Thirty six random healthy Oreochromusnilotica (O. niloticus) collected from Manzala Lake, wild Nile
River "El-Ryiah El-Tawfiky", El-Abbasa private fish farm and Gesrbahr el-baar agricultural drainage
(9 fish from each source). Concentrations of organochlorine pesticide residues (OCPs) were investigated
in both raw and grilled fish (dry heat treatment). Fish musculature samples were analysed for detection
the effect of grilling on level of organochlorine pesticides residues. Examination revealed that, samples
collected from El-Ryiah El-Tawfiki recorded the highest concentration of organochlorine pesticide
residues in raw O. niloticus followed by Manazla Lake, El-Abbasa fish farm and Gesrbahr el-baar
agricultural drain, respectively. Application of grilling revealed a great reduction in organochlorine
pesticides residues concentrations by ratio of 11% to 100% depending upon the type of pesticide residue,
its sensitivity to heat and locality of fish collection. In some cases thermal treatment showed unexpected
results represented by appearance of some residues which not detected in raw samples. This study
concluded that fish from some water resources in Egypt is highly contaminated with organochlorine
pesticide residues which greatly supposed to come from agricultural contaminated water. Moreover,
grilling is a good and highly recommended method to reduce organochlorine residues with uneven
degrees in fish muscles before consuming.