The Estimation of Radon Gas Annual Absorbed Dose in Rafsanjan and Anar Residents Based on Measurement of Radon Concentration Dissolved in Water

The most important natural radioactive resource to which people are exposed is Radon gas. Radon gas produced deep in the earth enters into underground waters and dissolves in them. The Radon gas in water supplied for home uses enters the body by either drinking water or inhaling Radon gas released into the air and causes stomach and lung cancers. The purpose of this study is determination of annual effective absorbed dose of Radon gas in Rafsanjan and Anar residents. This study is experimental and is done on 36 randomly selected resources of drinking and agricultural water in Rafsanjan. Measuring the concentration of Radon gas dissolved in water by the electronic detector RAD7 and statistical analysis of data, the annual absorbed dose of Radon gas by adults and children continually using water of these sources is estimated. The minimum and maximum amount of Radon gas concentration in drinking water are 0.32±0.12 Bq/lit and 13.90±2.45 Bq/lit while the minimum and maximum amount of Radon gas in agricultural resources of water are 3.68±1.25 Bq/lit and 24.51±3.87 Bq/lit, respectively. Therefore, the annual absorbed dose of Radon gas by adults and children using drinking water is between 3.16±1.17 µSv/year and 136.22±24.01 µSv/year and 4.33±1.61 µSv/year and 186.95±32.95 µSv/year, also it is between 36.06±12.25µSv/year and 240.20±37.93µSv/year and 49.49±16.81µSv/year and 329.66±52.05 µSv/year for those using agricultural water it has been concluded that the amount of Radon gas dissolved in the water of this region is approximately high; however, different methods of releasing the existing Radon gas of drinking water along with informing people about the dangers of this gas can decrease the natural exposure caused by Radon gas.