Melanomacrophage centres (MMCs), located in different organs of non-mammalian vertebrates, play a role in the destruction, detoxification or recycling of endogenous and exogenous materials. Cytochrome P450 monoxygenase 1A (CYP1A) is involved in xenobiotics biotransformation, and its liver expression is considered as a biomarker for detecting exposure to environmental pollutants. Atlantic bluefin tuna (ABFT), Thunnus thynnus L., liver samples were collected from: wild animals caught in the eastern Atlantic; juveniles reared in the central Adriatic; juveniles reared in the northern Adriatic; adults reared in the western Mediterranean. The samples were processed for basic histology, histochemistry and for CYP1A immunodetection. An unexpected high density of MMCs, containing ferric iron and lipofuscin-ceroids, was detected in the juveniles sampled in the northern Adriatic Sea. These individuals showed also a strong anti-CYP1A immunopositivity in hepatocytes and in the epithelium of bile ducts. This study supports the utility of MMCs as biomarkers of fish 'health status' and gives concern for a potential contaminant accumulation in ABFT.

No abstract

Mercury (Hg) and cadmium (Cd) were quantified in fish, cephalopods and crustaceans from Italian supermarkets. Sample compliance with European dietary standards as well as human health risks according to provisional tolerable weekly intake (PTWI) and the methodology of target hazard quotient (THQ) were evaluated. Both element levels were under European legal limits, except for some fish having Hg and Cd contents exceeding or equal to critical values. Estimated weekly intakes (Hg: fish = 0.07-1.44 µg kg(-1) bw week(-1); cephalopods = 0.05-0.15 µg kg(-1) bw week(-1); crustaceans = 0.04-0.08 µg kg(-1) bw week(-1); and Cd: fish = 0.04-0.32 µg kg(-1) bw week(-1); cephalopods = 0.07-0.27 µg kg(-1) bw week(-1); crustaceans = 0.05-0.11 µg kg(-1) bw week(-1)) as well as THQ < 1 were within safe limits. Although there seems to be no important risks associated with seafood consumption, Hg exposure was in some cases close to safety margins and thus levels of this metal should be under frequent surveillance.

No abstract

Mercury, cadmium, and lead concentrations were determined in various fishery products (fishes, cephalopod molluscs, and crustaceans) imported into Italy from many European and non-European coastal countries. Considerable differences were found in the concentrations of these metals among the products tested. The highest mean Hg concentration was found in fishes (0.21 μg g(-1) wet weight), whereas cephalopods had the highest mean Cd concentration (0.35 μg g(-1) wet weight). Swordfish (0.80 μg g(-1) wet weight), longtail tuna (0.53 μg g(-1) wet weight), and thornback ray (0.52 μg g(-1) wet weight) had the highest concentrations of Hg, whereas maximum Cd concentrations were found in samples of common cuttlefish (0.85 μg g(-1) wet weight) and common octopus (0.64 μg g(-1) wet weight). The majority of the samples analyzed were in compliance with European Union legislation, except for a few cases. The calculated mean weekly intakes of Hg, Cd, and Pb through consumption of the fishery products tested were all below the legislated respective provisional tolerable weekly intakes. In general, the samples analyzed were considered safe to eat with regard to the metal concentrations found and the allowable intakes based on legislation. Nevertheless, the consumption of some species may be of significant importance for consumer health.

Total concentrations of essential (Cu, Zn, Se and Cr) and non-essential (Hg, Cd, Pb and As) trace elements were measured in the flesh and hepatopancreas of Octopodidae (Eledone moschata, Eledone cirrhosa, Octopus salutii), Sepiidae (Sepia elegans, Sepia orbignyana) and Loliginidae (Illex coindeti, Loligo vulgaris) from the Mediterranean Sea. As expected, the hepatopancreas showed higher metal concentrations than flesh; the only exceptions were Hg and As, which were equally distributed in the two tissues. Regarding the edible portion, the highest toxic metal concentrations were in Octopodidae (Hg: 0.44, Cd: 0.49, Pb: 0.10 µg g(-1) wet weight) and Sepiidae (Hg: 0.27, Cd: 0.50, Pb: 0.12 µg g(-1) wet weight), while Loliginidae tended to accumulate less metal, especially Hg (Hg: 0.11, Cd: 0.30, Pb: 0.05 µg g(-1) wet weight). The other elements showed a heterogeneous distribution among the different cephalopod families. Loliginidae showed the highest Se concentrations (1.18 µg g(-1) wet weight), Octopodidae of Cu (37.37 µg g(-1) wet weight) and Zn (42.00 µg g(-1) wet weight) and Sepiidae of As (61.43 µg g(-1) wet weight), while Cr was uniformly distributed among the various families (0.38-0.43 µg g(-1) wet weight). In these seafoods, the concentrations of essential and non-essential elements were within the prescribed limits set by various authorities, except for Cu and As. Health risks posed by toxic elements to humans via dietary intake of these mollusks were assessed on the basis on Provisional Tolerable Weekly Intake (PTWI), while the estimated intakes of essential elements were compared to Dietary Reference Intakes (RDIs). A 70-g serving of these mollusks was shown to provide a large contribution to Cd intake (0.89 µg kg(-1) body weight), corresponding to 35.6% of PTWI. Concerning the essential elements, the consumption of these mollusks made an important contribution to daily dietary intake of Se, Cu and Zn.

Trace element (Hg, Pb, Cd, Zn, Cu, Ni, and Cr) occurrence was determined in the muscle tissue of swordfish collected in the Mediterranean Sea to assess whether the intakes complied with the recommended levels for essential metals and permissible levels for toxic elements. Metals were analyzed by an atomic absorption spectrophotometer (Shimadzu AA 7000). The methodology of Target Hazard Quotient (THQ) was also evaluated. The ranking order of toxic metal concentration was Hg > Cd > Pb, while for essential elements the distribution pattern followed the sequence Zn > Cu > Ni > Cr. The Estimated Weekly Intakes (EWI) as well as THQ for Cd and Pb indicated that swordfish consumption did not pose a risk to human health, whereas the major concern was for Hg. Fish size-related changes in Hg concentrations resulted in high EWI and THQ values relative to larger fish consumption, implying a potential risk to human health. For consumer protection, catches of swordfish approximately above 44 kg should be avoided as these fish have a higher risk of containing toxic levels of Hg.

No abstract