Roberto Giacominelli-Stuffler

Total and methylmercury residues in cartilaginous fish from Mediterranean Sea.

Concentrations of mercury and methylmercury residues were determined in the muscle tissue of three cartilaginous fishes Chimaera monstrosa (ghostshark), Torpedo nobiliana (electric ray) and Myliobatis aquila (eagle ray) from the Mediterranean Sea. The highest mean levels of total mercury were detected in ghostshark (3.14 mg/kg wet weight), followed by electric ray (2.42 mg/kg wet weight), and eagle ray (0.83 mg/kg wet weight). Such a variability is influenced by quite a number of factors, among which size, fish ecology and feeding habits. The percentages of the methylated form to total mercury ranged from a minimum of 72% in eagle ray to a maximum of 83% in ghostshark. Relationship between specimen size and mercury and methylmercury concentrations were found in ghostshark species.

Survey of total mercury and methylmercury levels in edible fish from the Adriatic Sea

Total mercury and methylmercury concentrations were measured in the muscle tissue of different fish species from the Adriatic Sea to ascertain whether the concentrations exceeded the maximum level fixed by the European Commission. Large species-dependent variability was observed. The highest total mercury mean concentrations were in benthic (0.20–0.76 μg g−1 wet wt) and demersal fish (0.22–0.73 μg g−1 wet wt), while pelagic species showed the lowest levels (0.09–0.23 μg g−1 wet wt). In 15% of frost fish, in 42% of skate and in 30% of angler fish samples total mercury concentrations exceeded the maximum level fixed by the European Commission (Hg = 1 μg g−1 wet wt); for the species for which the maximum level was set to 0.5 μg g−1 wet wt, concentrations exceeding the prescribed legal limit were observed in 6.4% of bokkem, in 6.6% of pandora, in 20% of megrin, in 12.5% of four-spotted megrim, in 16% of striped mullet, in 5.0% of forkbeard and in 5.3% of picarel samples. In all the different species, mercury was present almost completely in the methylated form, with mean percentages between 70 and 100%. Weekly intake was estimated and compared with the provisional tolerable weekly intake recommended by the FAO/WHO Expert Committee on Food Additives. A high exposure was associated with the consumption of only skates, frost fish and angler fish, thought the consumption of the other species, such as, megrim, four spotted megrim, red fish striped mullet and forkbeard, resulted in a weekly intake slightly below the established provisional tolerable weekly intake.

Relationship between Total Mercury Concentration and Fish Size in Two Pelagic Fish Species: Implications for Consumer Health

Total mercury concentrations were determined in different size classes of two pelagic fish species of great commercial importance, horse mackerel (Trachurus trachurus) and Mediterranean horse mackerel (Trachurus mediterraneus), to evaluate the relationship between total mercury concentration and fish size and to determine whether any differences might affect the quantitative assessment of mercury exposure for consumers. Mercury concentrations in horse mackerel and in Mediterranean horse mackerel were between 0.16 and 2.41 microg g(-1) of weight wet (mean, 0.68 microg g(-1)) and between 0.09 and 1.62 microg g(-1) (mean, 0.51 microg g(-1)), respectively. The regression curves revealed a significant relationship between mercury concentration and fish size (length and weight) for both species. Concentrations exceeding the proposed limit for human consumption were observed in 33.3% of the samples of both species and were associated with larger specimens. The consumption of the larger specimens could lead to an increase in mercury exposure for consumers. Estimated weekly intakes, calculated on the basis of concentrations relative to each size class, revealed a high exposure associated with the consumption of fish larger than 30 cm (horse mackerel, 11.63 to 20.16 microg/kg of body weight; Mediterranean horse mackerel, 5.86 to 13.55 microg/kg of body weight). An understanding of the factors leading to an increase in mercury exposure can help consumers make informed decisions about eating fish.

Toxic Metals (Hg, Cd, and Pb) in Fishery Products Imported into Italy: Suitability for Human Consumption

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.

Health risk of coplanar polychlorinated biphenyl congeners in edible fish from the mediterranean sea

The muscle tissue of different species of fish was analyzed for polychlorinated biphenyls (PCBs) in order to estimate the daily intake of these contaminants. Contamination levels among the different species varied between 108 and 678 ng/g lipid weight. Isomer-specific analysis in the muscle tissue of the various fish revealed a profile dominated by hexa- and pentachlorobiphenyls, followed by hepta- and tetrachlorobiphenyls. Other congeners, including those with fewer than four or more than nine chlorine atoms, were below the instrumental limit of detection in all samples. PCB dietary intake was below the range of 1 to 4 pg 2,3,7,8-tetrachloro-p-dioxin equivalents per kg body weight per day set by the World Health Organization. From a public health point of view, there is no indication of important risks associated with the consumption of these seafoods.

Contamination by polychlorinated biphenyls (PCBs) in striped dolphins (Stenella coeruleoalba) from the Southeastern Mediterranean Sea

Concentrations of polychlorinated biphenyls (PCBs) including dioxin-like PCBs (non-ortho, PCB 77, PCB 126, and PCB 169 and mono-ortho, PCB 105, PCB 118, and PCB 156) were measured in different organs and tissues (melon, blubber, liver, kidney, lung, heart, and muscle tissue) of striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean Sea (Adriatic Sea). The mean highest levels were in blubber and melon, followed by liver, kidney, lung, heart, and muscle tissue. PCB profiles were similar in all tissues and organs being dominated by the higher chlorinated homologues (hexa-CBs, 55.8–62.1%; penta-CBs, 15.4–20.0%; and hepta-CB PCB 180, 12.7–16.5%). Major PCBs in all tissues were congeners 138 and 153 collectively accounting for 50.6–58.3% of the total PCB concentrations, followed by PCB 101, 105, 118, and 180 constituting from 27.0% to 31.0%. PCB levels were higher in adult males than in adult females. The estimated 2,3,7,8-TCDD toxic equivalents of non- and mono-ortho PCBs were much higher than the threshold level above which adverse effects have been observed in other marine mammals species, suggesting that striped dolphins in this region are at risk for toxic effects.

Intake of essential and non-essential elements from consumption of octopus, cuttlefish and squid

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.

Levels and profiles of DDTs and PCBs in a gadiform fish (Phycis blennoides) from Mediterranean Sea

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PCBs and PCDD/PCDFs in fishery products: Occurrence, congener profile and compliance with European Union legislation

PCB and PCDD/F concentrations and congener specific profiles were determined in seafood (fish, cephalopods, crustaceans) purchased in supermarkets in Southern Italy. The results intended to assess and compare the levels and congener profiles among the various organisms and evaluate whether the pollutant concentrations exceed the maximum permitted levels according to European Union guidelines. Contaminant accumulation followed the order PCBs > PCDFs > PCDDs in all samples. Species-specific bioaccumulation of contaminants and differences in PCB and PCDD/F profiles among the three different groups of seafood were noted. Pollutant concentrations, given as sum of WHO-TEQ, in all samples (fish: 0.28 pg g(-1) wet wt; cephalopods: 0.01 pg g(-1) wet wt; crustaceans: 0.03 pg g(-1) wet wt) did not exceed the maximum limits for human consumption. Also the sum of six indicator PCBs (fish: 0.07-16.7 ng g(-1) wet weight; cephalopods: 0.05-0.21 ng g(-1) wet weight; crustaceans: 0.07-0.57 ng g(-1) wet weight) was below the level prescribed by the legislation in all the species tested. The estimated dietary intakes (fish: 0.52 TEQs/kg bw/week; cephalopods: 0.01 TEQs/kg bw/week; crustaceans: 0.02 TEQs/kg bw/week) were below the tolerable weekly intake (TWI) proposed by the European Commission. Therefore, the samples analyzed can be considered safe considering the levels obtained and the in-force legislation.

Comparative study on trace metal accumulation in the liver of two fish species (Torpedinidae): Concentration–size relationship

Metal concentrations (Hg, Cd, Pb, As, Cr, Cu, Zn and Ni) were measured in the liver of two fish, Torpedo nobiliana (electric ray) and Torpedo marmorata (marbled electric ray), from the Mediterranean Sea in order to comparatively investigate their current pollution status. Maximum mean levels of Hg were detected in electric ray (mean: 2.16μgg(-1) ww), while marbled electric ray accumulated especially Cd (mean: 0.06μgg(-1) ww), Cu (mean: 3.83μgg(-1) ww) and As (mean: 32.64μgg(-1) ww). The metal concentrations are similar to those reported in literature, except for Cd, As and Ni. Hg concentrations increased with increasing fish body length in both species, whilst no significant concentration-size relationship was found for other metals. To the best of our knowledge this is the first report providing information on trace metal levels and relationship between concentration and size of these cartilaginous fishes. Future studies on the concentrations and effects of environmental contaminants in various torpedinid species are surely needed.