Bioaccessibility of Hg, Cd and As in cooked black scabbard fish and edible crab

Mercury contents and potential exposure risk of rice-containing food products

Mercury (Hg), especially methylmercury (MeHg), accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals. In addition to being a food staple, rice is widely used as a raw material to produce a vast variety of processed food products. Little is known about Hg levels in snacking rice-food products and potential Hg exposure from consumption of them, besides previous studies on infant rice cereals. Aiming to provide complementary information for a more complete assessment on Hg exposure risk originated from Hg-containing rice, this study determined total Hg (THg) and MeHg levels in 195 rice-containing and rice-free processed food products covering all major types of snack foods marketed in China and the estimated daily intake (EDI) of dietary Hg from the consumption of these foods. The results clearly showed THg and MeHg contents in rice-containing foods were significantly higher than rice-free products, suggesting the transfer of Hg and MeHg from the rice to the end products, even after manufacturing processes. Moreover, significant positive correlations were observed between THg, MeHg, or MeHg/THg ratio and rice content for samples containing multiple grains as ingredients, further indicating the deciding role of rice for Hg levels in the end food products. Although the EDI of THg and MeHg via rice-based food products were relatively low compared to the reference dose, it should be considered these snacking food products would contribute additive Hg intake outside of the daily regular meals.

Behavior of diclofenac from contaminated fish after cooking and in vitro digestion

BACKGROUND

Seafood consumers are widely exposed to diclofenac due to the high contamination levels often present in aquatic organisms. It is a potential risk to public health due its endocrine disruptor properties. Limited information is available about diclofenac behavior after food digestion to enable a more realistic scenario of consumer exposure. This study aimed to evaluate cooking effects on diclofenac levels, and determine diclofenac bioaccessibility by an in vitro digestion assay, using commercial fish species (seabass and white mullet) as models. The production of the main metabolite 4'-hydroxydiclofenac was also investigated. Fish hamburgers were spiked at two levels (150 and 1000 ng g-1) and submitted to three culinary treatments (roasting, steaming and grilling).

RESULTS

The loss of water seems to increase the diclofenac levels after cooking, except in seabass with higher levels. The high bioaccessibility of diclofenac (59.1-98.3%) observed in both fish species indicates that consumers' intestines are more susceptible to absorption, which can be worrisome depending on the level of contamination. Contamination levels did not affect the diclofenac bioaccessibility in both species. Seabass, the fattest species, exhibited a higher bioaccessibility of diclofenac compared to white mullet. Overall, cooking decreased diclofenac bioaccessibility by up to 40% in seabass and 25% in white mullet. The main metabolite 4'-hydroxydiclofenac was not detected after cooking or digestion.

CONCLUSION

Thus, consumption of cooked fish, preferentially grilled seabass and steamed or baked white mullet are more advisable. This study highlights the importance to consider bioaccessibility and cooking in hazard characterization studies. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Multi-isotopic composition of brown crab (Cancer pagurus) and seafloor sediment from a mine tailing sea disposal impacted fjord ecosystem

Sea disposal of mine tailings in fjord ecosystems is an important coastal management issue in Norway and occurs at the land-sea interface. Here we studied accumulation of heavy metals in brown crab (Cancer pagurus) and seafloor sediment from Jøssingfjord, Norway during 2018 to evaluate long-term, legacy pollution effects of coastal mine tailing sea disposal activities. Nickel and copper sediment pollution in the mine tailing sea disposal area was classified as moderate and severe, respectively, under Norwegian environmental quality standards, and highlights the persistent hazard and legacy impacts of heavy metals in these impacted fjord ecosystems. Mercury, zinc, and arsenic had stronger affinities to brown crab muscle likely due to the presence of thiols, and availability of metal binding sites. Our multi-isotopic composition data showed that lead isotopes were the most useful source apportionment tool for this fjord. Overall, our study highlights the importance and value of measuring several different heavy metals and multiple isotopic signatures in different crab organs and seafloor sediment to comprehensively evaluate fjord pollution and kinetic uptake dynamics. Brown crabs were suitable eco-indicators of benthic ecosystem heavy metal pollution in a fjord ecosystem still experiencing short- and long-term physical and chemical impacts from coastal mining sea disposal activities.

Human exposure to elements through consumption of raw and cooked fish in an urban region of the central Brazilian Amazon biome: Health risks

Fish is an important source of animal protein for local communities in the Amazon basin, whose food safety must be assured. However, certain potential toxicants elements, can bioaccumulate in fish species, which inhabit anthropogenically polluted waters, ultimately posing a risk to human health. In the present study, the concentrations of nine elements (Al, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) were determined in raw and cooked samples of eight fish species consumed in Santarém (northern Brazil, Amazon biome). The potential for non- carcinogenic human health risks linked to the consumption of cooked fish were evaluated for adults and children in two different scenarios. Four carnivores, three omnivores and one detritivore, all of them regularly marketed and consumed by the Santarém population, were the target species. The safety reference values set by national and international guidelines for humans, in both raw and cooked preparations, were used. In most cases, the cooking process showed a trend to increase elements concentrations compared to raw samples, however the differences were not significant. Moreover, the risk assessment showed danger for children in relation to Hg from the consumption of fish, in both scenarios evaluated. For adults, in one of the scenarios, there was a health risk associated to Hg as a result of carnivorous fish consumption. In a context of combined exposure to all elements, children were at risk when consuming fish, especially carnivorous and omnivorous species. For adults, the mixture of elements posed a risk to health human only for carnivorous fish consumption. The results reveal an environmental scenario of Hg contamination, which requires monitoring actions to preserve the aquatic biodiversity and human health in the Brazilian Amazon biome.

Human health risks assessment of the fluctuations in mercury levels in seafood from different key regions of Rio de Janeiro, Brazil

Mercury (Hg) contamination on the Brazilian southeast coast has been highlighted, especially in relation to species of commercial importance. This study aimed to quantify the Hg concentration in species of mussels, fish, and crabs obtained from fishing colonies on the beaches of the west and south of the city of Rio de Janeiro, investigate the possible effect of seasonality, sex, and location sampling, and finally, the risk to consumer health in four different age groups. The difference between cooked and raw commercially available mussel samples was also verified. The main results highlight that the fish presented higher levels of Hg and that the mussel samples sold cooked presented lower levels of Hg when compared to the raw ones. For Micropogonias furnieri, Sardinella brasiliensis, and Callinectes spp., the season variable influenced Hg concentrations, while only for Merluccius merluccius was a difference between the sexes identified, with males having the highest values. Although Hg concentrations in animals were below the permitted limit, consumption of all species exceeded the monthly intake limit for this metal. For the hazard quotient (HQ) calculation, most species presented HQ > 1, especially when ingested by the child population. These results are fundamental for designing consumption strategies for these animals, in order to prioritize the acquisition of some species over others, depending on the location and/or season, for each age group, with the aim of maintaining seafood consumption with minimal risk to the population's health.

Quantitative benefit and risk assessment of arsenic and nutrient levels in tilapia products sold on Chinese e-commerce platforms

E-commerce platforms have become a significant sales channel for processed tilapia products such as frozen tilapia fillets, pickled tilapia, and canned tilapia in China. As food safety issues are worldwide concerned, the imbalance between the nutritional benefits of fish and the risk of contamination has become a major constraint on fish consumption. Therefore, it is necessary to assess the safety of tilapia products sold on e-commerce platforms. We conducted a quantitative benefit-risk assessment of arsenic and nutrient levels for tilapia products sold on Chinese e-commerce platforms using the hazard quotient (HQ). A total of 147 tilapia products were collected from the central Chinese e-commerce platforms Tmall, Taobao, and Jingdong for arsenic determination. Arsenic concentrations in tilapia products ranged from 0.004 to 0.820 mg·kg-1. The inorganic arsenic content of tilapia products was lower than the national limit (0.1 mg·kg-1). One-way analysis of variance revealed that there was no significant difference in arsenic levels in tilapia products among different regions (p > 0.05), while there was a significant difference in product form, with canned tilapia containing significantly higher arsenic levels than frozen tilapia fillets and pickled tilapia fillets (p < 0.05). We conducted an aquaculture experiment to analyze the nutrient levels of tilapia. The mean value of EPA + DHA content of tilapia was 20.634 mg·100 g-1. The HQ values of tilapia products ranged from 0.004 to 0.736. In a word, the nutritional benefits of consuming tilapia products exceed the risk of arsenic exposure. These data can help demonstrate that tilapia products are low-risk, high-yield nutritious food and provide relevant safety recommendations for consumers purchasing processed tilapia products online.

Bioaccessibility data of potentially toxic elements in complementary foods for infants: A review

The introduction of complementary foods (CFs) is a critical step in an infant's transition to solid foods, providing essential nutrients beyond breast milk. However, CFs may contain potentially toxic elements (PTEs), such as arsenic and cadmium that pose health risks to infants. In this context, understanding the bioaccessibility of PTEs is vital as it determines the fraction of a contaminant released from the food matrix and available for absorption in the gastrointestinal tract. Efforts have been made to standardize the assessment methodology for bioaccessibility, ensuring consistent and reliable data. Moreover, regulatory agencies have established guidelines for PTEs levels in food. However, important gaps still exist, which motivates many research opportunities on this topic.

Mercury bioaccessiblity in freshwater fish species from northern Canada

Indigenous communities in northern Canada rely on locally harvested traditional foods, including fish, which provides them with nutritional, cultural, and social benefits. However, mercury exposure from fish consumption can pose a health risk for populations that consume large amounts of fish with elevated mercury concentrations. The bioaccessiblity of mercury in the tissue of northern Canadian freshwater fish is not yet known. To address this, samples from five commonly consumed freshwater fish species (Lake Trout, Northern Pike, Walleye, Lake Whitefish, and Burbot) caught from lakes in the Northwest Territories and Yukon, Canada were examined. Total mercury concentrations, fatty acid composition, and total mercury bioaccessibility differed significantly among fish species and lakes. Mean total mercury bioaccessibility using an in vitro gastrointestinal model ranged between 56 % and 96 % in muscle tissue across fish species and waterbodies examined and was 39 % in liver tissue from Burbot. Mean total mercury bioaccessibility was much lower (range: 38 % to 42 %) for a subset of samples run through only the gastric phase of the digestion model. Total mercury bioaccessibility was significantly lower (on average 40 % lower) in a subset of samples that were pan-fried in water. Thus, although cooking increased total mercury concentrations in pan-fried fish samples (likely due to moisture loss), bioaccessible concentrations of total mercury were lower (on average 32 % lower). Results from this study contribute to addressing a large knowledge gap in the literature regarding bioaccessibility of total mercury in northern freshwater fish species. To the best of our knowledge, this is the first study to examine mercury bioaccessibility in raw and cooked liver samples from freshwater fish. It also adds to the growing literature indicating that mercury bioaccessibility varies among fish species, locations, and cooking/preparation methods.

Transformation of arsenic species from seafood consumption during in vitro digestion

Arsenic (As) species analysis is important for the risk evaluation of seafood. Until now, there has been limited information on the change of As species during digestion. Here, the As species in different types of seafood before and after in vitro digestion were investigated. Although inorganic As was not detected in digested fish samples, As(V) contents in digested crabs and scallops were 17.12 ± 1.76 and 138.69 ± 7.53, respectively, which were approximately 2-3 times greater than those of the pre-digestion samples. In further experiments, arsenocholine, dimethylarsinate, arsenobetaine, and monomethylarsonate were all convertible to As(V) during in vitro digestions with different rates. The transformation demonstrates a complex process and could be affected by many factors, such as pH, time, and digestion juice composition, of which pH seemed to be particularly important. Free radicals were responsible for the oxidation in the transformation reactions. Unlike arsenobetaine, arsenocholine seemed to be able to directly transform to monomethylarsonate without the intermediate dimethylarsinate. This study reveals and validates the potential of other species (oAs or/and unknown species) to convert to iAs, identifies the main factors affecting this process, and proposes a reaction pathway. There is an important implication for promoting a more accurate risk assessment of arsenic in foodstuffs.

Mercury contamination in seafood from an aquatic environment impacted by anthropic activity: seasonality and human health risk

Petroleum activity and the dumping of domestic and industrial sewage are important sources of mercury (Hg) contamination in the aquatic environment. Thus, this article aimed to biomonitor the Hg concentration in fish, mussels, and swimming crabs of commercial importance in southeastern Brazil. The quantifications were carried out over a year to verify the influence of seasonality. Finally, a risk assessment was applied to identify whether the concentrations found could lead to long-term damage to the population. Our results indicate that the contaminations were higher in spring, summer, and winter than in autumn, mainly among fish and swimming crabs. The results of quantification in the animal and estimated monthly intake, despite being below the limit established nationally and internationally, were indicative of risk for these two animals after calculating the Hazard quotient. The highest risk values were attributed to the infant population. Based on the data generated by this work, the consumption of mussels is encouraged throughout the year, to the detriment of the other types of seafood studied, especially during summer, spring, and winter. Our work reinforces the importance of risk assessment for a more reliable understanding of the impact of contaminants in seafood on the population's health.

Effects of Culinary Procedures on Concentrations and Bioaccessibility of Cu, Zn, and As in Different Food Ingredients

Although cooked diets are the primary sources for humans to absorb trace elements, there is limited data available on the concentrations and bioaccessibility of trace elements in cooked food ingredients. This work aims to evaluate the effects of culinary procedures on the concentrations and bioaccessibility of trace elements in common food ingredients. Twelve food species from the local market were treated with four culinary procedures (boiling, steaming, baking, and frying), then the bioaccessibility of copper (Cu), zinc (Zn), and arsenic (As) were evaluated using the in vitro digestion method. The subcellular distribution of these elements was also determined using the sequential fractionation method. The results show that culinary procedures decreased the retention rate of As during cooking (100% for raw and 65-89% for cooked ingredients) and the bioaccessibility of Cu and Zn during digestion (nearly 75% for raw and 49-65% for cooked ingredients), resulting in a reduction of the total bioaccessible fraction (TBF) of Cu, Zn, and As in food ingredients. The TBF of Cu, Zn, and As in all tested food ingredients followed the order: raw (76-80%) > steaming and baking (50-62%) > boiling and frying (41-50%). The effects of culinary procedures were associated with the subcellular distribution of trace elements. As was dominantly distributed in heat-stable proteins (51-71%), which were more likely to be lost during cooking. In comparison, Cu and Zn were mainly bound to the insoluble fraction and heat-denatured proteins (60-89% and 61-94% for Cu and Zn, respectively), which become less digestible in cooked ingredients. In conclusion, these results suggest that culinary procedures reduce the absorption of Cu, Zn, and As in various food ingredients, which should be considered in the coming studies related to nutrition and risk assessment of trace elements.

In Vitro Bioaccessibility and Health Risk Assessment of Arsenic and Zinc Contaminated Soil Stabilized by Ferrous Sulfate: Effect of Different Dietary Components

Iron-based materials have good stability in reducing the mobility and toxicity of heavy metals, but the behavior and human health risks of heavy metals could be affected by dietary components. This study investigated the effect of typical diets (lettuce, cooked rice and apples) on the bioaccessibility and morphological changes of arsenic (As) and zinc (Zn) in contaminated site after stabilization by ferrous sulfate (FeSO4). The results showed that the bioaccessibility of As and Zn were increased in a co-digestion system of food. The augmented effect on As bioaccessibility mainly occurred in the gastric phase: apple > lettuce > cooked rice (p < 0.05), while the augmented effect on Zn bioaccessibility mainly occurred in the intestinal phase: lettuce > apple > cooked rice (p < 0.05). FeSO4 weakened the dissolution effect of dietary components on As bioaccessibility, and reduced As bioaccessibility in the gastric and intestinal phases by 34.0% and 37.9% (p < 0.05), respectively. Dietary components and Fe fractions influenced the speciation and distribution of As and Zn. FeSO4 reduced the hazard quotient (HQ) and carcinogenic risk (CR) values of the contaminated soil by 33.97% and 33.59%, respectively. This study provides a reference for a better understanding of more realistic strategies to modulate exposure risks of heavy metal-contaminated sites.

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.

Assessing the factors impacting the bioaccessibility of mercury (Hg) in rice consumption by an in-vitro method

Mercury (Hg) in rice is drawing mounting concern since methylmercury (MeHg) was found capable of accumulating in rice. In-vitro bioaccessibility is a feasible and reliable method to assess the health effects of Hg in rice and has been utilized in a number of studies. This study was done to investigate the impact of cultivar, planting location, and cooking on the total mercury (THg) and MeHg bioaccessibility of rice, for which multiple statistical analysis methods were used to analyze the significance of their effects. The THg concentrations of rice samples taken from non-Hg contaminated areas of China were all below 15 ng/g and their MeHg concentrations were below 2 ng/g. Cooking could significantly reduce the MeHg bioaccessibility of rice because the MeHg was mainly combined with protein and the protein will be denatured during the cooking process, and then the denatured MeHg is difficult to be dissolved into the liquid phase. Indica- and japonica-type rice cultivars did not show significant differentiation in either the concentration of Hg or its bioaccessibility. However, the glutinous rice type differed significantly from the above rice types, and it showed greater bioaccessibility of THg and MeHg due to its distinct protein contents and starch properties. Planting location can affect the Hg concentration in rice and THg bioaccessibility but has a limited impact on MeHg bioaccessibility. Based on these results, two macro factors (rice cultivar, planting location) are presumed to impact Hg bioaccessibility by how they affect micro factors (i.e., Hg forms).

Bioaccumulation of total mercury, copper, cadmium, silver, and selenium in green turtles (Chelonia mydas) stranded along the Potiguar Basin, northeastern Brazil

Sea turtles face several threats and pollution has become a major concern for their conservation worldwide. We analyzed samples of the liver, muscles, and kidneys of 38 Chelonia mydas stranded along the Potiguar Basin, northeastern Brazil, between 2015 and 2018 to determine the total Hg concentration (THg), as well as the concentrations of Cu, Cd, Ag, and Se. The relation between turtle size and element concentrations revealed a negative correlation for THg and Se (liver, muscles, and kidneys), Cu and Cd (liver and kidneys) and a positive correlation for Ag in the three organs analyzed. Concentrations of THg, Cu, Ag, and Se were high in the liver, highlighting the Cu concentration (median = 25.1150 μg g^-1 w.w.), while the kidneys had the highest Cd levels (median = 12.2200 μg g^-1 w.w.). There was significant difference between element concentrations and the three organs analyzed, except for Ag and Se concentrations in the muscle and kidney samples. Our study showed that green turtles found in Potiguar Basin, northeastern Brasil, have bioaccumulated inorganic elements which indicate the need of further investigations on the environmental quality of the region.

Mercury bioaccessibility in fish and seafood: Effect of method, cooking and trophic level on consumption risk assessment

The bioaccessible Hg fraction in fish and seafood commonly present in the Mediterranean diet was assessed through three distinct in vitro extraction schemes. Each extraction method provided different results, highlighting the lack of a universal methodology to estimate mercury (Hg) bioaccessibility in those matrices. Bioaccessible Hg fractions ranged from 10 to nearly 90% of total mercury (T-Hg) and increased in predator species (Swordfish - Xiphias gladius, Blue Shark - Prionace glauca and Tuna - Thunnus sp.). Among the three extractions tested, the Unified Bioaccessibility Method (UBM) provided the highest estimation of Hg bioaccessibility for consumers. The tested cooking procedures (frying, grilling and steaming) considerably reduced the bioaccessible fraction. Results indicate that bioaccessible Hg found in ingested fish and seafood is far below the levels set by the current safety risk assessment legislation. These findings highlight the importance of integrating bioaccessibility measurements in food safety legislation.

Balancing the health effect between risks of methylmercury and benefits of nutrients in consumption of Chinese mitten crab (Eriocheir sinensis) in China

Aquatic products contain both beneficial substances such as polyunsaturated fatty acids and harmful compounds such as methylmercury, and their combined health effects should be assessed at a common end point for a rational analysis. We used a risk-benefit model to assess net IQ point gain from consumption of Chinese mitten crabs (Eriocheir sinensis) from Jiangsu Province. Levels of methylmercury in the edible parts of the crabs ranged from 0.79 to 69.47 μg/kg (mean: 26.88 ± 15.09 μg/kg). Levels of methylmercury did not differ by sampling location. In aquaculture experiments, we simulated artificial pond farming using either iced trash fish or formulated feed. Crabs fed iced trash fish contained 28.72 ± 2.30 mg/g of eicosapentaenoic acid and docosahexaenoic acid and crabs fed formulated feed contained 19.64 ± 3.62 mg/g of eicosapentaenoic acid and docosahexaenoic acid. Model calculations estimated a gain of 7.52 IQ points from consumption of crabs fed formulated feed and 11.00 IQ points from consumption of crabs fed iced trash fish. They are all above the maximum theoretical IQ point gain value. Chinese mitten crab is a kind of high-quality food which is beneficial to the neural development of infants. Our findings may assist in improving crab farming methods and consumption patterns, accelerating the sustainable development of the Chinese mitten crab industry.

Arsenic in soils contaminated by arsenic-containing chemical weapons in a site of Jilin, China: fraction and bioaccessibility

At the end of World War II, the Japanese abandoned arsenic (As)-containing chemical weapons (CWs) in China. During the long-term burial process, the As-containing agents leaked into the environment due to the corrosion of weapon shells. This study explored the surface distribution, fraction composition, and bioaccessibility of As in the soil contaminated by chemical weapons in a site of Jilin Province, China. Results showed that As was enriched in the soil of CWs buried and the maximum concentration of As in this area was 110 mg/kg (dry weight). In terms of fraction, As primarily accumulated in amorphous Fe/Al-oxides bound and residual fractions. Moreover, from the perspective of fractions with potential environmental risks, As accounted for 45.6-82.0% and 61.0-80.7% of the fractions extracted by Wenzel and Shiowatana sequential extraction procedure (SEP), respectively. Bioaccessibility can also be used to assess environmental risks. The mean values of As bioaccessibility were as follows: gastric phase (15.0%) > colon phase (14.8%) > small intestinal phase (13.3%), and the As bioaccessibility was closely related to the Fe/Al oxide bound fraction. Compared with the surrounding farmland, the potential environmental risk of soil pollution was more significant in the CW burial areas. This study provided support for remediation of As-containing agent-contaminated soil in China.

Bioaccessibility of Polycyclic Aromatic Hydrocarbons (PAHs) in Grilled Meat: The Effects of Meat Doneness and Fat Content

Exposure to polycyclic aromatic hydrocarbons (PAHs) through diet is gaining concern due to the risk it poses to human health. This study evaluated the bioaccessibility of PAHs contained in charcoal-grilled beef and chicken in different segments of the gastrointestinal tract (GIT) with regard to the degree of doneness and fat content of the meats. The levels of 15 PAHs in the grilled meat samples and bioaccessible fractions were determined using high-performance liquid chromatography (HPLC) equipped with PAH column, and UV and fluorescence detectors. Total PAHs were found in beef (30.73 ng/g) and chicken (70.93 ng/g) before its digestion, and different PAHs’ bioaccessibility were observed in the different segments of GIT, with the highest in the stomach followed by the small intestine, despite the relatively higher bioaccessibility of individual PAHs in grilled beef as compared to those in grilled chicken. Additionally, the PAHs’ bioaccessibility increased with the increase in the degree of doneness. Positive linear correlation was observed for the PAHs’ bioaccessibility and the fat contents of grilled meat. Overall, this study highlights the influence of meat doneness (cooking time) and fat contents on the bioaccessibility and bioaccumulation of PAHs.

Bioaccessibility and bioavailability adjusted dietary exposure of cadmium for local residents from a high-level environmental cadmium region

The critical health risks caused by cadmium (Cd) via dietary exposure are commonly assessed by detecting Cd concentrations in foods. Differently, in this study, the bioaccessibility and bioavailability of Cd in major local harvests were introduced to assess the dietary exposure of local residents from a high-level environmental Cd region. The results indicated that certain Cd was released into the digestive juice after in vitro digestion with a bioaccessibility of 20-63% for rice and 3-32% for leafy vegetables, and the released portion was partially absorbed by Caco-2 cells with a bioavailability of 2-21% for rice and 0.2-13% for leafy vegetables. The results obtained from the toxicokinetic model revealed that the predicted urinary Cd values from the estimated daily intake (EDI) of Cd, which accounted for bioaccessibility and bioavailability, were consistent with the actual measured values, and the EDIs were considerably lower than the acceptable daily intake. This suggests that the bioaccessibility and bioavailability adjusted dietary Cd exposure should be more precise. The key issues addressed in our study implores that a potential health risk cannot be neglected in people with high consumption of rice from high-level zone.

Effects of Speciation, Cooking and Changes in Bioaccessibility on Methylmercury Exposure Assessment for Contrasting Diets of Fish and Marine Mammals

Uptake of the neurotoxicant monomethylmercury (MeHg) from fish and marine mammals continues to present a public health concern in Canada and elsewhere. However, fish and marine mammals are key diet items contributing to food security for some Indigenous populations in Canada. Mercury (Hg) exposure is estimated assuming that 100% of Hg is methylated, that 100% will be absorbed by the consumer and that cooking does not affect MeHg concentrations. Some of these assumptions do not correspond to our current state of knowledge. The aim of this study was to assess the impact of additional variables on Hg exposure equation using probabilistic risk analysis. New variables tested were (1) the proportion of methylated Hg compared to total Hg (pMeHg, %), (2) the relative absorption factor (RAF, %) expressed as bioaccessibility and (3) the mass loss factor (MLF, unitless) that represents the loss of moisture during cooking, known to increase MeHg concentration in fish and mammals. For the new variables, data from literature were used in order to set point estimate values that were further used in the probabilistic risk analysis. Modelling results for both fish and marine mammals indicate that adding these new variables significantly influenced estimates of MeHg exposure (Mood's median test, p < 0.05). This study highlights that the evaluation of exposure to MeHg is sensitive to pMeHg, RAF and MLF, and the inclusion of these variables in risk assessment should be considered with care. Further research is needed to provide better food-dependent, population-specific estimates of RAF and MLF before formal inclusion in exposure estimates.

Foliar application of zinc and selenium alleviates cadmium and lead toxicity of water spinach - Bioavailability/cytotoxicity study with human cell lines

The present study investigated the effects of foliar application of zinc (Zn) and selenium (Se) on bioavailability of Zn and Se and toxicity of cadmium (Cd) and lead (Pb) to different water spinach ecotypes (LA and HA) grown in slightly (XZ) or moderately (LJY) contaminated fields via in vitro digestion combined with Caco-2/HL-7702 cell model. The obtained results revealed that foliar application of Zn and Se promoted yield, increased total, bioaccessible and bioavailable fractions of Zn and Se in plants, indicating that foliar application is a feasible way of biofortification. Although there was no significant effect on liver cell proliferation (MTT), membrane stability (LDH) and hepatocyte enzyme (ALT and AST) activities, the obvious ecotype and soil dependent fluctuations of lipid peroxidation (MDA) and antioxidant enzyme (SOD, POD and CAT) activities in serum highly suggest that the low accumulator and clean field should be used in agricultural production rather than the high accumulator and contaminated farmland. Moreover, foliar application of Zn and Se improved nutritional quality of all water spinach genotypes in both fields, including increased Fe, vitamin C, cellulose and chlorophyll, maintained concentrations of potassium (K), manganese (Mn), copper (Cu), protein, and nitrate. These results demonstrate that this agricultural management practice may prove to be an effective approach for minimizing health risk and alleviating "hidden hunger" in the developing countries.

Comparison of bioaccessibility and relative bioavailability of arsenic in rice bran: The in vitro with PBET/SHIME and in vivo with mice model

Rice bran, a super food or health food supplement, contains high arsenic (As) levels. However, the evaluation of relative bioavailability (RBA) or bioaccessibility (BA) is limited in the rice bran. In this study, the As-RBA in rice bran was determined based on mice model and compared to As-BA using in vitro methods. The As-BA from rice bran-amended feed in the gastric, small intestinal, and colon phases were 33.1-56.4%, 50.5-75.6%, and 35.5-71.4%, respectively. The As-BA was adversely associated with bioaccessible Ca and Fe concentrations in the gastrointestinal phases. Similarly, the As-RBA was significant negative relative with Ca, Fe, and Zn concentrations. The As-RBA values were 37.9-65.5%, 41.5-75.6% and 38.7-71.5% based on liver, kidneys, and combined endpoint (liver plus kidneys), respectively. The in vitro-in vivo correlations (IVIVCs) in the gastric (R² = 0.392) and colon (R² = 0.362) phases were weak. While the IVIVC (R² = 0.544) in the small intestinal phase was stronger than those of the gastric and colon phases. In addition, there was no significant difference in As speciation between colonic residual solids and faeces (p > 0.05). This work provides a better view of human health risk evaluation on rice bran As consumption in humans.

Risks of consuming cadmium-contaminated shellfish under seawater acidification scenario: Estimates of PBPK and benchmark dose

We aim to assess the risks of renal dysfunction and osteoporosis that is attributed to the seawater acidification caused cadmium (Cd) level increase in human consumed shellfish. A physiology-based pharmacokinetic model was used to estimate Cd concentrations in urine and blood among shellfish-only consumers and among the general population. We used the benchmark dose (BMD) method to determine the threshold limits of Cd in urine for renal dysfunction and in blood for osteoporosis for assessing the human health risk. Our results revealed that seawater acidification could increase the Cd accumulation in shellfish by 10-13% compared to the situations under current pH levels. Under the lower seawater pH level, the daily intake of Cd could increase by 21%-67% among shellfish-only consumers, and by 13%-17% among the general population. Our findings indicated that seawater acidification would lead to a marginal increase in Cd intake among humans in shellfish-only consumers. The results of BMDs of urinary Cd showed that the threshold limits for renal dysfunction at 5% were 3.00 μg g^-1 in males and 12.35 μg g^-1 in females. For osteoporosis, the estimated BMDs of blood Cd were 7.95 μg L^-1 in males and 1.23 μg L^-1 in females. These results of the risk of Cd intake showed that the consumption of Cd-contaminated shellfish in the general population is largely unaffected by changes in seawater pH levels. Notably, the potential impact of seawater acidification on renal dysfunction for males in shellfish-only consumers face a 14% increase of risk.

Green tea infusion reduces mercury bioaccessibility and dietary exposure from raw and cooked fish

Human exposure to mercury (Hg) and methylmercury (MeHg) through the ingestion of seafood raises human health-related concerns. In contrast, green tea has health benefits and its consumption potentially reduces bioaccessibility of dietary Hg. The present study aimed to assess the effect of green tea in total mercury (THg) and MeHg bioaccessibility in raw and cooked marine fish species commonly having high Hg levels. Preliminary results demonstrated that significantly higher reductions of bioaccessible THg were attained after the co-ingestion of green tea infusion (1 cup or more) in the oral and intestinal phases. Overall, the present findings clearly show that the co-ingestion of green tea along with seafood grilling strongly reduces THg and MeHg bioaccessibility in all fish species and consequently diminishes the probability of exceeding MeHg provisional tolerable weekly intakes through the consumption of these species with high Hg levels. Such results point out the need to better understand the beneficial/preventive role of green tea infusions and other food processing techniques in bioaccessibility reduction of other chemical contaminants present in food products. Such information is certainly useful to help consumers to wisely select their food, and to enable food safety authorities to integrate such information in risk assessment.

Study of Cd Content Distribution and Its Bioaccessibility in Edible Tissues of Crab Portunus trituberculatus from the Coastal Area of Shandong, China

Bioaccessibility study is of great significance to the health risk assessment of trace elements in the seafood. In this work, the most consumed crab (Portunus trituberculatus) in coastal area of Shandong, China was analyzed to study the distribution and the bioaccessibility of cadmium (Cd) in the edible tissues of crab, and the dietary risk from consumption of crab was also evaluated. Results showed that the content of Cd in the whole edible tissues of 109 crab specimens ranged from 0.052 to 8.89 mg/kg ww (wet weight) with mean of 2.26 mg/kg ww. The Cd content in 85% of the crab samples was higher than the national food safety limits (0.5 mg/kg ww) of China. The gender study indicated that there was no significant difference in Cd content in total edible tissues between the males and females (p > 0.05). Cadmium was highly concentrated in the brown meat with mean value of 4.13 mg/kg ww, which was about 5 times higher than that in the white meat (0.75 mg/kg ww). The bioaccessibility of Cd ranged from 48.1 to 71.0% in the white and brown meat. The risk assessment based on the bioaccessibility of Cd revealed that the consumption of the edible crab brown and white meat for adults should be limited in 0.13 kg and 1.56 kg per week respectively.

In-vitro bioaccessibility and bioavailability of heavy metals in mineral clay complex used in natural health products

Commercial mineral clays that claim to have healing properties are also known to contain trace amounts of heavy metals, albeit the risk of consuming many of them is not entirely known. The primary objective of this study was to evaluate the in vitro bioaccessibility and bioavailability of Arsenic (As), Cadmium (Cd) and Lead (Pb) in mineral clay samples collected from the Sierra Mountains (USA) using the Unified Bioaccessibility Research Group of Europe (UBM) method and the Caco-2 permeability assay, respectively. After UMB-gastric (UBM-G) digestion, As and Pb bioaccessibility were lower compared to Cd and decreased further in the UMB-gastrointestinal (UBM-GI) assay. Bioavailability estimates using the Caco-2 cell showed very low to non-detectable permeability for all 3 heavy metals. Thus, while initial heavy metal ranged from 3.8–17 ppm, 0.024–0.061ppm, and 5.8–20 ppm for As, Cd, and Pb, respectively, the bioavailability for these metals was reduced to very low levels that followed: non-detectable values of As, <0.007ppm of Cd, and <0.1ppm of Pb. Using UBM-digestion to mimic bioaccessibility, followed by Caco-2 cell bioavailability enabled us to conclude that in vitro assessment of heavy metal exposure associated with mineral clay-based natural health products does not pose a potential hazard to consumers.

Elemental content of brown crab (Cancer pagurus) - Is it safe for human consumption? A recent case study from Mausund, Norway

The brown crab (Cancer pagurus; the edible crab) is consumed worldwide and greatly appreciated for the essential elements (e.g., Zn, Se) that it contains. However, alongside these, it contains toxic elements that can pose serious risks for human health. For the brown meat parts of the brown crab, which contain considerable Cd concentrations, official legal limits of exposure are still lacking by regulatory bodies, rendering its consumption a potential food safety threat. In this study, a survey was conducted during 2016-2018 in a major Mid-Norway commercial crab fishing area of Mausund in Frøya municipality, Norway, where brown crab media samples were collected to assess the occurrence and profile of select elements, including toxic elements (Cd, Pb, Hg, Sr, As). A yearly median concentration ranging from 6.75 (2016) to 14.0 (2017) mg Cd/kg dry weight (est.: 2.11 (2016) to 4.37 (2017) mg Cd/kg wet weight) indicated high Cd concentrations, which were alarming when compared to the maximum allowed concentration of 0.5 mg/kg wet weight set by the E.U. for raw white crab meat. Human exposures were assessed by estimating intakes of elements per 100 g serving portion of dry edible media (white/brown meat), and the tolerable upper intake levels (ULs) (as specified by the United States National Academy of Sciences) were exceeded for Fe, Cu, Ni, Se, Ca, Mg and P. The median Se and Cd estimated human dietary intakes (EDIs) (from brown crab) were 8.21-8.59 and 9.64-20.0 μg/kg body weight, respectively. The human intake dose (ID) of Cd (from brown crab) reached the order of a few tens of milligrams (mg). In addition, 33% of brown crab samples were found to be suitable for human consumption when the Se:Cd concentration ratio was applied and a stoichiometric excess of Se over Cd was indicated.

Comparative study of raw and cooked farmed sea bass (Lates calcarifer) in relation to metal content and its estimated human health risk

Metallic contamination in seafood, especially fish, has been of increasing concern to human health. Moreover, with increasing dependency on farmed fish for fish resources, the metallic contamination in them is still questionable. This study aimed to investigate the effects of cooking (steaming) on heavy metal concentration in farmed fish and to estimate its potential human health risk. Farmed sea basses (Lates calcarifer) from Setiu Lagoon were used to study the difference in metal uptake through human consumption of raw and cooked (steamed) fish samples. Selected heavy metals, namely copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb), were measured using ICP-MS following Teflon bomb closed digestion of the fish samples. Cooking of the fish muscle by steaming was applied to investigate if cooking changes the concentration of heavy metals. Mercury and As were found accumulated more notably in the fish muscle, though only Hg was found to show significant (p > 0.05) increase when L. calcarifer is cooked. The amount of As in the fish muscle throughout its growth can be potentially harmful to humans, with the highest averaged concentration at 3.29 ± 0.65 mg/kg dw. above the standard set by the Malaysian Food Regulation (1985) of >1 mg/kg. All the other heavy metals were at relatively safe concentrations well below the standard set by both national and international guidelines. The PTWI per individual of L. calcarifer for As was at 0.84 mg/kg bw., which indicated that the amount of this fish safe for consumption without any adverse effect is 170 g/week. Therefore, long-term intake of these fish may pose a risk to human health due to the relatively higher Hg and As concentration found in these fishes.

Maize cultivars relieve health risks of Cd-Polluted Soils: In vitro Cd bioaccessibility and bioavailability

Dietary grain ingestion is the primary route of human exposure to the adverse effects of Cd; therefore, an understanding of the transfer characteristics of Cd in a system involving soil, grain, and humans is crucial for health risk alleviation and pollution control. In this study, Cd bioaccessibility and bioavailability for humans from grains of sweet maize (Zea mays convar. saccharata var. rugosa) cultivars grown on a contaminated field (1.05 mg Cd kg^-1 soil) were assessed by combining a simulated in vitro digestion method with a Caco-2 cell model. Results showed that cultivars differed significantly in grain Cd concentration, bioaccessibility, and bioavailability with the corresponding values of 0.07 to 0.20 mg kg^-1 DW (dry weight), 4.10 to 6.20%, and 0.01 to 0.04 µg g^-1grain, respectively. The estimated daily intake of Cd through sweet maize grain was within the range of 0.04 and 0.25 μg kg^-1 body weight, which is lower than the tolerable limit recommended by the Joint FAO/WHO Expert Committee on Food Additives (JEFCA). Conclusively, results from the present study indicate that most grain Cd remains non-bioaccessible and thus might not present adverse health effects in humans. Therefore, sweet maize cultivars could be used to produce healthy food crops in low-to-moderately Cd-contaminated soil.

Health risk assessment of fluorine in fertilizers from a fluorine contaminated region based on the oral bioaccessibility determined by Biomimetic Whole Digestion-Plasma in-vitro Method (BWDPM)

Due to potential adverse effects of excessive fluorine (F), interests regarding considerable accumulation of F in agricultural soils from application of fertilizers are increasing continually. However, less detailed information of hazard and risk of F in fertilizers to human directly by hand-to-mouth pathway can be obtained. Herein, the bioaccessibility of F (F_bio) in fertilizers is determined by Biomimetic Whole Digestion-Plasma in-vitro Method (BWDPM), which is developed to detect the behaviour of bioaccessible F in both the whole digestive system and plasma for the first time. Observations of higher F_bio in small intestinal phases (4.35-56.33%), large intestine (1.01-40.52%) and plasma (8.07-66.70%) yielded them as the major phases which are faced with higher exposure risk of F. Compared with phosphate fertilizer, more bioaccessible F was observed in compound fertilizer. Some studied factors, such as sweat and food, yield insignificant influences on F_bio, whereas can affect the exposure estimations of F considerably. Exposure risks based on F_bio of fertilizers should be highly concerned, especially the occupational exposure to local farmers. In a word, more explicit and realistic information of the potential risk of F on human health could be obtained by the introduction of F_bio.

Striped dolphins as trace element biomonitoring tools in oceanic waters: Accounting for health-related variables

In Europe, monitoring contaminant concentrations and their effects in the marine environment is required under the Marine Strategy Framework Directive (MSFD, 2008/56/EC). The striped dolphin (Stenella coeruleoalba) is the most abundant small cetacean species in Portuguese oceanic waters, representing a potential biomonitoring tool of contaminant levels in offshore waters. Concentrations of nine trace elements were evaluated by ICP-MS in kidney, liver and muscle samples of 31 striped dolphins stranded in the Portuguese continental coast. The mean renal Cd concentration was high (19.3 μg.g^-1 wet weight, range 0.1-69.3 μg.g^-1 wet weight) comparing to striped dolphins from other locations. Therefore, the present study reports a possibly concerning level of Cd in the oceanic food chain in Portuguese offshore areas. This study also aimed at evaluating potential relationships between trace element concentrations and striped dolphins' biological and health-related variables. Individual length was related with some of the trace element concentrations detected in striped dolphins. Indeed, Cd, Hg and Se bioaccumulated in larger animals, whereas the reverse was observed for Mn and Zn. Striped dolphins with high parasite burdens showed higher levels of Hg, while animals showing gross pathologies presented higher concentrations of Cd and Se. This study reported relationships between trace element concentrations and health-related variables for the first time in striped dolphins and it also provided information on the relative contamination status of Portuguese oceanic waters in comparison to other regions in the world.

Selenium and cadmium in bioaccessible fraction of organic weaning food: Risk assessment and influence of dietary components

BACKGROUND

The tendency of some sectors of the population to consume organic food has also come to include baby food. Nevertheless, it is necessary to develop studies to support the true nutritional and toxicological value of these products, making special emphasis in several trace elements. To our knowledge, no studies have been conducted on this type of organic food.

METHODS

Weaning foods with different formulations categorized as organic were analyzed to determine Se and Cd contents as well as its bioaccesibility. The analyses were conducted by electro thermal atomic absorption spectroscopy (ET - AAS) after the treatment of the samples with acid mineralization. Besides, macronutrient analyses (protein, fat and dietary fiber) were also developed. Finally, a novelty statistic approach such as @Risk was used to evaluate contributions to DRI or PTWI of Se and Cd derived for consumption of these weaning foods.

RESULTS

Se content ranged between 2.44-15.4 μg Kg ¹. Samples with meat ingredients showed the highest Se contents, while weaning foods consisting of fruits or vegetables presented the lowest concentrations. Se bioccessible concentration ranged between 1.90-4.35 μg Kg^-1 with a greater uniformity amongst analyzed samples. Regarding Cd, concentrations of this heavy metal ranged between 1.23 and 3.64 μg Kg^-1. Furthermore, Cd bioaccessibility of organic weaning foods ranged between 0.17 and 1.38 μg Kg^-1. The solubility of all samples studied was around 20% from the initial Cd concentration. A negative statistical correlation between fat content - Cd bioaccesible (p < 0.05; r = - 0.756) and Cd content - Se bioaccesible (p < 0.05; r = - 0.777) were also found.

CONCLUSIONS

Cd concentrations are considerably lower than those reported in weaning formulas which were not categorized as organic. On the other hand, the analysed organic jars did not represent a significant source of Se. The probabilistic assessment developed, showed that contributions to DRI of Se for infants 1-3 years old by consumption of these weaning foods, are excessively low (15% at best).

Does the addition of ingredients affect mercury and cadmium bioaccessibility in seafood-based meals?

Despite the bioaccessibility of nutrients and contaminants present in individual seafood products has been thoroughly studied, information is extremely limited in what concerns complete seafood-based meals, where interactions between ingredients may occur. Hence, this study aimed to evaluate the effect of different ingredients and cooking processes in mercury (Hg) and cadmium (Cd) bioaccessibility in complete meals of tuna (Thunnus spp.) and edible crab (Cancer pagurus), respectively. The addition of ingredients/side dishes decreased Hg levels in cooked tuna meals, but increased Hg bioaccessibility (up to 31% of bioaccessible Hg in complete meals, against 13.5% in stewed tuna alone). Cd levels in edible crab meals were significantly decreased by the addition of ingredients (~36% and ~65% decrease in boiled crab and paté, respectively), but its' bioaccessibility was not significantly affected (>94% in all cases). Results showed that the weekly consumption of 2 complete tuna meals does not exceed MeHg tolerable weekly intake (TWI), whereas Cd's TWI is largely surpassed with the consumption of 50 g/week of edible crab meals. This highlights the importance of determining contaminant levels and bioaccessibility in a whole seafood-based meal context, as such approach enables a more realistic assessment of the risks that seafood can pose to consumers.

Change in mercury speciation in seafood after cooking and gastrointestinal digestion

Mercury (Hg) is readily bioaccumulated in seafood, a common ingredient in indigenous cuisines throughout the world. This study investigates Hg speciation in cooked seafood after gastric and intestinal digestion. The results showed that the removal of Hg by washing was negligible. Additionally, the results of our calculations regarding the mass balance of Hg concentration indicated that cooking reduced Hg mainly by means of volatilization and that Hg²⁺ was more readily reduced than MeHg. Moreover, cooking lowered the bioaccessibility of Hg in seafood: the reduced percent of bioaccessible Hg²⁺ after cooking ranged from 2 to 35% (on average, 16%). The corresponding numbers were slightly lower compared with those for MeHg (on average, 19%). Furthermore, there might be a chemical transformation of Hg during in vitro gastrointestinal digestion. The results of in vivo tests in laboratory mice suggested that methylation of Hg mainly took place in the gastric tract, whereas demethylation of Hg occurred primarily during intestinal digestion. These findings indicate that the bioaccessibility of Hg²⁺ and MeHg was not only related to their initial concentrations in the food samples, but also that further studies on the mechanisms of Hg demethylation and methylation during gastrointestinal digestion are essential for more realistic risk assessments.

In Vitro and In Vivo Testing to Determine Cd Bioaccessibility and Bioavailability in Contaminated Rice in Relation to Mouse Chow

A combination of an in vitro physiologically based extraction test (PBET) and an in vivo mouse model was used to determine Cd oral bioaccessibility and estimate bioavailability in Cd-contaminated rice. The PBET found lower Cd bioaccessibility in the intestinal stage (40–50%) than in the gastric stage (93–98%) for both rice and mouse chow. No significant difference was found in Cd bioaccessibility between contaminated rice and Cd-amended mouse chow in the gastric or gastrointestinal phase (except for rice 1). The result of the in vivo bioassay revealed that Cd absorption in the kidney or liver of mice fed with contaminated rice were significantly higher than in the mouse chow group containing an equal Cd concentration. Correlation analysis between concentrations of different elements in mouse chow or rice and Cd concentrations in mice kidney or liver showed that Fe, Ca, Cu, and Zn had significant negative correlation (r² > 0.7, p < 0.01). These results suggest that nutritional elements in the diet could affect Cd absorption and distribution in organs and that different food matrices may result in unequal Cd health risks at an equal Cd concentration due to the specific mineral content of food.

Systematic review of arsenic in fresh seafood from the Mediterranean Sea and European Atlantic coasts: A health risk assessment

Arsenic in the environment pose major threats to human health, and especially the inorganic form can result in adverse health effects. This review analyse papers from 2004 to 2017 on As in fresh fish and molluscs caught in the Mediterranean sea and the European coast of the Atlantic ocean allowing the identification of the marine area with a greater As bioavailability and in particular the identification of the European populations more exposed to In-As by consuming fresh seafood. Results were separated on the base of the fishing site and the concentrations were reworked to assess the average daily intake to In-As as well as Target Hazard Quotient and Cancer Risk. Overall, the greater availability in Tot-As concentration in the pelagic compartment found in the Mediterranean Sea is not present along the European coasts of Atlantic Ocean. Furthermore, only in the Mediterranean Sea, results highlighted significant differences between Tot-As concentrations in seafood subgroups. In both areas, In-As concentrations showed the following trend: molluscs > pelagic > demersal with significant differences between subgroups. The European populations more exposed to In-As from fish and molluscs are the French, Spanish, Italian and Greek, with particular regards to children of 3-6 years old, which should minimize the consumption of molluscs to avoid carcinogenic and non-carcinogenic risks.

Effect of Cooking on Speciation and In Vitro Bioaccessibility of Hg and As from Rice, Using Ordinary and Pressure Cookers

Rice is the most widely consumed staple food for a large part of the world's human population, and owing to environmental pollution, it is a major source of human exposure to mercury (Hg) and arsenic (As). We evaluated the impact of cooking on the speciation and bioaccessibility of Hg and As from rice in this study. Results show that the dominant Hg and As species in rice from Guangzhou market in China were their inorganic forms (iHg and iAs), respectively. The cooking process modified the levels of Hg and As. Average Hg and As bioaccessibility in raw rice was 69.74 and 80.32%, respectively. Hg bioaccessibility decreased to 46.22 and 42.37% for pressure- and ordinary-cooked rice, respectively. In contrast, As bioaccessibility remained unchanged except after cooking with a large amount of water. Protein denaturation and the amount of soluble and volatile forms determine the bioaccessibility of Hg and As in cooked rice by being released into the cooking water or into the air. From the bioaccessibility data, the average established daily intake (EDI) values of Hg and As from pressure-cooked rice for children and adults were 0.034 and 0.025 μg kg^-1 day^-1 (Hg), and 0.735 and 0.559 μg kg^-1 day^-1 (As), respectively. This study provides novel insights into Hg and As exposure due to rice cooking.

Evaluation of the potential of ultrasound technology combined with mild temperatures to reduce cadmium content of edible crab (Cancer pagurus)

The consumption of crustaceans is correlated with certain health risks, particularly due to several highly toxic elements they contain, including cadmium (Cd). Although Cd content in one sole crab generally exceeds the total weekly recommended intake of cadmium as established by EFSA (especially in brown meat), efficient modern strategies to reduce Cd content in crabs still have not yet been developed. The objective of this research was therefore to evaluate the potential use of ultrasound technology in combination with temperature (50°-80 °C) with the purpose of releasing Cd from brown crab (Cancer pagurus), thereby reducing the Cd content in its meat. Female crabs were immersed in a water bath at 50, 65, and 80 °C in presence or absence of ultrasound; Cd concentration in the water was monitored along time. At the end of the process, Cd content in brown and white crab meat was likewise quantified. Treatment temperature did not bear an influence on the release of Cd in absence of ultrasound, but proved to be an important variable when ultrasound assisted the process. Ultrasound increased Cd release rates 8.7-, 2.1- and 2.7-fold in conjunction with the treatments at 50, 65 and 80 °C, respectively. The maximum percentage of Cd extracted (22.8%) was observed at 50 °C for an ultrasound input power of 200 W. These results have demonstrated for the first time that the application of ultrasound during the crab-cooking process could serve as an effective physical procedure for reducing the Cd content of crabs, thereby improving the product's safety for consumers.

Change of Arsenic Speciation in Shellfish after Cooking and Gastrointestinal Digestion

Shellfish is a common part of indigenous cuisines throughout the world and one of the major sources of human exposure to arsenic (As). We evaluated As speciation in shellfish after cooking and gastrointestinal digestion in this study. Results showed that washing and cooking (boiling and steaming) can reduce As exposures from shellfish. The use of spices during cooking processes also helped to reduce the bioaccessibility of total As. Through mass balance calculations, we verified the transformation of methylated As compounds into inorganic As in shellfish takes place during cooking and that As demethylation can occur during simulated gastrointestinal digestion. In vivo demethylation of As after gastrointestinal digestion was also demonstrated in laboratory mice. This increase in inorganic As during digestion suggests that risks of As toxicity from shellfish consumption are being underestimated. Further studies on the mechanisms of As speciation transformation in food are necessary for more thorough risk assessments.

Bioaccessibility and decomposition of cylindrospermopsin in vegetables matrices after the application of an in vitro digestion model

Research on the human exposure to Cylindrospermopsin (CYN) via consumption of contaminated food is of great interest for risk assessment purposes. The aim of this work is to evaluate for the first time the CYN bioaccessibility in contaminated vegetables (uncooked lettuce and spinach, and boiled spinach) after an in vitro digestion model, including the salivar, gastric and duodenal phases and, colonic fermentation under lactic acid bacteria. The results obtained showed that the digestion processes are able to diminish CYN levels, mainly in the colonic phase, especially in combination with the boiling treatment, decreasing CYN levels in a significant way. Moreover, the potential decomposition products in a pure CYN solution and in CYN-contaminated vegetables were evaluated using UHPLC-MS/MS Orbitrap. Under the conditions assayed, only two diastereoisomers of the same fragment with m/z 292.09617 have been detected in all the analysed samples, with the exception of digested vegetables. Therefore, in terms of risk assessment, the digestion seems to play an important role in reducing the final bioaccesibility of CYN, and the consumption of cooked vegetables (spinach) would be safer in comparison to raw vegetables.

Intake of arsenic and mercury from fish and seafood in a Northern Italy community

Regular consumption of fish is generally recommended by authorities because fish is an important source of essential nutrients. However, the presence of potentially toxic contaminants in fish has raised many concerns about the food's safety for human health. In the present study, we used a validated semi-quantitative food frequency questionnaire to assess the dietary habits of a representative sample of 719 individuals (319 males and 400 females) aged 18-87 years residing in Northern Italy. We estimated weekly dietary intakes of Arsenic (As) and Mercury (Hg), and we compared them with safety standards set by the European Food Safety Authority. In this population, fish was the main contributor to As and Hg intake. The highest levels of As were in sardine, sole/flounder and cephalopods, and of Hg in the biggest, predatory fish. About the other foods, cereals were the second contributor to the intake of these elements, especially rice for As and bread for Hg, and high levels of As and Hg were also found in mushrooms, coffee and wine. Average weekly intake of both contaminants was below recommended safety limits.