Are Granite Countertops harmful to Your Health??

Real Estate Agent with RE/MAX Compass, formerly RE/MAX WHP 0524642


What is all this talk about Radon & granite countter-tops? Excessive radon emissions? The research done  has clearly shown that actual levels of radon gas emissions from granites are so low as to be insignificant and generally represent no threat to the health and well-being of people who live or work in buildings with granite countertops, floor or wall tiles, furniture or any other furnishings made from granite. You may consider concrete contertops, they are  gorgeous, cheaper and very similar in appearance!


Posted by


Greg Nino
, Houston area Realtor®.
Helping residential buyers, sellers and tenants 7 days a week.
Available @ 832-298-8555 

RE/MAX Compass (Formerly RE/MAX WHP)




The information contained in this blog is believed to be reliable and while every effort is made to assure that the information is as accurate as possible, the author of this blog, and its comments disclaim any implied warranty or representation about it's accuracy, completeness or appropriateness for any particular purpose. All information is copywritten and the property of Greg Nino.  






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Shirley Parks
Sands Realty 210-414-0966 - San Antonio, TX
Broker, 210-414-0966, San Antonio TX Real Estate

This is the first time I have heard of this... leave it to the media, LOL... I can just envision homeowners everywhere having their granite countertops removed and replaced with something else.

May 15, 2008 02:09 AM #1


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

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


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

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

Here are some facts about Radon:


“Radon comes from the natural radioactive decay of radium and uranium found in the soil beneath the house. The amount of radon in the soil depends on complex soil chemistry, which varies from one house to the next. Radon levels in the soil range from a few hundred to several thousands of pCi/L. The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, and the suction within the house”.


“Houses act like large chimneys. As the air in the house warms, it rises to leak out the attic openings and around the upper floor windows. This creates a small suction at the lowest level of the house, pulling the radon out of the soil and into the house.( Just as natural stone filters radon emission as mentioned before.) You can test this on a cold day by opening a top floor window an inch. You will notice warm air from the house rushing out that opening; yet, if you open a basement window an inch, you will feel the cold outside air rushing in. This suction is what pulls the radon out of the soil and into the house. You might think caulking the cracks and the openings in the basement floor will stop the radon from entering the house. However, scientific studies show, it only takes enough unsealed cracks or pin holes in the caulking to equal a hole 1/2" in diameter to let all the radon in. It is unlikely that caulking the accessible cracks and joints will permanently seal the openings radon needs to enter the house. The radon levels will still likely remain unchanged.
Fortunately, there are other extremely effective means of keeping radon out of your home. Throughout the country, several million people have already tested for radon. Some houses tested as high as 2,000-3,000 pCi/L; yet, there hasn't been one house that could not mitigate to an acceptable level. The difference in reference to natural stone is that one the stone slab is removed from the source and exposed to the atmosphere the radon is vented in the same way ventilation of a house mitigates the radon emissions in the soil.

Levels of radiation from granite products, which technically are measurable, are in fact, small fractional values of established thresholds for environmental safety. The truth of the matter is that granite is a safe product. It’s been used for thousands of years and the relationship between granite and radon has been studied for years and years. How safe is granite? There have been mathematical models developed that show that one could live in an all-granite home or building, including sleeping on granite, for an entire year and still be within very safe levels of exposure.

Calculations show that, if an average countertop, traps an average uranium concentration of four ppm (parts per million), the concentration of radon that is given off by the countertop into the household air would be 270,000 times less than the level of radon in the outside air. The maximum contact level that you would receive over one year if you were to sit on a countertop all of the time would be about one quarter of the annual radiation from all sources. If you were just a few inches away from the granite (such as when doing the dishes), the dose would be too low to measure.

To Quote Donald Langmuir, PhD, Professor Emeritus of Geochemistry, Colorado School of Mines, & President, Hydrochem Systems Corp.
”To show how laughable are the concerns of radon emitted from natural stone, the typical granite countertop in our example will release 7.4 x 10 -7 pCi/L of air. This corresponds to 2.7 x 10 -8 atom decays per second (dps). This represents 0.85 decays per year. In other words, less than one atom of radon is produced by the countertop in one year. This is hardly worth getting excited about. I would suggest that a good way to reduce our exposure to the radon present in outdoor air would be to build an air-tight house out of granite countertops! There are certain properties of rocks that can increase their radon emanation efficiency, or in other words increase the release of radon from a given weight of rock. These are rock properties that maximize the exposure of internal or external rock surfaces to water or air, allowing any radon gas to escape. The author of 'Granite and Radon' argues that such properties, which include rock porosity, fissuring and mylonitization, will increase radon releases. This is probably true, however, a granite with such properties would be too brittle to make into a countertop, and too open to take a polish, and so would not be marketable as a countertop - unless the rock pores were first filled with a chemical sealant. Such sealing would also eliminate any possible radon release problems.”

In a more recent study that was conducted by L. L. Chyi, a Ph.D. and professor of Geochemistry and Environmental Geology at The University of Akron, Akron, Ohio. Dr. Chyi studied 13 of the most popular granites used throughout the United States as determined by an industry-wide survey. Due to their popularity these 13 granites, are believed to represent up to 85% of the granite countertop market in recent years. The granite types are as follows:

1. New Venetian Gold, Brazil; medium grained, yellow-beige gneiss with many dark red garnets
2. Uba Tuba, Brazil; A medium- to coarse grained, olive-green granite
3. Santa Cecilia, Brazil; A coarse-grained, yellow-grey gneiss with up to pie-sized, red garnets
4. Tropic Brown, Saudi Arabia; medium-grained, brown granite
5. Absolute Black, India; black basalt
6. Tan Brown, India; A black-brown igneous rock with big, shapeless, brown-red feldspar crystals
7. Giallo Ornamental, Brazil; coarse-grained, brown-yellow granulite with some brown-red garnets
8. Crema Bordeaux, Brazil; Juparana Crema Bordeaux (Brunello). A coarse- to very coarse-grained, pink to red granite with areas of quartz, alkali feldspar and quite a lot of ore
9. Baltic Brown, Finland; brown-black granite
10. Giallo Veneziano, Brazil; medium- to coarse-grained, ochre-yellow to golden-brown, also light pink, gneiss
11. Dakota Mahogany, USA; medium- to coarse-grained, brown-red granite
12. China Black, China, a fine-grained plutonic rock
13. Yellow Star, China, a medium-grained yellow to pink granite

The testing methodology was designed to measure the amount of radon which each granite type would add to the interior of a 2,000 square foot, normally ventilated home with 8 ft ceilings. The results show that Crema Bordeaux (the most active in terms of radon emissions) would contribute a concentration component of less than 0.28 pCi/L, or less than 7% of the EPA's recommended actionable level of 4.0 pCi/L. This radon amount is well below a level which might cause health concerns. Tropic Brown and Baltic Brown, second and third in radon emanation based upon Dr. Chyi’s testing, amounted to only 1% of this action level. The other granites tested added almost immeasurable amounts of radon to the house. Radon atoms in pore spaces and fractures are of minimal concern in the case of granite countertops

Dr. Chyi’s test results show that the granites that are currently found in the United States’ market place are insignificant contributors to radon levels in the home. “Based on the testing results and EPA standards, we can conclude that the most popular granites used as countertop surfaces pose no health threat to homeowners. If proper resealing is applied once a year or at other frequencies determined by the industry, the radon emanation can be further reduced”.

Daniel J. Steck, Ph.D. also ran a test on interior radon and granite, and this is what he had to say.

“The average radionuclide contents of your building material samples are similar to other average granite samples and other common earth-derived building materials such as brick and soil. Thus, the amount of gamma radiation emitted from similar masses of these building materials will be approximately the same;

There is little sample-to-sample variation in the radon family radionuclide concentrations; the radon flux is somewhat larger for the counter-top squares than for the smaller samples. This indicates that the effective diffusion length is only on the order of the thickness of the counter-top samples, i.e. several centimeters. Thus, material thicker than 5 cm (2") most likely will not emit more than the counter-top samples.

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

May 21, 2008 06:49 PM #2
Nothing to worry about, huh?

Jun 20, 2008 08:21 PM #3
Jerome (Jerry) Donahue
Prudential McHugh Realty - Maple Shade, NJ

Seems like another slow news day

Jun 21, 2008 12:56 AM #4

Seems like these stone guys are getting desparate to cover this up.  Here is another view on the subject

Jun 27, 2008 02:55 PM #5
Greg Nino
RE/MAX Compass, formerly RE/MAX WHP - Houston, TX
Houston, Texas

Oh the media and the internet. What doesn't kill you these days!

Jun 28, 2008 03:39 AM #6
Vicki Bishop GRI - Alabama Real Estate
Coldwell Banker United Realtors® - Bay Minette, AL

Well this is a new one on me, I had not heard about the radon, but it seems that most everything is harmful to you these days.

Jun 28, 2008 03:45 AM #7
Sue Riley
RE/MAX Four Corners - Van Alstyne, TX

I have not heard about the radon but I did catch a radio program ( I listen to the BBC World service in my car) about how the granite is harvested and the terrible working conditions that the people working on this suffer. I think that it was in india but I may be mistaken,it was a while ago. It makes me think twice about putting in granite in my own home. There are some new materials being used that are made of recycled products which I will look into when I remodel my kitchen.

I have seen the concrete and these are a great option,


Jun 28, 2008 03:54 AM #8
AJ Heidmann ~ CRS
McEnearney Associates, Inc. - Alexandria, VA
YOUR Alexandria & Arlington, VA Real Estate Expert

It appears that the phrase, Never let the Truth Get in the way of a Good Story, is at work here.  even is the stone, which is usually 1.5" thick or less were emitting detectable radon, the normal air circulation of the average home would take care of that, but I'm not a believer at this point.

Jun 28, 2008 04:03 AM #9
Greg Nino
RE/MAX Compass, formerly RE/MAX WHP - Houston, TX
Houston, Texas

I agree with you AJ & Jodee. A whole lot of hot air..

Jun 29, 2008 03:26 AM #10
Jeffrey Molloy
Check Mark - Westchester Home Inspections - Mount Kisco, NY

As many of you are already aware this is not the first time this issue has come up and, like many professionals in the area I have received about 10 requests for testing in the last few days. 3 tests are back and None had any real elevation. Averaging only about .5 pCi/L, these results are encouraging. This group also included a very recent "Brazillian" slab. So as the results come back I'll let you know what's happening. 

We must also remember that while radiation from Uranium decay which ultimately results in Radon Gas production is not measured by our testing methods. So harmful effects from the amount of Radiarion that one is subject to can of course be far different than the effects of Radon Gas we might inhale.

I dont have Granite in my kitchen yet but I am going to install it next year

Aug 04, 2008 10:20 AM #11
Debbie Small
Long & Foster Realtors - Martinsburg, WV

I must have my head in the sand...never heard about this. All the more reason to love AR. Great explanation Huligar. Wow Sue, something else to consider..."blood granite".

Aug 05, 2008 12:35 AM #12
Greg Nino
RE/MAX Compass, formerly RE/MAX WHP - Houston, TX
Houston, Texas

Debbie, Welcome to Active Rain & thanks for stopping by.

Jeffrey, way over my head! But I trust you know what your talking about!


Aug 05, 2008 04:23 AM #13
Sherry Scales
Austin Texas Homes, LLC - Leander, TX
Realtor, for Austin, TX and surrounding areas

I am amazed at how many people think granite is a solid surface counter-top. Like Corian or the likes.  WRONG!!!  Granite needs to be sealed just like concrete counter-tops.  Home Depot told one of my clients they now have a process that will seal it for good, But I haven't gotten the chance to check it out yet. But they are porous, and will soak up meat juices and the like when the sealant wears down. Just as they let gas through, they let liquid seep in too. (I was in Kitchen and Bath design before I got into real estate, so familiar with it.) 

Aug 08, 2008 03:15 PM #14
Chris Olsen
Olsen Ziegler Realty - Cleveland, OH
Broker Owner Cleveland Ohio Real Estate

Hi Greg -- Wow...Just when you thought you have heard it all.  I'm more worried about formaldehyde which is released from many products than perhaps trace amounts of radon.

Jun 20, 2009 04:51 AM #15
William James Walton Sr.
WEICHERT, REALTORS® - Briotti Group - Waterbury, CT
Greater Waterbury Real Estate

I think I need to keep my eyes and ears peeled for stuff like this in my local area. And you got 6 deals out of this? Good stuff. Too bad this is a localism post, otherwise, I'd reblog it for my area...

Jun 20, 2009 07:05 AM #16
Lisa Hill
Florida Property Experts - Daytona Beach, FL
Daytona Beach Real Estate

I never heard anything about this. Was this a localized cocern, in your area? Or was it nationwide news?

Jun 20, 2009 07:38 AM #17
An Marshall
Berkshire Hathaway - St. Augustine - Saint Augustine, FL
Your St Augustine Real Estate Consultant

i have not heard of this association.

Jun 20, 2009 11:18 AM #18
Kasia Zajac, GRI, SFR
Baird & Warner - Lake Zurich, IL

I've heard about that some time time ago but nevertheless I bought a new bathroom vanity with granite counter top. I have a little portable radon tester in my home, which I decided to try in my new bath. I placed it directly on the counter. Guess what...the radon level doubled in this room (but it was still under 4pCi/l). Then I sealed the granite and tested again; the radon level got lowered. So, sealing granite counters from time to time is very important.

Also, I heard that some granites (especially those more exotic) contain more radon than the others.

Jun 20, 2009 03:51 PM #19
Granite countertops

Granite or

Apr 09, 2011 01:02 PM #20
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