The environmental effects of the mining of lead-zinc mineralization in Enyigba area, Southern Benue trough were examined. The samples used for this study were obtained from abandoned mine sites, mine tailings, streams, hand-dug wells, mine pond and borehole. Collected samples were subjected to X-ray fluorescence, X-ray diffraction analyses, atomic absorption spectrometry and permeability tests. These were done using standard laboratory equipment and procedures. The concentrations of heavy metals present in analysed water samples fall below the world health organizations' (WHO) acceptable limits. Conversely, the soil, mine tailings and stream sediments indicate appreciable pollution level by some potential toxic metals (PTMs). Consequently, the habitual use of these soils for construction purpose by inhabitants has possible health hazards. The shaly lithology underlying the area is increasingly affected by weathering and lateritization, thus improving its permeability and the easiness with which PTMs can be conducted to the water table by leachate. Regular monitoring assessment is recommended to ensure adherence of miners operating in the area to existing environmental laws.

Assessment of the impacts of lead-zinc mining in Adudu-Imon metallogenic province was carried out. Reconnaissance and detailed field studies were done. Lithologies, stream sediments, farmland soils, mine tailings, artificial pond water, stream water, well water, and borehole water were collected and subjected to atomic absorption spectrometry (AAS) and X-ray fluorescence (XRF) analyses. Geochemical maps were generated using ArcGIS 10.1. Significant contamination with cadmium (Cd), iron (Fe), and lead (Pb) was recorded in the collected water samples. Virtually all collected soil samples were observed to be highly contaminated when compared with the European Union environmental policy standard. The discharge of mining effluents through farmlands to the Bakebu stream, which drains the area, further exposes the dwellers of this environment to the accumulation of potentially harmful metals (PHMs) in their bodies through the consumption of food crops, aquatic animals, and domestic uses of the water collected from the stream channels. The study revealed non-conformity of past mining operations in the Adudu-Imon province to existing mining laws in Nigeria. Inhabitants of this region should stop farming in the vicinity of the mines, fishing from the Bakebu stream channels should be discouraged, and domestic use of the water should be condemned, even as concerned government agencies put necessary mercenaries in place to ensure conformity of miners to standard mining regulations in Nigeria.

Auto junk markets have been observed to be one of the sources of heavy metal pollution in soils and water. The aim of this study is to assess the level of heavy metal pollution within two largest auto junk markets in Nigeria at Obosi and Nnewi, respectively. Twenty-four (24) composite soil samples including the background (control) samples at 0-15 and 15-30 cm depths, and six (6) water samples were randomly collected. Samples were properly digested and subjected to spectroscopic analysis using atomic absorption spectrometer (AAS) for trace metals. Seven selected heavy metals (Fe, Cu, Ni, Cr, Zn, Mn, and Pb) were analyzed in three replicates. The results revealed that trace metals' concentration (ppm) in 0-30 cm depth are well above the background values with Ni in excess of international standard. Metal enrichment is in the order of Ni > Fe >> Zn > Cu > Mn > Pb > Cr. Results of heavy metals obtained from the water samples revealed that Mn, Fe, Cu, and Ni are in excess when compared with the World Health Organization (WHO 2009) and Nigerian Standard for Drinking Water Quality (NSDWQ 2007) standards for drinking water. The pollution load index and contamination factor reveals that the soil around the automobile junk markets are at various stages of pollution with heavy metals, ranging from slight contamination to severe pollution. Water around the automobile junk markets are not advisable for domestic uses, as a result of its heavy metal contents, which are connected to the effects of industrial waste accumulation and indiscriminate domestic waste disposal as suggested by the principal component analysis.

The devastating impacts and mitigation measures for landslides in Nanka, Southeast Nigeria were studied. A procedure encompassing field mapping, laboratory analysis and limit equilibrium simulations were employed in the study. A total of 120 landslides in this area were documented during the field study. They were mainly shallow landslides with depth range of 0.2 m-1.8 m and slope angle range of 36 o-65 o. This study revealed that landslides in this area occur mainly during the rainy season, and are triggered by water infiltration in slopes with high gradient, where poorly consolidated sands overlies less permeable silty clay units in the Nanka Formation. The increase in pore water pressure due to soil saturation leads to reduction of the shear strength and loss of apparent cohesion. Geotechnical laboratory analysis showed that the thin silty clay soils found in the area have very high plasticity, while the sands are non-plastic. The limit equilibrium simulations revealed that as the slope angle increases, the potential slip mass volume increases. Our study in Nanka revealed that landslides have negatively affected the topography/morphology, settlement areas, agricultural lands and vegetation/land cover of the area and many areas are also threatened by this phenomenon. Standard mechanical drainage system and biotechnical slope protection have been suggested as mitigation measures. Finally, we suggested that landslide hazard information should be incorporated into long-term plans for Nanka and other areas prone to landslides, the public should be aware of the hazards and preventive measures.

Over the years, the people of Akpugo community in Nkanu West L.G.A., Enugu State, South-East Nigeria have suffered from frequent building collapse without knowing the cause. This study integrates geotechnical and geophysical techniques to evaluate possible factors responsible for this anomaly. Areas with cracked and non-cracked buildings were studied to assess the geotechnical properties of the soils. Samples were taken at different locations and subjected to x-ray diffraction analysis, grain size analysis, specific gravity, Atterberg limits, permeability, compaction, and triaxial tests. Electrical resistivity method was also used to delineate the geo-electrical layers and to image the lateral variations of the subsurface. Results revealed that problematic zone (areas with cracked buildings) has lower permeability (4.018-7.016× 10 −7 m/s), lower angle of shearing resistance (10-14°), and medium to high plasticity index (25.1-38.33), while the nonproblematic zone (areas without cracked buildings) has higher permeability (1.55-1.925×10 −6 m/s), higher angle of shearing resistance (15-18°), and low plasticity index (18.1-19.4). The x-ray diffraction results of the problematic zone revealed a significant amount of smectite which has a very high swelling and shrinkage potential. The presence of substantial quantity of smectite in the soils of the problematic zone may be a strong factor in the structural problems. The electrical resistivity profiling delineated the boundary between the problematic zone and non-problematic zone and showed that the problematic zone has lower resistivity values (2-25Ωm) while the nonproblematic zone has higher resistivity values (20-170Ωm).