Browsing by Author "THOMAS, Opeyemi John"

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    HEALTH RISK ASSESSMENT OF METALS IN DIFFERENTLYPROCESSED-AFRICAN MUD CATFISH (Clarias gariepinus Burchell, 1822) IN ABEOKUTA MARKETS, OGUN STATE, SOUTHWESTERN NIGERIA
    (2024-10-10) THOMAS, Opeyemi John
    ABSTRACT Fish is one of the major sources of animal protein for humans but with the tendency to bio-accumulate toxicants from the aquatic environment. This study assessed the health risk of metals in differently processed catfish (Clarias gariepinus) from four markets, (Adatan, Kuto, Olomore and Osiele) in Abeokuta metropolis, Ogun State, southwestern Nigeria. A total of 60 adult samples (20 samples from each market) of oven-baked, locally-smoked and non-locally-smokedcatfish were collected and analysed for Copper, Iron, Manganese, Zinc, Cadmium, Chromium, Nickel, and Lead (Cu, Fe, Mn, Zn, Cd, Cr, Ni and Pb) using the atomic absorption spectrophotometric method. Data collected were analysed using descriptive and inferential statistics. Health risk assessment was evaluated for Hazard Quotient (HQ), Hazard Index (HI) and Cancer Risk (CR).Results indicated Fe as the highest metal (8.10±6.80 - 70.7±30.8 mg/kg) in the fish samples. Concentrations of Cr (0.25±0.25 - 28.4±14.5 mg/kg) in the samples were found to be higher than the permissible limit of 0.2 mg/kg set by the joint Food and Agriculture Organization and the World Health Organization (FAO/WHO) in most of the analysed samples. Pb was only detected in few samples where it ranged from 0.20±0.20 - 0.80±0.70 mg/kg and were largely higher than the WHO/FAO permissible limit. The concentration pattern of non-toxic metals in the fish samples followed the decreasing order of Fe > Zn > Mn > Cu, while the toxic metals followed the decreasing order of Cr > Pb. Cadmium and nickel concentrations were below the detection limit of the analytical instrument (0.05 mg/kg). The occurrence of metals in different fish-processing types followed the sequence: Locally-smoked> non-locally-smoked>oven-baked. The distribution of metals across the markets had the pattern of Osiele>Olomore>Kuto>Adatan. The Principal Component Analysis revealed two likely contamination sources of metals in the fish samples as Pond/River and Vehicular emission. The health risk assessment revealed the HQ values greater than 1.0 for Cr in the oven-baked and non-locally-smoked (3.273±5.108 and 6.171±8.148, respectively) indicating non-carcinogenic adverse health effects on consumers while smoked-hawked types indicated HQ values<1.0 (0.470±0.447) meaning that they were safe for consumption. Other metals, had HQ<1.0 that were within their respective safe limits. The HI values were above 1.0 in the fish samples, indicating cumulative potential adverse health effects. The CR assessment of the metals in the fish samples also indicated value greater than the permissible limit of 1.0×10−4, for Cr(3.45×10-4±3.28×10-4 – 2.41×10-3±3.76×10-3) indicating possible risk of cancer to the consumers. Contribution of Cr to carcinogenic and non-carcinogenic adverse health effects were high ranging from 43% - 98% in the samples. This study established Cr as a metal of serious health concern in the processed-fish samples in the study areas, with the highest concentration in locally-smoked samples.