Elemental Concentrations and Potential Toxic Risks in Water Sources Affected by Nearby Open Dumpsite

Open dumpsite is one of the most common waste disposal practices in developing nations, monitoring the location and assessing the effect it has on the surrounding water sources and the probable toxicological risk to users is essential. The study evaluated the concentration and potential toxic risk of exposure to toxic elements (TEs) in water sources around the Saje Open dumpsite in Abeokuta, Ogun State, Nigeria. Twelve (12) water samples were collected from wells, streams and boreholes for analysis. Acid digestion (20 mL Conc. Nitric (HNO3) acid) and TE estimation using an Atomic Absorption Spectrometer (AAS). The concentration of TEs recorded (except Fe) in the samples was within the WHO guideline for water quality. There was a positively strong association between Fe and Ca; and Na and Mn, which suggests an emergence from geogenic sources. Dermal contact appears to be the major pathway of TE exposure to the human receptor in the locality. The Hazard Index (HI) value was in the descending order of Cu> Cr> Pb> Ag> Mn> Zn and Cu> Ag> Cr> Mn> Zn> Pb>Ni for adults and children respectively. The HI was less than 1, indicating no significant hazard effect of TE exposure in the water. Cancer risk due to Pb and Cr for the human receptor were within the threshold limit (1x10-6) indicating a negligible cancer risk to the users. The investigated water associated with the Saje dumpsite reveals no significant contamination and also poses no dangerous effects to the users at the time of the study.