en Radiation Biology Radiation Biology تحقيق بديع Original Research <b>Background:</b> Radon (²²²Rn) Measurement in the residential environments is very important because of its effecting on human health and causing cancer in the respiratory system. ²²²Rn is individually responsible for half of the natural radiation received in humans and influences on human by breathing. Hence, this study was undertaken to access the ²²²Rn level in the dormitories of Kerman university of medical science (southeast of Iran) to ensure its safety level. <b>Materials and Methods:</b> In this study, for measuring ²²²Rn level in seven dormitories of the Kerman University of Medical Sciences, the Lucas cell technique was used. This study was undertaken during the winter because of the high concentration of radon in this season due to closed building ambience. <b>Results:</b> In this study, the highest measured radon gas rate was 24.5 Bq/m³ in Boustan (1). Average concentrations of the radon gas in all dormitories were 4.7 Bq/m³, which is lower than the standard level. <b>Conclusion:</b> The results of this study showed that the ²²²Rn level in all dormitories was lower than the normal amount (48 Bq/m³) as well as the standard level. <b>Iran. J. Radiat. Res., 2012 10 (3‐4): 171‐175 </b> Radon gas, Medical Dormitory, Kerman, radioactive pollution, indoor air. 171 175 http://ijrr.com/browse.php?a_code=A-10-1-440&slc_lang=en&sid=1 A.R. Montazerabadi 790031947532846003054 790031947532846003054 No M. Ahmadian 790031947532846003055 790031947532846003055 No M.R. Vahed 790031947532846003056 790031947532846003056 No N. Yousefi 790031947532846003057 790031947532846003057 No A. Fatehizadeh 790031947532846003058 790031947532846003058 No P. Borhani 790031947532846003059 790031947532846003059 No A. Rajabizadeh 790031947532846003060 790031947532846003060 No A.R. Binesh 790031947532846003061 790031947532846003061 No A. Shakerizadeh 790031947532846003062 790031947532846003062 No A.H. Mahvi ahmahvi@yahoo.com 790031947532846003063 790031947532846003063 Yes