How Does Radon Get into the Body
People may ingest trace amounts of radon with food and water. However, inhalation is the main route of entry into the body for radon and its decay products. Radon decay products may attach to particulates and aerosols in the air we breathe (for example, cooking-oil vapors). When they are inhaled, some of these particles are retained in the lungs.
How Can Radon Affect Your Health
When radon is inhaled, the alpha particles from its radioactive decay directly strike sensitive lung tissue, causing damage that can lead to lung cancer. However, since radon is a gas, most of it is exhaled. The radiation dose comes largely from radon decay products. These enter the lungs on dust particles that lodge in the airways of the lungs. These radionuclides decay quickly, exposing lung tissue to damage and producing other radionuclides that continue damaging the lung tissue.
There is no safe level of radon; any exposure poses some risk of cancer. The National Academy of Sciences (NAS) studied and described the causes of lung cancer in two 1999 reports. They concluded that radon in indoor air is the second-leading cause of lung cancer in the U.S. after cigarette smoking.