Assessment of Excess Life Cancer Risk from Radon Concentration in Borehole water Samples collected from Katagum LGA, Bauchi State, Nigeria

Radon in potable water has turned out to be an issue of public health concerns, specifically when used immediately from supply for  domestic purpose and consumption without any pretreatment. In this study, 222Rn Concentration in 15 water samples collected from  ground water sources (borehols) in Katagum local government Bauchi State was determined, using Liquid scintillation counter (Tri-Carb- LSA1000) and the radiological risk was calculated. The study revealed that, 222Rn concentration ranges from 28.44 to 49.61 Bql-1 with  mean value of 39.55 Bql-1. These values were found to be higher than the permissible limits set by WHO, USEPA and UNSCEAR. The mean  value of annual effective dose due to ingestion for different age categories (adults, children and infants) are 0.29, 0.43 and 0.51 mSvy-1  respectively; and for inhalation the mean is 0.1 mSvy-1. Also, the mean value of excess life cancer risk due to ingestion for different age groups (adults, children and infants) are 0.0010, 0.0015 and 0.0018 respectively while that of inhalation is 0.0003. Thus, this study reveals  that borehole water around Katagum Local Government Area Bauchi State is not radiologically safe and there is need for constant  monitoring.