Residue levels of organochlorine chemicals and polychlorinated biphenyls in fish from the Alexandria region, Egypt.

Abstract

Residues of polychlorinated biphenyls (PCBs) and organochlorine chemicals were analyzed by capillary gas chromatography in five fish species from Abu Qir Bay as well as in Tilapia species from Idku and Maryut lakes in Alexandria, Egypt. σDDT and PCBs were the most predominant contaminants occurring in the muscle tissue of all fish samples. Remarkable variations in the concentrations of PCBs were noted among the species, and the concentrations of σDDT were higher than that of PCBs in all fish species. Elevated PCB concentrations were observed in muscle tissue ofSargus vulgarius from Abu Qir Bay, and inTilapia zillii from Forn El-Gieraia, Maryut lake. Also, variations were found in the relative proportions ofp,p′-DDT,p,p′-DDD, andp,p′-DDE in all fish samples. The results revealed an increase in chlorinated hydrocarbons with increase in body size and fat content. Neither α-endosulfan nor β-endosulfan was detected in fish from Abu Qir Bay; however, only α-endosulfan was detected in trace amounts in Tilapia species from Idku and Maryut lakes. With the exception ofSargus vulgarius, mirex and methoxychlor occurred in low levels in all other fish species. Potential health hazards are discussed with the tolerance levels recommended.