Health risk assessment of potentially toxic elements in public pipe-borne water from selected households in Abeokuta, Southwestern, Nigeria

Public pipe-borne water serves as a significant source of potable water in some communities in Abeokuta. However, the presence of potentially toxic elements (PTEs) at certain concentrations in drinking water can render it unsuitable for consumption due to associated health risks. This study assessed the health risks posed by PTEs in public pipe-borne water collected from ten households in six communities in Abeokuta, Southwestern Nigeria. Pipe-borne water samples were subjected to PTE (lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), and zinc (Zn) analysis using an Atomic Absorption Spectrophotometer, following standard digestion procedures for the water samples. The collected data were analyzed using descriptive and inferential statistics. The health risk assessment was conducted for the Hazard Quotient (HQ) and Cancer Risk (CR) using the USEPA IRIS models. The water quality index (WQI) was also evaluated. Results indicated varying levels of PTEs, with certain areas exceeding the permissible limits for Cd (0.01-0.02 mg/L), Cr (0.05-0.11 mg/L), and Pb (0.50-0.97 mg/L), posing significant health risks to humans. The health risk assessment revealed that the HQ for Cd, Cr, and Pb exceeded the permissible limit of 1.0 in pipe-borne water consumed by children and infants, indicating potential adverse effects. Additionally, the CR values for Cd, Cr, and Pb in water samples consumed by all age groups also surpassed the permissible limit of 1.0 × 10^-4, suggesting a probable risk of cancer development. The WQIs exceeding the threshold limit of 300 were observed in pipe-borne water samples, indicating that the water is unfit for consumption. Therefore, this study recommends the removal of potential toxic elements at the point of collection by using taps fitted with activated carbon filters.