Review of Contamination by Polycyclic Aromatic Hydrocarbons (PAHs) in Egyptian Aquatic Environment

Polycyclic aromatic hydrocarbons (PAHs), one of the major chemical constituents of petroleum, are widely used and are largely present in all environmental matrices, including aquatic environment. Polycyclic aromatic hydrocarbons are made of fused aromatic rings with no heteroatoms carrying substituents. Polycyclic aromatic hydrocarbons are produced naturally from various resources that include volcanic emission and forest fires. , They are present in tar deposits, coal, and oil, and are also produced as byproducts of fuel burning. Polycyclic aromatic hydrocarbons can also be present in foods. PAHs are highly lipophilic. They are strongly absorbed from gastrointestinal tract and rapidly distributed in various tissues with great tendency to localize fat. In the marine environment, fish and other animal groups can easily pick up residues of PAHs either directly from the water column or indirectly through their food. In this respect, PAHs are transported through the blood stream ending up in body tissues. Fish easily accumulate PAHs either through food and water ingestion, through their gills, and also from sediment. Hydrocarbon residues in Egyptian aquatic environment have been reported by several studies. This study portrays some of the major impacts of PAHs on marine ecosystem with special reference to studies conducted in Egypt.