Heavy metal contamination and health risks from dumpsite effluents in Enugu State Southeastern Nigeria

This study evaluates the concentrations and associated health risks of heavy metals in dumpsite effluents across selected locations in Enugu State, Southeastern Nigeria. Surface and groundwater samples were collected in and around active municipal dumpsites and analyzed using Atomic Absorption Spectrophotometry (AAS). Detected metals included lead (Pb), iron (Fe), cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), manganese (Mn), and nickel (Ni), with measured values compared to WHO and Nigerian drinking water standards. Elevated levels of Pb and Cd were observed, with Pb ranging from 1.5 to 5.1 μg/L and Cd from 2.1 to 4.8 μg/L. Fe and Mn concentrations reached 14.4 μg/L and 14.2 μg/L, respectively. Cr and Ni levels varied between 0.8-2.5 μg/L and 0.1-4.3 μg/L. Principal Component Analysis (PCA) and Pearson correlation revealed anthropogenic sources, notably leachate infiltration and waste decomposition, as primary contributors. Human health risks were assessed using USEPA models, estimating both ingestion and dermal exposure for adults and children. Hazard quotient (HQ) and hazard index (HI) values indicated significant non-carcinogenic risks, particularly for children exposed to Pb and Cd. Carcinogenic risk levels for Cr and Pb in several locations exceeded the acceptable threshold of 1.0 × 10-4. Communities depending on shallow wells and surface water near dumpsites showed the highest risk levels. The findings highlight the urgent need for improved waste management, regular water quality surveillance, and community health interventions. This work provides essential baseline data for environmental health governance and demonstrates the utility of chemometric tools for pollution source tracking and policy development.