the accumulation of high load of pollutants [35]. This process explains why heavy metal concentration in the water is extremely low in contrast to that of the sediments. The fate of metals is also affected by other parameters such as silt and organic matter concentration.
Cu and Zn are essential for the metabolism of organisms but can become toxic in high concentrations due to their influence in the redox balance of the cell while Pb has no clear biological function and exposure to them can impair enzymatic activity, reproductive capacity and development