Contamination and risk assessment of organochlorines in surface sediments of Egyptian Mediterranean coast

The levels of 20 organochlorine pesticides (OCPs) in addition to 10 polychlorinated biphenyls (PCBs) in sediments of Egyptian Mediterranean coast were investigated to evaluate their pollution potential on the environment. The OCPs were HCHs, DDTs and cyclodienes (aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, heptachlor, heptachloro epoxide, γ-chlordane, α-chlordane, methoxychlor, endosulfan I, endosulfan II and endosulfan sulfate). Concentrations of PCBs, HCHs, DDTs and cyclodienes ranged from 0.31 to 1.95, 0.09 to 3.31, 0.08 to 3.31 and 0.23 to 2.51 ng/g dry weight, respectively. Investigation of OCPs leads to the fact, that DDTs have greater potential for distribution than both HCHs and cyclodienes. Risk assessment of organochlorines in surface sediment was conducted and the results indicate that the concentrations of some OCPs contaminated in the sediments may pose few risks to the local aquatic system. Principal component factor and cluster analysis concluded that it is impossible to predict the distribution patterns of the OCPs in contaminated area, and there is a lack of correlation between PCBs and most of OCPs. This explains the variety of organochlorines input sources to studied locations.