Granite’s durability and decorative appearance make it a popular building material in homes and buildings. The rock comes in a wide range of colors that vary with the elements in it. Granite, like any other rock, can contain naturally occurring radioactive elements like radium, uranium and thorium. Some pieces of granite contain more of these elements than others.

If present, these radioactive elements will decay into radon, a colorless, odorless, radioactive gas. Learn more about the decay of radioactive elements.

The radon gas may be released from the granite over time. However, since granite is generally not very porous, less radon is likely to escape from it than from a more porous stone such as sandstone.

It’s important to know that radon originating in the soil beneath homes is a more common problem and a far larger public health risk than radon from granite building materials. Also, any radon from granite countertops in kitchens or bathrooms is likely to be diluted in the typical home since those rooms are usually well ventilated.

In addition to radon, the other natural radioactive materials in the granite can emit radiation. However, it is extremely unlikely that granite countertops in homes could increase radiation doses above the normal, natural background dose that comes from soil and rocks. Learn the Radiation Basics.

View EPA's Frequent Questions about Consumer Products, including granite countertops.

Testing

To reduce your risk of lung cancer from exposure to radon you should test the air in your home. There are many inexpensive do-it-yourself home radon test kits available at the retail level, online, or from 1-800-SOS-RADON (767-7236). Learn more about radon.

Identifying the presence and concentration of radioactive elements in granite requires expensive and sophisticated instruments. These instruments require proper calibration and interpretation of their readings requires a knowledgeable and trained user. At this time, there is no generally accepted home testing protocol for radiation in granite countertops.

If you have questions about testing your countertops, you can get information from your state’s radiation protection program. Visit the Conference of Radiation Control Program Directors (CRCPD) Exit website to find the radiation program contact for each state.