Radiological mapping of tin mining areas in Doguwa, Kano State, Nigeria

This paper presents an extensive radiological mapping of the Doguwa tin mining areas of Kano, Nigeria, where uranium has been found in quantities for commercial mining. The goal of this study is to provide detailed radiological information that could be used as a reference in monitoring any future environmental changes that may result from other natural or artificial activities in the area. A total of 701 gamma dose rate in situ measurements were taken covering the study area using a portable NaI (Ti) scintillation detector (identiFINDER (R) 2). The measured terrestrial gamma dose rate varied between 38 and 958 nGy/hr with a mean value of 202 nGy/hr which is 3 times higher than the reported world average value of 59 nGy/hr by the United Nations Scientific Committee on the Effect of Atomic Radiation. The results varied significantly in accordance to the magnitude of the mining activities from one location to another. A radiological map of the study area was plotted using an ArcGIS software. The calculated values of the mean indoor, outdoor annual effective dose, and excess life cancer risk for the adult members of the public in the study area are 1 mSv/y, 0.25 mSv/y and 4.38 x 10(-3) respectively. The findings in this study could be used for a proper radiation protection plan for the area.