Assessment of Gamma Radiation Dose Rate Associated With Artisanal Goldmine Sites at Northern Zamfara State, Nigeria

Abstract

This study assessed the gamma radiation dose rate associated with artisanal goldmine at Northern Zamfara State, Nigeria.  Measurements of gamma radiation dose rates in the area was carried out using a portable survey meter, Inspector Alert and the coordinates of each point was recorded using a global positioning system.  A total number of 166 average measurements were taken with the survey meter held at 1 m above the ground, with at least five readings taken at each location in order to minimize error. The mean GDR rate of the study area was found to be 32 nGy h-1 which is less than the world average value of 59 nGy h-1. Kaura Namoda local government area has the highest mean value of GDR rate of 38 nGy h-1, while Bakura local government area has the lowest mean value of GDR rate of 28 nGy h-1. Radiological health hazards; outdoor annual effective dose rate, lifetime dose and excess lifetime cancer risk were computed as 0.04 mSv y-1, 2.8 mSv, and 1.38 × 10-4 respectively. In general, it can be concluded that the artisanal mining activities doesn’t pose any significant effect within the study area.