Geo-Environmental Risk Assessment of Abandoned Petrol Stations in Essien Udim Local Government Area, Akwa Ibom State

Abstract

This study examines the contamination of soils and groundwater around abandoned petrol stations in Akwa Ibom State, Nigeria, the study further evaluate associated environmental and health risks. Six sites were purposively selected, and samples were analyzed for pH, Total Petroleum Hydrocarbons (TPH), lead (Pb), nickel (Ni), and benzene using standard APHA and ASTM procedures. Descriptive statistics and Pearson correlation were applied to quantify pollutant relationships. Results shows that, mean soil TPH (1575 ± 510 mg/kg) exceeded the DPR limit (100 mg/kg), indicating severe hydrocarbon pollution. Mean Pb (40.22 ± 11.7 mg/kg) and Ni (29.18 ± 9.3 mg/kg) were below regulatory limits but reflected anthropogenic influence. Groundwater TPH (0.048 ± 0.02 mg/L) and benzene (0.017 ± 0.009 mg/L) exceeded WHO limits (0.05 mg/L;0.01 mg/L). Significant correlations existed between TPH and Pb (r = 0.87) and between benzene and Ni (r = 0.76). Findings highlight hydrocarbon metal co-contamination and potential groundwater migration, necessitating remediation and continuous monitoring.