Total and subcellular distribution of trace elements (Cd, Cu and Zn) in the liver and kidney of green turtles (Chelonia mydas) from the Mediterranean Sea

This study investigated the subcellular distribution of Cd, Cu and Zn in liver and kidney of green turtles (Chelonia mydas) stranded along the Italian coast of the South Adriatic Sea (Eastern Mediterranean). Cd and Zn mean concentrations did not differ significantly between liver (4.26microgg(-1) and 34.53microgg(-1), respectively) and kidney (5.06microgg(-1) and 26.39microgg(-1), respectively), whereas the levels of Cu were significantly higher in liver (32.75microgg(-1)) than in kidney (8.20microgg(-1)) (p<0.009). Most of Cd, Cu and Zn was present in hepatic and renal cytosol, and their concentrations increased with total levels in both organs, indicating that cytosol has a crucial role in metal accumulation. Cd and Cu in hepatic and renal cytosol were present mostly in metallothionein fractions (MTs), whereas Zn was fractionated into MTs and high-molecular-weight-substances (HMWS). The comparison with the results of other investigations on individuals of the same species collected in different marine areas shows good agreement relatively to essential metals. For Cd our data are comparable with those encountered in specimens from the Mediterranean Sea (Cyprus) confirming the homogeneity of the area comprising the south-eastern basin of the Mediterranean Sea from an ecological point of view.

Mercury in fish: Concentrationvs. fish size and estimates of mercury intake

Total mercury concentrations were determined in different fish size classes of commercial importance such as, conger eel (Conger conger), starry ray (Raja asterias), forkbeard (Phycis blennoides), frostfish (Lepidopus caudatus), striped mullet (Mullus barbatus), red gurnard (Aspitrigla cuculus) and yellow gurnard (Trigla lucerna) in order to evaluate variations in consumer exposure to mercury as a function of fish consumption of a spectrum of different sizes. The highest mean levels of total mercury were detected in conger eel (0.80 microg g(-1)) and starry ray (0.75 microg g(-1)). Forkbeard (0.67 microg g(-1)), frostfish (0.59 microg g(-1)) and striped mullet (0.55 microg g(-1)) showed slightly lower levels, while red gurnard (0.33 microg g(-1)) and yellow gurnard (0.22 microg g(-1)) exhibited the lowest concentrations. The results of linear regression analysis showed a significant relationship between mercury concentrations and fish size for all species. Consequently, dietary consumption of larger size specimens leads to an increase in the exposure level for consumers. Understanding by consumers of all factors leading to an increase of exposure to mercury is the first step to enable them to make decisions about eating fish.

Polychlorinated biphenyls and other chlorinated organic contaminants in the tissues of Mediterranean loggerhead turtle Caretta caretta

Polychlorinated biphenyls including coplanar congeners and DDT compounds were measured in different organs and tissues (liver, kidney, lung and muscle tissue) of loggerhead turtles Caretta caretta from the eastern Mediterranean Sea. The highest levels of these compounds were found in liver (PCBs: 52.32 ng/g; DDTs: 18.27 ng/g), followed by kidney (PCBs: 19.05 ng/g; DDTs: 5.70 ng/g), lung (PCBs: 12.75 ng/g; DDTs: 3.76 ng/g ) and muscle tissue (PCBs: 4.65 ng/g; DDTs: 1.45 ng/g). PCBs revealed a profile dominated by hexa-, penta- and hepta-chlorinated congeners, while among DDTs, the compound in the greatest concentration was p,p'-DDE, (liver: 85.2%, kidney: 93.6%, lung: 86.4%, muscle tissue: 93.2%). The estimated toxic equivalents (pg TEQs/g wet wt) of non- and mono-ortho PCBs were in the range of 1.54-5.86 pg TEQs/g wet wt. Non-ortho coplanar PCB 77 accounted for more than 90% of the total TEQs leaving to mono-ortho only 2.6-6.2%.

Concentrations and composition of organochlorine contaminants in different species of cephalopod molluscs from the Italian waters (Adriatic Sea)

Persistent organochlorines, such as polychlorinated biphenyls including coplanar congeners and DDT compounds were measured in the liver of different species of mollusc cephalopods: broadtail squid (Illex coindetii), horned octopus (Eledone moschata) and spider octopus (Octopus salutii) collected in two different areas of the Adriatic Sea (central and southern Adriatic Sea). The concentration of PCBs exceeded DDT ones in horned octopus (PCBs: 617.0 ngg(-1) lipid weight, DDTs: 188.0 ngg(-1) lipid weight) and in spider octopus (PCBs: 590.0 ngg(-1) lipid weight, DDTs: 293.0 ngg(-1) lipid weight), while in broadtail squid PCB load (748.0 ngg(-1) lipid weight) was similar to those of DDTs (514.5 ngg(-1) lipid weight). No significant difference in PCB levels was observed among species, while DDT concentrations were higher in broadtail squid than in horned octopus and spider octopus. DDTs composition showed slight differences in relation to species, thought p,p'-DDE was the predominant compound in all cephalopod species (broadtail squid: 88.1%, horned octopus 94.1%, spider octopus: 97.5%). PCB isomer profiles were similar among species being hexachlorinated isomers the most abundant, followed by penta- and heptachlorobiphenyls, while tri- and tetrachlorobiphenyls made up a small percentage of the total PCB residues. Regarding coplanar congeners, non-ortho PCBs were below the detection limit in all samples and the 2,3,7,8-TCDD toxic equivalent (TEQ) concentrations were very low. The influence of biological and ecological factors (size/weight and location) on the bioaccumulation of organochlorine compounds has been discussed.

Occurrence and accumulation of organochlorine contaminants in swordfish from Mediterranean Sea: a case study

Polychlorinated biphenyls including coplanar congeners and DDT compounds were measured in the liver of a teleost species: namely, Xiphias gladius. PCB concentrations (median: 1121 ng/g lipid wt) were comparable with DDT levels (median: 1236 ng/g lipid wt). PCBs revealed a profile dominated by hexa-, penta- and heptachlorinated congeners. Among DDTs, the compound in the greatest concentration was p,p'-DDE, representing 70% of the total DDT burden, followed by o,p'-DDT>p,p'-DDT>p,p'-DDD=o,p'-DDD. Mean total 2,3,7,8-TCDD equivalent of five coplanar PCBs was 8.83 pg/g lipid weight. The isomers with higher TEQs values were non-ortho congeners than mono-ortho ones.

Cadmium and mercury in cephalopod molluscs: Estimated weekly intake

Cadmium 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.

Concentrations and hazard assessment of polychlorinated biphenyls and organochlorine pesticides in shark liver from the Mediterranean Sea

Concentrations 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 ngg(-1)) and DDTs (2392 ngg(-1)) were comparable, while in kitefin shark the hepatic concentrations of DDTs (4554 ngg(-1)) were significantly higher than those of PCBs (1827 ngg(-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.

Trace elements in loggerhead turtles (Caretta caretta) from the eastern Mediterranean Sea: overview and evaluation

Concentrations of trace elements (Hg, Cd, Pb, Zn, Cu, Fe, and Se) in different organs and tissues (liver, kidney, muscle tissue, spleen, heart, lung, and fat tissue) of loggerhead turtles Caretta caretta from eastern Mediterranean Sea were determined. The highest levels of mercury and cadmium were found in liver (Hg: 0.43 microg g(-1) wet weight; Cd: 3.36 microg g(-1) wet weight) and kidney (Hg: 0.16 microg g(-1) wet weight; Cd: 8.35 microg g(-1) wet weight). For lead the overall concentrations were low and often below the limit of detection. Copper and selenium tended to be higher in liver than in other tissues and organs, while for zinc the concentrations were quite homogenous in the different organs and tissues, except fat tissue (64.7 microg g(-1) wet weight) which showed a higher accumulation of this element. For iron the greatest concentrations were observed in liver (409 microg g(-1) wet weight) and spleen (221 microg g(-1) wet weight).

Cadmium in cephalopod molluscs: implications for public health

Cadmium concentrations were measured in the flesh and hepatopancreas (digestive gland) of 1,392 specimens of different species of cephalopod molluscs (broadtail squid, spider octopus, curled octopus, horned octopus, elegant cuttlefish, and pink cuttlefish) to determine whether maximum levels fixed by the European Commission were exceeded. In all species, mean cadmium concentrations were higher in hepatopancreas than in flesh. Large differences among the different species were also observed. Pink cuttlefish and spider octopus had the highest concentrations for both flesh (spider octopus, 0.77 microg g(-1); pink cuttlefish, 0.87 microg g(-1)) and hepatopancreas (spider octopus, 9.65 microg g(-1); pink cuttlefish, 18.03 microg g(-1)), and the lowest concentrations were encountered in broadtail squid (flesh, 0.13 microg g(-1); hepatopancreas, 2.48 microg g(-1)). The other species had intermediate concentrations of 0.20 to 0.30 microg g(-1) in flesh and 5.46 to 8.01 microg g(-1) in hepatopancreas. Concentrations exceeding the limit proposed by the European Commission (1.00 microg g(-1)) were observed in 44.4 and 40.0% of flesh samples of spider octopus and pink cuttlefish, respectively. The estimated weekly intake, 0.09 to 0.66 microg/kg body weigh, was below the provisional tolerable weekly intake set by the World Health Organization.

Content of mercury and cadmium in fish (Thunnus alalunga) and cephalopods (Eledone moschata) from the south-eastern Mediterranean Sea

Mercury and cadmium concentrations were measured in the flesh and liver (or hepatopancreas) of albacore (Thunnus alalunga) and horned octopus (Eledone moschata) to establish whether the concentrations exceeded the maximum levels fixed by the European Commission. In both species, mercury and cadmium mean concentrations were higher in liver (albacore: mercury = 2.41 microg g(-1) wet wt, cadmium = 9.22 microg g(-1) wet wt; horned octopus: mercury = 0.76 microg g(-1) wet wt, cadmium = 6.72 microg g(-1) wet wt) than in flesh (albacore: mercury = 1.56 microg g(-1) wet wt, cadmium = 0.05 microg g(-1) wet wt; horned octopus: mercury = 0.36 microg g(-1) wet wt, cadmium = 0.33 microg g(-1)). Mercury concentrations exceeding the prescribed legal limit of 1 microg g(-1) wet wt were found in almost all albacore samples (flesh: 71.4%; liver: 85.7%). For horned octopus, concentrations above 0.5 microg g(-1) wet wt were observed solely in hepatopancreas, while in flesh, the concentrations were below this limit in all the samples examined. Of the flesh samples of albacore, 42.8% exceeded the proposed tolerance for cadmium for human consumption, whilst for horned octopus, the established limit was not exceeded in any sample.

Polychlorinated biphenyl residues in deep-sea fish from Mediterranean Sea

Polychlorinated biphenyls including coplanar congeners were measured in the liver of different species of skates and ghostsharks. The mean concentrations of PCBs in skates (314 ng/g wet wt) were comparable with those in ghostsharks (285 ng/g wet wt). The specific analysis of PCB congeners in skates hepatic tissue revealed a profile dominated by hexa-, penta-, and heptachlorinated congeners followed by trichlorobiphenyls, tetra- and decachlorobiphenyls. A different profile dominated by hexa-, tri-, and pentachlorinated congeners, followed by heptachlorobiphenyl and decachlorobiphenyls was found in ghostsharks liver. The estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) of coplanar PCBs in skates and ghostsharks were 0.48 and 0.33 pg/g wet weight, respectively, with mono-ortho congeners PCB105, 118 and 156 contributing more than 90% to the TEQs.

Polychlorinated biphenyl and organochlorine pesticide residues in Lophius budegassa from the Mediterranean Sea (Italy)

Persistent organochlorines, such as polychlorinated biphenyls, including coplanar congeners and DDT compounds, were measured in the liver of a teleost species: namely, Lophius budegassa. The mean concentrations of PCBs (1249 ng/g wet wt) were comparable with DDTs mean levels (1459 ng/g wet wt). Among DDTs the compound found at the highest concentration was p,p'-DDE representing 76% of the total DDT burden. The PCB profiles were dominated by congeners 153, 180, and 138 accounting for 49.8%, 16.0% and 13.7% of the total PCBs. The total 2,3,7,8-TCDD toxic equivalent (TEQs) of six coplanar PCBs, including mono- and non-ortho congeners, was 0.98 pg/g wet wt. The congeners with highest TEQs values were non-ortho-congeners followed by mono-ortho ones.

Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, chlorinated pesticides (DDTs), hexachlorocyclohexane, and hexachlorobenzene residues in smoked seafood

Smoked seafoods were screened for the presence of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and other organochlorine compounds. Total PAH concentrations ranged from 46.5 ng/g (wet weight) for smoked swordfish to 124.0 ng/g (wet weight) for smoked herring. Among the carcinogenic PAHs, benzo(a)pyrene ranged from undetectable levels for several smoked fish to 0.7 ng/g for Scottish salmon, dibenzo(ah)anthracene was not present in any of the samples analyzed, and benzo(a)anthracene was found in all samples and at particularly high levels in salmon (23.2 ng/g). Benzo(a)pyrene concentrations were below the tolerance limit for all samples. PCB concentrations for the different samples ranged from 2 to 30 ng/g. Chlorinated pesticides (DDTs: p,p'-DDE, p,p'-DDT, o,p'-DDT, p,p'-DDD, and o,p'-DDD) were detected at levels ranging from 0.2 ng/g (wet weight) in bluefin tuna to 17.5 ng/g (wet weight) in salmon. Hexachlorocyclohexane isomers (alphaHCH + betaHCH + gammaHCH) were present in higher amounts in eels (6.5 ng/g) than in the other smoked fish. For 40% of the samples, PCB concentrations exceeded the limit fixed by the European Union, while pesticide levels were below the maximum acceptable limit proposed by the Food and Agriculture Organization.

Heavy metal residues in tissues of marine turtles

Heavy metal concentrations in the tissues of marine turtles are presented. The most frequently monitored elements are mercury, cadmium and lead; and the tissues mainly analysed in nearly all the stranded individuals are muscle, liver and kidney. The highest mercury and cadmium levels were found in liver and kidney respectively; the majority of the lead burden existed in bones and carapace, while arsenic was present mainly in muscle tissue. Mercury occurred quite completely as methylmercury in muscle, whereas in liver the main form was the inorganic one. Arsenic was exclusively present in the metallorganic form either in muscle tissue or in liver. Metals in the eggs were mainly present in the yolk. Significantly higher concentration of mercury, copper, zinc and iron were found in yolk than albumen, while shell contained highest levels of manganese and copper. The load of trace metals in these animals strictly correlated with the species seems to depend on their different food behaviour.

Total mercury and methylmercury content in edible fish from the Mediterranean Sea

The 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.

Heavy Metal, Polychlorinated Biphenyl and Organochlorine Pesticide Residues in Marine Organisms: Risk Evaluation for Consumers

This survey provides information on the levels of heavy metal, polychlorinated biphenyl and organochlorine pesticide residues in marine organisms to ascertain whether these concentrations exceeded the prescribed legal limits. In order to assess the potential human health impact, the weekly intake was estimated. Most of the organisms analysed showed higher levels of mercury than the maximum permissible limit, while cadmium and lead were below the proposed permissible limits in all samples. The estimated intake was far above the established Provisional Tolerable Weekly Intake for all metals, except for total mercury.

Levels and congener pattern of polychlorinated biphenyls in the blubber of the Mediterranean bottlenose dolphins Tursiops truncatus

Isomer specific concentrations of individual polychlorinated biphenyls (PCBs) including toxic non-ortho (IUPAC 77, 126, 169) and mono-ortho (105, 118, 156) coplanar congeners were determined in the blubber of nine bottlenose dolphins (Tursiops truncatus) stranded along the Eastern Italian coast. The total PCB concentrations ranged from 3534 to 24375 ng/g wet wt. The PCB profile was dominated by congeners 138 and 153 collectively accounting for 55% of the total PCB concentrations. Among the most toxic congeners the order of abundance was 126>169>77. The mean total 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent of six coplanar PCBs in the blubber of bottlenose dolphins was 45596 pg/g. Non-ortho congeners contributed greater to the 2,3,7,8-TCDD toxic equivalents than mono-ortho members. Particularly, PCB 126 was the major contributor to the estimated toxic potency of PCBs in dolphins.