Assessment of Groundwater Quality and Potential Non-carcinogenic Health Risk Around Epie Creek, Yenagoa, Nigeria

Abstract

Groundwater is the primary source of domestic water supply in Yenagoa, Bayelsa State, yet increasing urbanisation and poor sanitation practices raise concerns about its quality and potential health implications, particularly around surface water bodies such as Epie Creek. This study assessed groundwater quality and evaluated non-carcinogenic human health risks associated with borehole water consumption around Epie Creek, Yenagoa. Groundwater samples were collected from 15 boreholes distributed across creek-side, residential, and peri-urban zones using a triplicate sampling design. In situ parameters, including temperature, pH, electrical conductivity, total dissolved solids, and turbidity, were measured using calibrated portable meters. Major ions were analysed using titrimetric and flame photometric methods, while heavy metals (Fe, Mn, Pb, Cd, Cr, Ni, and Zn) were quantified using Atomic Absorption Spectrophotometry after acid digestion. Non-carcinogenic health risks were assessed for adults and children using estimated daily intake, hazard quotient, and hazard index models. Groundwater was slightly acidic, with pH values ranging from 5.2 to 6.8. Electrical conductivity varied between 148 and 612 µS/cm, and turbidity reached up to 12.4 NTU in some boreholes. Iron concentrations ranged from 0.18 to 1.24 mg/L, exceeding recommended limits in most samples. Lead (0.002–0.031 mg/L) and cadmium (<0.001–0.006 mg/L) exceeded guideline values in several locations, particularly near Epie Creek. Hazard quotient values for children reached 0.91 for lead and 0.70 for cadmium, while the cumulative hazard index exceeded unity for children (HI = 2.82), indicating potential non-carcinogenic health risk. Groundwater around Epie Creek shows signs of metal contamination and potential non-carcinogenic health risks, especially for children. Continuous monitoring, improved sanitation, and appropriate household water treatment are necessary to safeguard public health.