Comparison of heavy metals levels in muscles, liver and gills of three fish species collected from agricultural drainage water AT El- Abbassa fish farm, Sharkia, Egypt.

The concentration of  heavy metals; iron, zinc, copper, lead and cadmium (Fe, zn, cu, Pb, and Cd) were determined in water and Nile tilapia, common carp and catfish caught from agricultural drainage water at El- Abbassa fish farm in the period from February to April 2016. Metals concentrations in the water were ranked in the following order Fe>Zn > Cu>Pb> Cd. the concentrations of Cu, Zn and cd in water were below the permissible levels according to the Egyptian Standards. Fe and Pb in the water samples exceeded the permissible limits. The fish muscles, gills and liver were carefully dissected out for digestion and determination of heavy metals. The concentration of heavy metals was analysed in tissues of muscles, gills and liver. The results revealed that Fe and Zn concentrations were the highest in all tissues analyzed, followed by Cu, Pb, and cd in almost all three fish species. The highest concentration of Iron (463.8±3. μg /g dry. wt) was detected in the gills of catfish. Whereas the lowest (255.1±7.3 μg /g dry. wt) in the muscles of common carp. The highest concentration of zn (203.0±1. μg /g dry. wt) was found in the gills of cat fish. While, the lowest (133.8±5.0 μg /g dry. wt) was recorded in the muscles of common carp. The highest concentration of copper (39.2±3.8 μg /g dry. wt) was detected in the liver of the catfish. While the lowest value (24.5±1.2 μg /g dry. wt) in the muscles of the Nile tilapia. For lead and cadmium the highest were found in the liver of catfish (3.7± 0.4and 2.4±0.19 μg /g dry. wt), while, the lowest in the muscles of common carp (1.6±.6and1.1±0.12 μg /g dry. wt). The results of the present study revealed that the abundance of heavy metals in fish organs followed the order: fe>Zn> Cu >Pb and cd. The concentrations of heavy metals detected in samples of the three fish species, were lower than the recommended maximum level allowed in food by (E.O.S.Q.C.2005), (fAO/WHO1999), (EOS 1993) and (WHO 1989).