Groundwater Quality and Health Risk Assessment Related to Waste Electrical and Electronic Equipment Dumpsites in Benin

Abstract

Introduction: Groundwater represents the main source of drinking water. However, this natural resource is sometimes exposed to anthropogenic pollution which can affect the wellbeing and human health. Aims: This study aims to assess the metal contamination of wells located near Waste Electrical and Electronic Equipmentdumps in three cities in Benin (Cotonou, Abomey-Calavi, and Natitingou), and to evaluate the health risks to local populations. Methodology: Water samples were collected at distances of 0, 50, and 100 metres from the sites and analysed. Eight heavy metals including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) were quantified using Microwave Plasma-Atomic Emission Spectrometry. Water quality was evaluated using the Metal Index and Heavy Metal Pollution Index, while non-carcinogenic and carcinogenic risks were estimated via Health Risk Assessment methodologies. Results: The results indicated several heavy metals present at concentrations far exceeding WHO guideline values; for instance, cadmium reached 0.48 mg/L in Cotonou, approximately 160 times the recommended 0.003 mg/L. Lead concentrations peaked at 0.76 mg/L in Natitingou, significantly surpassing the 0.01 mg/L threshold. Iron levels were recorded at 8.76 mg/L versus a guideline of 0.3 mg/L. Metal Index and Heavy Metal Pollution Index confirmed marked metal pollution, with Heavy Metal Pollution Index values reaching 8,698 in Cotonou. Health risk assessment revealed Hazard Indices well above 1 for both adults and children, alongside Cancer Risks exceeding 10⁻⁴, with children in Natitingou exhibiting a CR of 2.29 × 10⁻³ (USEPA, 2011). Conclusion: The quality of the studied well waters is a significant public health concern, underlining the urgent need to strengthen ecological management of Waste Electrical and Electronic Equipment and groundwater monitoring.