Geochemistry and Environmetric Approaches to Estimate Pollution Impacts on Soils around Okaba Coal Mines

Abstract

Soil samples were collected during dry season from Okaba coal mine areas to establish the level of impact. Impact evaluations were carried out using correlation analysis, factor and cluster analyses, determination of enrichment factor (EF), contamination factor (CF), pollution load index (PLI), anthropogenic factor (AF) and index of geo-accumulation (Igeo). The AF gave this order: Pb>Ni>Cu>Zn>Fe>Cd. The Igeo index, EF and CF also revealed the same rank as AF. The pollution load index indicated that all sampled sites have been polluted with locations Ok06, Ok16, Ok17, Ok03, Ok10 and Ok08 as the most impacted. At P<0.01 level, very strong correlations exist between Na-K, K-Mg, Ca-Zn while at P =.05 level, strong correlations were recorded between Na-Mg, Ca-Fe, Na-Pb, Pb-Cd and Ni-Pb. The R-mode factor suggested that factors one and three were both natural and anthropogenic while factor two was due to natural processes. The R-mode cluster analysis suggested that cluster one was anthropogenic and clusters two and three were pseudo anthropogenic. Based on the indices, Pb, Ni and Cu were the most impacted heavy metals on soils. While detailed study is apt, the author recommend immediate and total reclamation of the ponds/mines and treatment of all affected areas.