POPs in Sediments from the Eastern and Western Egyptian Mediterranean Coast; a Comparative Study

Abstract

The residual concentrations of α,β,γ-hexachlorocyclohexane (HCHs), sum of aldrin, endrin and dieldrin (TC), sum of o, p-DDE, p, p-DDE, o, p-DDD, p, p-DDD, o, p-DDT and p, p-DDT (DDTs), total petroleum hydrocarbons (THCs) and sum of 7 individual polychlorinated biphenyl (PCBs) were investigated at different depths collected from 18 stations of sediment samples distributed along the eastern and western coast of the Egyptian Mediterranean Sea. The maximum concentrations of HCHs, TC, DDTs, THCs and PCBs in the Eastern coast of Egypt were 0.19ngg -1 , 0.90 ngg -1 , 36.30 ngg -1 , 3540 ngg -1 and 136.20 ngg -1 , respectively. In the Western coast of Egypt, these concentrations were 0.21 ngg -1 , 8.80 ngg -1 , 15.90 ngg -1 , 9030 ngg -1 and 28.60 ngg -1 , respectively. Although no significant correlation was observed between total pesticides and total organic carbon (TOC) in sediment samples, there emerges a positive correlation between PCBs and TOC for sediment samples with r = 0.785 and 0.926 at 30 m and 50 m depths, respectively. This is can be attributed to the low solubility of PCBs in water and consequently precipitated reaching bottom waters and contaminated in sediments. The average concentrations of HCHs, TCs, DDTs, TP were much higher in sediment of the western part compared with the eastern one of the Egyptian Mediterranean coast. On contrast, PCBs and TOC% were higher in sediment samples of the eastern part compared to the western one. The present study declared that all recorded concentrations of pesticides and PCBs in the Egyptian Mediterranean coasts were much lower than those reported as permissible levels given by National Academy of Sciences and National Academy of Engineering.