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Kitchens Forum | Post
Posted by outwest_2007
Sun, Jul 29, 07 at 16:56
|In response to my request for pictures of red granite,
Carpentershop pointed out that red granites are more
radioactive. Interesting, I had never heard that.
Anyway, I think the issue is whether the radiation is
harmful. Of course the granite people say no. Here is one
Here is a link that might be useful: Granite
Radiation Danger A Myth
|I am always suspect of any article which is on a sight
that is prejudiced one way or the other. This happens to be on
a Stone Sight, would you really think they would post anything
not favorable to stone? I visited a stone forum, when the
article they were touting said "more bacteria is killed on
granite than any other surface, there fore it must be more
sanitary". When I asked how many bacteria were present to kill
they couldn't answer. This is a case where figures can lie.
More bacteria grew on granite than any other surface, so of
course, more could be killed with cleaning. It really is buyer
I have not been able to find a truely independant
study on countertops. As in most things in life, follow the
$$, and read the fine print.
|If you read the abstract of the article linked on the red
granite thread you'll notice a few things. The study was done
by researchers at Shaanxi Normal University. Only chinese
granites were examined, most granites we use in our kitchens
are from Brazil, or India. This is not to say that stones from
those locations will be different or the same, just that they
would need to be examined before judgement is passed. The
measurements are reported in becquerels per kilogram, which is
a very sensitive measurement (by sensitive I mean it is a
small unit). Back in the day when Marie Curie was first
measuring radioactivity she was using a Curie (abbreviated as
Ci) as the unit. One Ci is equal to 37000000000 becquerels.
One would need to read the entire article to determine if
those levels would be any sort of health risk. I wouldn't jump
to any conclusions without doing so. Its worth noting that we
are constantly bombarded by radiation. Perspective matters, ie
would it really make a difference or
|As far as I know, post 9-11, large metropolitan areas are
routinely checked for radioactive substances. My guess would
be that a granite radioactive enough to cause a health threat
would not be in the yard for very
|As far as I know, post 9-11, large metropolitan areas
are routinely checked for radioactive substances. My guess
would be that a granite radioactive enough to cause a health
threat would not be in the yard for very long.
If they're sniffing for radiation, they're not going to
track down the small amount of radiation from a piece of
granite. As alku points out, it's a very small amount, and
radiation falls off according to an inverse-cube law; if I'm
standing 1 foot away from a radiation source, and you're
standing 2 feet away, I am receiving 8 times the
radiation you are. Move 10 feet away and you're getting only 1
thousandth of the radiation that I am. Unless that granite
were highly radioactive, by the time you get out to the
street, it's lost in the noise of background radiation that's
This is not to say that working at a faintly radioactive
countertop (which in my house is at about ovary level for me
and uncomfortably close to the jewels for my husband) for long
periods of time wouldn't be a concern.
The notions of becquerels and Curies (events per second
basically; as alku says a becquerel is teensy and a Curie is
huge) aren't very useful in assessing risk. They only tell you
how often something decays. That says nothing about the energy
of the released radiation, and that's the important thing. (We
are rapidly reaching the limits of my knowledge in this area;
I teach physics but not nuclear physics and it's been a while
since I've studied it.) You have to start looking at absorbed
doses, and then what kind of particle made up the dose because
you can absorb equal doses of different kinds of radiation and
suffer very different effects. Judging from the abstract these
researchers compared this kind of information to international
standards and found that this red and pink Chinese granite
exceeded those standards.
I'd look for something else, myself, but I also wouldn't
freak out about it.
|Granite and radiation, radon, and bacteria are myths
perpetrated by the Corian salespeople. Don't take any of it
|Truth is, Granite can not be used in commercial food
preparation areas, as it can not be certified by NSF 51. NSF
is the National Sanitation Foundation, while it may be sealed
properly when installed, there is no way for them to determine
if it will continue to be sealed as time goes on. Care and
cleaning will greatly effect the surface of granite. ES and SS
are approved for NSF 51 areas.
Remember anyone can dig anything out of the ground, it can
be of any quality, they can call it whatever they want and
anyone can fabricate it... and it comes with no warranty. To
get the best stone, hire the best stone fabricator, only they
can assure you your getting a quality stone. And you will not
get an $80 stone for $39.. you will get a $39 stone for $39.
It is truely buyer beware with stone. Engineered Stone and
Solid Surface are backed by large corporations, with a 10 year
warranty and the fabricators have to attend class's every few
years to maintain their certification.
All types of
products are good, but some may not be the best for certain
applications or cercumstances.
|Oh brother! If you're going to buy into this story, then
don't forget that your pillow could be loaded with dustmite
feces; each time you flush your toilet, urine is atomized into
the air (possibly contaminating your toothbrush!); the sun
emits radiation; copper is poisonous and is leaching into your
water from the pipes that carry it to your taps; or that an
asteroid could come crashing into your house at any moment!!!
Why not just go to bed (without your pillow!), pull your
blanket over your head, turn your face to the wall and lie
there trembling in fear. If your granite countertops don't get
you -- something else will.
|Reminds me of a friend who has a teenaged daughter who
went from California to a summer program at a college about 50
miles from Three Mile Island. The mother was all freaked about
the danger of terrorists blowing up the power plant. I
reminded her that the cross-country plane flights to and from
PA were probably more of a risk, as was the sight-seeing trip
they went on in Washington, DC when she dropped her daughter
Crossing the street is a lot more dangerous to your health
than your granite.
|Everyone who pays attention to health issues knows that
radon is a legitimate concern, and houses built on or of
granite are more likely to have radon.
But is the amount of radiation present in a granite
countertop a problem? Seems unlikely, but I'm not really
qualified to say.
I wish someone who IS qualified could take a look at the
numbers and tell us whether the difference in radiation levels
is worth considering when choosing stone.
It's maddening that the stone people and solid surface
people are acting just like politicians, playing and endless
game of 'gotcha', twisting everything to their own agendas.
I wonder if the stone bits mixed into the plastic of
Silestone and the like are tested for radiation level. If so,
lets see some numbers; if not, they'd better stop pointing
|"Why not just go to bed (without your pillow!), pull your
blanket over your head, turn your face to the wall and lie
there trembling in fear. If your granite countertops don't get
you -- something else will."
LOL. I agree with this. I am more concerned about all of
the imported foods and items in my house. Antifreeze in the
toothpaste. Lead on the toys. Botulism in my chili. E Coli on
|Vjrnts - Its been a long time since I've been in a
chemistry class, so please bare with me, but I seem to
remember that radiation is everywhere - in sunlight, the food
we eat, the rocks in our backyards, the crushed stone and
shells in our children's sandboxes, etc. Radiation in and of
itself is not bad. Sniffers are designed to detect *harmful*
levels of radiation. If they went off at lower levels would
they ever stop buzzing?|
|I got my degree in Physics, and work in the industry, so I
know a bit about radiation...
Many things are radioactive at some level. Beach sand is
one of the higher level items you will find in the normal
course of life. Depending on where granite comes from, it can
likely have the same levels.
Here is my advice: If you have the smallest amount of
concern, skip that granite and go for something else. That
little bit of concern is going to take away some of the
enjoyment, which is ht reason for building / remodeling. For
me, I would not worry about it - I get way more exposure at
work (still safe levels) than a peice of granite is likely to
If you really want it, get a piece tested (yellow pages
under testing labs).
Best of luck.
|Interesting Tom that you are still touting the NSF! line
against granite. I thought you might have put that one to bed.
Granite does not get an NSF rating because it is
unnecessary, This was stated in a presentation at the Stone
Expo in Las Vegas in 2006 during a ES presentation.
presentation was given by THE representitive of the NSF. It is
only required by our government on the man made chemically
That being said, IF granite were radioactive, I and our
staff would be in trouble. There are over 30,000 granite slabs
in our distribution center.
|A reputable website?
|I'm reminded of an old saying... |
"If the lie is big
enough, anyone will believe it"!!
|...and don't stand too close to your microwave!!!!! What
about those IR waves between your tv and your remotes??? Oh
and your cellphone gives off bad stuff too. Our whole town is
wireless, so I guess I'm doomed. Invisible waves everywhere...
oh dear, oh dear. Hello???|
|Junkscience.com is a website run by Steven Milloy, who is
not a scientist but is actually affiliated with right-wing
think tanks and Fox News. Its purpose is political, not
scientific. The study cited in the post above was published
with the intention of demonstrating that standards for
radiation exposure are absurdly low, in the opinion of
junkscience.com. I expect that Milloy would be mortified that
it was being used in an effort to make a point about the
dangers of granite countertops.|
I am not going to continue to hijack
this thread and get off topic much further. That being said, I
do not know much about the radiation issue except that it is
scoffed at by anyone associated in the stone business. Rightly
or wrongly, who knows? Based on the current level of
information out there, it sounds like bunk, but the world was
flat once remember. I walk through a warehouse with nearly
30,00 slabs in it, this is making me want to go by a Geiger
As for the NSF rating, that is just one piece of
disinformation the ES guys shove and it pops my gasket.
The seminar you scoffed at Carpenter, was given in Vegas
in 2006, my company's owner and our magazine editor were asked
to participate as representitives of the stone industry, there
were numerous members on the panel including a rep from the
NSF. The question was asked why can't stone be certified by
the NSF and the answer from him was that it is not necessary.
It is my understanding that quite a dialogue followed and the
bottom line is that stone is safe in a kitchen, period,
industrial or residential. No certification necessary. Now
convince the ES guys of that.
As always I send blessings.
Thanks for the civil reply. Still, this tread
is about the health issues of granite countertops, so the NSF
rating, or lack of, is relevant.
One of the issues here is shops that sell only one product.
I do both stone and quartz, and don't understand why most
stone shops don't, pretty much the same tooling and process,
why not give your customers a choice? For some, it makes the
best choice, for others solid surface or laminate is better
and for some, only granite will do.
Choice is good.
I would like to see some proof about what you said about
the NSF and granite. I post links to back up things, easy to
do if the data is out there.
Keep in mind that NSF is exactly like Underwriters
Labratory, anyone can have their product certified, if it will
pass, but it isn't a one time thing, but a continuing process.
If quartz can pass this tough standard, you need to certify
your product or concede the ground to quartz on this issue.
Sorry, but quoting from a stone show, a stone shop owner
and a stone magazine doesn't meet the smell test.
I will get time this weekend and look up the NSF procedure
or call one of my peers that has been involved for more info
and post what I find.
On the junkscience site report on the radiation, it is
about how silly the protesters are, but that doesn't make the
data any less valid. This is science, politics has no place in
science. If you want to claim they published something
innaccuate, flail away, but be specific so your claims can be
checked out. Research a way, we know you have the internet
available, post some links to proof backing up your claim of
bias and let the chips fall where they may.
Or just cast aspersions with out backing them up. Your
call...... What I call a big lie is granite only shops
naysaying the radiation levels of granite through ignorance or
to prevent losing sales. The science is undisputed, and yes
granite will go off around
|Carpentershop, I'm not trying to be uncivil, and I hope
I'm not coming across that way. I'm mainly just pointing out
that you've cited a report in support of your position, when
the purpose of that report was to establish a position exactly
the opposite of yours.
In your post, you state that your link is "to a science
site, very reputable". I can give a couple of quick quotes,
but all anybody really needs to do is to visit junkscience.com
themselves to see what it's about. If it isn't clear to
someone from a visit to the site that its purpose is to sway
public opinion to the Republican side on certain hot public
policy debates, I'm sure that I couldn't add anything to
change their mind.
From Milloy himself:
"Junk science" is bad science used
to further a special agenda, such as personal injury lawyers
extorting deep-pocket businesses; the "food police,"
environmental Chicken Littles and gun-control extremists
advocating wacky social programs; overzealous regulators
expanding bureaucratic power/budgets; cut-throat businesses
attacking competitors; unethical businesses making bogus
product claims; slick politicians; and wannabe scientists
seeking fame and fortune.
From the New York Times (Dec. 18, 2005):
After the EPA released a report on the dangers of
secondhand smoke in 1992, the Tobacco Institute berated the
agency for preferring "political correctness over sound
science". Within a year Philip Morris helped to create a group
called The Advancement of Sound Science Coalition (TASSC),
which challenged the risks not only of secondhand smoke but
also of pesticides, dioxin and other industrial chemicals.
(The executive director of TASSC in the late 1990’s was Steven
Milloy, who now "debunks" global warming and other
environmental threats in the Foxnews.com column "Junk
|Most areas of this country require NSF certification for
any product in commercial food preparation areas. Even sink
drains have NSF stamps on them, Stainless Sinks used in
commercial food service areas will carry an NSF stamp on each
sink. Granite, while it can be fairlly sanitary when sealed
properly, can not for the life of the surface be assured it
will stay sanitary, hence it does not have an NSF
certification. There is NO product used in commercial food
prep areas that do not need or have an NSF certification. Even
faucets, water pipes etc. If you look at many plumbing
supplies you will se the little NSF stamp. NevaMar laminate
was not NSF approved till the last 10 years or so. I did a
restaurant in the Chicago area using NevaMar laminate, which
was specified by the architect, only to have to rip it all out
and put a different laminate in its place, only because it
didn't have the NSF stamp on the sheets. |
True some areas
health departments are very lax, but the vast majority will
not allow stone in any food preparation areas. With all the
cleaning and sanitizing done in a typical commercial kitchen,
how long do you think a sealer would last before it would need
to be reapplied? How can the health department make sure it is
sealed properly when its needed?
My personal feeling is
for a residential kitchen its not a major problem, but the
consumer should not be mislead into thinking a stone counter
is maintenance free. Depending on the type and quality of
stone, the maintenance could be considerable. Hiring the best
fabricator you can find is the best assurance of geting a
quality stone job.
Get what you like, do your homework and
do the proper maintenance on whatever product you choose.
There is NO one perfect product, that is right for everyone.
All the products are good for particular application.
|NSF certification is limited to manmade products and
materials, I believe. Stone (or any similar natural product)
can't be certified as there is variance from one sample to
another ~ cert would need to be done on a case by case basis,
which is unrealistic.
So yes, stone isn't certified by the NSF as it's out of
their scope for compliance testing.
|Thank you Pauline for putting into the right words what I
was trying to say.|
|I'm not too worried about the radiation with there being
so many other things to worry about..... I just want by
kitchen to look pretty! Ha! LOL!!|
|You're welcome vrjames (!) and thank you for your
knowledgable input on stone and granite
|From reading all this, it seems like a greater concern for
the home owner is sanitation, rather than radiation. I know
lots of people with granite countertops who rarely, if ever,
reseal them. We're struggling with the granite vs. quartz
issue and, today at least, I'm leaning towards Caesarstone
which I won't have to maintain and can be sure is
|Sealing stone and sanitizing it is not the same thing.
Sealing is not done for "sanitizing" the
|I know that I'm far more worried about sanitation issues
than I am about radiation issues with my own granite. When our
granite was installed, the entire surface was rough and
pitted. There is not 1 square inch of my granite that is not
pitted. The installers later did something to it to smooth the
surface out. We were told it was a sealer at the time, but
from everything I've read, it sounds more like some type of
resin was used to fill in the pits.
Right now, with the pits filled in, the surface of our
granite is smooth and easy to clean. But how long is that
resin going to last? And is it o.k. to have such a large
amount of resin on a countertop?
|Well. I'll just crawl back into my bubble
|Good God! The yo-yo's in California have legislated a
requirement that any item, substance or food stuff that has
been shown to cause cancer in rats (even if it would require
exposure in quantities far larger than would be encountered in
several lifetimes), must be labeled as a suspected carcinogen.
So far, I don't think that even California requires such a
label on granite countertops. This despite the fact that
restaurants selling French fries, sea food counters in all
grocery markets, and cosmetic counters throughout the state
must post a warning of the possible risks associated with
fries, tuna fish and ordinary lipstick.
Believe me. if the tort lawyers in California haven't
already started suing the purveyers of granite countertops --
you're probably in no danger.
|But the NSF can only address quantifiable materials, like
glass, etc: if they declared [for instance] 'Uba Tuba granite'
to be food safe, every one would call their stone 'Uba Tuba',
even if it were little more than compacted manure.
The NSF could only declare a stone safe if the precise
chemical makeup of every square millimeter could be defined,
and every millimeter of every slab coming out of the quarry
could be compared to this. Basically impossible.
Worth remembering that the government practically banned
wood cutting boards a few years ago [too porous], only to
later admit that bacteria actually dies faster on maple than
synthetic or glass...
The problem with studies of this sort is that it doesn't
allow us to compare the risks [and I'm perfectly willing to
admit there could be some]of granite with risks from
alternative products. Granite has radition, but presumably so
does the stone ground up to make silestone and the like, and
for the most part these are the people pushing the radiation
story. What about VOC outgassing from the chemicals used for
plywood and the adheasives used on a formica type counter? Are
the petro chemicals of swanstone or corian really better?
We all know that UV from sunshine causes skin cancer. A lot
of people slather on the SPF 50 before leaving the house
everyday. But LACK of sunshine also causes MS, colon cancer, a
wide range of issues: we didn't evolve in the dark. You
wouldn't know it from the evening news: the media turns to
dermatoligists for sun info, and the only organ the dermas
care about is the skin.
So it becomes a balancing act, choosing risks and degree of
|Yo-yo in California with a question here...but why would
granite, a natural material, be radioactive? How, in the
millions of years it has been inside a mountain or
underground, was it exposed to radiation? Probably a stupid
question but I really have no idea. Is all stone radioactive?
|Silica dust from granite may increase risk of esophageal
cancer in workers. Also--granite outcroppings are a source of
radon. Overall the amount of granite used for counters seems
minimal--but then again, 3/4 of my yard is made up of granite
|I'm just wondering if there have been any studies linking
granite with an increased risk of cancer in those who have it
in their homes?
If a strong enough correlation has been found, we would
then need to know what it is about granite countertops that
causes cancer. Is it in the *nature* of the stone (ie
radiation) or is it in some aspect of the *processing* of the
stone (ie resin, sealers, etc.) that is to blame?
|Busymom, such a study is nearly impossible. Cancers take
many years to develop, and any study done now would simply be
a list of anecdotes without any controls at all. There is
probably nothing about granite countertops causing cancer.
Worry about the real things that you can do in your own life,
such as not smoking, diet and exercise. It isn't the
|Fairegold - I tend to agree with you about the health
"issue" (or not) that granite poses. But people have been
using granite in their homes for a long time. So a study, at
least on radiation dangers, should be possible. Since sealers
and resins haven't been around as long and the types used may
have changed over time, a study may not be so clear cut on
them. But, if they can study the health effects of Windex, I
suppose they can also study the health effects of granite
With the popularity of granite these days, I would actually
be surprised if someone *didn't* do a study in this
|Snookums, radiation is natural, and everything is
radioactive to some degree. The heat and pressure under which
granite is formed causes it to be more radioactive than some
Just remember uranium comes out of the ground,
|My husband gets more radiation at his job(a trace amount)
then he does from our granite counter tops. He is a mechanical
eng. by degree with Nuclear and a bit of electrical eng.
thrown in to boot. So if he says there is nothing to worry
about I tend to believe him. He laughed when he read some of
the posts here. Without knowing what some of the people do
here for employment he asked if some were salesmen for Corian.
We have had our granite counter tops for over 12 years. We
didn't have mutant babies during our childbearing years,
neither of us have any type of cancer and we all still have
our own teeth and hair, so I guess all those years standing at
the counters didn't really have any effect on us. Oh wait,
does your husband forgetting to get you a anniversary card
count!?? Good grief what will those non-granite fabricators
come up with next! NancyLouise
|Sorry, I totally did not mean to start a fight! I am not
getting the red granite, but not because of radiation
|Oh, Outwest, you didn't start it. What type of granite are
you going with?
By the way, I was wrong about those guys being new posters,
they have been around a while. My
|Interesting snippet about radiation exposure for the
average person. Except for the sleeping next to a person
example, these list annual exposure amounts. |
granite countertops are pretty safe. You need to surround
yourself in granite with high uranium content to get a fair
amount of exposure. I think sleeping in a separate room from
your significant other will play a bigger part in reducing it!
Being exposed to really low doses gives the cells a chance
to repair, as oppposed to high doses in quick succession. The
cells can't keep up with the damage it
Here is a link that might be useful: PBS
|alex9179, that was a good link. Did you see the FAQ about
plutonium? I had no idea that it was that safe to handle.
Still, the link mentioned that the granite in our capitol
was so radioactive that it couldn't be used a a nuke site.
Either the nuke site rules are too tough, or that is some
really radioactive granite.
The junkscience.com used the same unit of measurement,
microrems as the PBS site. I see some things on the PBS site
that I don't understand. It says that sleeping next to another
person gives you a 2 microrem dose, but there are 365 nights a
year or a dose of 730 microrems a year, far in excess of what
they say is the normal exposure of 250 to 300 (the higher
number is from a CDC site ). Which figure is correct? Actually
for those of us who have been married quite a while, it might
Still, if the rate of exposure in our capitol buildings is
correct, that is 60 Millirem per year, on top of what we get
from natural sources. They said that it means a one chance in
one thousand of developing a fatal cancer over a lifetime. So
depending on the actual dose, expect from one in a thousand to
one in two hundred increase in the chance of developing a
fatal cancer in your lifetime.
If cancer runs in your familiy, like it does in mine,
perhaps it makes you more concerned about this
|FWIW, I'm a homeowner who just completed his first, and
probably only, kitchen remodel. I work in the insurance
industry. The countertop in our new kitchen is Corian. There
is no granite in my home.|
|More than one outstanding idea in your post, fori. In the
interest of changing the tone, here are 3 photos of one of the
buildings in question from the first "study" cited in this
unfortunate thread. These are from a family vacation to
I have seen speculation by those whose judgments should be
taken seriously that the Library of Congress may be the most
beautiful building in America. If you go to D.C., don't miss
|"Solid surface is a polymer, where two molecules crosslink
into a new larger molecule which is completely inert."
Only to the extent that the reaction goes to completion.
They NEVER do.
The monomers remaining are often
relatively hazardous, though in an industrial setting they can
be pretty well controlled to low levels.
"…60 Millirem per year…"
Not enough to worry about.
I work at cyclotrons testing
devices for use in satellites.
No one would even look
twice at 60 mRem.
It is below the allowable exposure limit
of 5 mRem, or even the ‘general public’ limit of 0.1 Rem (100
mRem) per year.
Here is a link that might be useful: Exposure
|The granite used in the Capitol Building isn't the stuff
that's going to go in the average kitchen, and don't forget
the massive amount used in the construction. THAT granite has
high uranium content. It doesn't say ALL granite. It's not
like it's closed to the public or workers for a hazardous
I saw uranium content listed from 4 ppm to 100 ppm. I'd
wager that most household granites are at the low end. I think
sandstone was a little over 2 ppm, for
|Revans, surly you could have put each of those in a
|Yes, carpentershop, I still will use granite in my home
and it is still not a concern. I doubt myself or anyone for
that matter will use as much granite in their kitchen or bath
as the whole Capital building in Washington. You are really
grasping at straws with that one. Awesome pictures by the way
nice to see some technical info and yes
some polymers don't "cook" all the way. I warn about solid
surface from small plants with little investment in equipment
that forces them to use one of the three catylast systems that
is vastly inferior to the other two. The major brands use
either continuous cast, and the temp and humidity is
controlled to insure the most complete cure possible, or open
pour with a long steam retort curing process to force all the
chemical to cross link.
One of the most famous companies that tried to pour their
own was Jetta corp, a maker of fine hot tubs, but really,
really bad countertops. The stuff was porous, would change
color and texture as it cured out, in the customers home. What
we think of as a solid, hard surface is anything but on the
molecular level, and these molecules will eventually find each
other, bringing on all sorts of quality issues when they do.
Think green or yellow when you bought white..... Durability is
an issue as well.
I really don't care what the crap product is made of, I
point them out as I see them.
Your point about the monomers being unlinked is valid for
some products, including resined stone and quartz, which is
about 35% solid surface. The quartz is post cured, while the
granite is not, so this is the most likely to be a problem
with resined stone that solid surface or quartz.
See, I don't mind when someone comes up with valid points
to consider, I respect that very much. It points to missing
links in my knowledge, ones that I address quickly. I am as
afraid of what I don't know as I am of what I do know on some
I am especially glad to see someone with radiation exposure
experience to be joining in the discussion, but am a bit
confused by one of your sentences
"No one would even look twice at 60 mRem.
It is below
the allowable exposure limit of 5 mRem,...."
I am totally confused by that, while I understand the
difference between milli and micro, isn't 60 larger than 5?
Wouldn't that be 12 times the allowable exposure limit?
Another question, is the remainder of the quote, "or even
the ‘general public’ limit of 0.1 Rem (100 mRem) per year."
The link at the end of this post shows the natural exposure to
be 300 mRem, not 100 mRem. Is there debate on the allowable
levels that one is subjected to, and if so, who has the last
say on the matter? This would radically change the risk if the
allowable level was three times lower as you point out.
Another question is the math involved, never my strong
point, so forgive if this is a stupid question, but you state
that 0.1 Rem is 100 mRem, but the same CDC site states that
the symbol "m" refers to milli and states that is .oo1 or one
thousands of a Rem. Is .1 Rem 100 mRem or 1000 mRem
Even if I am ignorant of the math, wouldn't an allowable
exposure of 100 mRem that you state, after getting 60 mRem
from a granite countertop, leave you with only 40 mRem left
for natural occuring radiation? If so, this ties in with what
I and others have pointed out, if you are at risk or near the
limit because of natural exposure, or employment exposure
factors, better that you pick a safer material?
My main expertise is in the bacterial aspect of granite,
learning about the more technical aspects of radiation as the
need arises, so forgive the questions.
Thanks for the link to exposure levels. I will spend some
time there later this week.
Exactly what type of granite was used in the
Capitol building? How can you be so sure that it isn't used in
I would like to see that link about the ppm of granite,
what you have quoted sounds close to what I have on file, and
sandstone isn't used much.
Keep in mind that you figures do point out that one type of
granite can have 25 times the level of radiation that another
Isn't that what started this entire thread, my saying that
some red granites have elevated levels of radioactivity?
I love a good debate, but when you guys prove my point, it
makes me wonder why we are still
|I wade in again, with great trepidation. First, I feel
compelled to point out that some posts to this thread have
been removed, including at least one of my own. We did not
play well together, and Gardenweb did the right thing by
taking them out. It does, however, mean that this thread won't
"flow" now, because there are references included herein to
things that no longer appear.
Early on, we were pointed to a report on junkscience.com
which stated that a person who spent 2000 hours per year just
outside the Library of Congress Jefferson Building (photos
above) would be exposed to 60 mRem of radiation from the
granite contained therein. This page
has lots of very interesting information about that building,
not least of which is the fact that it is constructed of
409,000 cubic feet of granite. Brickeyee, who appears to have
superior experience and knowledge in this area, has stated
above that 60 mRem is "Not enough to worry about."
I am prepared to stand by my previous conclusion that
granite countertops do not present a clear and present (or
even unclear and remote) danger to a homeowner.
God bless us, everyone.
|okay, Snookums, lovingdw and busymom 2006, |
something I found. There has been a study done in Cyprus on 28
commerical "granites". It showed the annual dose from living
in a home with granite used at differnt rates, from 25% to 100
%, or with varying use of granite. Keep in mind, living in a
brick home, with tile floors and sheetrock walls all add to
this level, which might bring you up to the 100% level.
Here is what happens when you work in an uranium mine:
1.56 mSv average exposure for an open pit uranium mine
worker according to http://www.wise-uranium.org/ruxfw.html
Here is the annual exposure rate of having granite in your
as much as 2.97 mSv according to this Cyprus study:
look at the end of the Abstract.
One suprise was Cafe Brown was the worst, followed by Rosa
Balmoral and Rosa Ghiandone.
What does Rosa mean? Rose, or red. Here is a link to some
pictures of Rosa granites
So hopefully this will end this debate. Red granite has
more radioactivity than most, with the exception being Cafe
Brown, and it is possible to be exposed to twice the radiation
that an open pit uranium mine worker is exposed to. Note also
that many of the granites were from Brazil, including cafe
brown, the most radioactive granite of those studied.
I wonder what they missed, since they studied only 28
|One could conceivably slip and bonk one's head on granite.
|100 mRems would be .1 Rems (100 x .001 = .1)
This looked like an interesting site: about
|Just don't put your poodle in a MW on top of a granite
countertop - he'll get a double dose of radiation
|I read the study from Cyprus. A previous post states:
"Here is the annual exposure rate of having granite in your
as much as 2.97 mSv according to this Cyprus study:
look at the end of the Abstract."
I believe this to be a more accurate reprisal of what it
Cafe Brown granite was, by far, the most radioactive of any
in the study, and was several to many times more radioactive
than almost all the rest. If you built a "massive" (their
word) home in such a way that 50% of the building materials
used were Cafe Brown granite (countertops, floors, walls,
etc), and you stayed in that home an average of 19.2 hours per
day every day (80% of the time), then the annual radiation
exposure would be a little over half of what brickeyee is
legally allowed to be exposed to in his job.
I am prepared to stand by my previous conclusion that
granite countertops do not present a clear and present (or
even unclear and remote) danger to a homeowner.
God bless us, everyone.
|Well, not quite. |
They mentioned utilization and
furnished several sections on the graph for values with
varying levels of utilization. The question left unanswered
was if they were talking about utilization of common granite
materials, or a home made out of granite, which would be quite
So look at it this way, granite could be used for counters,
sills, and flooring, and the amount could vary, say granite
tile in the kitchen and carpet in the living room and
bedrooms. That is what I understood the study to mean as far
as utilization rates.
This is in addition to background radiation, and what ever
radiation is present in your sheetrock, ceramic tile, brick or
any other number of slightly radioactive building materials.
The point is this, red granite has more radioactivity than
most, the exception being cafe brown. Even at half the dose
that brickeyee is exposed to, it adds to the annual dose and
will contibute toward cancer risk later in life.
The point to the orignial poster was, pick another
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