Seasonal and Spatial Variability of Trace Elements in Livers and Muscles of Three Fish Species from the Eastern Mediterranean

Risk Assessment, Interdependencies, and Source Appraisal of Bioaccumulated Heavy and Essential Metals in Seafood as Pollutants

Fish as seafood is a bioindicator for chemical substances like trace metals in the water systems that accumulate in fish bodies. Fe and Zn as essential and Pb, Ni, and Cd as heavy metals were quantitatively analyzed in fish muscle samples by an atomic absorption spectrophotometer (Perkin Elmer, Model AAnalyst-700). Fe and Zn's results agreed with the food quality guidelines. Fe was the highest in the range of 2.6-9.4 in mg kg-1. The Zn content indicates the contribution of anthropogenic agents through the food chain. Ni > Pb > Cd was found in marine fish species and Pb > Ni > Cd in freshwater fish. The results have been explored for source appraisal of bioaccumulated trace metals and categorized selected marine and freshwater species based on characteristics (like life cycle and habitats) by applying multivariate principal component analysis to risk assessment parameters. The Pearson correlation coefficients were applied to the risk assessment parameters for interdependencies of metals. Interestingly, synchronized outcomes were obtained with trace metal data. The study results were interpreted in the context of the fish type, habitat, surroundings, feed, life cycle, etc. The living habitats strongly affect trace metal accumulation, target hazard quotient (THQ), and target cancer risk (TR) attributes. The fishermen's community was at higher risk for carcinogenic effects than other seafood consumers. Overall, determinations for fish species were under safe limits as described by international regulatory bodies (FAO, WHO, ANHMRC, WAA).

Developing an Approach for Integrating Chemical Analysis and Transcriptional Changes to Assess Contaminants in Water, Sediment, and Fish

Pharmaceuticals in aquatic environments pose threats to aquatic organisms because of their continuous release and potential accumulation. Monitoring methods for these contaminants are inadequate, with targeted analyses falling short in assessing water quality's impact on biota. The present study advocates for integrated strategies combining suspect and targeted chemical analyses with molecular biomarker approaches to better understand the risks posed by complex chemical mixtures to nontarget organisms. The research aimed to integrate chemical analysis and transcriptome changes in fathead minnows to prioritize contaminants, assess their effects, and apply this strategy in Wascana Creek, Canada. Analysis revealed higher pharmaceutical concentrations downstream of a wastewater-treatment plant, with clozapine being the most abundant in fathead minnows, showing notable bioavailability from water and sediment sources. Considering the importance of bioaccumulation factor and biota-sediment accumulation factor in risk assessment, these coefficients were calculated based on field data collected during spring, summer, and fall seasons in 2021. Bioaccumulation was classified as very bioaccumulative with values >5000 L kg-1, suggesting the ability of pharmaceuticals to accumulate in aquatic organisms. The study highlighted the intricate relationship between nutrient availability, water quality, and key pathways affected by pharmaceuticals, personal care products, and rubber components. Prioritization of these chemicals was done through suspect analysis, supported by identifying perturbed pathways (specifically signaling and cellular processes) using transcriptomic analysis in exposed fish. This strategy not only aids in environmental risk assessment but also serves as a practical model for other watersheds, streamlining risk-assessment processes to identify environmental hazards and work toward reducing risks from contaminants of emerging concern. Environ Toxicol Chem 2024;00:1-22. © 2024 SETAC.

Seasonal Variation and Association of Heavy Metals in the Vital Organs of Edible Fishes from the River Jhelum in Punjab, Pakistan

The toxic effects of heavy metals are drastic, including accumulation. Fish species are important bio-indicators of heavy metal pollution in aquatic bodies. The current study aimed to assess the seasonal variation of heavy metals in the vital organs of mostly consumed fishes in River Jhelum, Pakistan. Samples of fish, including Wallago attu (Malhi), Rita rita (Khagga), and Mystus seenghala (Singhari), were collected from four different sites, i.e., Khushab, Muhammad Wala (M. Wala), 8.R.D and Rasool barrage during summer and winter seasons. Heavy metals such as iron (Fe), lead (Pb), chromium (Cr), cobalt (Co) and Cadmium (Cd) were estimated through acid digestion and spectrometric analysis. Results showed a significantly higher (P < 0.05) amount of these metals in the liver, followed by the kidneys of fish species. There were seasonal variations in the absorption of these metals as well. Cr (11.71) and Fe (58.66) were detected in higher amounts in Khagga which showed the greatest affinity for certain metals in some cases. In contrast, Singhari showed the greatest affinity to other metals in other cases. Comparative analysis revealed that there was a highly significant (P < 0.05) difference for the accumulation of almost all metals in both seasons and summer had the highest concentration of Cd, Pb, Co, Cr and Fe as compared to winter in all four sampling stations in the case of kidney and liver of all the three fishes. Elevated levels of heavy metals were detected in the summer due to increased temperature. Heavy metals found in the River Jhelum may demonstrate that metals can significantly affect the fish species.

Heavy metal concentrations in sharks, rays and chimaeras from the western Mediterranean Sea

The potential bioaccumulation of pollutants, such as heavy metals, may pose a threat to the western Mediterranean chondrichthyans and human consumers. Therefore, the first extensive assessment of cadmium (Cd), lead (Pb), and copper (Cu) concentrations in the muscle tissue of 17 species of sharks, rays, and chimaeras in this region was conducted via Microwave Assisted Extraction (MAE) and Graphite Furnace Atomic Absorption Spectrometry (GFAAS). Significant differences between species were observed, particularly related to the rabbit fish (Chimaera monstrosa) and the velvet belly lantern shark (Etmopterus spinax), which exceeded the European Union (EU) Commission Regulation 2023/915 threshold of Cd. Overall, heavy metal concentrations correlated negatively with size and trophic level but positively with depth. Although the consumption of these species may entail minimal risk to adult humans, caution is advised, especially for children. These findings are important due to the widespread consumption of chondrichthyans in many western Mediterranean regions.

Assessment of elemental composition in commercial fish of the Bay of Cádiz, Southern Iberian Peninsula

The assessment of trace metal content in our fish diet is important due to the adverse effect on human health. Despite the increasing interest about the fish quality, little information is available for Southern Spain, a region characterized by high seafood intake. Nine species from the Bay of Cádiz with high commercial value were selected. Similar values were measured in the nine studied species for most of the elements, except for the macroelements Ca and S, and the microelements Fe, Mn and As, which showed significant differences among species. Metal Pollution Index (MPI) did not differ among species, and it was similar to those obtained for other Atlantic and Mediterranean locations. The values measured for the nine species were below the health limits provided by World, European and Spanish legislations, indicating that, in general terms, consumption of these species is safe in the study area.

Determination of metals in estuarine fishes in a metropolitan region of the coastal zone of the Brazilian Amazon

The aim of the present study was to determine concentrations of cadmium, copper, chromium, manganese and iron in fishes in the São Marcos (SMB), São Jose (SJB) and Arraial (AB) Bays. Metal concentrations were determined using inductively coupled plasma optical emission spectrometry. Mean Cd and Cr levels were above the permissible limits set by different international or national guidelines in all three bays, whereas copper levels were well below the maximum acceptable limit. High concentrations of iron were found in all species analyzed, whereas high concentrations of manganese were found, especially in specimens caught in SJB. Spatial analysis indicated significant differences among the elements investigated. Copper was correlated more with SMB and AB as well as the species Macrodon ancylodon (carnivore) and Sciades herzbergii (omnivore). Cadmium and iron were strongly associated with AB and SJB, while manganese was only associated with SJB, mainly in carnivorous and herbivorous species.

Trace elements, dioxins and PCBs in different fish species and marine regions: Importance of the taxon and regional features

Chemical contaminant concentrations in wild organisms are used to assess environmental status under the European Marine Strategy Framework Directive. However, this approach is challenged by the complex intra- and inter-species variability, and the different regional features. In this study, concentrations in trace elements (As, Cd, Hg and Pb), polychlorinated biphenyls (PCBs), polychlorodibenzo-para-dioxines (PCDDs) and polychlorodibenzofuranes (PCDFs) were monitored in 8 fish species sampled on the continental shelf of three French regions: the Eastern English Channel (EEC) and Bay of Biscay (BoB) in the Northeast Atlantic Ocean, and the Gulf of Lions (GoL) in Western Mediterranean Sea. Our objectives were to identify species or regions more likely to be contaminated and to assess how to take this variability into account in environmental assessment. While concentrations were higher in benthic and demersal piscivores, PCB and PCDD/F concentrations (lipid-weight) were similar in most teleost species. For Cd, Hg and Pb, the trophic group accumulating the highest concentrations depended on the contaminant and region. Concentrations in Hg, PCBs and PCDD/Fs were higher in the EEC and/or GoL than in BoB. Cadmium and Pb concentrations were highest in the BoB. Lipid content accounted for 35%-84% of organic contaminant variability. Lipid normalisation was employed to enhance robustness in the identification of spatial patterns. Contaminant patterns in chondrichthyans clearly differed from that in teleosts. In addition, trophic levels accounted for ≤1% and ≤33% of the contaminant variability in teleost fishes in the EEC and BoB, respectively. Therefore, developing taxa-specific thresholds might be a more practical way forward for environmental assessment than normalisation to trophic levels.

Trace metal contents in the mussel Mytilus galloprovincialis from Atlantic coastal areas in northwestern Morocco: Levels of contamination and assessment of potential risks to human health

The bioaccumulation of trace metals Cd, Cr, Cu and Zn in soft tissues of the mussel Mytilus galloprovincialis was studied seasonally along the Atlantic coast of northwestern Morocco. Average concentrations (μg g^-1 dry weight) decreased in the following order: Zn (141.61 ± 78.06) > Cr (22.57 ± 15.47) > Cu (18.95 ± 20.01) > Cd (16.33 ± 19.01), with higher amounts during wet seasons. The "Metal Pollution Index" and "Individual Multimetal Bioaccumulation Index" suggested a higher mussel contamination in industrialized areas. Moreover, Cd and Cr concentrations were above the permissible guidelines' limits. The related risks to human health associated with mussel consumption were also assessed. The "Target Hazard Quotient" for Cd and Cr revealed a threat to children when mussels originated from polluted stations, while the "Hazard Index" indicated a hazard to them in all stations. Regarding the "Maximum Safe Consumption", children should not consume mussels, even in low quantities. This study represents the first datum in Morocco to assess such a risk to human health.

Metal accumulation in relation to size and body condition in an all-alien species community

Metal pollution is one of the main environmental threats in freshwater ecosystems. Aquatic animals can accumulate these substances and transfer them across the food web, posing risks for both predators and humans. Accumulation patterns strongly vary depending on the location, species, and size (which in fish and crayfish is related to age) of individuals. Moreover, high metal concentrations can negatively affect animals' health. To assess the intraspecific relationship between metal accumulation and size and health (proxied by the body condition) of individuals, the concentration of 14 metals (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Se, Zn) was analyzed in six alien species from the highly anthropogenically altered Arno River (Central Italy): five fish (Alburnus alburnus, Pseudorasbora parva, Lepomis gibbosus, Ictalurus punctatus, and Silurus glanis) and one crayfish (Procambarus clarkii). We found that in P. clarkii, Cu was negatively related to size, as well as Al in L. gibbosus and Mg for adult I. punctatus. Positive size-dependent relationships were found for Hg in L. gibbosus, Fe in S. glanis, and Cr in juvenile I. punctatus. Only Co and Mg in S. glanis were found to negatively correlate with individual health. Since metal concentrations in animal tissue depend on trade-offs between uptake and excretion, the few significant results suggest different types of trade-offs across different species and age classes. However, only predatory fish species (L. gibbosus, I. punctatus, and S. glanis) presented significant relationships, suggesting that feeding habits are one of the primary drivers of metal accumulation.

Mercury levels in Merluccius merluccius muscle tissue in the central Mediterranean Sea: Seasonal variation and human health risk

In this study we analysed total mercury (THg) levels in European hake (Merluccius merluccius) - an ecologically and commercially important species throughout the Mediterranean - caught in the northern and central Adriatic Sea. To the best of our knowledge, this is the first study evaluating THg levels in hake fillets in relation to ecological (season) and biological (body size, sex, sexual maturity, lipid content) parameters. THg levels in muscle showed no sex-related differences; in contrast, significant season-related differences were found in females, with higher levels in spring-summer compared with autumn-winter. No season-related differences were seen in males. A significant sex effect was found for body size and sexual maturity. Females showed a correlation between THg level and length, THg being significantly higher in mature compared with immature specimens. No significant sex effect was found for muscle lipid content, because a correlation between THg concentration and tissue lipids was found in both sexes. Since the mean THg concentration found in M. merluccius fillets (0.64 ± 0.29 mg kg^-1 dry weight; range, 0.20-1.53) was consistently under the level set by EU regulations, this study demonstrates that European hake caught in the northern and central Adriatic is safe for human consumption.

A Food-Safety Risk Assessment of Mercury, Lead and Cadmium in Fish Recreationally Caught from Three Lakes in Poland

Simple Summary

The research aimed to determine the content of lead (Pb), cadmium (Cd), and mercury (Hg) in water, sediment, and freshwater fish species roach (Rutilus rutilus), perch (Perca fluviatilis), and pike (Esox lucius) from the Dratów, Syczyńskie, and Czarne Sosnowickie lakes located on Polesie Lubelskie, Poland, as well as a food safety assessment for the consumer. Pb and Cd were measured by graphite furnace atomic absorption spectrometry, while Hg was measured by cold vapor atomic absorption spectrometry. The research results showed that both the waters and the sediments of the studied lakes are characterised by a low concentration of Pb, Cd, and Hg, which indicates the lack of a moderate influence of anthropopressure on these reservoirs. The range of heavy metal contents in the muscles of roach, pike, and perch for Pb was 0.0399–0.1595, 0.0305–0.0920, and 0.0296–0.1057 mg kg⁻¹, respectively; for Cd 0.0014–0.0095, 0.0010–0.0015, and 0.0020 mg kg⁻¹, respectively; and for Hg 0.0123–0.0499, 0.0185–0.0255, and 0.0216–0.0583 mg kg⁻¹, respectively. The content of heavy metals in fish muscles was low and conformed to requirements as defined in the European Union (EU) food legislation. The health risk assessment with regard to the heavy metal contents in the muscles of fish confirmed the safety of this food for consumers.

Abstract

Heavy metals are introduced into water due to anthropogenic activities and can significantly affect an entire ecosystem. Due to their close integration with the water environment, fish are a sensitive indicator of contamination. In addition, fish is an important element in human diets, therefore, monitoring the concentrations of metallic contaminants in their meat is particularly important for food safety. This study aimed to assess the pollution of water ecosystems with selected toxic heavy metals in lakes Dratów, Czarne Sosnowickie, and Syczyńskie. The concentration of Pb, Cd, and Hg in water, sediment, and freshwater fish muscle tissue was determined, and a food safety assessment was performed. The analysis of water and sediments showed that the sediments were characterised by a significantly higher concentration of heavy metals. Presumably, this ecosystem element plays an important role in the uptake of heavy metal contaminants by fish whose levels were higher in planktonophagous and benthophagous fish species as compared to predatory fish. The food safety assessment showed that amounts of heavy metals in the muscle tissue posed no threat to the health of consumers ingesting that fish species, neither individually (THQ) nor collectively (TTHQ).

Metals in tissues of marine fish from the Thermaikos Gulf, Eastern Mediterranean Sea: Detection of changes with trophic level

Concentrations of 27 metals and elements were investigated in the tissues of 28 demersal and pelagic marine fish species from the Eastern Mediterranean Sea. The analysis indicated highest concentrations of accumulation for the majority of elements in the gills, liver, and scales; whereas, lowest assimilation of elements was reported in the muscle. Pelagic fish accumulated higher concentrations of elements than demersal fish. An inverse correlation due to the growth dilution effect was revealed among element concentrations in the gills, liver, muscle, and skin tissues, and fish size. Patterns of biomagnification for Cs solely were recorded in the muscle and patterns of biodilution for most elements were evident in the gills, liver, muscle, and skin tissues. A positive correlation was determined between trophic level and element concentrations in the scales which could not only be associated with fish diet, but also with metal concentrations in the ambient environment and scales size.

Heavy metal concentration levels and biometric analysis of Liocarcinus depurator from different locations on the western Black Sea coast of Turkey

The aim of the current work is to examine the concentrations of nine heavy metals such as chromium, nickel, copper, cadmium, zinc, cobalt, iron, lead, and metal (aluminium) in two body parts (carapace and walking legs) of Liocarcinus depurator from different stations (İlyas bey, Cide koyu, Anadolu feneri, igneada) in the western Black Sea coast of Turkey. And this study was carried out to examine morphological properties of Liocarcinus depurator in the region. The sex ratio (female/male) of 387 samples was calculated as F/M = 1:0.945. The mean carapace length and width were measured as 20.41 ± 2.41 mm and 25.10 ± 2.78 mm for female and 25.49 ± 3.33 mm and 32.32 ± 4.50 mm for male individually. The mean weight of crabs was measured as 4.09 ± 1.37 g for females and 8.33 ± 3.35 g for males. The samples were investigated trace metals by inductively coupled plasma-optical emission spectrometry (ICP-OES). Ranges over trace metals in all samples of L. depurator as follows: Cr 0.6-1.5, Mn 21-130, Cu 8-37, Zn 6-40, Cd 0.2-1.5, Pb 0.1-3.6, Co 0.1-1.1, Fe 22-160, and Ni 0.6-1 mg/kg wet wt. The walking legs and carapace/exoskeleton of female and male crabs were analyzed and contained various concentrations of Pb, Co, Ni, Cr, Cd, Fe, Cu, Zn, and Mn elements. The order of the heavy metal in all samples of L. depurator is shown as Fe > Cu > Mn > Zn > Cr > Cr > Ni > Cd > Pb > Co. In this research, metal levels of the crab samples compared between female and male and found highest mean metal concentrations in the station number 3 (Anadolu feneri) that the Al concentration in the carapace of female was 295.0 mg/kg wet wt and in the walking legs was 306.67 mg/kg wet wt, in the carapace of male was 264.4 mg/kg wet wt, and in the walking legs was 162.61 mg/kg wet wt in station number 3 (Anadolu feneri). The purpose of this work is to analyze the metal composition of this type of crab, which is abundant in the Black Sea region and is not planned to be attached to fisherman's nets, to evaluate whether it will be useful or not.

Chemical Characterization and Quantification of Silver Nanoparticles (Ag-NPs) and Dissolved Ag in Seafood by Single Particle ICP-MS: Assessment of Dietary Exposure

This study provides a first insight on the chemical characterization and quantification of silver nanoparticles (AgNPs) and dissolved Ag in processed canned seafood products, where food-grade edible silver (E174) is not intentionally added nor is the nanoparticle contained in the food contact material. The aim was to evaluate the bioaccumulation potential of AgNPs and to contribute to the assessment of AgNPs and ionic Ag human dietary intake from processed seafood. It is known how seafood, and in particular pelagic fish, is a precious nutritional source of unsaturated fatty acids, protein, and different micronutrients. Nevertheless, it may cause possible health problems due to the intake of toxic compounds coming from environmental pollution. Among emerging contaminants, AgNPs are widely applied in several fields such as biomedicine, pharmaceutical, food industry, health care, drug-gene delivery, environmental study, water treatments, and many others, although its primary application is in accordance with its antimicrobial property. As a consequence, AgNPs are discharged into the aquatic environment, where the colloidal stability of these NPs is altered by chemical and physical environmental parameters. Its toxicity was demonstrated in in-vitro and in-vivo studies, although some findings are controversial because toxicity depends by several factors such as size, concentration, chemical composition, surface charge, Ag⁺ ions released, and hydrophobicity. The new emerging technique called single-particle inductively coupled plasma mass spectrometry (spICP-MS) was applied, which allows the determination of nanoparticle number-based concentration and size distribution, as well as the dissolved element. Our findings highlighted comparable mean sizes across all species analysed, although AgNPs concentrations partly follow a trophic level-dependent trend. The low mean size detected could be of human health concern, since, smaller is the diameter higher is the toxicity. Dietary intake from a meal calculated for adults and children seems to be very low. Although seafood consumption represents only a small part of the human total diet, our findings represent a first important step to understand the AgNPs dietary exposure of the human population. Further studies are needed to characterize and quantify AgNPs in a large number of food items, both processing and not, and where AgNPs are added at the industrial level. They will provide a realistic exposure assessment, useful to understand if AgNPs toxicity levels observed in literature are close to those estimable through food consumption and implement data useful for risk assessors in developing AgNPs provisional tolerable daily intake.