Health Risk Assessment Of Potentially Toxic Element Concentrations In Fish And Vegetables Obtained From Six Selected Dams In Osun State, Nigeria

This study aimed to assess the levels of certain heavy metals in tilapia fish (Oreochromis niloticus), as well as vegetables, and to evaluate  the potential health risks associated with the presence of toxic elements from Dec. 2019 to June 2023. A total of 60 tilapia fish, 12 okra  (Abelmoschus esculentus) and 12 bitter leaf (Vernonia amygdalina) from six major dams in Osun State were prepared for analysis using  wet digestion with aqua-regia. The concentrations of heavy metals were measured using an Atomic Absorption Spectrophotometer  (Shimadzu AA-630). The health risk associated with fish consumption was estimated using various parameters. Statistical analysis was  conducted using the Statistical Package for Social Sciences (SPSS) version 16.0. The concentrations of micro elements followed the order  of Fe > Zn > Cu > Mn in decreasing concentrations. These concentrations exceeded the permissible limits set by the World Health  Organization (WHO) for Ni, Cd, Pb, and Cr, which are 0.6, 0.3, 0.3, and 0.7 mg L-1, respectively. The results obtained for okra and bitter leaf  were within the limits established by the World Health Organization (WHO). Therefore, the presence of these metals indicates the  need for close environmental monitoring of the six selected dams.