Organophosphorus pesticides residues in fish samples from the River Nile tributaries in Egypt

The concentration of organophosphorus pesticides in fish samples from different tributaries of the Nile River in Egypt was monitored. Fish samples were collected from El Menofiya, canal water supplies (El-Sarsawia, El-Bagoria and Bahr Shebin), in addition to El-Embaby, El-Menofi and Miet Rabiha drainage canals each 2 month during periods of 16 month, June 2007-Septemper 2008. Chloropyrifos, cadusafos, diazinon, prothiphos and malathion were detected in fish tissues samples at level below the maximum residue limit. The highest average amount of chlorpyrifos (9.38 ng g(-1)) and malathion (8.31 ng g(-1)) were detected in El-Embaby drain. Prothiphos were found in tissues collected from El-Sarsawia canal and Miet-Rabiha drain at mean concentration of 4.91 and 6.55 ng g(-1), respectively. Diazinon was only found in one fish sample that collected from El-Menofi drain at the level of 9.23 ng g(-1).