Seasonal variations of heavy metals levels in water, sediment and soft parts of edible bivalve Donax trunculus collected from Port Said coast, Egypt

The aim of this study was to get quantitative data on the seasonal variations of heavy metals levels (i.e. Fe, Mn, Cu, Zn, Pb and Cd), in different samples (i.e. surface water, sediment and soft parts of the bivalvian Donax trunculus) collected from four consecutive sites over the four seasons; El-Gamil airport, El-Gamil inlet, El-Fardous, and El-Manasra along Port Said Coast, Port Said, Egypt. The relationships between physicochemical parameters (i.e. pH, Temperature, Salinity and D.O) and heavy metal concentrations were assessed, as well. The obtained results showed that the order of mean of the heavy metals concentration in water was appeared as Zn ˃ Fe ˃ Pb ˃ Cd ˃ Cu, while their order in the soft parts of D. trunculus was appeared as Fe˃ Mn ˃Zn˃ Pb ˃Cu˃ Cd. Furthermore, the data rveaed that the mean of heavy metals concentration in sediment samples was appeared as Fe˃ Mn ˃Zn˃ Pb ˃Cu˃ Cd. Additionally, the concentrations of the heavy metals in water samples recorded the lowest value compering to their concentrations in the soft parts of D. trunculus and sediment samples. As a result, Fe recorded its higher value in the soft parts of D. tranculus during spring season which was 854.8, 542.6, 352.7 mg/g dry weight in El-Gamil airport, El-Gamil inlet and El-Fardous sampling sites, respectively. . The obtained data indicated that there was a noticeable relationship between physicochemical parameters (i.e. pH, Temperature, Salinity and D.O) and heavy metal accumulation in surface water, sediment and soft parts of the molluscan D.trunculus Therefore studies on chronic toxic effects of heavy metals in marine organisms, especially edible bivalvia, are needed as a possible public health threat from sea food dietary.