en Radiation Biology Radiation Biology تحقيق بديع Original Research <span style="font-weight: bold">Background:</span> Natural Radioactivity, though natural requires concentration monitoring, especially for the health/ environmental checks of the populace. <span style="font-weight: bold">Materials and Methods: </span>The activity concentrations of 40K, 238U and 232Th in the waters from wells with depths ranging between 141.0 - 214.0 feet were randomly sampled and determined from 20 locations in Ago-Iwoye town in South Western, Nigeria. <span style="font-weight: bold">Results:</span> The activity concentrations obtained were in the ranges of (9.9-50.9)Bq/kg with mean value of (25.1± 10.7) Bq/kg for 40K, (BDL-15.0) Bq/kg with mean value of (1.2 ± 3.2) Bq/kg for 238U and (BDL-6.2) Bq/kg with mean value of (1.6 ± 1.7) Bq/kg for 232Th. <span style="font-weight: bold">Conclusion:</span> According to the results obtained for the activity concentrations from 20 well water samples in Ago Iwoye, Southwestern, Nigeria it was observed that the v40K, 238U and 232Th values were still within the tolerance level indicating minimal radiological health burden on the human populace and the environment. Iran. J. Radiat. Res., 2010 7 (4): 207-210 Well water, depth, locations, activity concentration, health hazard, Ago Iwoye. 207 210 http://ijrr.com/browse.php?a_code=A-10-1-338&slc_lang=en&sid=1 O.O. Fasunwon sfasunwon@yahoo.co.uk 790031947532846001807 790031947532846001807 Yes S.K. Alausa 790031947532846001909 790031947532846001909 No R.K. Odunaike 790031947532846001910 790031947532846001910 No I.M. Alausa 790031947532846001911 790031947532846001911 No F.M. Sosanya 790031947532846001912 790031947532846001912 No B.A. Ajala 790031947532846001913 790031947532846001913 No