Analysis of six trace elements (Cd, Cr, Cu, Ni, Pb and Zn) in Diplodus sargus and Siganus rivulatus fish in three sites along the Lebanese coast
Abstract
The Lebanese coast is subjected to a strong urban, touristic and industrial pressure. The wastewater of the littoral zone eventually reaches the sea without undergoing, in general, any pretreatment.This precarious situation escalates with the absence of laws that address the "food security" and “environmental” aspects throughout the Lebanese coast or the non-applicationof the existing ones. The fisheries sector inparticular, suffered the consequences. Indeed, in Lebanon, the consumer’s interest for fish is growing. For them the sea products in particularly fish are considered as a healthy food, or even as a luxury food. The sea food restaurants lining the coast are among the most expensive and the most prestigious in the country. But consumer confidence has been eroded by media reports evoking the maritime pollution in the country. It is in this context that we chose to study the metal pollution of two species of fish (Diplodus sargus and Siganus rivulatus) in a region particularly affected by pollution which run from Tabarja to the north of Beirut and end at Ouzaï located at the south of the capital. The captured fishes was completely grounded, lyophilized and mineralized. The mineralization was conducted in a microwave digester. After that, the six trace elements were analyzed by atomic absorption spectroscopy: Cd, Cr, Cu, Ni, Pb and Zn. The obtained results are in general, consistent within international studies : the fish accumulation for the metal contaminants (with exception of Hg) is low. The recorded values are less or equal than the maximum limits in food set by international bodies. Considering the season factor, we note a seasonal fluctuation in the concentration of the studied metals. By comparing the metal level for the three sites, we note that the Ouzaï site is in general, the most polluted one.