The spatial distribution, potential origin and associated health impact of certain trace elements in groundwater of Ado-Ekiti southwestern Nigeria were evaluated. Sixty (60) raw water samples were evaluated for the concentration of Mn, Fe, Pb, Zn, Cu and Cr. The results were presented as spatial iso concentration maps with respect to the World Health Organization (WHO) and the Nigerian standards for drinking water. The result showed that the mean concentrations of the trace elements exceeded the threshold values stipulated by the WHO and the Nigerian standard for drinking water at several sampling locations. However, all of the sampled wells recorded Pb concentration below both water quality standards. The weathering of minerals of the underlying bedrocks is suspected to be the source the trace elements in the groundwater. The health risk assessment was undertaken using Hazard Quotient (HQ) and Hazard Index (HI). The HI values revealed that the risk of contamination through oral ingestion pathway ranges from low through medium to high levels for both adults and children. However, the children are more susceptible to the non-carcinogenic risks than adults in the study area. Hence, an urgently proactive steps is required to avert the consequences of these chemicals.
Keywords: Groundwater, Trace Elements, Contamination, Hazard Quotient, Hazard Index
