DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (
-   General Home Improvement Discussion (
-   -   Are granite countertops bad for your health? (

!joh 05-22-2008 10:14 AM

Are granite countertops bad for your health?
In what seems to be a genuine concern of the effects of radon emissions in residential homes. A certain website from a non-profit organization out of Houston has made it a point to imply without scientific proof, that natural stone could be a major contributor of radon in a household.

The allusion that seems to be made, that natural stone installed in your home is dangerous to your health is raised repeatedly on the website and in a recent local Houston TV news program.
It’s interesting to note that the two major contributors of this non-profit organization are manufacturers of engineered stone. One of those contributing manufacturers has a marketing executive on the board of directors of this particular organization.

From what may be perceived on the surface as perhaps another “going green” ad campaign, seems to be a different slant on the ongoing battle of the engineered stone manufacturers against natural stone.

Keep in mind that granite as does most natural components found in building material, allows vapors to pass through them that might contain trace amounts of radon. There are very small amounts of uranium found in trace minerals such as biotite in some natural stones. When quarried if a large cluster of biotite is exposed the result initially would be a radon reading. However, once a piece of granite or natural stone exposed to a large amount of uranium rich mineral in the ground is removed from the source and exposed to the air, the radon vapor transmission would weaken drastically and then dissipate. Simply put, think of natural stone as a very dense sponge that allows water, air and yes radon to pass through the stone. Once the stone is removed from the source of radon (the earth) the stone has no radon to filter through it.
We do endorse Radon testing but to allude that natural stone is a main contributor seems ludicrous.

While we feel that health safety is a great concern especially in our homes, for an industry to attempt to gain financially by “scare tactics” or under the auspices of “Eco friendly” is reprehensible. We urge the consumer to not be taken in by these alarmist tactics.

you can read the rest of article at Radon In Granite Causes Cancer | Newsflash2

yesitsconcrete 06-19-2008 04:37 AM

this IS alarming as i cannot believe anyone would use scare tactics to promote a political agenda,,, shame, SHAME !!!!!!!!!!!!!,,, its a sad day for the nation when we can't even trust the n y times !

Charlie 06-19-2008 06:05 AM

I had not heard this and will have to look in to it, but I know they can be bad for your back :)

Al Gerhart 06-19-2008 08:09 PM

To start with, Hulligar runs a stone website for stone repair. He has posted the same paragraphs in a hundred places on the internet. As I run across them, I set the record straight.

There have been dozens of studies on the issue of granite and radiation/Radon. Most warn of the need to test, especially those that reported granites with alarming levels of radiation, and in some cases Radon.

Currently, the Build Clean organization is testing homes in Houston, over 100 tested so far. They were funded by two quartz companies, but both submitted their product for testing. I have submitted three brands of quartz products for testing as well, but I can tell you that there is no radiation of any concequense.

Silestone also sells Sensa, a natural stone line, that has been submitted for testing as well.

One of the problems with Hulligars comments is the vast ignorance of the subject of radiation and granite. He claims that the radon will not continue after removal from the ground, which is completely false. Radon comes from the Uranium radioactive decay chain. Once the atom of Uranium has decayed in to Radium, the next step is Radon, then into the so called progeny or lower elements, which in turn continue to decay, giving off radiation as they do so.

So Radon will be emitted practically forever in our scale of time, millions, even billions of years before all the Uranium cycles through the decay chain.

Basically Hulligar is attempting to load the internet with falsehoods on this subject, whether out of ignorance or out of personal gain. I have a blog set up on these issues

I do sell solid surface along with granite, quartz, laminate and soapstone, but granite is the big seller these days. We test each and every slab prior to purchase, very easily done with a scintillator or a geiger counter.

Yesterday I sent a portion of a slab to two scientists, one that Hulligar says supports his position (he doesn't, is testing stone currently) and the other is the physcist that was on the Houston TV report. The slab in question emitted 171 times background radiation and the next slab in the bundle emitted twice that, 340 times more radiation than were present from natural sources. That last slab would give you as much radiation in an hour as you would get from a chest X ray.

So this is a serious issue, maybe 5% of granites shouldn't be sold, another 10% should carry warnings. The Chinese have been doing this for years, they test every slab and put a sticker on it. At least 15% of the high end granites sold are high enough that Chinese law won't allow it to be used in a home, day care, or hospital.

Al Gerhart 06-23-2008 09:32 PM

NASA on granite and bacteria

While I am no huge fan of granite, I hate to see false hoods told about any material. Not that you are, but someone told you a whopper on the granite resurfacing.

I've never heard of a need to resurface, resealing is needed pretty often depending on the cleaner used and how often it is cleaned, strips the sealer off unless you are using a stone cleaner (usually has diluted sealer in the cleaner).

Resurfacing would be a job, lots of water needed. We top polish some granites, seams and small imperfections, but many granites aren't easily top polished at all.

Repair experts say that surface damage around sinks from water is pretty common, heard a cleaning lady mention that today as well. Spot repairing that might be possible, but a total resurface would be $$$$$.

Bacteria and granite, that one is very true. This NASA report speaks about granite from a desert having 100,000 bacteria per gram of stone and some indication that the bacteria are reproducing to maintain the population.

NASA on granite and bacteria

I did some work last year on bacterial growth on the different surfaces. Turns out that sealed granite grew more bacteria according to the tests, but a few months later we found out why. It seems that the pores in granite (yes, lots of pores) were trapping the bacteria, actually capillary action was sucking in the rinse solution along with much of the bacteria that had grown on the samples.

A lab we were getting quotes from mentioned that unsealed edges and backs of the samples would alter the outcome due to capillary action. We got sidetracked on the granite radiation issues and never tried sealing the edges and backs to see if it changed the outcome. One of these days.....

Anyway, granite can be sanitized on the surface, but it is an ideal enviroment for bacteria, pores larger than the average bacteria, lots of food and moisture available, little UV light reaches deep into the crevices, and an ideal temprature for growth. We sanitized the samples in our testing with bleach water, but after three or four days incubation, the bacteria was back in large colonies. I would guess that the bleach was prevented from reaching the bacteria in the crevices and cracks by surface tension (although bleach ought to act to break some of that tension). Bacteria can double in population in 20 minutes under ideal conditions, so it is no suprise that the population rebounded.

Quartz did better than most of the granites. The MicroBan ones didn't do any better though. Solid Surface did the best, with quartz coming in second, granite last.

Al Gerhart 06-23-2008 09:51 PM

only one case has been directly linked to food illness from granite, Moore Oklahoma back around 2002 or so. Still no one knows to look for the connection. The health dept won't allow it locally for resturant food zones, nor is there any with a NSF51 rating for food splash zone use. One sealer made a NSF51 rating, but not for splash zone use, but for zones where the food was thrown out if it came in contact.

Here is a study done on granite versus plastic

Note that the breast muscle strain is the same as the packaging strain. I had some contact with one of the authors of the study and she said granite did poorly in all the testing except one example.

inspectorD 06-24-2008 05:43 AM

Great job Al
Welcome Al. Good advice there and links.
Stone has always been an issue with counters and food. Folks building those concrete tops also have this same issue. Stones are a porous material, just like wood. We do not use wood tops and stay healthy either.
My suggestion to all who want the perfect expensive tops is stainless steel. Been used commercially for a long time...easy to clean and no bacteria issues.
As far as the radon in tops, we cannot put our femto-tech radon machines on a granite top for testing...they come out to high in picocuries per liter of air.
My buddy also works for the Border patrol scanning trucks. When the granite trucks come through ,they read uranium big time and need to be checked. Gov $$ at work.:D

Al Gerhart 06-27-2008 04:56 PM

Thanks for the welcome, Inspector D.

So the granite tops affect the radon detectors? I could see that happening. Do they have a fan that sucks in room air or is it entirely passive?

Granite trucks, yeah, the larger the stack the hotter it reads. It is kind of weird, you can take two remnants, say a 60 uR/hr granite and a 200 uR/hr granite and lean them against each other then measure one side. The result is higher than both measured separately and added together. One theory is that going through one slab lowers the energy levels enough that more of the radiation is detected by our Geiger counters.

All times are GMT -6. The time now is 10:50 PM.