Radiological Effects of Iron-Ore Mining and Processing at Itakpe, Kogi State.

Abstract

Gamma spectroscopy was employed in the analysis of soil samples collected from the mine site, industrial plant site, and mill tailing dumps site of National Iron-Ore mining Project (NIOMP), Itakpe, Kogi State. The mean measured activity concentrations of ⁴⁰K, ²²⁶Ra, and ²³²Th  were 207.6±39.4(ND-515.0), 17.6±2.4(ND-31.5), and 31.7±8.6(ND-118.0)Bqkg^-1, respectively, which are all less than the world mean of 370.0, 25.0, and 25 Bqkg^-1 for ⁴⁰K, ²²⁶Ra, and ²³²Th, respectively. The calculated outdoor mean effective doses for the sites were respectively74.8±20.0µSv, 47.0±7.0µSv and 17.0±1.0µSv for industrial plant, mining waste and mill tailing deposit sites. These values are comparable to the control mean value of 74.3±46.2µSv (obtained from unmodified environment soil samples) which in turn is comparable to the world mean of 60µSv, thus suggesting that the mining company does not constitute radiological problem to its workers and the public. The calculated activity index, I, for the company mill tailings is 0.122, the value which is equivalent to an excess gamma dose of 0.122mSv/year over that received outdoors if used as a building material.