Assessment of heavys metals and physicochemical properties from artisanal mining site at Rimin Zayam Toro local government area of Bauchi State, Nigeria

Abstract

Artisanal and small- scale mining (ASM) activities are prevalent in many part of Nigeria and have been linked to significant environmental and public health concern. This study investigated the concentrations of heavy metals and the associated physicochemical properties of soil collected from an artisanal mining site in Rimin Zayam Toro Local Government Area of Bauchi State Nigeria. To assess the extended of environmental contamination and provide baseline data for environmental monitoring and remediation efforts. Soil samples were obtained from three different sites namely; abandoned mining site, active mining site and non - mining site respectively. The heavy metals concentrations were determined and quantified for Cd., Cr, Cu, Fe, Mn, Ni, Pb and Zn using Atomic Absorption Spectroscopy (AAS). Physicochemical properties such as the pH, total organic carbon, total organic matter, electrical conductivity and soil particle size were analyzed using standard methods. The soil examined under the following abandon, active and non-mining sites. From the results soils pH reveals slightly alkaline in nature for all mining sitesi.eabandon, active and non-mining site having 6.04, 6.45 and 6.35 respectively; with moderate electrical conductivity of 31.30, 42.66 and 26.75 (µS/cm) respectively; low to medium value of total organic carbon of 0.062, 0.423 and 0.452 (%); medium to high total organic matter value of 0.844, 0.729 and 0.780 (%) and ECEC values are 7.385, 4.003 and 3.994 for abandon active and non-mining sites respectively. All the values were lower than the maximum allowable concentrations in soils for mining sites. Although appreciable amounts of all the metals were detected in the various site but were within the permissible limit (WHO /FAO). Cd, Cu and Pb were below detectable limits in the three sites. The findings indicate the absence of environmental contamination from heavy metals and physicochemical properties due to early stage mining activities have not yet significantly impacted the surrounding environment. This is a wakeup call for a proactive environmental management. The current baseline data can serve as an essential environmental changes and guiding regulatory oversight in artisanal mining operations.