برآورد دوز معادل سالانه ارگان هاي حساس و دوز موثر سالانه ساكنين شهرهاي استان كردستان ناشي از گاماي محيطي

Evaluation of annual effective dose and equivalent dose of sensetive organs of general population in Kurdistan province, arising from environmental gamma radiation

Background and Aim: Natural sources of ionizing radiation have always been a part of the human environment. Ionizing radiation from environmental sources is called natural background radiation. Evaluation of equivalent effective dose is a useful method to estimate biological effects of ionoizing radiation. In this research work annual gonadal and bone marrow equivalent dose from environmental gamma radiation have been estimated. The effective dose that is an indication of risk of whole body irradiation has also been calculated. Materials and Methods: In order to determine the annual rate of environmental gamma radiation (outdoor), in every city four stations were selected along the four main geographical directions, a fifth station was selected at the city center. Considering the most common type of building materials used in the province, two indoor stations were also chosen in every town. Environmental gamma dose rate was measured by a survey meter (RDS-110) mounted horizentally on a tripod of one meter height. Results: Annual absorbed dose arising from environmental gamma radiation for inhibitants of Kurdistan province are equal to:1.41, 1.21, 1.31, 1.1 1, 1.13, 1.33, 0.96 mGy respectively for Baneh, Bijar, Divandareh, Saqes, Sanandaj, Ghorvah, Kamiaran and Marivan. Annual effective dose and equivalent doses of gonads and bonemarrow have also been computed by utilizing annual absorbed dose and other related dosimetric factors. Conclusion: The results indicate that annual effective dose exposing general population living in towns of Kurdistan province is %3 to %36 higher than doses received by residents of normal area.