Radon

Since radioactive substances are found in small amounts in soil and water throughout the world, we can actually ingest it through the food and water we drink. Even the air we breathe contains some radioactive materials in the form of radioactive gases like radon and thoron. These gases are present due to the decay of radioactive rocks (like uranium and thorium) within the earth’s crust. The gases move up through the earth until they become dispersed through the air. Some of the decaying products of these gases attach to dust particles within the air. When this happens, these radioactive gases can be inhaled and may cause damage to our lungs.