Assessment of persistent organochlorine pollutants in sediments from Lake Manzala, Egypt

• Published in: Marine pollution bulletin Vol. 64; no. 8; pp. 1713 - 1720
• Main Authors: Barakat, Assem O., Mostafa, Alaa, Wade, Terry L., Sweet, Stephen T., El Sayed, Nadia B.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-08-2012
• Subjects: Assessments; Concentration (composition); Contaminants; DDT; DDT (pesticide); Discharge; Distribution; Ecotoxicological risk; Egypt; Environmental Monitoring; Freshwater; geographical distribution; Geologic Sediments - chemistry; Hydrocarbons, Chlorinated - analysis; Lake Manzala; Lakes; Lakes - chemistry; Marine; metabolites; Organochlorines; Pesticides - analysis; Pollutants; polychlorinated biphenyls; Polychlorinated Biphenyls - analysis; risk; sampling; Sediment; Sediments; sewage; urbanization; Water Pollutants, Chemical - analysis; water pollution; Water Pollution, Chemical - statistics & numerical data; Egypt; MED, Egypt, Arab Rep; Sediment; Lake Manzala; Ecotoxicological risk; Organochlorines; Distribution
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2012.03.022

► High levels of OCs were found at sites near wastewater discharges. ► The composition of DDT and its metabolites suggest old input of DDT. ► Levels of OCs were low to moderate compared to other coastal regions worldwide. ► Areas of expected potential ecotoxicological risk were identified. ► The profiles of ∑OCPs and ∑PCBs in core sediments revealed recent inputs.
Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in surface and core sediment samples collected from Manzala Lake, the largest of the Egyptian coastal lakes. Total concentrations of OCPs and ∑7 PCBs (ICES) in sediments ranged from 0.63 to 31.31ng/g and 0.26 to 31.27ng/g, respectively. Geographical distribution indicates that levels of contaminants were significantly higher in areas which are mainly influenced by municipal discharge, indicating significant sources of these compounds in urbanised areas. The composition of DDT and its metabolites suggest old input of DDT. The levels of contaminants in Manzala Lake were similar or lower than those observed in comparable areas worldwide. The profiles of ∑OCPs and ∑PCBs in a core from a site heavily impacted by sewage discharge have highest concentrations in the surface core section indicating recent inputs. Assessment of ecotoxicological risk indicated that sediments in two sites were likely to pose potential biological adverse impact.