Assessment of pesticides and polychlorinated biphenyls (PCBs) in sediments of the Egyptian Mediterranean Coast

In an attempt to evaluate the toxicological condition of the Egyptian Mediterranean Sea from El-Sallum to El-Arish, 10 surficial sediment samples were collected from different locations covering the region that receives the majority of the industrial, agricultural and urban effluents (land-based activities), and thus is expected to be contaminated with different degrees of pollution. Sediment samples were analyzed for PCBs (PCB 18, 28, 44, 52, 101, 118, 138, 153, 180 and 194), and organochlorine pesticides (α-HCH, β-HCH, γ-HCH, δ-HCH, heptachlor, methoxychlor, heptachlor-epoxide, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, γ-chlordane, α-endosulfane, β-endosulfane, p,p′-DDE, p,p′-DDD, p,p′-DDT). The investigated sediments were dominated by the sand fraction, except Rosetta station. The concentration of organic pollutants in sediments followed the order: Total cyclodienes > PCBs > DDTs > HCHs. Sediments were dominated by the metabolites of DDT (DDD and DDE) indicating that the detected DDTs in the bay sediments are not recently introduced into the bay. At the same time, DDE concentrations were higher than DDD in all the sediment samples (except El-Sallum and Sidi-Kreer) indicating oxic conditions. The risk assessment for organic pollutants were studied, indicating a greater possibility of the occurrence of toxic adverse ecological effects with respect to all investigated organic pollutants and frequent toxic effect is expected for lindane and p,p′-DDT.