Exposure to PBDEs and PCDEs associated with the consumption of edible marine species

In the present study, the concentrations of PBDEs and PCDEs were determined in 14 edible marine species widely consumed by the population of Catalonia (Spain). The daily intake of PBDEs and PCDEs associated with this consumption was also determined. A total of 42 composite samples were analyzed by HRGC/HRMS. The highest PBDE levels (ng/kg wet weight) were found in salmon (2015) followed by mackerel, swordfish, and red mullet (1124, 978, and 769, respectively), while those of PCDEs (ng/kg wet weight) were detected in red mullet (7088) followed by sardine (1829), anchovy (1606), tuna (1292), and mackerel (1031). For a standard male adult, total PBDE and PCDE intakes through edible marine species were 20.8 and 39.4 ng/ day, respectively. The highest contributions to these intakes (ng/day) corresponded to the consumption of tuna (5.7), salmon (3.6), and hake (3.5) for PBDEs, and tuna (13.1), hake (7.3), and sardine (6.9) for PCDEs. Although currently there is not evidence of the dioxin-like behavior of PBDEs, further research is necessary to assess if long-term exposure to PBDEs, mainly through the diet, may mean adverse effects to humans. With respectto PCDE congeners, to establish TEF values would be of great value to evaluate human health risks.     

Mercury and Fatty Acids in Canned Tuna, Salmon, and Mackerel

ABSTRACT: Canned tuna ( n = 240), salmon ( n = 16), and mackerel ( n = 16) were analyzed for mercury and fatty acids. Average mercury levels were 188, 45, and 55 ppb, respectively, and below the FDA Action Level of 1000 ppb. "Light tuna in water" contained lower mercury (x = 54 ppb) compared with "white/albacore tuna in water," which contained higher eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) x= 711 mg/100 g wet tissue). Mercury residues in salmon (x = 45 ppb) and mackerel (x = 55 ppb) were lower than in tuna products, but the EPA/DHA levels were higher (salmon, ×= 1623 mg/100 g wet tissue; mackerel, ×= 851 mg/100 g wet tissue). Information from this study will help women of childbearing age to limit their intake of mercury while obtaining healthy fats from fish.     

Mercury in UK imported fish and shellfish and UK-farmed fish and their products

Total mercury concentrations were measured in fish and shellfish and their products imported into the UK and also in UK-produced farmed salmon and trout. Three hundred and thirty-six samples were collected using a two-stage sampling plan. The sample plan was weighted to reflect consumption, but with some bias towards fish that might accumulate higher levels of mercury, such as large predatory fish at the top of the food chain. The highest levels of total mercury were found in billfish (swordfish and marlin) and shark. Mercury concentrations in the five samples of fresh/frozen shark ranged from 1.006 to 2.200 mg kg -1 , all above the European Commission limit for the species, and concentrations in 20 samples of fresh/frozen billfish ranged from 0.153 to 2.706 mg kg -1 with 13 samples above the 1.0 mg kg -1 limit for the species. One sample of Antarctic ice fish was collected and had a mercury concentration of 0.664 mg kg -1 . The limit for this species was 0.5 mg kg -1 . One sample of fresh/frozen tuna out of the 20 collected had a mercury concentration above the limit of 1.0 mg kg -1 (1.5 mg kg -1 ), but all other fresh tuna samples were well within the regulatory limit (average 0.4 mg kg -1 ). Mercury concentrations in canned tuna were lower with concentrations on average half that measured in fresh/frozen tuna. Mercury concentrations in UK-farmed salmon and trout were relatively low. The maximum concentration found in 46 samples of fresh/frozen or smoked trout and salmon was 0.103 mg kg -1 .     

Human exposure to lead,cadmium and mercury through fish and seafood product consumption in Italy: a pilot evaluation

The presence of selected toxic heavy metals, such as cadmium (Cd), lead (Pb) and mercury (Hg), was investigated in fish and seafood products, namely, blue mussel, carpet shell clam, European squid, veined squid, deep-water rose shrimp, red mullet, European seabass, gilthead seabream, Atlantic cod, European hake, Atlantic bluefin tuna and swordfish so as to assess their human exposure through diet. Metals were detected by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and hydride generation atomic absorption spectrometry (Hg-AAS). Measurements of Cd, Pb and Hg were performed by means of analytical methods validated in compliance with UNI CEI EN ISO/IEC 17025 [2005. General requirements for the competence of testing and calibration laboratories. Milano (Italy): UNI Ente Nazionale Italiano di Unificazione]. The exposure assessment was undertaken matching the levels of Cd, Pb and total Hg with consumption data related to fish and seafood products selected for this purpose. In order to establish human health implications, the estimated weekly intakes (EWIs) for Cd, Pb and Hg were compared with the standard tolerable weekly intakes (TWI) for Cd and provisional tolerable weekly intakes (PTWIs) for Pb and Hg stipulated by the European Food Safety Authority (EFSA) and the Food and Agriculture Organization/World Health Organization (FAO/WHO) Joint Expert Committee on Food Additives (JECFA). The found metal concentrations were largely below the maximum levels (MLs) established at the European Union level with the exception of Cd. This metal exceeded the MLs in squid, red mullet, European hake and Atlantic cod. Squid and blue mussel showed the highest Pb concentrations which accounted for 60% and 10% of the MLs, respectively. Highest Hg levels were found in predatory fish. The concentrations of Hg in swordfish, Atlantic bluefin tuna and red mullet accounted for 50%, 30% and 30% of the MLs, respectively. The EWIs for Cd, Pb and Hg related to the consumption of fish and seafood products by the median of the Italian total population accounted for 20%, 1.5% and 10% of the standard TWI for Cd as well as PTWIs for Pb and Hg, respectively. Furthermore, the EWIs estimated using consumption data concerning Italian consumers did not exceed the standard TWI and PTWIs, except for Cd at 95th percentile.     

Mercury, arsenic, lead and cadmium in fish and shellfish from the Adriatic Sea

The aim was to measure concentrations of total mercury, total arsenic, lead and cadmium in common edible fresh fish and shellfish from various areas of the Adriatic Sea. Estimates of intake of these elements were made through seafood consumption by the general population. Samples were either wet digested for mercury and arsenic, or dry ashed for lead and cadmium analysis. Mercury was measured by cold vapour atomic absorption spectrometry (CV AAS) and arsenic, lead and cadmium by electrothermal atomic absorption spectrometry (ET AAS). Quality control procedures of analytical methods, which included analyses of dogfish muscle-certified reference material DORM-2, confirmed the acceptability of methods. The highest mercury and arsenic concentrations were found in hake ( Merluccius merluccius ) and the lowest in mackerel ( Scomber scombrus ). The respective values in hake were 0.373 ±0.075 and 23.3 ±3.6, and in mackerel 0.153 ±0.028 and 1.06 ±0.29 mg kg -1 fresh weight (mean ±SD). Lead and cadmium concentrations were about 10 times higher in shellfish than in analysed fish. The highest lead and cadmium concentrations were found in mussel ( Mytilus galloprovincialis ) and the lowest in hake. Respective lead and cadmium values in mussel were 0.150 ±0.009 and 0.142 ±0.017, and in hake were 0.007 ±0.004 and 0.002 ±0.001 mg kg -1 fresh weight. The concentrations of analysed elements were below acceptable levels for human consumption set by the Croatian Ministry of Health, except for total arsenic. The estimated intake of those trace elements included in this study through seafood consumption by the general population did not exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Expert Committee on Food Additives.     

Survey of total mercury in some edible fish and shellfish species collected in Canada in 2002

Total mercury was measured in the edible portions of 244 selected fish and shellfish purchased in Canada at the retail level. By species, average mercury concentrations ranged from 0.011 μg g^-1 for oysters to 1.82 μg g^-1 for swordfish. The predatory fish contained the highest concentrations of mercury: swordfish (mean 1.82 μg g^-1, range 0.40-3.85 μg g^-1), marlin (1.43, 0.34-3.19 μg g^-1), shark (1.26, 0.087-2.73 μg g^-1), and canned, fresh and frozen tuna (0.35, 0.020-2.12 μg g^-1). Levels of mercury in the fresh and frozen tuna contained a mean of 0.93 μg g^-1 (range 0.077-2.12 μg g^-1) and were substantially higher than in the canned tuna (0.15, 0.02-0.59 μg g^-1). In the canned tuna, mercury concentrations varied with subspecies, with the highest average concentrations being found in Albacore tuna (mean 0.26 μg g^-1, range 0.19-0.38 μg g^-1) and the lowest (0.047, 0.025-0.069 μg g^-1) in five samples for which the subspecies of tuna were not identified. Mean concentrations of mercury in swordfish and fresh and frozen tuna were up to three times higher than reported for the USA. Dietary intake estimations found that provided fresh and frozen tuna, marlin, swordfish or shark are consumed once a month or less, the dietary intakes of total mercury by women of child-bearing age, averaged over 1 month, would fall below the Joint FAO/WHO Expert Committee on Food Additives provisional tolerable weekly intake for total mercury. The current Canadian advisory to children and women of child-bearing age is to limit their consumption of fresh and frozen tuna, swordfish and shark to no more than one meal per month.     

Concentration and Exposure Assessment of Mercury in Commercial Fish and Other Seafood Marketed in Oman

The results of this study present analytical data of the mercury levels in several fish and shellfish species to create awareness among individuals of the risks associated with consuming fish contaminated with mercury. Mercury concentrations varied from a mean of 0.02 mg/kg in Indian mackerel to 0.19 mg/kg in shark in both fresh and frozen fish, from 0.02 mg/kg in sardines to 0.18 mg/kg in skipjack tuna in canned fish, and from 0.02 mg/kg in Indian mackerel to 0.79 mg/kg in shark in dried fish. Shellfish contained a slightly higher amount of mercury than fresh or frozen fish with a mean of 0.09 mg/kg. Trophic position, followed by habitat, was the most important factors for variability in mercury concentrations in fish and shellfish. The maximum safe weekly intake (MSWI) values of mercury were significantly higher for herbivores than for carnivores. The MSWI value for total mercury in the case of consuming most (72%) fish species was more than 5 kg; however, the MSWI value was never more than 5 kg in most (66%) shellfish species. Risks were identified upon consumption of 120 g of dried shark when exceeding the provisional tolerable weekly intake threshold (1.6 μg/kg) for methylmercury. Therefore, fish‐eating populations should reduce the quantity of dried shark to efficiently diminish the exposure to mercury.     

Exposure to polycyclic aromatic hydrocarbons through consumption of edible marine species in Catalonia, Spain

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs; naphthalene, acenaphtylene, acenaphtene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene) were determined by gas chromatography-mass spectrometry in samples of 14 edible marine species (sardine, tuna, anchovy, mackerel, swordfish, salmon, hake, red mullet, sole, cuttlefish, squid, clam, mussel, and shrimp) collected in March and April 2005. These species are widely consumed by the population of Catalonia, Spain. PAH intake was also estimated for eight age and sex groups of this population. Mussel, clam, and shrimp had the highest PAH concentrations (22.4, 21.5, and 15.9 ng/g of fresh weight, respectively). In contrast, sole (2.5 ng/g of fresh weight) and cuttlefish and squid (both 3.0 ng/g of fresh weight) had the lowest mean concentrations. The highest PAH intake was found in women and girls (5.3 and 5.2 ng/kg/day, respectively), but female adolescents and female seniors had the lowest PAH intakes (3.3 ng/kg/day in both groups). The intake of benzo[a]pyrene and six other PAHs that are probably human carcinogens through consumption of these marine species would be associated with 0.27/10(6) increase in the risk of development of cancer over a 70-year life span.     

Selected polycyclic aromatic hydrocarbons in smoked tuna, swordfish and Atlantic salmon fillets

The presence of polycyclic aromatic hydrocarbons (PAHs) in commercial smoked fillets of tuna, swordfish and Atlantic salmon was studied. In Europe, the smoking technique is widely used in fish processing and these species are the most representative of the taste of consumers for smoked products. Samples were purchased on the Italian market and analysed by HPLC. Mean concentrations (ng g⁻¹) of acenaphthene (4.4, 6.2, 11.2), phenanthrene (11.5, 18.5, 8.9), anthracene (2.4, 5.2, 1.8), fluoranthene (17.0, 9.4, 4.7), benzo( k )fluoranthene (0.3, 0.1, 0.2) and benzo( a )pyrene (1.3, 0.1, 0.4) were found in Atlantic salmon, tuna and swordfish respectively. Benzo( b )fluoranthene (1.2 ng g⁻¹) was detected only in Atlantic salmon whereas dibenz( a,h )anthracene was never detected in this species, but only in tuna (0.5 ng g⁻¹) and swordfish (1.1 ng g⁻¹). Atlantic salmon contained the highest level of benzo( a )pyrene (2.8 ng g⁻¹) which is below the European regulatory level of 5 ng g⁻¹.     

Total mercury levels in muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) from the Mediterranean Sea (Italy).

This study was carried out to determine the current levels of total mercury in the muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea with the purpose of ascertaining whether the concentrations exceeded the maximum level fixed by the European Commission Decision. In addition, specimens of each species were divided into different ranges of weight to investigate the influence of size on mercury accumulation in order to provide data upon which commercial fishing strategies and marketing of swordfish and bluefin tuna may be based. Higher mean levels of total mercury were found in bluefin tuna (1.02 microg g(-1) wet wt) than in swordfish (0.49 microg g(-1) wet wt). In 4.3% of swordfish and in 44.3% of bluefin tuna analyzed, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg = 1 microg g(-1) wet wt). Besides, for bluefin tuna the total mercury level variability observed, due to size, suggests that there should be greater regulatory control by the authorities.     

Comparison of aroma characteristics of 16 fish species by sensory evaluation and gas chromatographic analysis

The aroma properties of fish broths prepared from 16 fish species (10 saltwater, three freshwater, two anadromous and one brackish water species) were described quantitatively by reference to 10 sensory attributes. Principal component analysis (PCA) and cluster analysis of sensory attributes classified the fish into four groups. Group 1, characterised by a strong ‘green’ odour, comprised all three freshwater species (loach, pond smelt and carp), two saltwater whitefish species (snapper and conger) and eel. Group 2 included migratory coastal species (sardine, banded blue‐sprat and mackerel) and was distinguished by strong ‘fish oil’ and ‘grilled fish’ notes. Group 3 consisted of swordfish, sablefish and salmon, which exhibited a strong ‘fried chicken’ note. Group 4 included flounder, cod, tuna and goby, which were scored high for ‘cooked fish’, ‘roasted soy sauce’, ‘canned tuna’ and ‘sweet’ aromas. Partial least squares regression (PLSR) models derived from selected influential peaks in the gas chromatograms of the volatile components in the broths for each attribute were highly predictive (R² ≥ 0.936). The selected peaks corresponded well to each sensory attribute. © 2003 Society of Chemical Industry     

Blue fish burgers: nutritional characterisation and sensory optimisation

In order to reduce waste of marine resources, valorise fishing discards and move towards fish consumption, a new ready-to-cook seafood product was developed. In particular, a chemical investigation on chub mackerel and hake was conducted to the aim of mixing the two fish species to produce nutritionally balanced fish burgers. In addition, to evaluate consumer opinion about these new fresh products and best acceptability of different proportions of mackerel and hake, focus group interviews and consumer test were also performed. The results of the chemical analyses achieved on both selected fish species gave rise to minimally processed fish products with a high amount of chub mackerel, therefore providing the desired nutritional properties and low level of hake in order to obtain firmer and wetter burgers. By means of focus group interviews, the novelty and high level of convenience of the developed fresh commodity was highlighted. Consumer test declared that the most successful sample was that with 70% chub mackerel and 30% hake.     

Taurine content of raw and processed fish fillets/portions

The health benefits of seafood are well recognised and fish and fish products are increasingly being advocated as functional foods. Taurine is also well recognised as beneficial to cardiovascular health, and seafood is a good source of this compound. This study investigated the taurine content of different fish species and also the use of vacuum tumbling and injection procedures for introducing additional taurine into fish. The taurine content of fish purchased in supermarkets was in the order plaice (146), cod (108), mackerel (78) and farmed salmon (60 mg/100 g fresh weight). Spot-sample tests on 14 other fish species showed a wide range (6–176 mg/100 g fresh weight) in taurine contents. Vacuum tumbling and injection in/with a taurine/sodium tripolyphosphate solution were used successfully to enrich tuna cubes (800 mg/100 g fresh weight) and salmon sides (891 mg/100 g fresh weight), respectively, with taurine thus making them (potentially) functional foods. The added taurine was well retained in processed tuna cubes and did not adversely affect the sensory acceptability of the samples. Taurine retention in cooked taurine-enriched tuna cubes was best for grilling followed by microwave heating and steaming.     

Glutathione Peroxidase Activity During Storage of Fish Muscle

Activity of fish muscle glutathione peroxidase, which presumably protects muscle from oxidative deterioration during storage and processing, was found in both Japanese jack mackerel and skipjack tuna. Activity of the peroxidase and level of reduced glutathione (enzyme substrate) decreased during 5 days storage at 4°C. Lipid hydroperoxides were substantially formed in the fish muscles during the storage.     

Characterization of Mexican Fishes According to Fatty Acid Profile and Fat Nutritional Indices

The fatty acid profile of crevalle jack was compared with that of Atlantic bluefin tuna, Atlantic Spanish mackerel, red snapper, and Nile tilapia. Crevalle jack and Atlantic Spanish mackerel showed similarities in their fatty acid profiles, with the saturated fatty acid > monounsaturated fatty acid > polyunsaturated fatty acid pattern. Atlantic bluefin tuna and red snapper followed a similar pattern to each other, with the polyunsaturated fatty acid > saturated fatty acid > monounsaturated fatty acid pattern, and the pattern for Nile tilapia was saturated fatty acid > monounsaturated fatty acid ≈ polyunsaturated fatty acid. In winter, the DHA+EPA content of crevalle jack (493.2 mg/100 g fillet) was 37% lower than Atlantic bluefin tuna and Atlantic Spanish mackerel, 35% higher than for the red snapper, and 2.8 fold higher than for the Nile tilapia. The best nutritional indices were for Atlantic bluefin tuna > red snapper > Atlantic Spanish mackerel > crevalle jack > Nile tilapia.     

Effect of freezing on theβ-hydroxyacyl-CoA-dehydrogenase (HADH) activity of fish meat

Changes in the β-hydroxyacyl-CoA-dehydrogenase (HADH) activity of squid (Loligo vulgaris), mackerel (Scomber scombrus), tuna (Thunnus alalunga), sea bream (Pagellus centrodontus), sole (Solea solea), hake and small hake (Merluccius merluccius) meat due to freezing treatment at ?10° C, ?18° C, ?35° C, ?80° C or ?196° C were investigated. With the exception of the small hake, the HADH activity of aqueous extracts from meat was significantly higher (p<0.0001) in all frozen/thawed fish species studied than in unfrozen animals because during freezing there was a release of HADH. HADH activity values of frozen/thawed squid, unfrozen mackerel, frozen/thawed and unfrozen sea bream and unfrozen hake were affected by the storage time in crushed ice.     

A SURVEY OF HISTAMINE LEVELS IN COMMERCIALLY PROCESSED SCOMBROID FISH PRODUCTS12

Analysis of 100 samples of each of 3 types of commercially processed scombroid fish products obtained at the retail level showed mean histamine concentrations (mg/100 g) of 3.58 for chunk light tuna, 1.50 for albacore tuna, and 2.56 for mackerel. Only 2 samples of chunk light tuna and 2 of mackerel contained greater than 10 mg% histamine. The highest level of histamine found in albacore tuna was 5.35 mg/100 g, while 99% ofthe samples had less than 5 mg% histamine. Chunk light tuna samples contained up to 28.0 mg/100 g, and mackerel samples contained up to 31.5 mg/100 g; 92% of the chunk light tuna and 95% of the mackerel had less than 5% histamine. The histamine levels found in these products were far below any level associated with food poisoning incidents.     

Detection of fish DNA in ruminant feed by PCR amplification

The Japanese Government has prohibited the use of seafood protein, as well as mammalian protein, in ruminant feed. There is an official method to detect meat and bone meal, but no method is yet available to detect fishmeal in ruminant feed. We tried to develop a suitable method to detect fishmeal in ruminant feed, similar to the official method "PCR detection of animal-derived DNA in feed". Our previously reported primers (fishcon5 and fishcon3-1) showed low sensitivity, so we designed new primers based on a DNA sequence from yellowfin tuna mitchondrial DNA. Among the primers, FM5 and FM3 specifically detected fish DNA (sardine, yellowfin tuna, skipjack tuna, chub mackerel, Pacific saury, salmon, rainbow trout, Japanese anchovy, codfish and Japanese horse mackerel) from fish meat, and did not amplify DNA from animals and plants. The sensitivity for detection of the presence of fishmeal in ruminant feed was 0.01-0.001%.     

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.     

On the specificity of tuna-directed primers in PCR-SSCP analysis of fish and meat

Single strand conformation polymorphism (SSCP) of an amplicon (148 bp) obtained by polymerase chain reaction (PCR) of the mitochondrial cytochrom b gene used to identify tuna species was studied with other fish and animal species. Single-stranded DNA (ssDNA) patterns of two to four strong bands were obtained with blue ling, carp, haddock, mackerel, mackerel shark, saithe, catfish, Alaska pollack, and skipjack which, however, differed from those obtained with tuna samples. Other fish species resulted in weak (cod, spined dogfish) or no ssDNA bands (Atlantic salmon, halibut, herring, pike-perch, plaice, redfish, sprat, trout). Samples from animals other than fish resulted in strong ssDNA bands differing from those of tuna and from each other (crayfish; cattle, European rabbit, fallow deer, hare, horse, red deer, roe deer; goose, turkey), in bands differing from tuna but not from each other (domestic goat/sheep, domestic pig/wild boar), or in weak bands (octopus, shrimp; chicken, duck). Increasing the stringency of PCR caused a more pronounced difference between strong and weak ssDNA bands. Inter-laboratory reproducibility of the method was good.