Comparison of Indoor and Outdoor Dose Rates from Environmental Gamma Radiation in Kurdistan Province

Background & Aims: Studying about background radiation is important because human beings are continuously exposed to these radiations which leave energy in tissues and the transferred energy leads to undesirable biologic effects. The level of background radiation differs in indoor and outdoor places. Since, people spend more time indoors, in this research environmental gamma dose rate for indoor and outdoor places of Kurdistan towns was determined and compared. Methods: To estimate dose rate at outdoors, four stations in the length of main directions and one in the center of each city were selected. To estimate dose rate at indoors, two stations in each town according to the type of buildings were selected. In each station gamma dose rate was measured for one hour by RDS-۱۱۰ servimeter at one meter height from the earth. Results: The average of outdoor and indoor environmental gamma dose rate for Kurdistan towns obtained as follows: Baneh ۱۳۴ (SD=۵), ۱۶۶ (SD=۲۵) nSv/h, Bijar ۱۱۳ (SD=۱۷), ۱۴۱ (SD=۸) nSv/h, Divandareh ۱۱۰ (SD=۸), ۱۳۴ (SD=۱۲) nSv/h, Saqez ۱۰۵ (SD=۱۲), ۱۳۴ (SD=۱۱) nSv/h, Sanandaj ۱۱۰ (SD=۱۲), ۱۳۳ (SD=۴) nSv/h, Qorve ۱۱۴ (SD=۲۰), ۱۶۰ (SD=۴) nSv/h, Kamyaran ۹۲ (SD=۴), ۱۱۵ (SD=۱۴) nSv/h, Marivan ۱۱۰ (SD=۹), ۱۲۲ (SD=۱۸) nSv/h. Conclusion: Data shows that indoor dose rates in Baneh (%۲۴), Bijar (%۲۴), Divandareh (%۲۲), Saqez (%۲۸), Sanandaj (%۲۱), Qorveh (%۴۰), Kamyaran (%۲۵) and Marivan (%۱۱) exceed outdoor dose rate in these towns.