2.0 LITERATURE REVIEW 2.1 History background and action level Radon is a gaseous highly radioactive element discovered by English physicist Ernest Rutherford in 1899. The discovery is also credited to German physicist Friedrich Ernst Dorn in 1900. More specifically, Rutherford discovered radon's alpha radiation and Dorn discovered that radium was releasing a gas. Radon (chemical symbol Rn) is a naturally occurring radioactive gas found in soils, rock, and water throughout the U.S. It has numerous different isotopes, but radon-220, and radon-222 are the most common (EPA, 2009). The EPA suggests an “action level” of 4 picocuries per litter in air. Lutgens & Tarbuck suggest that this level corresponds to about 8 to 9 atoms of radon decaying every minute in every litre of air. According to Cohen, the mean radon level in houses throughout the western world is about 1 pCi/l. Cohen has expressed the risks of radiation …show more content…
High level of radon in domestic water might also give high exposure through the intake of water taken directly from the tap but the dose and risk in this case may be small compared to the inhalation (WHO Regional Office for Europe, Copenhagen, Denmark, 2001). Radon can dissolves in water, but is easily removed when water is heated or uses for other purposes. Ingestion also routes that contribute to exposure by food that is contain radium and long-lived radon progeny (WHO Regional Office for Europe, Copenhagen, Denmark, 2001). In indoor air, radon produces a series of short-decay that may attach to aerosol particles present in the air or deposit on the room surfaces (Quindos, L.S. et al.,1991). It is the inhalation and deposition in the airways of short-lived airborne radon decay products that give rise to irradiation by alpha particles of sensitive cells in lung tissues such as the basal cells of the bronchial epithelium (Aggazzotti G et al,