Metal Concentrations in Samples of Frozen Cephalopods (Cuttlefish, Octopus, Squid, and Shortfin Squid): An Evaluation of Dietary Intake

Exploiting specific properties of squid pens for the preparation of oligochitosan hydrochloride

Herein, we describe in first the application of squid pens for the preparation of pharmaceutical-grade oligochitosan hydrochloride with the physicochemical characteristics corresponding with the requirements of the European Pharmacopoeia. It is shown that the use of specific properties of squid pens as a source of parent chitosan allows preparing the product with a high yield at relatively moderate process conditions used for squid pens treatments and chitosan depolymerization.

Cadmium, lead, and mercury in two commercial squid species from the north Adriatic Sea (central Mediterranean): contamination levels and health risk assessment

In this study, lead (Pb), cadmium (Cd), and total mercury (Hg) concentrations in European squids (Loligo vulgaris) and flying squids (Todarodes sagittatus) from the northern Adriatic Sea (Italy) were analyzed. The risk of the Italian population being exposed to potentially hazardous metal concentrations through the consumption of these products was also assessed. Compared to European squids, flying squids showed three times higher total Hg concentrations and one hundred times higher Cd concentrations to the point that more than 6 and 25% of the samples exceeded the maximum Hg and Cd limits established by the current legislation. From the evaluation of dietary exposure levels, it emerged that the consumption of flying squids was associated with the highest Pb intake by children and, consequently, with the lower margin of exposure values in relation to the risk of neurotoxicity (margin of exposure=33). Consumption of flying squids, especially by children, was also associated with higher intakes of Cd, inorganic, and methyl-Hg, which, respectively, accounted for 156, 113, and 23% of the tolerable weekly intakes established for these contaminants at European level. The obtained results raise concern and it may be necessary to provide specific dietary advice on the moderate dietary consumption of some cephalopod species, especially to the youngest and most vulnerable segment of the population. However, besides the highly conservative deterministic method adopted in this study, a refined consumer exposure assessment should be performed through the probabilistic methodology, which is more suitable to represent the real exposure scenario.

Toxic metal and metalloid contamination in seafood from an eutrophic Brazilian estuary and associated public health risks

Guanabara Bay (GB) is a highly contaminated estuarine system and an important fishing area in Southeastern Brazil. In this regard, knowledge concerning the association of certain contaminants in seafood to abiotic factors and human health risk assessments is still understudied. Therefore, this study aimed to quantify nine toxic elements in highly consumed crabs, shrimp, and squid, and associate the results with abiotic factors. A human health risk assessment was also performed. Our findings indicate that crabs are the main bioaccumulators. Transparency and depth were noteworthy for all three taxonomic groups. In general, contaminant concentrations were below the limits established by different international agencies, except for As, which was higher than the Brazilian limit (1 mg kg^-1). However, the Hazard Index identified risks to consumer health for the ingestion of seafood. This study emphasizes the importance of jointly evaluating different toxic elements, for a more accurate health risk assessment.

Toxic Metals (Al, Cd, Pb) and Trace Element (B, Ba, Co, Cu, Cr, Fe, Li, Mn, Mo, Ni, Sr, V, Zn) Levels in Sarpa Salpa from the North-Eastern Atlantic Ocean Region

Sarpa salpa is a fish belonging to the Sparidae family and is usually found in local markets. Toxic metals such as aluminum (Al), cadmium (Cd), lead (Pb) and trace elements such as boron (B), barium (Ba), cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), strontium (Sr), vanadium (V) and zinc (Zn) are incorporated into fish tissues and remain there. The liver has the highest concentrations of all the analyzed toxic metals and almost all the analyzed trace elements. The consumption of 100 g/day of S. salpa muscle tissue does not pose a health risk. However, 100 g/day of liver consumption may pose a serious health risk due to the intake of Cd (572% of the tolerable weekly intake for adults with a body weight of 68.48 kg) and Pb (117% of the tolerable daily intake for adults weighing 68.48 kg). The consumption of liver of this species is not recommended due to its possible harmful effects on health.

Human Exposure to Iodine from the Consumption of Edible Seaweeds

The increasing consumption of wakame algae (Undaria pinnatifida) and kombu (Laminaria ochroleuca) because of their culinary appeal and beneficial properties means there is a need to study the composition of these new foods. Algae stand out for their high iodine content, this being an essential element whenever it is ingested at recommended levels but which, ingested in high quantities, can cause harmful effects to health such as hyperthyroidism and even goiter. The iodine content in 30 samples of algae from different geographical origins (Asia and Europe) has been determined by oxidation-reduction titration with sodium thiosulfate. European kombu algae (27.7 ± 5.4 mg/kg dry weight) have the highest mean average iodine concentrations. European algae have higher iodine content than Asian algae. Significant differences (p < 0.05) have been recorded among wakame algae according to geographical origin. The consumption of 4 g/day of European kombu algae means an intake of 111 μg/day of iodine, which is a value close to the RDI (recommended daily intake) set at 150 μg/day. It is necessary to monitor iodine levels in algae to avoid excessive intakes and harmful effects on health.

Human exposure assessment to macro- and trace elements in the most consumed edible seaweeds in Europe

Seaweed consumption has increased considerably in Europe as a result of new trends in food. The macroelement (Na, Ca, K, Mg) and trace element (B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sr, V, Zn) levels in different species of edible brown seaweeds were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). European Himanthalia elongata species had the highest recorded concentrations of K (57480 mg/kg dry weight). Asian Undaria pinnatifida species had the highest Fe content (58.8 mg/kg dw). Five grams/day of dehydrated seaweed of the Asian U. pinnatifida species mainly contributes to the admissible daily intake of Mg (9.32% adults) and Na (7.05% adults). In any case which exceeds the maximum intake values of any of the elements analyzed, the macro- and trace element levels can vary considerably in a short period of time, so it is necessary to assess the toxic risk in edible seaweeds.

Toxic Metals and Trace Elements in Artisanal Honeys from the Canary Islands

Honey is a natural product made by honey bees from the nectar of flowers or secretions produced by other living plant parts. The metal content of the honeys is related to the levels of metals in the environment. Due to the importance of honey in the human diet and the increase of environmental pollution, it is necessary to determine the content of metals in honey to evaluate the toxicological risk derived from its consumption. The objective of this study was to determine the content of 20 metals (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V, and Zn) in different samples of artisanal honey from the Canary Islands (Spain) in order to evaluate the dietary intake derived from the consumption of these honeys. A total of 161 samples of different types of Canary honey were analyzed by ICP-OES (inductively coupled plasma-optical emission spectrometry). K (825 mg/kg) was the macroelement found in highest concentration, while B (4.25 mg/kg) was the trace element with the highest mean concentration. Al (3.33 mg/kg) was the most abundant toxic metal, followed by Pb (0.040 mg/kg) and Cd (0.002 mg/kg). A mean consumption of 25 g/day of honey mainly contributes to the recommended daily intake of Cu (1.34% adults) and K (0.67% adults). As regards the toxic metals, the contribution percentage to the TDI (tolerable daily intake) of Pb at 2.92% for adults is noteworthy. However, the consumption of honey does not imply a high intake of metals and, therefore, does pose a risk to the health of adult men and women.

Metal Concentration in Muscle and Digestive Gland of Common Octopus (Octopus vulgaris) from Two Coastal Site in Southern Tyrrhenian Sea (Italy)

Octopus vulgaris constitute an important part of most suitable marine resources for human consumption, however, they can represent a source in chemical contaminants intake such as heavy metals. In this scenario, the aim of the study was the evaluation of the concentration of lead (Pb), cadmium (Cd) and mercury (Hg) in the muscle and digestive gland of octopus caught from two different locations along Campania coast (Castellammare di Stabia and Napoli) and the estimation of their weekly human intake derived from the ingestion of octopus. Analysing 38 samples showed a higher concentration of Pb in the muscle of octopus in Castellammare di Stabia than in Napoli. No statistical differences were reported for Cd, Pb and Hg concentrations in the digestive gland of octopus between two sampling sites. Differences were observed between the two tissue types, with a higher level of Cd and Pb observed in the digestive gland compared with the muscle. Noteworthy, the consumption of muscle from Castellammare di Stabia could increase Pb intake in heavy consumers of local octopus. In conclusion, the present work determines that it is important to improve strategies to minimize environmental pollution sources in these areas.

Toxic metals (Al, Cd, Pb and Hg) in the most consumed edible seaweeds in Europe

Algae are becoming increasingly common because of their importance in vegan and vegetarian diets. Although they are a source of essential minerals, vitamins and antioxidants, these marine organisms have a high absorption capacity that can lead to the accumulation of toxic metals which are dangerous in humans. The objective of this study is to determine the content of toxic metals (Al, Cd, Pb and Hg) in edible seaweed samples marketed in Spain (Europe) to assess the toxicological risk from the intake of these metals. A total of 73 European and Asian algae samples marketed in Tenerife (Canary Islands, Spain) were analyzed by ICP - OES (Inductively Coupled Plasma - Optical Emission Spectrometry) and by CV-AAS (Cold Vapor - Atomic Absorption Spectrophotometry). The major toxic metal was Al, whose highest level was recorded in seaweed salad (57.5 mg Al/kg dry weight). Regarding the origin, the highest concentrations of Al (38.9 mg/kg dw), Cd (0.59 mg/kg dw) and Pb (0.40 mg/kg dw) were found in Asian algae, which may be due to the high levels of industry in the Asian countries. However, the highest concentration of Hg (0.017 mg/kg dw) was found in European algae. The consumption of 5 g of dehydrated seaweed per day represents a percentage of contribution to the tolerable weekly intake of Cd of 22.7%, this percentage may entail a risk when considering total Cd intake. However, the consumption of 5 g a day of dehydrated seaweed would not, pose a risk to the health of adults.

Exposure to Metals from Artisanal Cheeses Made with Goat's Milk

Cheeses are an important source of essential elements. Nevertheless, the level of some metals could pose a health risk. Therefore, the concentration of trace elements and toxic metals (Cr, Cu, Li, Ni, Sr, Pb, Cd, and Al) has been determined in artisanal cheeses from different geographical locations, and the intake of these metals from cheese consumption has been evaluated. The metal concentration was determined in a total of 90 cheese samples from different locations by using inductively coupled plasma atomic emission spectroscopy. The highest concentration of Al (35.1 ± 4.42 mg/kg, wet weight) was found in artisanal cheeses from Zamora (Spain), followed by Sr (6.85 ± 0.35 mg/kg, wet weight) in artisanal cheeses from Cadiz (Spain). A daily consumption of 23.2 g of cheese provides a significant dietary contribution for Al of 0.82% of its tolerable weekly intake of 1 mg/kg of body weight per week. Canary Islands cheeses have a higher metal content than the non-Canary cheese, which could be because of the volcanic characteristics of the island soils. The intake of toxic metals and trace elements poses no risk to the health of adults.

Metal Concentrations in Wild-Harvested Phaeophyta Seaweed from the Atlantic Ocean (Canary Islands, Spain)

Seaweeds are being consumed more often worldwide and are a source of essential minerals, fiber, vitamins, amino acids, and various bioactive compounds that have many beneficial effects on human health. However, marine pollution and the high capacity of seaweed to absorb metals may mean this food can also be dangerous to human health. The concentrations of some trace elements (B, Ba, Fe, Ni, Li, and V) and toxic metals (Al, Cd, and Pb) were determined in various species of wild seaweeds in the Phaeophyta group of brown algae from the Atlantic Ocean. Inductively coupled plasma atomic emission spectrometry revealed high concentrations of Al (256 mg/kg dry weight), Pb (3.92 mg/kg dry weight), and Cd (0.20 mg/kg dry weight) in Padina pavonica. Pb contributed the most to the tolerable daily intake (TDI) of toxic metals in these samples; 57.2 and 45.3% of the TDI for Pb was found in 5 g of dehydrated P. pavonica and Halopteris scoparia, respectively. This percent contribution is half of the recommended TDI for this metal, which is 34.24 μg/day; therefore, high consumption of these species is discouraged. The maximum TDIs established by various institutions for the other metals were not exceeded from the daily consumption of 5 g of the other dehydrated seaweeds evaluated in this study.