Estimate the effective dose of gamma radiation in Iran cities: lifetime cancer risk by Monte Carlo simulation model.

Background radiation can be different in both indoor and outdoor places. Background radiation is always in the environment, and all people in the community are constantly exposed to it. The most important source of exposure to gamma ray is natural radionuclides. Gamma rays can have harmful effects on the human body. The purpose of this study was to evaluate the health risk of gamma-ray exposure and to simulate using the Monte Carlo simulation. In this study, gamma-ray data were extracted from the studies carried out at intervals January 1, 2000, to December 31, 2018. Iranian and international databases were used to search for the articles. A total of 11 studies were found. To determine the health effects of gamma-ray radiation, the annual effective dose and excess lifetime cancer risk were calculated. To determine the uncertainty, a health risk assessment was conducted via Monte Carlo simulation. In outdoor, the mean, highest, and lowest absorbed dose of gamma ray were 117.82 nSv/h, 295.17 nSv/h, and 49 nSv/h, respectively. Ardabil Province and Chaharmahal and Bakhtiari Province have the highest and lowest gamma ray concentrations, respectively. In indoor, the mean, highest, and lowest absorbed dose of gamma ray were 118.22 nSv/h, 141 nSv/h, and 60.2 nSv/h, respectively. The last column, the mean, maximum, and minimum of excess lifetime cancer risk values for gamma-ray radiation were 2.45E-3, 4.17E-3, and 4.61E-4, respectively.