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Item Time-lapse Geological Assessment of Groundwater; A Case Study of Oghara Farmlands, Delta State, Nigeria(2026) Ozobeme Azubike Anslem; Osisanya Olajuwon Wasiu; Airen Osariere John; Ibitoye Taiwo Abel; Saleh A. SalehThe use of mineral fertilizers and nutrients is widely adopted in conventional agricultural practices, playing an essential role in maintaining optimal crop yields and improving overall quality. To aid farmers in effective fertilization and crop management strategies, non-invasive geophysical techniques can offer insights into the nutrient distribution within the soil. This study deemed it imperative to assess the physicochemical parameters and heavy metals (HM) present in the groundwater of the study area. A total of three groundwater samples and five soil samples were collected and tested for different heavy metals (HMs). The checked HMs included iron (Fe), chromium (Cr), lead (Pb), copper (Cu), zinc (Zn), nickel (Ni), manganese (Mn), and cadmium (Cd). Recently, electrical resistivity tomography (ERT) has been used in local studies to measure changes in soil properties. Unfortunately, the signals we measure from the ground are mixed up because of changes in the soil both sideways and up and down, making it hard to figure out what each change is contributing. The analysis of groundwater revealed that, with the exception of a few parameters, groundwater samples fell below the WHO permissible limit. The soil's porosity, permeability, and the surrounding topography influence the migration rate. The rates of migration vary between the first and second locations. It has been found that if the vertical migration rate in the dry sand layer (which is about 13.7 meters thick based on drilling data) stays the same, the fertilizer contaminant will take about 0.5 years to reach the wet sandy layer below it in the first location, while in the second location, it will take around 1 year. Detailed calculations to determine the arrival time at the sandy layer have been conducted. Ultimately, it is imperative for the government to guarantee the installation of water purification plants during the process of borehole drilling, as this will help further decrease the existing salinity levels in the groundwater.Item Heavy Metal Contamination and Human Health Risk Assessment of Groundwater in Osubi, and it environ, Delta State, Nigeria(Faculty of Science Applied and Health Science, Anchor University Lagos, 2025) Osisanya, W.O.; OnifadeY.S.; Auta, T.A .; Ukulu, H.S.This study evaluated the concentrations and potential health risks of selected heavy metals in groundwater resources within Osubi, Delta State, Nigeria, a rapidly urbanizing region influenced by industrial, domestic, and oil-related activities. Groundwater samples were analyzed for Fe, Mn, Zn, Cr, Cd, Ni, Pb, and B, and the results were assessed using contamination indices (Cf, PLI, DOC, MPI) and multivariate statistical tools (CM, ICM, PCA, CSC, TVE). The findings revealed that the concentrations of the studied metals were largely below critical contamination thresholds, with spatial mapping highlighting localized hotspots near Osubi Airport, Winner Chapel Osubi, Usman, BM, and CNAW. Health risk assessment showed that hazard quotient (HQ) values for both children and adults were all below 1, indicating no immediate non-carcinogenic risks. However, children exhibited higher HQs than adults due to their greater intake per unit body weight, underscoring their heightened vulnerability. While Fe, Mn, and Zn were present at non-hazardous levels, Cr, Cd, and Pb, although below threshold values, require close monitoring because of their toxicity and cumulative effects. Weak inter-metal correlations suggest multiple diffuse sources, likely from anthropogenic activities such as waste disposal and effluent discharge. Overall, the study indicates low to negligible pollution levels in Osubi groundwater but emphasizes the need for proactive measures, including regular monitoring, simple household water treatment practices, improved public awareness, and stricter regulation of industrial discharges to safeguard groundwater quality. Sustaining these relatively low contamination levels is critical for ensuring long-term water safety and public health in the Osubi community.