Health Risks Associated with Heavy Metal Levels and Physicochemical Characteristics in Water and Sediment from Sagbama Local Government Area, Bayelsa State

Abstract

Water and sediment quality assessments are crucial for understanding environmental contamination and potential health risks. This study evaluates the physicochemical properties, heavy metal concentrations, and associated health risks of water and sediment samples from Ossiama, Odoni, and Agoro in Bayelsa State, Nigeria. Water samples were analyzed for pH, turbidity, total suspended solids (TSS), electrical conductivity (E.C.), biochemical oxygen demand (BOD), chemical oxygen demand (COD), and nutrient levels, while sediment samples were assessed for heavy metal contamination using standard analytical techniques. Results showed that water pH ranged from 6.2 to 6.51, slightly below the WHO guideline of 6.5–8.5. Turbidity levels were significantly elevated, with Ossiama recording 25.12±6.361 NTU, exceeding the WHO limit of 5 NTU. TSS levels ranged from 28.97±0.879 to 44.65±0.645 mg/L, all below the 100 mg/L WHO threshold. Heavy metal analysis of sediments revealed cadmium (0.127–0.151 mg/kg), chromium (0.668–2.320 mg/kg), lead (0.297–2.094 mg/kg), and nickel (0.158–1.064 mg/kg) exceeding WHO permissible limits, indicating anthropogenic pollution. Estimated chronic daily intake (CDI) and hazard quotient (HQ) values were below the safety threshold of 1, suggesting no immediate noncarcinogenic health risks. However, carcinogenic risk indices (RI) for chromium in Ossiama (1.934E-6) and nickel in Agoro (3.014E-6) slightly exceeded the 1E-6 threshold, indicating potential long-term health concerns. These findings highlight the need for continuous monitoring and mitigation strategies to manage water quality and heavy metal contamination in the region.