Water, sediment, and mine spoil samples were collected within the vicinity of the Okpara coal mine in Enugu, Southeastern Nigeria, and analyzed for trace elements using ICP-MS to assess the level of environmental contamination by these elements. The results obtained show that the mine spoils and sediments are relatively enriched in Fe, with mean values of 1,307.8(mg/kg) for mine spoils and 94.15% for sediments. As, Cd, Cr, Mn,Ni, Pb, and Zn in the sediments were found to be enriched relative to the mean values obtained from the study area, showing contamination by these elements. The mean values of Fe, Mn, Cu, and Cr in the mine spoils and mean values of Fe, Cu, Pb, Zn, Ni, Cr, and Mn in sediments, respectively, are above the background values obtained from coal and shale in the study area, indicating enrichment with these elements. The water and sediments are moderately acidic, with mean pH values of 4.22±1.06 and 4.66±1.35, respectively. With the exception of Fe, Mn, and Ni, all other elements are within the Nigerian water quality standard and WHO limits for drinking water and other domestic purposes. The strong to moderate positive correlation between Fe and Cu (r=0.72), Fe and Zn (r=0.88), and Fe and As (r=0.60) at p<0.05 as obtained for the sediments depict the scavenging effect of Fe on these mobile elements. As also shows a strong positive correlation with Mn (r=≥ 0.70, p<0.05), indicating that Mn plays a major role in scavenging elements that are not co-precipitated with Fe. In water, the strong positive correlation observed between Cr and Cd (r=1.00), Cu and Ni (r=0.94), Pb and Cu (r=0.87) and Zn and Cu (r=0.99); Ni and Pb (r=0.83) and Zn and Ni (r=0.97); and between Pb and Zn (0.84) at p<0.05 may indicate similar element-water reaction control on the system due to similarities in chemical properties as well as a common source. Elevated levels of heavy metals in sediments relative to surface water probably imply that sorption and co-precipitation on Al and Fe oxides are more effective in the mobilization and attenuation of heavy metals in the mine area than acid-induced dissolution. The level of concentration of trace elements for the mine spoils will serve as baseline data for future reference in the study area.

The quality of soil in the vicinity of Madaka mining sites were investigated in this study using Environmental Pollution Indices. Geological mapping of the study area indicated that the area was dominated by schist and granite. The static water level measurement revealed a westward groundwater flow direction which also coincides with the regional structural trend of the area. Laboratory analyses of soil and stream sediment were carried out in National Geosciences Research Laboratory Kaduna. The results of the soil analyses revealed high concentrations of mercury, cadmium, lead and arsenic. The results of the laboratory analysis were further elucidated using pollution indices such as geo-accumulation index, contamination factor, degree of contamination, elemental contamination index and metal pollution index. These environmental indices revealed that the soil is seriously polluted with mercury, cadmium and lead, moderately polluted with arsenic, lightly polluted with iron and copper and very lightly polluted with manganese, zinc, nickel and cobalt in the order of: Hg > Cd >Pb> As > Fe > Cu > Mn > Zn > Ni > Co. The mean concentrations of the first four metals (Hg, Cd, Pb and As) exceeds their average crustal abundance, which is an indication of possible pollution. The concentrations map of the analyzed heavy metals indicated a westward decrease in concentration away from the mine sites. This was in agreement with the flow direction and the possible reduction in pollution intensity away from the mine sites could be attributed to the natural attenuation mechanism of soil in the course of groundwater migration as well as hydrogeological attributes of the area. The study recommends that the miners be grouped into association and trained on modern mining techniques that are environmental friendly. The polluted soils in the area should be remediated and proper sensitization on the dangers associated with artisanal mining should be carried out in the area. Periodic monitoring of the soil quality in the area is advocated. Keywords