Trace metal analysis of edible portion of Oreochromis nilotica in relation to growth

In this study, some metals were analyzed in edible portion of 57 samples of fresh water Oreochromis nilotica to study the potential human risk of consumption and the relationship between the metal load of fish and some other biological aspects (i.e. size and condition factor). The contents of all metals (i.e. chromium, copper, iron, manganese, nickel and zinc) were determined by flame atomic absorption spectrophotometry (FAAS). Mean concentration (ugg^-1 dry weight) of metals in edible portion of wild Oreochromis nilotica have been found to be as 93. 306 ±72.14 (Zn), 26.012 ±25.194 (Cu), 31.925 ± 18.935(Ni), while Cr, Mn and Fe were not detected in all fish samples. The relationship between metal concentration and fish size (length and weight) was found non significant, but highly significant correlation was observed between metal concentration and condition factor except zinc. Overall the metal limits set by World Health Organization for human consumption in edible parts of the fish samples do not exceed the actual concentration found in fish samples and so not pose a risk for human health.