Assessment of radiological and chemical pollutants and their effects on the marine ecosystems along the Mediterranean Sea Coast between Alexandria and port said City-Egypt

Abstract EN

The Environmental Monitoring Program for the Egyptian coastal waters of the Mediterranean Sea was established to initiate a monitoring data base system.

This was done by applying quality control assessments to evaluate and protect the coastal zone, which ensure its sustainable use.

An environmental risk assessment was performed, including a screening level ecological risk assessment (SLERA) and a human health risk assessment (HHRA).

The aim of SLERA risk assessment was to determine which classes of chemical pollutants could possibly cause adverse ecological effects to benthic species and to determine whether hot spots exist or not.

Investigation of the sediments revealed that the region which extends from the Alexandria harbor area to Port Said City is enriched with trace metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides.

Polychlorinated biphenyls (PCBs) were detected but in lower concentrations compared to the other organic compounds.

The spatial distribution of the different contaminants investigated here showed that the Nile Delta region is more influenced by wastewater discharge than the rest of the Egyptian coastal regions.

In addition to sediments, two mussel species (Mactra corallina and Tapes decussate) were successfully used as bioindicators of marine environmental quality.

The concentrations of most pollutants investigated (except organochlorine pesticides, and some trace metals) were higher in the tissues of the mussels, especially M.

corallina, than in sediments.

The highest concentration of PAHs in sediments and mussels were observed in front of the Alexandria harbor and Nile Delta, they possibly affected by shipping activities.

Natural radioactivity of surface sediments and sea water samples were measured along the coastal Mediterranean Sea between Alexandria and Port Said City.

The main source of radiation along the area is the black sands, which is rich in radionuclides.

The measured values of 238U and 232Th for seawater are low.

The lower 40K values for seawater have been detected at stations receiving low saline water discharged from inland sources.

The salinity affects the behavior of 40K in surface seawater.