Selenium intake from tuna in Galicia (Spain): Health risk assessment and protective role against exposure to mercury and inorganic arsenic.

This study aims to quantify the selenium contribution from tuna to the Spanish diet and evidence the Se protective role against mercury and inorganic arsenic toxicity. Selenium concentrations in tuna were determined by ICP-MS spectrometry (expressed as mg kg-1), and the risk assessment was evaluated joined to Hg and iAs contrasting criteria of regulatory agencies with those that consider the Se protective role. Differences between Se average concentrations in fresh (1.24) and preserved (1.17) tuna were not statistically significant. In canned tuna species, Se presented higher mean levels in Thunnus albacares (1.28) than Thunnus alalunga (1.01) with statistically significant differences (p = 0.002), and among canned preparations a decreasing sequence was observed in different preparation-packaging media: oil (1.42) > natural (1.01) > pickled (0.92). Statistical study showed Hg-iAs as the only pair significantly correlated in all samples. The HI (sum of individual target hazard quotients -THQs-) on the consumption of tuna in Spain, due to exposure to Se, Hg and iAs, revealed the possibility of risk of adverse chronic effects in the six-year-old children group (1.09). According to the maximum allowable tuna consumption rate in meals/week (CRmw) and the THQs obtained, tuna intake, especially in children, should be moderated. The health benefit values (HBVSe) were positive in all samples, 14.53 and 15.65 in fresh and preserved tuna, respectively, which allows tuna to be considered safe. The benefit-risk value (BRV) evidenced the Se molar excess with respect to Hg that reached a surplus of 14.32% on Se AI in adults. Since iAs reduces the Se bioavailability, applying a new BRV criterion, the aforementioned percentage decreased to 13.49% of Se AI. In conclusion, tuna offers high levels of selenium to counteract adverse effects by the presence of Hg and iAs, and to provide consumers an important source of this essential element safely.

Arsenic, cadmium and lead in fresh and processed tuna marketed in Galicia (NW Spain): Risk assessment of dietary exposure.

Currently, metal bioaccumulation in fish is increasing and is a cause of concern due to toxicity. Total arsenic, cadmium and lead concentrations in fresh and processed tuna (110 samples) marketed in Galicia (NW Spain) were determined by ICP-MS spectrometry. The average concentrations of As and Cd, 3.78 and 0.024 mg kg-1 w.w., respectively, in fresh tuna were statistically significantly higher than those in processed tuna (p < 0.001). The contents in processed tuna were 0.295-7.85 mg kg-1 for As and ND-0.045 mg kg-1 for Cd. The Pb content was negligible in both types of tuna. In canned tuna, decreasing As and Cd concentrations were observed in different preparation-packaging media: olive oil > natural > pickled sauce. Of the two species studied in canned tuna, Thunnus alalunga showed statistically significant higher levels both for As 1.28 mg kg-1 (p < 0.001) and Pb 0.013 mg kg-1 (p = 0.0496) than Thunnus albacares. No samples surpassed the limits set by the EU for Cd and Pb. The limit for As in fish has not been established, but the arsenic contents in fresh tuna reported here are important, as they are among the highest reported in the literature. Considering public health in children and adults with respect to the investigated metals, the estimated daily intakes (EDIs) did not exceed the tolerable intakes. No chronic systemic risk was found since all the target hazard quotients (THQs-TTHQs) were far below 1 (critical value), and the carcinogenic risk (CR) for As did not exceed the acceptable value of 10-5. Thus, tuna consumption in the Galician diet does not pose a risk for different population groups in terms of these studied metals/metalloids.

Total mercury in fresh and processed tuna marketed in Galicia (NW Spain) in relation to dietary exposure.

Mercury is a toxic trace metal, which can accumulate to levels threatening human and environmental health. In this study, contents of total mercury have been determined by ICP-MS spectrometry in fresh and processed tuna (110 samples) purchased from supermarkets in NW Spain. Mercury was present in all samples analyzed; however, only one sample of fresh tuna (1.070 mg kg-1 wet weight (w.w.)) slightly exceeded the limit of the EU (1.0 mg kg-1 w.w.). The average mercury concentration in processed tuna was lower than fresh, 0.306 mg kg-1 w.w., and ranged from 0.080 to 0.715 mg kg-1 w.w. Results were compared with literature data. In regard to the three types of preparation-packaging media for canned tuna, total Hg content was found in the following order: olive oil > natural > pickled sauce; the last showed significant statistical differences (p < 0.01) with the other two preparations. Between the two evaluated canned tuna species, significant statistical differences (p = 0.008) were observed and Thunnus alalunga presented a greater mean content (0.332 ± 0.114 mg kg-1 w.w.) compared to Thunnus albacares (0.266 ± 0.171 mg kg-1 w.w.).Taking into account the AESAN recommendation for adults and children, as well as the EU regulations and the tuna consumption by the Spanish population, the Hg levels obtained in this study pose no risk to consumer health. However, additional studies, a monitoring process, and efforts to reduce Hg concentration in tuna would be necessary, as well as considering other sources of exposure to Hg.

Cadmium in edible mushrooms from NW Spain: Bioconcentration factors and consumer health implications.

Mushrooms do not constitute a significant portion of the human diet, but the consumption of wild and cultivated mushrooms has become increasingly in recent years. Some species accumulate high levels of toxic metals, both in unpolluted and polluted areas. In this study, we examined the accumulation capacity of cadmium in edible mushrooms in relation to certain factors and their possible toxicological implications. Cadmium concentrations were determined by an ICP-MS spectrometer in 238 samples of the fruiting bodies of 28 wild and cultivated growing edible mushrooms species and the underlying soil. The hymenophore (H) and the rest of the fruiting body (RFB) were analysed separately. The highest mean cadmium concentration (mg/kg dry weight) was found in Agaricus macrosporus (52.9 in H and 28.3 in RFB). All mushroom species accumulated cadmium in relation to the underlying soils. There were statistically significant differences between the hymenophore and the rest of the fruiting body (p < 0.001). Cadmium concentrations were compared to data in the literature and to levels set by legislation. It was concluded that consumption of our studied mushrooms is not a toxicological risk as far as cadmium content is concerned, although the species A. macrosporus should not be consumed.

Triazine residues in raw milk and infant formulas from Spanish northwest, by a diphasic dialysis extraction.

Residue levels of herbicides (triazines) were determined in milk by a new and sensitive analytical method. A total of 312 samples were collected (70 infant formulas and 242 raw milk) biweekly during a 24-month period. A method is reported for the analysis of triazine with extraction by diphasic dialysis and determination by gas chromatography with nitrogen-phosphorus detection (CG/NPD) and by liquid chromatography/mass spectrometry (LC/MS) to confirm positive results. Detection limits (LODs) were 0.01 mg/l for terbuthylazine, 0.07 mg/l for simazine and 0.04 mg/l for atrazine by CG/NPD. Optimal extraction was obtained with dichloromethane at 34 °C, and stirring at 200 rpm for 4 h. This extraction method improves recovery by up to 89% for terbuthylazine, 75% for simazine and 116% for atrazine. The frequency of total samples containing triazine residues was 12.50%; considering, separately, raw milk and infant formulas, this percentage was 16.11% and 5.71%, respectively. Finally, because one sample contained triazine levels slightly higher than established MRLs and owing to the known effects of these contaminants on infants health and development, urgent actions are needed for monitoring and controlling of the level of contamination in infant formula which not exceeds tolerable limit recommended by European and Spanish legislation.

Lead in edible mushrooms: levels and bioaccumulation factors.

Lead content was determined in 238 samples of 28 species of edible mushrooms collected from different sites in the province of Lugo (NW Spain) during 2005 and 2006. The hymenophore (H) and the rest of the fruiting body (RFB) were analysed separately. The analyses were carried out by an anodic stripping voltammetric technique using drop mercury as the working electrode. The highest mean lead contents (mg/kg dry weight) of 3.6 and 4.1, 3.0 and 2.2, 2.5 and 2.3, 2.4 and 2.3 were determined in Coprinus comatus, Agaricus campestris, Lepista nuda and Calvatia utriformis in hymenophore and the rest of fruiting bodies, respectively, while the lowest in Agaricus bisporus (0.35 in H and 0.54 in RFB) and Fistulina hepatica (0.41 in H and 0.50 in RFB). All mushroom species were bioexclusors of lead (BCF<1) in relation to the underlying soils. There were not statistically significant differences between lead levels in hymenophore and in the rest of the fruiting bodies. The lead concentrations were compared to literature data and levels set by legislation. It can be concluded that the consumption of these mushrooms can not be considered as a toxicological risk from lead content point of view, and they provide a nutritional requirement to the diet.