Heavy metal composition of some solid minerals in Nigeria and their health implications to the environment

Heavy metals overload taken via ingestion, inhalation and dermal have been found to be detrimental to both the occupationally exposed group and member of the public. The body burden of these metals has been a source of concern in environmental safety regulatory programs. The risk factor becomes potentially high in an environment where regulatory safety criteria are either neglected or not available. The implication of indiscriminate or unregulated mining activities has been pointed out as a major risk to public health. In order to assess the potential toxicological and radiological health hazard posed to the environment due to mining activities in Nigeria, solid mineral ores (iron, tin and tantalite) from south-western and north-central (Kogi and Ekiti States) part of the country were analysed for their trace-metal contents. The analysis was performed using Energy Dispersive X-Ray Fluorescence (EDXRF) analyses spanning several months between 2005 and 2006. The samples were found to contain some major, minor and trace elements of varying concentrations. The elements reported here are K, Ca, Ti, V, Cr, Mn, Fe, Ni, Sr, Y, Zr, Nb, Sn, Ta, Re, Th, U, Sc, Cd, Bi, Ra and Zn. Toxic metal of serious environmental and public concern like Cadmium was detected. The possibility of altering heavy metal constituents of the natural ecosystem as a result of mining activities and the implications of such alterations has been enumerated. Possible pathway into the food chain as a result of mining activity has also been presented.