Polychlorinated biphenyl and organochlorine pesticide residues in surface sediments from the Mediterranean Sea (Egypt)

The distribution pattern of organochlorine residues in sediments of the Mediterranean Sea (Egypt) has been investigated. The concentration of total organochlorine pesticides (OCPs) in surface sediments ranged from 0.11 to 50.73 with a mean of 14.52 ng/g dry weight. The ratios used (DDD+DDE)/∑DDT, DDE/DDD and p,p′-DDT/∑DDT, indicate the degree of DDT׳s decomposition and identify the fresh input of DDTs. The predominant γ-HCH and the α-HCH/γ-HCH ratios indicate that there is a fresh input of lindane in some locations. The possible sources of OCs in the studied locations were estimated using multivariate statistical methods (principal component analysis (PCA), cluster analysis) for the data matrix obtained from the OC׳s analysis of the sediments. The potential environmental risk assessment associated with POPs measured in the sediments was conducted using the Risk Quotient (RQ).