Assessment of cancer risk and tissue equivalent dose in rainwater samples in Iraq

Objective: In this study, we investigate the radiological safety of rainwater samples at specific sites in Iraq by determining the dose rate, annual effective dose (AED), tissue equivalent dose and excess lifetime cancer risk (ELCR). Natural and anthropogenic sources of environmental radioactivity can be transported by atmospheric precipitation; therefore, rainwater is an important indicator of the radiological status in the environment. Tests were performed using a calibrated FS-600 Geiger– Müeller (GM) detector in a controlled vacuum chamber to reduce background effects.The measured dose rates ranged from 0.026 to 0.132 µSv/h, and none of the values were found to exceed the international standard reference limit of 0.274 μSv/h (UNSCEAR).Estimated annual effective doses calculated ranged from 0.021 to 0.033 mSv/y; these levels are lower than suggested public exposure limit of 0.48 mSv/y.Excess life-cancer risk associated with outdoor radiation absorbed by skin varied between for both genders: 81 ×10⁻³ -128×10⁻³ which is well below global reference value of excess life cancer risk estimate-,029 x10⁻³.The results show that the radioactivity from rainwater to the public exposure for the studied sites is low and can be considered as not dangerous to health. The results were in agreement with ICRP and UNSCEAR reports, and can be used as established data for environmental radiation monitoring in Iraq. Monitoring needs to be ongoing to ensure the radiological safety and environmental protection.