Evaluation of the Spatial Distribution and Human Health Risks of Heavy Metal Pollution in Soil and Groundwater Around Steel Recycling Industry in Kwara State, Nigeria (Published)
Rapid industrialization has resulted in widespread environmental contamination, particularly from steel recycling industries that discharge untreated effluents containing elevated concentrations of heavy metals. This study investigated the spatial distribution and accumulation of heavy metals (Pb, Cd, Cu, Zn, Fe, and Mn) in soil and groundwater samples collected from areas adjacent to steel recycling operation in Kwara State, Nigeria. Soil samples were collected at 10 cm depth from five locations, while water samples were obtained from six hand-dug wells during a six-month period (July–December, 2025). Physicochemical parameters and heavy metal concentrations were analyzed using standard methods and atomic absorption spectrophotometry. Results revealed that soil samples exceeded Federal Environmental Protection Agency (FEPA) permissible limits for Zn (413.3 ± 0.06 mg/kg), Cd (222 ± 0.05 mg/kg), Mn (894.74 ± 0.03 mg/kg), Fe (1293.22 ± 0.04 mg/kg), and Pb (33.4 ± 0.3 mg/kg). Groundwater analysis indicated pH values ranging from slightly acidic to alkaline (6.63–7.81), with heavy metal concentrations exceeding WHO guidelines, particularly for Pb (0.80–0.81 mg/l) and Fe. Wells situated closest to the industrial facility exhibited the highest contamination levels, demonstrating a proximity-dependent pollution gradient. Statistical analysis using ANOVA and Duncan’s multiple range test (p < 0.05) confirmed significant temporal and spatial variations in metal concentrations. Health risk assessment revealed significant non-carcinogenic risks (HI > 1) for children and adults through multiple exposure pathways, with carcinogenic risks exceeding acceptable limits (CR > 10⁻⁴) for Pb and Cd. The findings indicate severe soil and groundwater contamination rendering them unsuitable for agricultural and domestic purposes, posing significant health risks to local communities through direct and indirect exposure pathways.
Keywords: Heavy Metals, Soil Samples, groundwater samples, health risk assessment., steel industry
Heavy Metal Contamination and Health Risk Assessment of Groundwater Sources to Waste Dumpsites in Port Harcourt (Published)
Heavy metal contamination and health risk assessment of groundwater ingestion in proximal relation to waste dumpsites in Port Harcourt were investigated during the rainy and dry season of 2020. Five (5) sampling points were established and designated as Groundwater (GW) as follows: GW1, GW2, GW3, GW4, and GW5 respectively. The control station used was GW5. Nine (9) heavy metals (Cd, As, Mn, Cu, Hg, Ni, Fe, Pb, and Zn) were assessed during the period using an atomic absorption spectrometer and were compared with National Standard for Drinking Water Quality (NSDWQ) of Nigeria. The Estimated Daily Intakes of Metal (EDIM) of these metals for adult males, females, and children revealed no significant health issues during the wet and dry seasons. However, the Health Risk Index (HRI) for non-carcinogenic revealed that during the wet season Pb in the control station (GW5) had a concentration of 4.000E+0 mg/kg/day that was far higher than unity (HRI<1) for females. The Arsenic (As) values for children at GW1, 2, and 3 were also higher than unity. The pollution index for each heavy metal across sample location showed that Fe in GW1 and 3 during the dry season was high while in the wet season, values for Cu in GW4 was very high, Fe in GW1 and 2, and Mn in GW2 were higher than the unity. The overall pollution index of the heavy metal studied revealed that only Fe exceeded the unity value during the dry season whereas Cu, Fe, Pb, and Mn concentrations were also higher during the wet season. This calls for concern considering the vulnerability of children and women who may have been exposed to groundwater sources via ingestion. The heavy metal contamination as observed in this study may have occurred due to anthropogenic activities superimposed by the unregulated insanitary waste disposal phenomenon.
Citation: Alaye A.S. Bibiye; David N. Ogbonna; Sodienye A. Abere; Augusta Ayotamuno (2022) Heavy Metal Contamination and Health Risk Assessment of Groundwater Sources to Waste Dumpsites in Port Harcourt, International Journal of Environment and Pollution Research, Vol.10, No.2 pp.34-49
Keywords: Groundwater, Heavy Metal, Pollution Index, Waste Management, health risk assessment.