion over gentlemen. Over 10 pCi/L from 18 square feet of granite in a 96 square foot room.

    forum.solidsurfacealliance.org • View topic - Four Seasons Granite Radon Test Is Underway

    Test those granite tops, some are potential risks.


  31. #31
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    Default Re: High Radon and Radiation from some granite counters

    How nice of Al to tell us to shut up and listen to him!

    Erby Crofutt, Georgetown, KY - Read my Blog here: Erby the Central Kentucky Home Inspector B4 U Close Home Inspections www.b4uclose.com www.kentuckyradon.com
    Find on Facebook at: https://www.facebook.com/B4UCloseInspections

  32. #32
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    Default Re: High Radon and Radiation from some granite counters

    Quote Originally Posted by Al Gerhart View Post
    Discussion over gentlemen. Over 10 pCi/L from 18 square feet of granite in a 96 square foot room.
    www. removed link.com
    Test those granite tops, some are potential risks.

    I guess the link you included was your own.


  33. #33
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    Default Re: High Radon and Radiation from some granite counters

    Well, I would not call that an impartial or valid test. Why not have an independent third party who has no affiliation with any particular group (like solid surface folks) perform a valid test.

    I'm not saying that it is not possible to have radon in any natural stone product, including concrete or quartz.

    Scott Patterson, ACI
    Spring Hill, TN
    www.traceinspections.com

  34. #34
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    Default Re: High Radon and Radiation from some granite counters

    Every few years there has been a "SCARE" that in part produces a revenue stream for home inspectors. Lead in water supply and paint ,Asbestos and radon. Radon is the second leading cause of cancer after cigarettes. Radon form counter tops is not part of the equation. Interesting there are counter top Radon testers.[IMG]file:///C:/G] "MicroRdevice
    it sells for about $500.
    Research shows counter top radon in a non event.
    ]


  35. #35
    Al Gerhart's Avatar
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    Default Re: High Radon and Radiation from some granite counters

    Scott,
    how is a femto tech CRM that produces a paper tape record of the results not "impartial"? It is a machine....

    Some of the leading researchers of Radon are participating with this test, loaning equipment, calculating the ACH values, they even helped set the protocols. Plus the results were actually lower than predicted from the results of testing samples from a sister slab (next one in the block of stone) in THEIR labs. Why? Because our room leaks more than their small emanation chambers.

    This is just a real world test of what has already been proven, some granites do pump out serious levels of Radon and thoron. Kitto's work is done (NY state health dept) and is working through peer review, and it should satisfy your independent organization testing requirement (which I agree is the better method). Dr. Steck has tested over 200 slabs so far, he is finding hot stones, and Dr. Llope is on record all over the internet discussing the dangers of some granite types.

    By the way, concrete has been proven to produce Radon, but Quartz has been tested by several researchers and has been found to have little to no Radon. This is purely a granite countertop issue.

    Jory,

    yes there are many Radon testing firms now testing granite including the one that was selling the PM 1703 meter. There is some residual resistance from some, but AARST(Radon scientists) and CRCPD (state radiation officials) both are running committees that are setting protocols and maximum levels for Radon/radiation emission allowed for granite countertops. ANSI and ASME have conducted conference calls to form groups to look into the problem for their organizations.

    Guys, I appreciate skeptic thinking, but there is a point where you have to reconsider your stance. The science has developed to the point that we are far past that point.

    CYA, bring this up with your customers or at least exempt it from what your inspection covers. I know some have already done this.


  36. #36
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    Default Re: High Radon and Radiation from some granite counters

    Oh Boy Al's Back.
    .
    .



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  37. #37
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    Default Re: High Radon and Radiation from some granite counters

    I want one of Billy's meters.


  38. #38
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    Default Re: High Radon and Radiation from some granite counters

    Quote Originally Posted by Al Gerhart View Post
    Scott,
    how is a femto tech CRM that produces a paper tape record of the results not "impartial"? It is a machine....

    Some of the leading researchers of Radon are participating with this test, loaning equipment, calculating the ACH values, they even helped set the protocols. Plus the results were actually lower than predicted from the results of testing samples from a sister slab (next one in the block of stone) in THEIR labs. Why? Because our room leaks more than their small emanation chambers.

    This is just a real world test of what has already been proven, some granites do pump out serious levels of Radon and thoron. Kitto's work is done (NY state health dept) and is working through peer review, and it should satisfy your independent organization testing requirement (which I agree is the better method). Dr. Steck has tested over 200 slabs so far, he is finding hot stones, and Dr. Llope is on record all over the internet discussing the dangers of some granite types.

    By the way, concrete has been proven to produce Radon, but Quartz has been tested by several researchers and has been found to have little to no Radon. This is purely a granite countertop issue.
    I never said it was not possible, heck I have even placed a few CRMs in a home with granite tops in the kitchen, bathrooms and even a built-in desk in a child's bedroom and have found interesting readings. All I was saying is that it would be better if an independent 3rd party company/lab/person with no affiliations did this type of test and announcement.

    My take is that pretty much anything that comes out of the ground "could" produce radon. With granite being on the higher probability end of the spectrum.

    Scott Patterson, ACI
    Spring Hill, TN
    www.traceinspections.com

  39. #39
    William Levy's Avatar
    William Levy Guest

    Default Re: High Radon and Radiation from some granite counters

    Hi All thread followers,

    take a look at the granite radon data on Home data pages..

    In a 96 sq ft room the 10 pCi/l from the granite relate to real life home.....If test room is 8' high V1 = 768 cu ft

    Lets look at a small 1800 sq ft home with 8' ceiling has a volume of 14,400 cu ft = V2 ratio of V1 to V2 is 1:18.75 thus the static 0.0 ACH radon produced from the same granite would be 0.53 p/l

    I just finished a radium 226 source radon emanation test in our 75L glass emanation chamber using 4 clock face #s ( fit in to a 1/2" vinyl tube 1" long) from an antique alarm clock, to yield over 100 pCi/l in 4 days and is still waiting for equilibrium... plot attached ?? I think never had luck with PDF attachments

    Graph of Ra226EmanTest12_084ClockNumb.pdf

    Bill

    Radon Specialist

    ASSOCIATED RADON SERVICES

    Associated Radon Services | Certified Radon Analytical Laboratory | Radon From Granite Testing | Radon Testing | Apartment Radon Testing Specialists | Building Material Radon Emanation and Soil Radium testing | Radium-226 | condo radon testing | e-pe


  40. #40
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    Red face Re: High Radon and Radiation from some granite counters

    Good stuff Bill, BUT!

    The issue isn't just radon from a few granite species. It's also gama.

    Since you are a radon specialist you must be familiar with ALARA (it's a radiation protection term that stands for As Low As Reasonably Achievable for the non radon testers). You should also be familiar with Time, Distance & Shielding.

    The question is, if you know you have a hot counter top, how much time are you spending, how close are you spending it and what is between you and it, if anything?

    When I'm cutting vegetables for the dinner salad, what do you suppose is leaning right against the counter?

    My entire point is why would you take the risk of increased radiation exposure when you don't have to.

    Test your granite, if it's high, replace it and don't expose yourself or your family.

    Bruce



  41. #41
    Al Gerhart's Avatar
    Al Gerhart Guest

    Default Re: High Radon and Radiation from some granite counters

    Scott,
    You are right on an independent organization being the best option. I look at what we do as "pre testing", showing others that there is a real concern that needs looking at by the experts.

    Another problem is that most of the labs aren't set up to handle 400 pound granite countertops, nor do they have a large enough emanation chamber.

    All I ever ask of anyone is not to dismiss the issues until they have seen what all is out there.

    What kind of readings are you finding?

    Hi Bill,

    We chose the 18 square feet because it was a very conservative amount of granite. The ratio of kitchen square footage to countertop square footage varies greatly, but it is between 16 and 50%. Our test used 19% ratio. Now that doesn't take in account how much granite an 1800 square foot home will use. From our jobs, I'd estimate two slabs, 100 to 120 square feet if the bath vanities were used.

    Really though there are homes with granite tile, granite showers, widow sills, full backsplashes, lots more uses besides countertops. Add some of that famously hot concrete you guys in Florida have to deal with, and it all adds up.

    My point is that even if the rise is only .53 pCi/L, homeowners ought to have the right to make an informed decision. That and we business owners, be it countertop or inspection service companies, will be held accountable for perceptions, not facts. Anyone who thinks otherwise hasn't yet graced the hall ways of a court house. CYA and ALARA are pretty much the same thing.

    Bruce,
    I used two Arrow dosimeters on some low level granite last week, 2 mrem per week gamma. The same test on quartz yeilded 1 mrem per week, most of which is likely background from our concrete building along with the usual sources.


  42. #42
    William Levy's Avatar
    William Levy Guest

    Default Re: High Radon and Radiation from some granite counters

    Hi all,

    The gamma radiatition exposure risk has been evaluated by CHP's far more knowledgabe about human tissue abasorbed radiation dose than I with the conclusion that no material yet tested presents a " siginificant health risk".

    The Niagara Gold supplied sample we tested has a gross gamma surface gamma scan of 25x background in several spots but when when tested by others with a a Bicron Absorbed tissue measurement device using CHP protocols was OK. The Niagara Gold supplied sample is the highest level gamma ( by almost a factor of 10) test level we have yet encountered in the lab or in the field.

    I wonder how the results of the home inspectors, who purchased the PM1703's that AirChek put up for sale with the neat 25µR threshold calibration stick, look ? ?

    The radon emanation from some concrete we encounter in Florida is a bit different as the total area of concrete is so large and in many cases includes the cieling which is the slab of the floor above thus a low radium 226 content over these large areas can result in elevated radon in the units. It looks like the same radon emenating building material problem is showing up elseware when upper floors are tested !

    Cheers & all have a great holiday



    Bill

    Associated Radon Services


  43. #43
    Al Gerhart's Avatar
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    Default Re: High Radon and Radiation from some granite counters

    Bill,

    We just shipped Dr. Steck a PM 1703 so he can use it alongside his Bicron unit when testing granite slabs. Might have an answer on that in a few weeks or so.

    And 25 times background isn't that hot, your sample came out of a slab remnant that hit 220 uR/hr (36 times our local background) and other slabs in that bundle hit 550 uR/hr (91 times background).

    Steck is setting up a distance range with a couple of fairly hot slabs, using both PM 1703 and Bicron meters. I bet he will want to hold the data close till peer review and publication, but I might get a little info from the testing. If not, will just have to wait till it is published.

    What is up with the 25 uR/hr calibration stick? Air Chek was advocating using 80 uR/hr last I heard. This is good, 25 uR/hr is what we use as a maximum radiation level to fabricate and sell.


  44. #44
    William Levy's Avatar
    William Levy Guest

    Default Re: High Radon and Radiation from some granite counters

    Hi Al & all

    Take a look at Granite and Radon and see the video AirChek make..I think the source is a "calibrated" piece of welding rod ??? anyway the one I have checks out at 25µr/hr gross gamma on my Ludlum 44-10 and it sets the 1703 threshold at just over 31 here in the radon lab 25 + FL's 6.82... I don't know how many have been sold but 100's of home inspectors checking will sure increase the data base of knowledge available from sources other the MIA's engineering consultant....


    Cheers and Holiday Greetings to all
    Bill

    Associaed Radon Services


  45. #45
    Al Gerhart's Avatar
    Al Gerhart Guest

    Default Re: High Radon and Radiation from some granite counters

    Hi Bill,

    Take a closer look at that Air Chek video on scanning granite countertops with a PM 1703. During the video, Maggie shows how to use the welding rod/check source to set the alarm level, which she says is around 80 uR/hr. Look around minute 1:30 into the six minute video.

    I take it from your post that Florida background radiation levels are around 6.82, so that would be around 12 times background, a significant radiation source in my opinion. But in all of this discussion about granite, we all need to remember that soil based Radon and other building material like concrete must be checked as well. Using Air Chek's three test kit method will make sure nothing is over looked as well as pinning the blame on the granite if it is indeed the source.

    Some state radiation officials are advocating using the NRC cleanup levels of less than 25 mrem exposure per year from the contaminated source (which is exactly what I have always advocated, 25% of the allowable 100 mrem per year), using consumer contact as the distance portion of the protocol. The MIA's own experts advocated using 4 hours per day exposure for countertop owners, which the two committees setting the standards and protocols are likely to accept. Do the math, 25,000 divided by four hours = 6,250, then divided by 365 days = 17 uR/hr.

    Air Check considers a granite countertop that is 4.7 times that amount is "safe".

    By the way, most of the granite countertops that inspectors will run into will be below 17 uR/hr and there is a huge selection of granite that will meet that 17 uR/hr standard so the granite industry still can sell plenty of stone.

    Oh, and an early Christmas present for inspectors and those of us in the granite/Radon/radiation controversy. If anyone runs into a verfiied instance where a granite installation has raised a room's level significantly (say 2 pCi/L), we have a university professor who is one of the nations top Radon researchers, willing to verify your results at no cost.

    Now, the conclusions of the test can be shared with you and your customer, but the data is going to be publicized later in a research paper on the subject. Of course no one will know who or where the homeowner is beyond maybe naming the state, maybe the city, so it is completely confidential.

    Let me know if anyone has a verified (your test kit or CRM verified) case and I will connect you to the researcher.

    Merry Christmas to all,

    Al


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