Determination of Some Heavy Metals in Shellfish

The concentrations of Cu, Cd, Pb, As and Hg in the edible portions of four species of Egyptian common
invertebrates namely, undulate venus (Paphia undulata), peregrine shrimp (Metapenaeus stebbingi),
Pelagic swim crab (Portunus pelagicus) which were collected from two different fishing areas (El- Max and
Abu-Qir Bay) and wedge clam (Donax trunculus) which was collected from Edkou beach, were determined
by atomic absorption spectrophotometer technique. Analysis of variance for heavy metal levels as affected
by location, season and species and their first order interaction (location × season, location × species and
seasons × species of shellfish) indicated that, the concentrations of Pb, As and Hg showed significant differences,
while Cu and Cd concentrations showed no significant differences between locations (El-Max and
Abu-Qir Bay). All heavy metal concentrations showed significant differences between seasons, except Cu
concentrations which showed no significant differences. All heavy metal concentrations showed significant
differences between the studied species. The ANOVA data showed no significant interactions between
(location × season), (location × shellfish species) and (seasons × shellfish species) in the concentrations of
heavy metals, except As content in interaction (seasons × shellfish species). The highest concentrations of
Cu, Cd, Pb, As and Hg were recorded in the summer season, while the lowest levels were observed during
the spring season. The highest concentrations of Cu, Cd, Pb, As and Hg were found in the edible portions
of the three shellfish samples obtained from Abu-Qir Bay. No significant differences with respect to the
levels of Cu and Cd between the two sampling areas were detected. The highest concentrations of Cd, Pb,
As and Hg were obtained in the edible portions of Paphia undulata, while Portunus pelagicus contained
the highest level of Cu. On the other hand, the lowest concentrations of Cd, Pb, and As were recorded for
the edible portions of Metapenaeus stebbingi, while Paphia undulate had the lowest concentration of Cu
and Portunus pelagicus had the lowest concen