INVESTIGATION OF THE ENVIRONMENTAL IMPACTS OF TIN MINING IN SABON-BARKI AND GYEL AREAS OF JOS-PLATEAU, NORTH CENTRAL NIGERIA

Abstract

This study was carried out to assess the environmental impacts of tin mining in Sabon-Barki and Gyel, areas on the Jos-Plateau (Lat. 90 45’ 31 N; 90 49’ 60N and Long. 80 48’ 20E; 80 52’55E). The study area was surveyed using Digital Global Equipment (GPS), and samples of soil and water were collected at marked locations for analysis. The samples were analysed for heavy metal pollutants in addition to some in-situ measurements. For the purpose of this study 22 water samples, and 22 soil samples were collected and analysed. The results showed that mining activities caused enormous environmental damages to about 776 hectares of land. The mean concentrations of heavy metals in Sabon-Barki water are in the increasing order of: Co < As < Cr < Pb < Mn < Zn < Cu < Fe (0.461mg/l). At Gyel the order is: Co < As < Cr < Mn < Pb/Zn < Cu < Fe (0.172mg/l). Except for As and Fe (t > t0.05) heavy metal concentrations in all the water sampled at Sabon-Barki showed no significant difference compared with the control area (t < t0.05). At Gyel, there were no significant differences in the mean values of heavy metals concentrations in the water samples. The level of pollution in the soil was evaluated based on the determination of geo-accumulation indices (Igeo) of heavy metals, and the results showed that the soil samples in both Sabon-Barki and Gyel were extremely Fe-enriched geochemically. Gyel soils were heavily contaminated with Co, while other heavy metals in both locations were between the range of moderate to uncontaminated and practically uncontaminated. The myriad of mining features which characterize the landscape have resulted in the formation of waste land, disruption of natural drainage system, pollution and destruction of natural habitat. Consequently the socio-economic activities in the area have been greatly reduced, while the mining features continue to constitute safety hazards to human and animals. An effective reclamation of mining damaged lands in the study area can generate productive ecosystems.