Natural Radioactivity in Building Materials
- Indoor radon is a more common and a far larger public health risk than radiation from building materials.
Natural radioactivity can be found in some building materials, including decorative rock and stone, bricks, and some materials that are added to concrete.
About Natural Radioactivity in Building Materials
Some building materials, such as granite, brick, marble and other items, contain natural radioactivity. The amount of radioactivity in building materials depends on the type of material, but the amount of radiation released from these materials is typically very, very low.
Many homes contain decorative rock and stone, such as granite and marble. Because these rocks were formed in the Earth’s crust, they may include a small amount of naturally-occurring radioactive materials from Earth. Granite contains naturally-occurring uranium, thorium and their radioactive decay products.
Brick contains the radioactive materials uranium and thorium. While the levels of radiation present in bricks are low, they are slightly higher than some other building materials used for homes, such as wood.
When concrete is created, chemical additives are used to decrease the amount of water in the mixture. These additives may contain materials that are naturally radioactive. For example, instead of disposing of all waste created by burning coal for electricity, a waste called fly ash is added to certain types of concrete. Even with additives, the radiation levels in concrete are very low. Learn more about Radioactive Wastes From Coal-fired Power Plants.
When the natural radioactivity found in building materials decays, it releases the radioactive gas radon. This release of radon may contribute to elevated radon levels in homes and buildings. Indoor radon is a more common and a far larger public health risk than radiation from building materials. When radon levels are high, it can be a risk to human health. Learn more about Radon.
What You Can Do
- Know the facts. Building materials, such as brick, marble and granite, contain very low-levels of naturally-occurring radioactivity. However, these materials can emit radon as the materials decay, which can elevate the indoor radon levels in your home. It’s important to test your home for radon and to correct elevated levels.