Heavy metals in seafood purchased from a fishery market in Hungary

Characteristics of arsenic speciation in mainly cultured shellfish from Sanmen Bay, Zhejiang Province, China

Sanmen Bay plays a crucial role in economic shellfish aquaculture in China, yet few studies exist on the arsenic speciation of shellfish from this area. In this study, arsenic speciation of 11 cultured shellfish species from Sanmen Bay were analyzed by HPLC/ICP-MS. The results showed that organic arsenic particularly AsB, was the dominant arsenic species, constituting 21 %-71 % of the total arsenic. Conversely, the levels of inorganic arsenic were relatively low, ranging from 0.007 to 0.093 mg/kg, only accounted for 0.2 %-5.7 % of the total arsenic. There was no significant level correlation between inorganic arsenic and total arsenic in Sanmen Bay shellfish, so the concentration of inorganic arsenic did not increase with the total arsenic. Overall, the present study firstly revealed the arsenic speciation of shellfish from Sanmen Bay and also suggested that the proportion of inorganic arsenic should be considered in the revision of arsenic limit values.

Utilizing mollusk soft tissue and shells as biomarkers for monitoring heavy metal pollution in mangrove forests

The primary objective of the study was to examine the distribution of various elements, namely Cadmium (Cd), Copper (Cu), Iron (Fe), Nickel (Ni), and Lead (Pb), in the soft tissues, shells, and associated surface sediments of Cerithidea obtusa (C. obtusa) mangrove snails collected from Sungai Besar Sepang. To conduct the analysis, the preferred and most convenient methods employed were Instrumental Neutron Activation Analysis (INAA) and Atomic absorption spectrometry (AAS). The results showed that the mean concentration of elements in the sediments and soft tissues followed the order Fe > Cu > Ni > Pb > Cd, while for the shell of C. obtusa, it was Fe > Ni > Cu > Pb > Cd.•Iron (Fe) showed the highest concentration among all elements monitored in sediments, soft tissues, and shells of C. obtusa.•The PF results indicated higher incorporation of Pb and Ni into shells.•BSAF results showed that C. obtusa shells accumulated more Cu and Cd from sediments, making them effective biomonitors.

Quantitative determination of heavy metal contaminants in edible soft tissue of clams, mussels, and oysters

Aquatic environments are important sources of healthy and nutritious foods; however, clams, mussels, and oysters (the bivalves most consumed by humans) can pose considerable health risks to consumers if contaminated by heavy metals in polluted areas. These organisms can accumulate dangerously high concentrations of heavy metals (e.g., Cd, Hg, Pb) in their soft tissues that can then be transferred to humans following ingestion. Monitoring contaminants in clams, mussels and oysters and their environments is critically important for global human health and food security, which requires reliable measurement of heavy-metal concentrations in the soft tissues. The aim of our present paper is to provide a review of how heavy metals are quantified in clams, mussels, and oysters. We do this by evaluating sample-preparation methods (i.e., tissue digestion / extraction and analyte preconcentration) and instrumental techniques (i.e., atomic, fluorescence and mass spectrometric methods, chromatography, neutron activation analysis and electrochemical sensors) that have been applied for this purpose to date. Application of these methods, their advantages, limitations, challenges and expected future directions are discussed.

Metal Load of Potentially Toxic Elements in Tuna (Thunnus albacares)-Food Safety Aspects

The consumption of marine fishes has a positive effect on a consumer's health; however, it poses a potential risk due to their level of heavy metals in their body. Heavy metals can be naturally found in the environment, but their concentration can be increased with anthropogenic activities. Samples of tuna (Thunnus albacares) were collected at a fishery market. The potentially toxic elements (arsenic, cadmium, lead, and mercury) were determined with a validated method in the flesh of fish using inductively plasma optical emission spectrometry after microwave digestion. Generally, the average concentration of them was below the official limit values regulated by the European Union, except for lead. Based on the concentrations of arsenic (inorganic derivates: 0.05 ± 0.02 mg/kg) and cadmium (0.03 ± 0.01 mg/kg) in the tuna fish samples, and their calculated EDI values (As: 0.03-0.09 µg/kg/day; Cd: 0.05-0.07 µg/kg/day), the investigated food could be declared safe for human consumption. Generally, mercury content was below the official regulated limit, and the calculated EDI value was below the dietary reference value (0.3 μg/kg/day) in most of the samples (90%), exceeding it only in two samples (0.69 and 0.82 μg/kg/day); thus, they may not be harmful to the consumer. The concentration of lead above the official maximum limit (0.30 mg/kg) in 40% of tuna samples (0.30-1.59 mg/kg), as well as the exceeding of the dietary reference value for lead (adult: 0.16 μg/kg/day; children: 0.26 μg/kg/day) based on the calculated EDI values (0.28-1.49 μg/kg/day), draw attention to the importance of environmental pollution and the protection of consumers' health.

Health risk assessment of dietary cadmium intake in children aged 2-17 years in East China

Food is the main way for people to be exposed to heavy metal cadmium (Cd), and Cd pollution will affect human health. In this paper, exposure and health risk assessment of dietary Cd intake were conducted in children aged 2, 3, 4, 5, 6-8, 9-11, 12-14 and 15-17 years in East China. The results showed that the total exposure of dietary Cd intake in children exceeded the standard limits. The total exposure of all age groups were 1.11 × 10-3, 1.15 × 10-3, 9.67 × 10-4, 8.75 × 10-4, 9.18 × 10-4, 7.75 × 10-4, 8.24 × 10-4, 7.11 × 10-4 mg kg-1 d-1, respectively, and the highest was the children aged 3 years. The hazard quotients of children aged 2 and 3 years were 1.11 and 1.15, respectively, at an unacceptable health risk level. The hazard quotients of dietary Cd intake in children of other ages were less than 1, at an acceptable health risk level. Staple foods were the most significant contributor to the dietary Cd intake in children, and the contribution ratio of non-carcinogenic risk of dietary Cd intake in all age groups were more than 35%, the proportion of non-carcinogenic risk in children aged 6-8 and 9-11 years were as high as 50%. This study provides scientific basis for the health of children in East China.

Biomonitoring-Health Risk Nexus of Potentially Toxic Metals on Cerithidea obtusa: A Biomonitoring Study from Peninsular Malaysia

The present study aimed to assess the human health risks of six potentially toxic metals (PTMs) (Cd, Cu, Fe, Ni, Pb and Zn) in 21 populations of popular mangrove snails, Cerithidea obtusa, collected from Malaysia. In general, the concentrations (mg/kg wet weight) of Cd (0.03-2.32), Cu (11.4-35.2), Fe (40.9-759), Ni (0.40-6.14), Pb (0.90-13.4) and Zn (3.11-129) found in the snails in all populations were lower than the prescribed maximum permissible limits (MPL)s for Cd, Cu, Ni, Pb and Zn. However, in the investigated snail populations, Cd (14%), Pb (62%), Cu (19%), and Zn (10%) were found in exceedance of the MPL of the respective metal. The target hazard quotient (THQ) values in all populations for Cu, Ni, Fe and Zn were all found to be below 1.00. However, for the THQ values of Cd and Pb, two populations exceeded 1.00, while others were below the threshold level. The estimated weekly intake (EWI) of all six metals for all populations was only 0.03-4.65% of the provisional tolerable weekly intake. This conclusively indicates that, based on the EWI, there are no health risks of the six PTMs in the consumption of snails from Malaysia since the assessments are dependent on the consumers' body weight and consumption rate. Nonetheless, the present results indicate that the amounts of snails consumed should be limited to minimize the potential health risks of PTMs to consumers. The relatively low and weak but positive correlations of Cu, Ni, Pb and Zn between C. obtusa and their habitat sediments indicate that C. obtusa can be a potential biomonitor for Cu, Ni, Pb and Zn. This is important for effective mangrove management from the perspective of the sustainable resources from the intertidal mangrove environment. Hence, the biomonitoring-health risk nexus of PTMs in mangrove snails is proposed in the present study.

Elements in Mediterranean mussels from Istanbul and exposure assessment

In this study, concentrations of elements were determined in edible tissues of Mytilus galloprovincialis by means of inductively coupled plasma mass spectrometry (ICP-MS). The mean levels (mg kg^-1) of 0.67 for Cd, 6.9 for As, 0.79 for Pb, 2 for Ni, and 42.6 for Zn exceeded the maximum limits in the digestive glands. Also, the mean concentrations of Cd and As in muscle and of Cd and Ni in gills were above the maximum limits. The highest value was found for As in a digestive gland, with 65.4% of the Provisional Tolerable Weekly Intake. In addition, the lowest percentage belonged to Zn with 0.2% of PTWI in muscles and 0.3% of PTWI in gills of the mussels. Mercury concentrations were well below legal limits.

Toxic elements in Sardina pilchardus and food toxicological significance

Cd, Hg, and Pb concentrations were investigated in Sardina pilchardus fish. Samples originated from the Atlantic Northeast fishing area 27 and were analysed by inductively coupled plasma optical emission spectroscopy. The aim of the study was to estimate the health impact of consumption, based on the concentrations and calculated exposure for each element. Based on the average total arsenic concentration of 3.26 ± 0.39 mg/kg in the samples, the estimated inorganic arsenic content and calculated PTWI suggested that the samples do not pose a health risk for consumers. Cadmium content of the samples was also not considered hazardous, as both the measured concentrations and PTMI values were below the specified limits. Lead concentration exceeded the maximum limit in 73% of the samples, while calculated average weekly intake was below the recommended level. The measured mercury concentrations exceeded the maximum limit in only 5% of the samples.

Heavy Metals in Unprocessed or Minimally Processed Foods Consumed by Humans Worldwide: A Scoping Review

Heavy metals (HM) can be accumulated along the food chain; their presence in food is a global concern for human health because some of them are toxic even at low concentrations. Unprocessed or minimally processed foods are good sources of different nutrients, so their safety and quality composition should be guaranteed in the most natural form that is obtained for human consumption. The objective of this scoping review (ScR) is to summarize the existing evidence about the presence of HM content (arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), methylmercury (MeHg), and aluminum (Al)) in unprocessed or minimally processed foods for human consumption worldwide during the period of 2011-2020. As a second objective, we identified reported HM values in food with respect to Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) International Food Standards for Maximum Limits (MLs) for contaminants in food. This ScR was conducted in accordance with the Joanna Briggs Institute (JBI) methodology and PRISMA Extension for Scoping Reviews (PRISMA-ScR); advance searches were performed in PubMed, ScienceDirect and FAO AGRIS (Agricultural Science and Technology Information) databases by two reviewers who independently performed literature searches with specific eligibility criteria. We classified individual foods in food groups and subgroups according to the Global Individual Information Food Consumption Data Tool (FAO/WHO GIFT). We homologated all the reported HM units to parts per million (ppm) to determine the weighted mean HM concentration per country and food group/subgroup of the articles included. Then, we compared HM concentration findings with FAO/WHO MLs. Finally, we used a Geographic Information System (GIS) to present our findings. Using our search strategy, we included 152 articles. Asia was the continent with the highest number of publications (n = 79, 51.3%), with China being the country with the largest number of studies (n = 34). Fish and shellfish (n = 58), followed by vegetables (n = 39) and cereals (n = 38), were the food groups studied the most. Fish (n = 42), rice (n = 33), and leafy (n = 28) and fruiting vegetables (n = 29) were the most studied food subgroups. With respect to the HM of interest, Cd was the most analyzed, followed by Pb, As, Hg and Al. Finally, we found that many of the HM concentrations reported exceeded the FAO/OMS MLs established for Cd, Pb and As globally in all food groups, mainly in vegetables, followed by the roots and tubers, and cereals food groups. Our study highlights the presence of HM in the most natural forms of food around the world, in concentrations that, in fact, exceed the MLs, which affects food safety and could represent a human health risk. In countries with regulations on these topics, a monitoring system is recommended to evaluate and monitor compliance with national standards. For countries without a regulation system, it is recommended to adopt international guidelines, such as those of FAO, and implement a monitoring system that supervises national compliance. In both cases, the information must be disseminated to the population to create social awareness. This is especially important to protect the population from the consumption of internal production and for the international markets of the globalized world.

Application of the maximum cumulative ratio (MCR) as a screening tool for the evaluation of multiple metal mixtures in shellfish in Chinese population

The objective of this study was to investigate the potential effects from exposure to multiple metals, including cadmium (Cd), chromium (Cr), arsenic (As), mercury (Hg), nickel (Ni) and lead (Pb) that exist in shellfish in Chinese populations, and evaluate the impacts of cumulative exposures among individuals. A total 15,469 individual shellfish samples were analyzed following a protocol for elemental analysis. A total of 25,669 respondents were selected through stratified multi-stage cluster sampling from  31 survey sites in China. Individual shellfish consumption data and body weight were collected and analyzed with a 24-hour dietary recall method on three non-consecutive days. The consumers were divided into two groups: aged 2-12 years group and aged ≥13 years. Exposure levels were estimated based using a semi-probabilistic risk assessment method and cumulative exposures among individual persons using the maximum cumulative ratio (MCR) method. The mean, median and 95th percentile of all metals exposure for age 2-12 years group were higher than age ≥13 years group, but none exceeded the respective reference doses of the metals. The mean hazard indices (HI) of each metal in shellfish for both age groups were less than 1. The MCR values calculated among 1283 consumers ranged from 1.28 to 3.25 with the average MCR value was 2.22. There were 51 (3.98%) consumers in group I, 1186 (92.44%) consumers in group II, 26(2.03%) consumers in group III A, and 20 (1.56%) consumers in group III B. And cadmium (Cd) and lead (Pb) produced the HQ_Max that trigged cumulative exposures. It was concluded that heavy metals did not present a potential health risk to people solely through shellfish. The cumulative risks indicated that 7.56% of the surveyed consumers were of concern because of high HI of metals exposure, and Cd, Pb, and Ni made significant contributions to the potential risk.

Review of the toxic trace elements arsenic, cadmium, lead and mercury in seafood species from Algeria and contiguous waters in the Southwestern Mediterranean Sea

An assessment is made of published data on concentrations of four toxic trace elements arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), and methyl mercury (MeHg) in seafood species from Algerian coastal waters. The data relate mainly to fish and mollusks, with Pb and Cd being the most studied elements. In contrast, no studies were found for As and MeHg in mollusks and crustaceans, and none for total Hg in crustaceans. Data analysis has shown that the element concentrations depend on the element analyzed, in particular its chemical form, and they vary with the species studied and the area where the organisms were sampled. As concentrations in muscle of sardine (Sardina pilchardus) from the eastern zone (Bejaia) (2.98 mg kg^-1 wet weight), Pb in muscle of tuna (Euthynnus alletteratus) (0.49 mg kg^-1 wet weight) from the western region (Mostaganem) and in muscle tissue of the mussel (Mytilus galloprovincialis) (10.67 mg kg^-1 dry weight) from Oran all exceed the threshold risk limits set by national and international regulations. Given these findings, to guarantee seafood safety for the Algerian consumer, it is recommended to carry out monitoring of these trace elements in seafood species caught along the Algerian coast, particularly the most consumed fish, i.e., sardines, and predators such as swordfish and tuna which can accumulate high concentrations of toxic metals, particularly Hg. Obtaining a regional assessment based on similar analyses from Tunisia and Morocco was severely hampered since few similar species or taxonomic groups were analyzed in all three countries.

Heavy metals and PAHs in mussels on the Serbian market and consumer exposure

The goal of the study was to investigate the concentration of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in 84 samples of mussels, collected from supermarkets and fish markets in Serbia. Lead, cadmium, mercury and arsenic concentrations were determined using an inductive coupled plasma mass spectrometry method. Sixteen PAHs were determined using a gas chromatography-mass spectrometry method. Heavy metals in the mussels were in the range (mg/kg) of 0.01-0.74 for lead, 0.01-0.38 for cadmium, 0.01-0.15 for mercury and 1.12-5.87 for arsenic. Metals and PAHs levels in all analysed samples were under the legal European and Serbian legislation limits. The provisional tolerable intake values were calculated on the base of the obtainable values of heavy metals. Mussels are considered to be safe for human consumption. However, one should take care of the amount and frequency of mussel consumption, primarily due to consumer's cadmium and mercury burden.

Arsenic in shellfish: A systematic review of its dynamics and potential health risks

Arsenic is the most toxic element for humans. Presenting naturally in aquatic ecosystems and due to anthropogenic action, this semi-metal transfers to shellfish through the food chain. This systematic review aims to explain the dynamic of arsenic in the marine aquatic system, investigating factors that affect its bioaccumulation. A total of 64 articles were considered from three databases. The key abiotic factor influencing the presence of arsenic in shellfish is anthropogenic contamination, followed by geographic location. The crucial biotic factor is the genetics of each species of shellfish, including their diet habits, habitat close to the sediment, metabolic abilities, physiological activities of organisms, and metal levels in their habitats and food. Finally, arsenic presents an affinity for specific tissues in shellfish. Despite containing mostly less toxic organic arsenic, shellfish are a relevant source of arsenic in the human diet.

Possible food safety hazards of ready-to-eat raw fish containing product (sushi, sashimi)

It is undeniable that with the popularity of sushi and sashimi over the last decade the consumption of raw fish has extremely increased. Raw fish is very appreciated worldwide and has become a major component of human diet because of its fine taste and nutritional properties. Possible hazards concerning fish safety and quality are classified as biological and chemical hazards. They are contaminants that often accumulate in edible tissue of fish and transmit to humans via the food chain affecting the consumer's health. Although their concentration in fish and fishery products are found at non-alarming level of a daily basis period, they induce hazardous outcome on human health due to long and continuous consumption of raw fish. Regular sushi and sashimi eaters have to be aware of the contaminants found in the other components of their dish that often add up to acceptable residue limits found in fish. Hence, there is the urge for effective analytical methods to be developed as well as stricter regulations to be put in force between countries to monitor the safety and quality of fish for the interest of public health.