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ABSTRACT: This study clarified the suitability of fishes caught from illegal fish farms to human consumption and their hazards to public health. For this purpose, the concentrations of some metals (Al, Cd, Pb, Hg and Ni) in water and Nile tilapia (Oreochromis niloticus) fish samples collected from an illegal fish farm, in addition to pathological conditions of the fish tissues, were examined. The illegal farm water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in tissues of O. niloticus in concentrations higher than those of farm water. Kidney of O. niloticus contained the highest concentrations of the detected metals, while muscle and skin contained the lowest concentrations. The examination of fish tissues revealed various histopathological lesions which related directly to the pollution of the illegal farm water. Moreover, metals levels in O. niloticus muscle were higher than the maximum permissible levels for human consumption. Consequently, the flesh of fishes from the illegal farms could be considered hazardous to human health. Therefore, warning against eating fish caught from the illegal fish farms should be announced. Moreover, removal of such illegal fish farms is necessary for the public health protection.
Ecotoxicology and Environmental Safety 07/2012; 84:163-72. · 2.29 Impact Factor
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ABSTRACT: The purpose of this study was to assess metal concentrations (Al, Cd, Pb, Hg and Ni) in Sabal drainage canal (Al-Menoufiya Province, River Nile Delta, Egypt) water as well as their accumulation in some selected organs (skin, muscles and kidneys) of Oreochromis niloticus fish to evaluate their hazard levels in relation to the maximum residual limits for human consumption. Drainage canal water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in organs of O. niloticus in concentrations higher than those of canal water. Kidneys of O. niloticus contained the highest concentrations of the detected metals, while skin appeared to be the least preferred site for the bioaccumulation of metals as the lowest metals concentrations were detected in this tissue. The present study shows that fish organs contained high levels of metals exceeding the permissible limits values. Metals in muscle of fish were higher than the maximum permissible concentrations for human consumption. Thus, consuming fish caught from drainage canals is harmful to the consumers.
Environmental Monitoring and Assessment 03/2012; · 1.40 Impact Factor
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ABSTRACT: This study was carried out to assess the ability of using pawpaw (Carica papaya) seeds as a natural reproduction inhibitor for tilapia fish (Oreochromis niloticus) culture to control its breeding. Biochemical, physiological and histopathological effects ofpawpaw seeds on male tilapia fish were also determined. Mature male tilapia were stocked for 4 weeks and treated with low dose (3 g/kg/day) and high dose (6 g/kg/day) of ground dried pawpaw seeds mixed with their feed. The obtained results showed that the pawpaw seeds induced permanent sterility in the high dose treated fish while the low dose treatment showed reversible results. The results also demonstrated that fish treated with high dose of pawpaw exhibited higher biochemical and physiological effects as: low meat quality, a progressive fall in erythrocyte (RBCs) count, hemoglobin (Hb) content and haematocrit values. Also the high dose revealed a significant increase in the leukocytes (WBCs) count, serum glucose, total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine and uric acid levels. Moreover, serum total lipids revealed a significant decrease compared to control group. On the other hand, the low dose treatment revealed lower biochemical and physiological changes. Histological sections of testis showed disintegration of sperm cells and focal necrosis of seminefrous tubules in the high dose treated fish, hepato-pancreas and posterior kidney tissues also showed severe changes in high dose treated fish. Milder degenerative changes in some necrotic foci and slight changes in hepato-pancreas and posterior kidney were observed in the low dose treated fish. The study concluded that pawpaw seeds which are cheap and easy to obtain, can be incorporated into fish feeds with adjusted amount and be used to control breeding of tilapia fish in growing ponds instead of unfavorable and expensive hormonal use.
Pakistan Journal of Biological Sciences 12/2011; 14(24):1117-23.
