Are Your Granite Countertops Killing You?

The truth about granite countertops and radon

For the last few months newspapers and TV stations from Texas to Iowa, from New York to Seattle and points in between have been telling us that granite countertops can emit hazardous radon gas. But it wasn’t until the New York Times published "What’s lurking in your countertop?"  on July 24, 2008 that we began to receive calls asking us to comment on this increasingly emotional and controversial issue.

We have spoken with our own experts here at HomeAire and its parent company Spruce Environmental Technologies as well as with radon researchers and scientists across the country. All agree that radon is a dangerous gas that is known to cause lung cancer. (Radon-induced lung cancer kills more than 21,000 Americans each year.) They also agree that the most significant potential source of radon in your home is the rocks and soil beneath it, but that building materials such as granite also can emit radon.

Because of the escalation of public concern, the Technical and Science Committee of the American Association of Radon Scientists and Technologists (AARST), whose members include many of the world’s leading radon researchers, educators and mitigation experts, released a statement on August 5, 2008 that presents the current opinion regarding the danger of granite countertops and recommends steps for determining whether you and your family are at risk from radon in your countertops.

Here is an excerpt from the AARST statement:

Radon Risk

The primary concern about indoor radon gas is the increased risk of lung cancer that exists from breathing radon and its byproducts. The magnitude of the risk depends on the radon concentration in the air you breathe and how long you are breathing it. Radon gas is a serious national concern. The risk of radon-related lung cancer increases the longer you are exposed although any exposure to radon poses some risk.
 
Testing for radon in the air you breathe should be a high priority and the first step for anyone concerned about radon gas. The US Surgeon General, US EPA, AARST and the American Lung Association recommend that all homes be tested for radon gas.
 
At this time, the EPA does not believe sufficient data exists to conclude that the types of granite commonly used in countertops are significantly increasing indoor radon levels.

Radon Sources Including Granite

Soil, sand, and rock underneath the home are the primary sources of indoor radon gas. The soil under a house always contains traces of uranium that eventually decays into radium that then decays directly into radon. This soil constitutes an enormous surface area for release of radon gas into the air and into buildings. Materials inside a building such as concrete, granite, slate, marble, sand, shale and other stones can also contain traces of radium that release radon with varying intensities. While natural rocks such as granite may emit some radon gas, the subsequent levels of radon in the building that are attributable to such sources are not typically high. The contribution from building materials to the indoor radon concentration is very dependent upon the building ventilation rate.

Practical Diagnostic Radon Test

Diagnostic measurements of the radon in the air you breathe can provide better risk estimates.
 
Perform a radon measurement according to testing protocols (specified by EPA or AARST as noted below) in the lowest level (or lived-in level) of your home.
 
At the same time, perform another test in the room where the granite countertop or other suspect building material exists. You may also want to test in a highly occupied room, like your bedroom. (Use different rooms if these locations are on the same floor.)
 
Place the test devices at least 20 inches off the floor according to testing protocols and at least 20 inches away from the countertop or suspect material. Carefully follow all manufacturers’ test kit instructions.
 
You may also contact a State licensed or nationally certified radon measurement professional to conduct the measurements for you.
 
If any of the test results are at or above the EPA recommended action levels retest these areas to confirm the initial results.
 
Interpreting Radon Test Results
For guidance on test results and protocols for measurements of radon in the air, see documents such as EPA’s Citizens Guide to Radon or other EPA publications at http://www.epa.gov/radon/pubs.   The full AARST Position Statement on Granite Countertops is on the AARST website.

If confirmed measurements are at, or above, the EPA recommended action levels, contact a State licensed or nationally certified mitigation professional to fix the home to reduce the radon levels.

If you decide to test your home – and the room(s) in which you have granite countertops – yourself, HomeAire can help. Our radon test kits include analysis by a nationally recognized, certified radon testing laboratory. Click here to order.

We can also help if you need a qualified measurement or mitigation professional. Click here to find a professional.