Persistent organic pollutants in edible fish: a human and environmental health problem

Many persistent organic pollutants (POPs) pose serious health hazards to both the environment and human. Among these, polychlorobiphenyls (PCBs) are probable human carcinogens and can also pose non-cancer health hazards to intellectual functions and the nervous, immune and reproductive systems. The risks and hazards associated with POP residues in tissues are a function of the dioxin-like compound toxicity and an individual's exposure. Fish consumption might become a serious problem because of bioaccumulation as revealed in many studies worldwide. We report data concerning the accumulation and pattern of hexachlorobenzene (HCB), p,p'-DDE and PCBs in edible tissues of commercial fish species (bluefin tuna Thunnus thynnus, swordfish Xiphias gladius, Atlantic mackerel Scomber scombrus) from Italian Seas and of the Antarctic toothfish Dissostichus mawsoni from the Ross Sea (Antarctica). The species analyzed are part of the human diet. 2,3,7,8-TCDD toxic equivalents (TEQs) and tolerable weekly intake (TWI) were also calculated to evaluate the toxic hazard for the population that include them in their diet. Gaschromatography revealed 0.16 +/- 0.24 and 0.4 +/- 0.2 ng/g wet wt of HCB in Antarctic toothfish and bluefin tuna, respectively. p,p'-DDE concentrations were 38 +/- 29 and 31 +/- 38 ng/g wet wt in swordfish and bluefin tuna muscle, respectively, and 0.66 +/- 0.57 ng/g wet wt in the Antarctic toothfish. PCBs showed higher concentrations and they were 89 +/- 82, 80 +/- 86 and 5.2 +/- 4.0 ng/g wet wt in the muscle of swordfish, bluefin tuna and Antarctic toothfish, respectively. In Mediterranean fish, the most abundant congeners were the most persistent PCB numbers 153, 138, 180, 118 and 170, which accounted for 51% and 47% of the total PCB residue in tuna fish and swordfish, respectively, and 18% in the Antarctic toothfish. TEQs were 1.97 and 4.65 pg/g wet wt in bluefin tuna muscle and gonads, respectively, and 0.11 pg/g wet wt in Antarctic toothfish. The TEQ weekly intake was calculated and values ranged 197-465 Pg(TEQ)/week when consuming 100 g of Mediterranean fish and therefore lower than the recommended TWI Those values were higher (788-1860 Pg(TEQ)/week) than the recommended TWI, if 400 g of fish/week was consumed (with the exception of Antarctic fish). (C) 2004 Elsevier B.V. All rights reserved.