Level of chlorinated hydrocarbons in a teleost fish and a bivalve from the Egyptian Mediterranean Coast and Nile Estuary

Abstract

The residues of 22 organochlorine pollutants in fish Mugil cephalus and a bivalve Donax sp. collected from three different locations, i.e. Abu-Quir bay, Demiatta and Gamasa, were analysed by capillary GLC. The pollutants studied were 1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) isomers, cyclodiene compounds, dodecachlorooctahydro-1.3.4-metheno-2H-cyclobuto[cd]pentalene (Mirex), methoxychlor, toxaphene and hexachlorobenzene (HCB), Aroclors 1248 and 1254 as well as ten individual polychlorinated biphenyl (PCB) congeners. Extractable organic matter (EOM) levels ranged from 48.0 to 133.0 mg/g, and from 33.0 to 73.0 mg/g in bivalves and fish, respectively. 2,2-bis(p-Chlorophenyl)-1,1-dichlorethylene (p,p′-DDE) dominated other 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) analogues in fish (2.0–4.0 ng/g). 1-chloro-2,2-bis(p-chlorophenyl)ethylene (DDMU) dominated in the bivalve, its concentration ranging from 9.0 to 15.0 ng/g. The concentration of heptachlor was negligible, while endrin and dieldrin were the dominant cyclodienes, occurring in high levels in fish (0.6 and 1.3 ng/g) and bivalves (1.5 and 2.4 ng/g), at Gamasa and Demiatta, respectively. The Aroclor 1248 level was two- to threefold that of Aroclor 1254. As far as the individual PCBs are concerned, less chlorinated biphenyl congeners (from mono- to penta-chloro-biphenyls) were less concentrated except for PCB 200 and PCB 206. Toxaphene was detected at all three locations, at a maximum level of 9.7 ng/g in bivalves from Demiatta.