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

Bioaccessibility of toxic heavy metals/metalloids in edible seaweeds: Exposure and health risk assessment

This study assesses the health risk due to heavy metals/metalloids (HMs/Ms) in edible seaweeds (Caulerpa racemosa, Kappaphycus alvarezii, and Ulva lactuca) through an in vitro bioaccessibility study. The percentage of bioabsorbed HMs/Ms in unprocessed and processed C. racemosa, U. lactuca, and K. alvarezii ranged from 3 % to 46 %, 3 % to 42 %, and 3 % to 40 %, respectively. The levels of HMs/Ms in seawater, sediment, and seaweeds were below the levels recommended by the European Commission (EC) and World Health Organization/Food and Agriculture Organization (WHO/FAO). The maximum accumulation of HMs/Ms was found during monsoons and post-monsoon seasons, and Cd, Pb, Hg, Cr, As, and Pb were predominant in all the samples. Tukey's post hoc test and t-test confirmed that thermal processing significantly reduced HMs/Ms in seaweeds. On the basis of the bioabsorption of HMs/Ms, the TTHQ values were found to be < 1, and the LCR values were within the acceptable limit (10-06 to 10-04), indicating no carcinogenic risks through seaweeds.

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.

Health Risks for Consumers of Forest Ground Cover Produce Contaminated with Heavy Metals

BACKGROUND

The activity of heavy metal (HM) mining and processing industries causes soils contamination with HM. The metals could be transferred from contaminated soils to edible plants and fungi. This study aimed to assess the content of Cd, Pb, Hg, As, and Ni in berries and edible mushrooms collected in the forests located near Miasteczko Slaskie zinc smelter and in the Lubliniec region, in the context of consumers' health risk.

METHODS

The ET-AAS method was used to determine the content of Cd, Pb, Ni, and As. Mercury concentration was determined using the CV-AFS method.

RESULTS

The studies showed high levels of Cd and Pb in the examined products. A statistically significant impact of the distance from the smelter on the Cd concentration in the berries was observed. Total non-cancer health risk from the combined exposure of adults to all HM in mushrooms and berries was significant when consuming the most heavily contaminated produce. The risk to children was significant, even when consuming products with moderate levels of the metals. Ingestion of Cd by children with mushrooms was related to a high cancer risk. The uncertainty of the results was determined.

CONCLUSIONS

It is recommended to take action to increase awareness among residents of the areas adjacent to the forests regarding the existing health risk and to take possible measures to reduce exposure to HM.

The Impact of Various Types of Cooking on the Fate of Hg and Se in Predatory Fish Species

This study addresses the effect of various cooking approaches on total Hg (HgT) and total Se (SeT) contents in three predatory fish species. For this purpose, samples of swordfish, dogfish, and tuna from regular French (fish) markets were cooked by boiling, steaming, grilling, and frying, respectively. The levels of HgT and SeT in raw and cooked samples were determined by inductively coupled plasma-mass spectrometry. The data showed a significant increase in HgT and SeT levels between raw and cooked samples (33% of the samples for SeT and 67% for HgT) due to the water loss during the cooking. High intra-species variation related to HgT and SeT levels was found. Considering the level of exposure to HgT through fish consumption and taking also into account the possible protective effect of Se (expressed here via the Se/Hg molar ratio), the safest cooking approach corresponds to grilled swordfish, fried tuna, and steamed dogfish, which show Se/Hg molar ratios of (1.0 ± 0.5), (4.3 ± 4.2), and (1.0 ± 0.6), respectively.

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.

Effects of cooking methods and co-ingested foods on mercury bioaccessibility in pontic shad (Alosa immaculata)

Human mercury (Hg) exposure is mostly caused by eating fish. However, there are major differences between the measured and predicted mercury concentration on Hg bioavailability. This study investigated the effects of cooking (steaming, baking, frying, marinating, and smoking) and selected components' co-ingestion on Hg bioaccessibility. Baking and frying reduced Hg bioaccessibility compared to the raw sample. The bioaccessible Hg fraction in fish was assessed through in vitro digestion method. Hg bioaccessibility varied from 4.31 to nearly 24.95% and the Hg recovery rate varied from 63.44 to 78.74%. Co-ingested garlic and broccoli with pontic shad had a positive effect on decreasing fish Hg bioaccessibility. The antioxidant activity of co-ingested food items was also calculated and correlated with mercury bioaccessibility. These results highlighted a possible positive role of plant-based foods and other food processing techniques in the bioaccessibility reduction of other chemical contaminants found in food sources.

Total Mercury Content in the Tissues of Freshwater Chelonium (Podocnemis expansa) and a Human Health Risk Assessment for the Amazon Population in Brazil

Researchers recognize the silent, negative and deleterious effects caused by mercury pollution in gold mining areas. Freshwater turtles are culturally part of the diet of riverside populations in the Amazon region and this area presents mercury (Hg) pollution issues mainly due to gold mining activities. Thus, this research aimed to evaluate the total mercury (THg) content in the different organs of Amazonian giant river turtle (Podocnemis expansa) and carry out a human health risk assessment associated with the consumption of these animals. This study was conducted in the Vila Balbina, municipality of Presidente Figueiredo, state of Amazonas, Brazil. Skin (n = 28), muscle (n = 19) and brain (n = 2) samples were analyzed by Atomic Absorption Spectrometry (TDA-AAS) and a DMA-80™ mercury analyzer was used for the total mercury determinations. The average values found for THg in the skin, muscle and brain samples were, respectively, 0.1045 mg·kg-1, 0.1092 mg·kg-1 and 0.0601 mg·kg-1. Thus, THg was observed even though the P. expansa were kept in captivity, possibly due to previous contamination by air, water and food. The Hazard Quotient (HQ) was calculated considering a 9.07 g·day-1 intake dose of P. expansa and the consumption of turtles once a week showed an HQ = 2.45, which may cause long-term injuries to human health. Although the muscle concentrations were below the maximum limit established by the World Health Organization (WHO) and Brazilian regulatory agencies, it is important to evaluate consumption factors such as amount ingested, frequency and animal gender, which may cause a potential risk to regular consumers due to mercury bioaccumulation. The WHO may consider various aspects in order to warn the Amazon population about the severity and silent hazard of this metal, especially due to the importance of this matrix in the region. This region urgently needs government actions to inhibit clandestine mining and to prevent future serious, chronic health problems of the entire population.

Concentration of mercury in human hair and associated factors in residents of the Gulf of Trieste (North-Eastern Italy)

The Gulf of Trieste (Northern Adriatic Sea, Italy) is the coastal area of the Mediterranean Sea most highly contaminated by mercury (Hg) due to fluvial inputs from the Isonzo/Soča River system, draining over 500 years' worth of cinnabar extraction activity from the Idrija mining district (Western Slovenia). The aim of this research is to investigate the concentration of Hg in hair samples taken from the general population of the Friuli Venezia Giulia (FVG) Region coastal area, as a marker of chronic exposure to Hg. Three hundred and one individuals - 119 males and 182 females - were recruited by convenience sampling in Trieste in September 2021. An amount of approximately 100 mg of hair was collected from the occipital scalp of each participant to measure the respective Hg concentrations (expressed as mg/kg). Moreover, participants completed a self-report questionnaire collecting extensive socio-demographic and life-style information. A multiple linear regression analysis was employed to investigate factors associated with increased levels of Hg concentration in hair. A mean Hg concentration in hair of 1.63 mg/kg was found, slightly above the 1.0 mg/kg threshold recommended by the WHO for pregnant women and children, although still well below the no observed adverse effects level (NOAEL) of 10 mg/kg. Among respondents, 55.6% showed a Hg concentration in hair > 1 mg/kg, 22.9% > 2 mg/kg, and 2 participants exhibited Hg levels > 10 mg/kg. The adjusted mean hair Hg level increased in those subjects who reported a preference for shellfish/crayfish/mollusks (RC = 0.35; 95%CI: 0.16; 0.55), whereas it decreased in those who reported a preference for frozen fish (RC = -0.23; 95%CI: - 0.39; - 0.06). Though a risk alert for Hg exposure for coastal residents from FVG is deemed unnecessary at this time, it is recommended that pregnant women limit their ingestion of locally caught fish to < 4 servings/month.

Genes Involved in DNA Repair and Mitophagy Protect Embryoid Bodies from the Toxic Effect of Methylmercury Chloride under Physioxia Conditions

The formation of embryoid bodies (EBs) from human pluripotent stem cells resembles the early stages of human embryo development, mimicking the organization of three germ layers. In our study, EBs were tested for their vulnerability to chronic exposure to low doses of MeHgCl (1 nM) under atmospheric (21%O₂) and physioxia (5%O₂) conditions. Significant differences were observed in the relative expression of genes associated with DNA repair and mitophagy between the tested oxygen conditions in nontreated EBs. When compared to physioxia conditions, the significant differences recorded in EBs cultured at 21% O₂ included: (1) lower expression of genes associated with DNA repair (ATM, OGG1, PARP1, POLG1) and mitophagy (PARK2); (2) higher level of mtDNA copy number; and (3) higher expression of the neuroectodermal gene (NES). Chronic exposure to a low dose of MeHgCl (1 nM) disrupted the development of EBs under both oxygen conditions. However, only EBs exposed to MeHgCl at 21% O₂ revealed downregulation of mtDNA copy number, increased oxidative DNA damage and DNA fragmentation, as well as disturbances in SOX17 (endoderm) and TBXT (mesoderm) genes expression. Our data revealed that physioxia conditions protected EBs genome integrity and their further differentiation.

Health risk of consuming Sphoeroides spp. from the Navachiste Lagoon complex due to its trace metals and organochlorine pesticides content

The Navachiste complex (NAV) is impacted by neighbored human activities and is located in the southwestern coastal zone of the Gulf of California. The study determines the trace metal (TM) and organochlorine pesticides (OCP) health risk content in the edible tissue of Sphoeroides spp. from NAV. The daily intakes (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic and non-carcinogenic risks were calculated. Twenty OCP and seven TM were detected. Cd, Cu, Fe, Mn, Pb, and Zn were above MRLs. The γ‒Chlordane was the most frequent OCP. The highest average concentration was for α‒HCH, followed by γ‒chlordane. With the high ratios of γ‒HCH, p, p'‒ DDD and p, p'‒DDD, and the absence of p, p'‒ DDT, the higher ratios for dieldrin and endrin than for aldrin, α‒ chlordane, γ‒chlordane, heptachlor, and heptachlor epoxide indicates historical contamination. In contrast, the residual products of methoxychlor, endosulfan, and its isomers indicate endosulfan's recent use. The TM EDI, THQ > 1 (at 120 g day^-1), and the ILCR (> 1 × 10^-6) were above minimum levels, showing a high-risk potential for cancer development in the long term.