Study of polycyclic aromatic hydrocarbon contamination in sediments and northern waters Lebanon: Rivers, transition zones and port sites.

Contamination of the marine environment is associated with continental activities, marine activities and accidental spills. Providing answers to the origin of the contamination ofthe aquatic environment by PAHsis an objective of the present work. The originality of this work is to study pollutants in two types of matrix (water and sediments) during2 seasons (dry and wet) for an environmental monitoringof 6 years. This study provides a more complete overview of the state of contaminationin three coastal rivers, their transition zones and harborsin the Eastern Mediterranean following the Jiyyeh oil spill in 2006.Contaminantsconcentrations wereexpressed asthe sum of the 16 PAHs classified as prority substances by the United StatesEnvironmental Protection Agency(US-EPA). Overall,contamination was noted for all the analyzedsites. Oil spill seem to be one of the main sources of pollution in the area, as the highest levels of PAH(> 9000 ng.g-1s.w&> 8000 ng.L-1) were reported in the coastal environment of the three rivers and harbors.High levels of PAHswere also observed in rivers transitional zones, revealing the importance of terrestrial inputs (untreated wastewater discharge, leachate, solid wastes, etc.).Comparing the PAHsconcentrations measured in the sediments of the sitesanalyzed with the empirical sediment quality criteria "SQG" for the support of the general assessment of sediment toxicity, we can notice that some individual PAHand their sum can present a significant ecotoxicological risk to aquatic organisms. Further research through monitoring campaigns and toxicity tests is encouraged, as the exposure of the resident aquatic organisms and human population to these chemicals might be expected to increase over the years.