Bioavailability of heavy metals in fresh water Tilapia nilotica (Oreachromis niloticus Linnaeus, 1758): Potential risk to fishermen and consumers

The present study was undertaken to assess the accumulation of some heavy metals (Cr, Co, Cu, Ni, Zn, Pb and Cd) in different tissues (muscle, gills, heart, liver, brain, bone and skin) of Tilapia nilotica. It is one of the most edible fish species in Egypt and was collected from a common fish farm in order to evaluate their potential risk to fishermen and consumers. This fish farm is fed with discharged water containing agricultural, industrial, sewage and domestic wastes. The length-weight relation and condition factor calculation of Tilapia nilotica samples showed a significant linear regression (r2 ) 0.920) and an average condition factor of 4.1 g/cm3. This indicated that the health status for the studied fish samples was good. Metal pollution index (MPI) values for the detected heavy metals in the different tissues reflected that the muscle was the only tissue that had the lowest content. Provisional Tolerable Weekly Intake (PTWI) values for the investigated heavy metals were lower than those reported for the permissible limits. The data were evaluated by using ANOVA statistical anal. For appraising the human health risk effects of heavy metals in fish muscle, estimated dietary intake (EDI) and hazard quotient (HQ) were detected. HQ levels indicated that Cr and Co were the only heavy metals among the detected ones that had values more than unity. Also, their relative contributions in fish consumptions were Cr> Co> Pb> Ni> Cu> Cd> Zn. The authors concluded that based on the results from the study, the highest average HQ value of chromium detected in this study refers to the possible adverse effects of Cr on human health. Accordingly, the potential public health risks from dietary exposure to hazardous contaminants in fish species from fish farms must be continually subjected to research, regulation and debate.

Authors: El-Sadaawy, Manal M.; El-Said, Ghada F.; Sallam, Neama A. ;Full Source: Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes 2013, 48(5), 402-409 (English) ;