eng Science and Education Publishing International Journal of Physics 2333-4576 2016-08-06 4 5 119 122 10.12691/ijp-4-5-1 IJP2016451 article Laith Ahmed Najam prof.lai2014@gmail.com 1 Mahmood Salim Karim 2 Taghreed Khalid Hameed 2 Department of Physics, College of Science, University of Mosul, Mosul, Iraq Department of Physics, College of Education, Al-Mustansiriyah University, Baghdad, Iraq In the present work, we have measured the radon gas concentration in environmental water sample of selected regions in Wassit governorate by using alpha-emitters registrations which are emitted from radon gas in (CR-39) nuclear track detector. The results of measurements indicate that the highest average radon gas concentrations in tap water samples were found in Nuamaniya region, which was equal to (0.820±0.04 Bq/L), while the lowest average radon gas concentration was found in Jassan region, which was equal to (0.325±0.02 Bq/L), with an average value of (0.563±0.12Bq/L). The highest value of annual effective dose (AED) in tap water samples was found in Nuamaniya region, which was equal to (0.08 μSv/y), while the lowest value of annual effective dose (AED) was found in Jassan region, which was equal to (0.03μSv /y), with an average value of (0.05±0.01 ̦Sv/y), the tap water in Wassit governorate is safe as far as radon concentration is concerned. http://pubs.sciepub.com/ijp/4/5/1/ijp-4-5-1.pdf water sample tap water radon concentration CR-39 detector