Organochlorine pesticide residues in raw and grilled freshwater fish (Oreochromis niloticus) collected from various locations along the Nile basin in Egypt.

The current study aimed to assess meat quality of samples of Nile tilapia fish (Oreochromis niloticus), along with examining organochlorine pesticide (OCP) residues in these samples and their potential risks to humans. About 55 samples were collected from eleven sites on the Nile River in Egypt: Damietta, El-Behera, El-Dakahlia, Kafrelsheikh, El-Gharbia, El-Menoufia, Cairo, El-Giza, El-Fayoum, El-Menia, and Aswan Governorates. Fish samples were analyzed fresh and grilled for meat quality characteristics and the presence of OCP residues using the QuEChERS method for extraction and cleanup accompanied by detection using GC-MS (gas chromatography-mass spectrometry) system. Then, risk hazards of OCP residues were calculated. Results showed that all quality criteria of raw and cooked meat samples were within the permissible levels set by the Egyptian Organization for Standardization and Quality (EOS). The detected residues of OCPs in fresh samples were hexachlorocyclohexanes (α-HCH, β-HCH, and δ-HCH), heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin aldehyde, endosulfan, and p,p'-DDE. Endrin aldehyde was detected in all tested sites, while heptachlor epoxide was found in eight (73%) out of the 11 tested locations. After grilling, aldrin, heptachlor epoxide, endosulfan, and endrin aldehyde compounds were found in fish meat. Cooking fish samples reduced the OCP residue amounts by at least 95% of detected amounts in fresh meat.