Organochlorine pesticides in water, sediment and fish from the Nile River and Manzala Lake in Egypt

To assess the risks of organochlorine pesticides discharged into the hydros pheric environment of Egypt, river and lake water, drinking water, suspende d solids, sediments and fish were collected during 1993-1994 from the Nile River and Manzala Lake in Egypt and were transported to Japan for chemical analysis. Among different organochlorine pesticides analyzed, p,p'-DDE was the most predominant in fish (7.6 to 67 ng/g wet wt.), sediments (3.2 to 43 2 ng/g dry wt.) and suspended solids (5.3 to 138 pg/L). However, in the dis solved phase of water samples HCH compounds predominated (alpha-HCH, 71 to 2,815 pg/L). Concentrations of organochlorine pesticides, except chlordane, were higher in Manzala Lake than in the River Nile. Concentrations of orga nochlorine pesticides in fish corresponded with those in sediments from eac h location. Comparison of organochlorine concentrations in Nile River water with those reported in earlier studies suggested a decrease in concentrati ons during the last decade. However, concentrations of p,p'-DDE has increas ed in fish. It appears that the release of this metabolite from contaminate d sediment is the major source of p,p'-DDE in fish during recent years.