Radon (222Rn) is a noble gas formed from radium (226Ra), which is a decay product of Uranium (238U). Uranium and radium occur naturally in soils and rocks. Radon gas, which has a half-life of 3.8 days, emanates from rocks and soils and tends to concentrate in enclosed spaces like underground mines or houses. It is a major contributor to the ionizing radiation dose received by the general population. When radon gas is inhaled, densely ionizing alpha particles emitted by deposited short-lived decay products of radon (218Po and 214Po) can interact with biological tissue in the lungs leading to DNA damage.
