The Risk of Getting Lung Cancer From Granite Countertops

Granite Countertop
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Whether granite countertops could cause lung cancer due to the emission of radon gas has been a matter of some debate. On one side is that dangerously high levels have been found in some countertops, while arguments on the other claim that the amount of radon emitted are very small relative to radon that may occur in homes. The answer is likely somewhere in the middle, and for those who are concerned, testing may be wise.

We know that exposure to radon in our homes is a very important cause of lung cancer, and is the leading cause of lung cancer in nonsmokers. Radon is a naturally occurring gas that arises from the normal decomposition of uranium in the soil. Since granite countertops may also contain varying amount of uranium, many people have wondered if this could be a problem, and how to find out if it is safe. Let's take a look at what we know at this time.

How Granite Countertops Could Cause Lung Cancer

The concern about granite countertops leading to lung cancer came about because we know some of these natural surfaces can emit radon. The normal decay of uranium present in granite produces radon gas, but the amount of this gas can vary tremendously. To better understand the potential risk, it's important to back up and talk about radon exposure in homes and lung cancer.

Radon and Exposure and Lung Cancer Risk

Exposure to radon gas in our homes—possible anywhere in the world and in all 50 States—is thought to be the second leading cause of lung cancer overall, and the leading cause of lung cancer in non-smokers. Since lung cancer in never smokers is the 6th leading cause of cancer deaths in the United States, these are not small numbers. For a quick comparison, there are roughly 40,000 women who die from breast cancer in the U.S. each year. There are 27,000 people who die from radon-induced lung cancer. Yet, we certainly hear more about breast cancer.

Hearing the word radon may put a picture of miners in your head, but in fact, the greatest risk is to those who spend the most time in the home: women and children.

Radon gas results from the normal decay of uranium, which can be present in varying degrees in the rock beneath our homes. When released into the air outside, it is not a problem as it diffuses widely. When trapped in our homes, however, the levels can build up abnormally high, and eventually, lead to cancer.

Most radon exposure occurs due to radon that seeps into our homes through the foundation by way of cracks, sump pumps, and drains. The age of your home isn't important, and newer homes may actually grant a higher risk due to being more tightly sealed.

Countertops and Radon Exposure

Studies have shown that granite countertops can emit radon and radiation. While this is usually at levels that are well below the limit recommended by the Environmental Protection Agency (EPA), that's not always so. The EPA recommends that radon mediation be performed in homes that have a radon level greater than or equal to 4 pCi/L (picocuries per liter) and that it should be considered at levels between 2 pCi/L and 4 pCi/L. While very uncommon, levels as high as 100 pCi/L have been found in some countertops.

It's important as well, before looking specifically at granite, to realize that many "natural" products will, by their very nature, carry radon to some degree. Products ranging from the clay in bricks to marble, to natural gas, may contain radon, and since granite is less porous than some of these other products, should be of even less concern.

Color and Texture of Granite and Radon Risk

Whether some granite countertops are more likely to emit radon based on color and texture hasn't been extensively studied. A 2006 study found that pink and red granites emitted roughly three times as much radon as black or gray, and it's thought that lighter granites, in general, might pose more risk.

Large veins (striations) are also thought to be an indicator of higher uranium content. Uranium deep in the countertop would be of less concern as only uranium near the surface is likely to release radon gas.

When to Be Concerned

If you are concerned about potential radon in your granite countertops, there are steps you can take. It's believed that there is no safe level of radon exposure, and since granite countertops are in homes where young children reside, some researchers believe it's important for homeowners to be aware of the potential risk.

Test Your Home

If you haven't tested your home for radon, the first step would be to forget about your countertops and do radon testing for your home. Your chance of being exposed to radon in your home is much greater than your chance of exposure from your countertops. In fact, raising a concern about granite countertops without testing your home could be considered analogous to being worried about secondhand smoke, while continuing to smoke yourself. Kits are available at most hardware stores for around $10. If your level is high radon mitigation is recommended.

Consider the Possibility of Radon in Your Countertops

If you wish to get an idea on your own if your granite countertops are of concern, you might consider doing one radon test in the lowest level of your home, and another in the room where you have a granite countertop. (And perhaps a 3rd test in a room at a distance but on the same floor as your granite countertop.) If you try this, it is recommended that you place both kits at least 20 inches off the floor, and at least 20 inches away from the granite countertop. If the levels are abnormal, retest both areas to get a second reading.

You can also order a kit designed specifically to test radon from countertops from the National Safety Council.

What If Your Granite Countertops Are Emitting Radon?

Even if your granite countertops are emitting a significant amount of radon, this does not necessarily mean they need to be removed. Ventilation techniques to improve indoor air might lower the radon level to acceptable levels. 

If you are still concerned that your granite countertops may be raising the radon level in your home after mitigation, there are a few options. The EPA suggests that you may hire a certified radon professional to test for other sources of radon in your home in addition to granite countertops. The American Association of Radon Scientists and Technologists has a list of qualified professionals. It's important to note that, according to the EPA, some of the measurements currently being used (Geiger counter measurements) are not very accurate.

Currently, no regulations require manufacturers to test for the presence of radon in building materials, but this may change in the future as we learn more.

A Word From Verywell

While there is a potential risk of radon exposure due to granite countertops, this risk pales in comparison to the risk posed by elevated radon levels in the home related to radon in the soil beneath homes or even in groundwater. Since there is no known safe level of radon, and since levels vary widely in granite countertops with some having been very high, it's probably wise to test and either put your mind to ease or begin planning a redecoration project.

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