Organochlorine contaminants in water, sediment and fish of Lake Burullus, Egyptian Mediterranean Sea

Lake Burullus is one of the Delta lakes, connected with the Mediterranean Sea through El Boughaz opening. Concentrations of organochlorine contaminants were measured in water, sediments and biota of the lake because of concerns about their effects on its productivity. The concentrations of chlorinated hydrocarbons decreased in the order of PCBs > DDTs > TC > HCHs for all water samples collected from Lake Burullus during 2006. Higher concentrations were recorded during summer season, this clearly affected by higher agricultural and sewage activities. The concentrations of DDTs in water were ranged from 0.07 to 221.9 ng L-1; 46.3-656.5 ng L-1; 94.3-882.6 ng L-1 and 24.8-233 ng L-1 during winter, spring, summer and autumn, respectively. Among DDTs metabolites p,p-DDE was the most dominant with a maximum of 520.13 ng L-1 recorded at station 10 ( El Boughaz opening). In sediment samples, PCBs concentrations were ranged from 4.6 to 213.9 ng g(-1) with an average 47.2 ng g(-1); dry weight. Total pesticides were higher than PCBs for mostly all sediment samples of Lake Burullus. Concentrations of DDTs in fish tissues were ranged from 2.76 to 24.23 ng g(-1) and from 14.16 to 45.13 ng g(-1); wet weight for Oresochromus niloticus and Clarries sp., respectively.