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This study assessed the levels of heavy metals present in waterleaf (Talinum triangulare) from various sources in Ota, Ogun State. Eighty (80) samples of waterleaf were obtained from 5 domestic (non-hazardous) dumpsites, 5 non-dumpsites, 5 markets and 5 streets in Ota. The non-dumpsites were locations in industrial areas. Also, over 500 questionnaires were randomly administered to residents in Ota to assess the extent of consumption of waterleaf. Standard method was followed for sample treatment, digestion, and analysis of selected heavy metals: lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni) and cobalt (Co) using Atomic Absorption Spectrometer. The results showed that in waterleaf from domestic dumpsites the concentration (mg/kg) of heavy metals were: Pb (14.50-20.10), Cd (0.05-0.60), Cr (0.19-2.48), Ni (2.75-7.30) and Co (3.40-6.05); from non-dumpsites: Pb (12.20-24.45), Cd (ND-0.60), Cr (ND-2.79), Ni (ND-24.00), Co (3.75-5.75); from markets: Pb (0.35-3.85), Cd (ND), Cr (ND-7.11), Ni (ND-5.10), Co (1.05-2.45); and from streets: Pb (ND-5.00), Cd (ND), Cr (ND), Ni (3.50-7.25), Co (1.50-2.50). Generally, all the heavy metals were highest in waterleaf from domestic dumpsites and non-dumpsites. There were 502 respondents to the questionnaire; of which 82% consumed waterleaf. Out of those who consumed waterleaf, 41% consumed it daily, 32% at least once in a week, and 19% at least once in two weeks. It may be concluded that there is the high tendency of exposure to heavy metals by those who consume waterleaf in the studied locations since the levels in waterleaf from all sources studied generally exceeded the FAO/WHO limits.© JASEM https://dx.doi.org/10.4314/jasem.v21i6.29

Aquatic organisms such as fish are prone to contamination by water pollutants such as heavy metals. This study aims at assessing the levels of heavy metals in the fillet tissues of 75 fish samples comprising Clarias gariepinus (Catfish), Oreochromis niloticus (Tilapia) and Chrysichthys  nigroditatus (Bagrid catfish) from five (5) different fishing locations along the Ogun River, Ogun State. The fillet tissues of the fish samples were digested and analysed for Zn, Pb, Fe, Cr and Cd using a Perkin Elmer, AAnalyst – 200 Atomic Absorption Spectrometer. The concentration of Zn in Clarias gariepinus, Oreochromis niloticus and Chrysichthys nigroditatus were 5.37±2.558, 6.58±2.35 and 5.11±1.55 respectively; while the levels of Pb in the species were Clarias gariepinus (1.30±3.099), Oreochromis niloticus (1.01±0.95) and Chrysichthys nigroditatus (0.35±0.59). Concentrations of Fe, Cr and Cd in the species were Clarias gariepinus (8.87±3.547, 0.08±0.098 and 0.09±0.100), Oreochromis niloticus (8.96±2.21, 0.12±0.11 and 0.11±0.11) and Chrysichthys nigroditatus (8.16±3.88, 0.11±0.11 and 0.11±0.11). The data revealed that most of these values were lower than  FAO/WHO permissible except Pb and Cr. Some of the fish sampled may pose health hazards to the consumers. There is a need for constant monitoring of pollutants in Ogun River. Keywords: Heavy metals, Clarias gariepinus, Oreochromis niloticus, Chrysichthys nigroditatus, Ogun River