Annual effective dose associated with radon, gross alpha and gross beta radioactivity in drinking water from gold mining areas of Shanono and Bagwai, Kano state, Nigeria

Artisanal gold mining activities in Shanono and Bagwai local governments of Kano state Nigeria is a serious threat to the quality of drinking water in the area. This work was carried out to assess the radon, gross alpha and gross beta radioactivity in drinking water sources from artisanal gold mining villages in Shanono and Bagwai local government areas of Kano state, Nigeria. Water samples were collected and analysed for gross alpha and beta radioactivity using a non-gas proportional counter with model protean instrument corporation MPC 2000DP single channel and for Rn-222 using liquid scintillation counter (Tri-Carb-LSA1000). Rn-222 , gross alpha and beta radioactivity had average concentrations of 36.101, 0.142 and 0.285 Bq/L respectively. The annual effective dose for the ingestion of Rn-222 , gross alpha and beta radioactivity were 0.264, 0.228, 0.457mSv/year for adults; 0.395, 0.114, 0.229mSv/year for children and 0.461, 0.057 and 0.114mSv/year for infants respectively. These values were higher than the ICRP, WHO, UNSCEAR and USEPA recommended safety limits, indicating that the water is not safe for drinking and domestic purposes in terms of radiological consequences.