1,721,059 research outputs found
Polychlorinated biphenyls in seafood contamination levels and human dietary exposure
No full textDifferent species of fish and crustaceans from the Adriatic Sea, were analysed for polychlorinated biphenyls (PCBs) to estimatethe update of daily intake of these contaminants from food. The estimates of the daily TEQs intake b.w. resulted below the range of1–4 pg TEQs/kg b.w./day set by the World Health Organisation for almost all the species examined except for conger and mackerel.This result supports the assumption of a substantial reduction in intake of these compounds from seafood.[...
Cadmium and mercury in cephalopod molluscs: estimated weekly intake
No full textCadmium and mercury concentrations were measured in the flesh and hepatopancreas of different species of cephalopod molluscs (European squid, common octopus, curled octopus, horned octopus, pink cuttlefish, common cuttlefish) in order to establish whether the concentrations exceeded the maximum levels fixed by the European Commission. In hepatopancreas, the levels of cadmium were substantially higher than those in flesh (flesh 0.11-0.87 microg g(-1) wet weight, hepatopancreas 2.16-9.39 microg g(-1) wet weight), whilst the levels of mercury (flesh 0.13-0.55 microg g(-1) wet weight, hepatopancreas 0.23-0.79 microg g(-1)) were approximately double those in flesh. Concentrations exceeding the maximum permitted limit of cadmium were found in 39.8 and 41.0% of common octopus and pink cuttlefish flesh, respectively. For mercury, concentrations above the limit were found only in octopuses, and precisely in 36.8, 50.0 and 20.0% of flesh samples of common, curled and horned octopus, respectively. In the hepatopancreas, concentrations of cadmium and mercury were above the proposed limits in all the samples examined. The estimated weekly intake of between 0.09 and 0.49 microg kg(-1) body weight for cadmium and between 0.05 and 0.24 microg kg(-1) body weight for mercury made only a small contribution to the provisional tolerable weekly intake (cadmium 1.3-7.0%, mercury 1.0-4.8%) set by the WHO.[...
Total mercury and methylmercury content in edible fish from the Mediterranean sea
No full textThe objective of this study was to determine the current levels of total mercury and methylmercury in the muscle tissues of different fish species caught in the Mediterranean Sea to ascertain whether these concentrations exceed the maximum level stipulated by the European Commission Decision. Total mercury concentrations in the muscles of skates ranged from 0.18 to 1.85 mg/kg (wet weight) (average, 1.00 mg/kg) while levels of 0.11 to 1.92 mg/kg (wet weight) (average, 0.70 mg/kg) and 0.21 to 1.74 mg/kg (wet weight) (average, 0.70 mg/kg) were recorded for blue whiting and red mullet, respectively. For 66.7% of long nose skate samples, 61.4% of thornback ray samples, 42.8% of winter skate samples, and 38% of starry ray samples, the total mercury concentrations exceeded the prescribed legal limit (1.0 mg/kg [wet weight]). Concentrations exceeding the maximum total mercury level stipulated by the European Commission Decision (0.5 mg/kg [wet weight]) were observed in 63.6 and 40% of blue whiting and striped mullet samples, respectively. Mercury was present in the different species almost completely in the methylated form at 55 to 100%. Weekly intakes were estimated and compared with the provisional tolerable weekly intake recommended by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives.[...
Accumulation of mercury, cadmium, lead and arsenic in swordfish and bluefin tuna from the Mediterranean sea: a comparative study
No full textIn this paper, the presence and amount of mercury and polychlorobiphenyls (PCBs) were determined in more than 1000 food items collected monthly in the period 2001–2010 in commercial food shops in Siena (Tuscany, Italy), in order to assess risk to humans due to food consumption. The overall results clearly show a strong difference in concentration of the two contaminants between foods from the terrestrial trophic web and those from the marine trophic web. Particular attention was paid to study the Mediterranean swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) because anthropic impact on these species is great due to their topmost position in trophic webs; thus it is very important to know their health status and evaluate their toxicity for humans. Many samples of bluefin tuna and swordfish show mercury levels higher than 0.5 mg/kg f.w., which is the maximum level set by the European Commission (EC, Regulation n. 1881/2006) for most fish species. Taking into account the important nutritional contribution that fish makes to the diet, it is advisable that women of childbearing age, pregnant and breastfeeding women as well as young children select fish from a wide range of species, without giving undue preference to large predatory fish such as swordfish and tuna. In any case, it is interesting to note a significant decrease in levels of both mercury and PCBs in bluefin tuna and swordfish found in the Sienese market over the course of the past ten years.[...
Concentrations and hazard assessment of polychlorinated biphenyls and organochlorine pesticides in shark liver from the Mediterranean sea
No full textConcentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (DDTs), were determined in the liver of two different shark species Prionace glauca (blue shark) and Dalatias licha (kitefin shark) from the Mediterranean Sea. In blue shark liver, the concentrations of PCBs (2482 ng g(-1)) and DDTs (2392 ng g(-1)) were comparable, while in kitefin shark the hepatic concentrations of DDTs (4554 ng g(-1)) were significantly higher than those of PCBs (1827 ng g(-1)). Contamination levels differed between species, with kitefin shark showing consistently higher concentrations of DDTs, and blue shark higher levels of PCBs. Congener-specific PCB profiles, similar between the two species were dominated by the higher chlorinated congeners (hexachlorobiphenyls: 62.8-63.9%, penta-: 15.2-21.3%, hepta-: 13.4-14.5) with most of the lower chlorinated congeners being absent or present at very low levels. In both species, the total 2,3,7,8-tetrachlorodibenz-p-dioxin toxic equivalent (TEQs) concentrations (blue shark: 2.51 pg/g; kitefin shark: 1.46 pg/g) seem to be relatively modest. Regards to DDT component pattern, p,p'-DDE was dominant in the liver of both species (blue shark: 81.5%; kitefin shark: 38.0%), while the percentage composition of the other metabolites was differently characterized. The composition pattern of DDTs and the low value of p,p'-DDE/DDTs ratio in the specimens from Ionian Sea suggest that organochlorine pesticide contamination is still continuing in this marine environment. (c) 2005 Elsevier Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
POLYCHLORINATED BIPHENYLS, HEXACHLOROBENZENE AND ORGANOCHLORINE PESTICIDE RESIDUES IN MILK FROM IN APULIA
No full textHeavy metals in mussels (Mytilus galloprovincialis) from the Ionian Sea (Italy)
No full textConcentrations of six heavy metals (Hg, Pb, Cd, Cr, Zn, and Sn) were determined in mussels (Mytilus galloprovincialis) collected between June and September 1997 from 10 locations along a sound formed by two inlets (Mar Piccolo) near the Gulf of Taranto (Ionian Sea, Italy). The average concentrations of the heavy metals found in mussels samples were 0.15 mg/kg for Hg, 1.19 mg/kg for Pb, 0.64 mg/kg for Cd, 0.31 mg/kg for Cr, 5.15 mg/kg for Zn, and 0.54 mg/kg for Sn. The concentrations of heavy metals in mussels from the first inlet did not differ greatly from those observed in mussels from the second inlet. The concentrations of heavy metals in the mussels analyzed were below acceptable levels for human consumption.
Polychlorinated biphenyl, heavy metal and methylmercury residues in hammerhead sharks: Contaminant status and assessment.
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