Assessment of Cadmium and Lead in Water, Sediment and Different Organs of Procambarus Clarkii (Girard, 1852) in The River Nile

Cadmium and lead were assessed in water, sediment and some organs (exoskeleton, gills, digestive glands and muscles) of crayfish, Procambarus clarkii (Girard, 1852), in four areas (I: Gezyrat El-Warrak, II: Manial Sheeha, III: Al-Hawamdia and IV: Helwan) along the River Nile at Great Cairo, Egypt. Samples of water, sediment and P. clarkii collected and analyzed by atomic absorption spectrophotometer. The present results showed that the concentration of Cd was markedly lower in water while the concentration of Pb was higher in areas II, III and IV, respectively (p< 0.001), in comparison to area I (control area). The concentration of Cd in sediment increased while it decreased in case of Pb in the three studied areas in comparison to control. The highest bioconcentration factor (BCF) of Cd in four organs observed in area IV while the highest BCF of Pb observed in area I. This study shows that the lowest concentrations of Cd and Pb were in the crayfish muscles in comparison to the exoskeleton, gills, and digestive gland. Also, these results indicate that the analysis of Cd and Pb in different organs of P. clarkii might be a useful as a bioindicator for trace metals pollution in the freshwater system, due to their ability to rapidly accumulate and retain them in their tissues for long periods of time.