Potential human health risks from metals (Hg, Cd, and Pb) and polychlorinated biphenyls (PCBs) via seafood consumption: estimation of target hazard quotients (THQs) and toxic equivalents (TEQs)

PCBs contamination in farmed European sea bass from different Italian rearing systems

The chemical composition and the level of twelve PCB congeners (IUPAC Nos. 18, 28, 31, 44, 52, 101, 118, 138, 149, 153, 180 and 194) were determined in 133 specimens of European sea bass (Dicentrarchus labrax), collected from four Italian aquaculture facilities: extensive valley, semi-intensive ponds, intensive concrete tanks and sea-cages. Fish muscle composition varied based on the rearing system (P<0.001): moisture was higher and fat concentration was lower in fish from the extensive system in comparison to fish from intensive tanks; intermediate values were found in fish from semi-intensive ponds and sea-cages. Concentrations of the 12 measured PCBs (PCB(tot)) and of the seven indicator congeners (PCB(7)) (Nos. 28, 52, 101, 118, 138, 153 and 180), when expressed on fat weight, were lower in extensively-reared sea bass (112.0 and 74.6 ng g(-1) fat, respectively) with respect to sea bass from the other systems (average values: 179.7 and 123.2 ng g(-1) fat) (P<0.001). When the values were expressed on fresh muscle weight, PCB(tot) and PCB(7) were lower in extensively-reared sea bass (3.412 and 2.266 ng g(-1)fw), intermediate in fish from semi-intensive ponds (15.398 and 10.632) and sea cages (13.123 and 8.882), and higher in specimens from the intensive tanks (18.176 and 12.440) (P<0.001). PCB 153 was the most abundant in all of the rearing systems. Within farm, muscular fat content and slaughter weight were positively correlated (r=0.79). PCB(7) concentration expressed in ng g(-1) fat and in ng g(-1) fw was positively correlated with both fish slaughter weight (r=0.71 and 0.73) and muscular fat concentration (r=0.86 and 0.96).

Intake of essential minerals and metals via consumption of seafood from the Mediterranean Sea

Edible marine species (fish and cephalopod molluscs) from the Mediterranean Sea were analyzed for their metal content (Hg, Cd, Pb, Cr, Cu, Zn, and Ni). Human health risks posed by these elements via dietary intake of seafood were assessed based on the provisional tolerable weekly intake, reference dose, and recommended dietary allowances. Metal concentrations varied widely among the different organisms, indicating species-specific accumulation. On a wet weight basis, the maximum concentrations of Hg were found in fish (1.56 microg g(-1)), and the maximum concentrations of cadmium were found in cephalopod molluscs (0.82 microg g(-1)), whereas for Pb the concentrations were generally low (fish, 0.01 to 1.18 microg g(-1); cephalopod molluscs, 0.03 to 0.09 microg g(-1)). For the essential metals, cephalopods had higher concentrations (Cr, 0.40 microg g(-1); Zn, 33.03 microg g(-1); Cu, 23.77 microg g(-1); Ni, 2.12 microg g(-1)) than did fish (Cr, 0.17 microg g(-1); Zn, 8.43 microg g(-1); Cu, 1.35 microg g(-1); Ni, 1.13 microg g(-1)). The estimated weekly intake of Cd and Pb indicated increased health risks through the consumption of various seafoods. Conversely, a health risk was ascribed to the intake of Hg from consumption of certain fish, such as albacore (10.92 microg kg(-1) body weight) and thornback ray (5.25 microg kg(-1) body weight). Concerning the essential metals, cephalopod mollusc consumption made an important contribution to daily dietary intake of Cu, Zn, and Ni.