Risk Assessment of Outdoor Background Gamma Radiation at Duhok City, in Kurdistan Region, Iraq

In this study, a model „ADM606M Portable Multifunction Ratemeter /Scalar“ (Gamma GP110 Detector) was used to estimate the effective dose rate in (µSv.h^-1). The data were analyzed for three specified hours per day (9:00 a.m., 11:00 a.m., and 1:00 p.m.) from January 2009 to June 2016. In July 2019, the gamma scout radiation meter (dosimeter) was used to measure the outdoor gamma effective dose rate (µSv.h^-1) for the same building every minute for three hours, from 10 a.m. to 1 p.m., at 1m above the second floor of the building. The average effective dose rate and average Annual Effective Dose Rate were 0.158±0.013 µSv.h^-1 and 0.2614145 mSv.y^-1, respectively, within acceptable limits. The excess lifetime cancer risk (ELCR) value was also assessed to be (0.91495×10^–³), which was found to be greater than the UNSCEAR, 2000 stated world average (0.29×10^–³). The risks of cancer morbidity and mortality for specific organs and tissues from external sources of low linear energy transfer (LET) radiation were also assessed. They showed biological effects associated with the potential long-term exposure of Dohuk city residents to natural background radiation.