World Aquaculture 21 mended for human consumption by WHO (1989). Similarly, the metal levels detected during this study in O. niloticus collected from site I were extremely high (0.15, 3.9, 6.37 ppm for Cd, Cu and Pb, respectively) in comparison to those reported by Mourad (1996) for Tilapia zilli in Lake Timsah (0.05, 0.34 and 0.4 ppm for Cd, Cu and Pb, respectively). The concentration of heavy metals is variable from one place to another as well as from one agency or jurisdiction to another. The WHO (1989) for Cd in fish, for instance, states that a concentration of 0.2 ppm is permissible, while only 0.1 is allowed under Spanish guidelines (Blasco et al. 2002 ). On the other hand, the maximum permissible limits for are 50 ppm for Cu and 2.0 ppm for Pb according to the Ministry of Agricultural Guidelines in Hong Kong and FAO (EPD 1995, FAO 1994). The metal levels found in the current study are considerably higher and beyond the permissible levels established by the sources cited. We found that the heavy metal levels were higher in the sediments of the water supplies than in sediments of the corresponding growout ponds. This is expected because all the ponds are completely drained and dried after each harvest in addition to tilling the pond bottom as soon as it is drained. Periodic drying and tilling help eliminate the accumulation of heavy metals and kill disease-causing organisms. It is clear that commercial fish farming, especially at site I is a source of a higher level of biological and chemical contamination in the aquatic environment and finfish than those in Lake Timsah. It can be concluded that the use of aquaculture products in the Suez Canal area may pose a human health hazard. Although we were not able to estimate all of the different kinds of pollutants found in the water sources and fish ponds, it is highly likely that the fish produced in the ponds is also contaminated by other pollutants. Recommendations 1. 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