IKPOBA HILL OBA MARKET

This study investigated the levels of nickel (Ni), cadmium (Cd), and mercury (Hg) contamination in tomatoes from Ikpoba Hill and Oba Market in Benin City, as well as their oxidative stress status. The concentrations of Ni, Cd, and Hg in tomatoes were determined using atomic absorption spectroscopy (AAS), while the oxidative stress status was assessed by measuring the activities of antioxidant enzymes and levels of lipid peroxidation. The results showed that tomatoes from both locations were contaminated with varying levels of Ni, Cd, with higher concentrations observed in tomatoes from Ikpoba Hill compared to Oba Market. Specifically, the mean concentrations of Ni, Cd, and Hg in tomatoes from Ikpoba Hill were Ni [0.05±0.02_] mg/kg, Cd (0 .01±0.009)mg/kg, and Hg[ ND], respectively, while in tomatoes from Oba Market, the concentrations were NI [ 0.06±0,02mg/kg,] Cd[0] mg/kg, and [Hg] ND, respectively. Additionally, tomatoes from Ikpoba Hill exhibited higher levels of lipid peroxidation and lower activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), compared to Oba Market. The activities of SOD, CAT, and POD in tomatoes from Ikpoba Hill were SOD [3.017±0.22], CAT [0.07±0.007], and MDA [0.49-0.06] U/mg protein, respectively, while in tomatoes from Oba Market, the activities were [3.17±0.22], [0.14±0.01], and [4.84±02.8] U/mg protein, respectively. the levels of lipid peroxidation, as indicated by the concentration of malondialdehyde (MDA), were higher in tomatoes from Ikpoba Hill compared to Oba Market, with values of [9.00E-18] nmol/mg protein and [3.00E-22] nmol/mg protein, respectively. Despite the higher levels of heavy metal contamination and oxidative stress in tomatoes from Ikpoba Hill, the concentrations of Ni, Cd, and Hg in tomatoes from both locations were below the maximum allowable limits set by the World Health Organization (WHO), suggesting that tomatoes from Ikpoba Hill and Oba Market are generally safe for consumption in terms of heavy metal contamination