Preliminary Health Risk Assessment of Water from Asa River, Ilorin, North-Central Nigeria

Abstract

This study was carried out to establish health impacts of some trace elements (Al, As, Ba, Cr, Cu,Fe, Mn, Ni, Pb and Zn) in Asa-river, using Inductively Coupled Plasma-Mass Spectrometer technique for the chemical analysis. Laboratory results show that Al, Fe and Mn average concentrations are higher than prescribed limits unlike others. The Contamination Indexes reveal that the elements are heavily loaded in  the water. The exposure dose in both adults and children ranges from 0.021 in As to 181 in Fe (in adults) and from 0.068 in As to 576 in Fe  (in children). The average Hazard Quotient (HQ) values for adults and children are generally lower than one except Mn that has average  value greater than one in both age groups. However, for children, individual HQ in Fe in some of the locations are >1. The Hazard Index  (HI)for adults and children ranged from low to high. The average values of Chronic Daily Intake (CDI) are generally <1. However, in children, values for Fe in some locations are >1. The average Carcinogenic Risk (CR) of Cr and Pb computed for adults and children  indicated that the values are greater than the risk limit of 10^-6 and 10^-4 . This could result in potential health risk to the consumers. The  sources of these trace elements are largely from various anthropogenic activities and slightly from weathering of rocks in the study area.  It is recommended that adequate and well monitored precautions need to be taken to safeguard the health of the consumers especially  the children with low immunity.