A total 45 fish samples (Tilapia , Claris )were collected from EL-Bagoria, EL-Menofi drainage and Bahr
Shibin for detection and determination of organophosphorus pesticides (diazinon, Malathion and
chlorpyrifos). Organophosphorus pesticides could not be detected in Bahr Shibin. No diazinon in Tilapia
from EL-Bagoria but mean value of of Malathion 5.50±2.0, chlorpyrifos 5.0±1.66butfrom EL-Menofi
drainage mean level of diazinon 3.33±0.65, Malathion 4.98±1.22 and chlorpyrifos3.0±0.71but in Claris
samples , there were no diazinon, no Malathion, no chlorpyrifos from EL-Bagoria canal but from ELMenofi drainage, mean value of diazinon 6.8±1.42, Malathion 4.64±0.81 and chlorpyrifos 4.0±0.96.
Pesticidesare one the main contaminant of water sources which are considered the natural environment of
fish . On the other hand, fish could be contaminated by pesticides either directly by gills breathing or
indirectly through contamination of feeding items so it is very important to analyzefish samples to detect
to what extent the rate of accumulation of pesticides residues in fish flesh and organs.