Measurement of radon concentration in indoor air of residential and public buildings in Nourabad Mammasani city and estimation of its effective dose

Radon gas is one of the environmental risk factors which can increase the risk of lung cancer and it is well known as the second-leading cause of lung cancer after smoking. The aim of the present study was to investigate indoor radon gas concentration in residential and public environments of Nourabad Mammasani city and to estimate the effective dose due to radon exposure. In this study, 52 homes and 8 public places were investigated to measure the concentration of indoor radon gas. Indoor radon concentrations were measured using passive sampling approach, alpha-track detectors (CR-39) for three months, and after that, detectors were sent to the laboratory to count the number of tracks. The results of this research showed that the average radon concentration (± SD) in the homes and public places was 42.4(±14.7) and 32.9(±20.1) Bq/m3, respectively. All radon concentration values were lower than the US Environmental Protection Agency standard and WHO guideline. The average of annual effective dose due to the radon exposure in homes was estimated to be 1.07 mSv. The evaluation of the results showed that there was a significant relationship between the room type and the number of floors with radon concentration in the residential buildings. The results indicated that the indoor radon concentration as an environmental risk factor in the studied places was lower than the WHO guideline levels. Consequently, the indoor radon is not likely a major environmental risk factor in the studied environments.