Bioaccumulation of heavy metals in some tissues of fish in the Red Sea, Egypt

Elucidating the Environmental and Health Risks of Trace Element Pollution in Red Sea Fish from Nuweiba City, Aqaba Gulf, Egypt

Trace element bioaccumulation in marine organisms is a rising international issue due to possible health concerns for humans. Thirteen trace elements were analyzed in the sediment, water, and muscular tissue of Red Sea fish. Additionally, the average daily intake (EDI), the cancer risk (CR), the hazard index (HI), and the target hazard quotient (THQ) of those elements have been taken into consideration when evaluating any possible health concerns related to their consumption. All species presented quantifiable values in muscle for all the analyzed elements (arsenic (As), lead (Pb), copper (Cu), aluminum (Al), boron (B), iron (Fe), barium (Ba), manganese (Mn), nickel (Ni), cadmium (Cd), chromium (Cr), zinc (Zn), and mercury (Hg), except for Cd and Hg, being Fe and Zn the most accumulated elements in all species. Conversely, in water samples, most elements were undeleted except for aluminum, boron, iron, and zinc. All Red Sea fish, however, had concentrations of Zn, Ni, Fe, Cu, and Mn below the upper limit allowed, although most species had higher levels of As, Cr, and Pb (0.48 ± 0.83-5.10 ± 0.79, 1.97 ± 0.46-5.25 ± 0.67 and 2.12 ± 1.01-6.83 ± 0.93 µg/g, respectively).The studied Red Sea fish showed contamination degrees (CD) of Mn, Cu, Fe, Ni, Zn, and Pb were ≤ 1, indicating minimal contamination, with As and Cr showing higher contamination degrees. However, the pollution index values (MPI-elements) can be represented according to ascending order: Lethrinus ramak < Cephalopholis hemistiktos < Pagellus affinis < Trachurus japonicus < Cheilinus lunulatus < Siganus luridus < Parupeneus forsskali < Caesio suevica. The study found that edible tissues are safe for human consumption, with HI values for children and adults less than ten, indicating negligible non-cancer hazards. However, fish consumption presents health risks due to chromium, lead, and arsenic, with THQ values several times greater than 1, and CR-Ni, CR-Cr, and CR-As values exceeding the acceptable 10-4 value in all studied species. This study provides critical insights into trace element contamination in marine fish species, highlighting the need for ongoing monitoring and proactive measures to ensure safe marine fish consumption in the Aqaba Gulf.

Assessing of trace elements health risks in the crab Portunus segnis from northern Tunisian lagoons

The current study aims to examine the concentrations of eight trace elements (TE) (nickel, aluminum, copper, cadmium, lead, cobalt, chromium, and zinc) in the edible tissue of the invasive blue crab Portunus segnis in two southern Mediterranean lagoons (i.e., Bizerte Lagoon (BL) and Ghar El-Melh Lagoon (GML)) between 2020 and 2021. The samples were analyzed for TE using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the mean concentrations in P. segnis muscles were significantly lower in Ghar El-Melh (0.183 mg/kg DW, 1.887 mg/kg DW, and 0.986 mg/kg DW for Cd, Cu, and Al, respectively) compared to Bizerte Lagoon (0.227 mg/kg DW, 8.016 mg/kg DW, and 3.658 mg/kg DW for Cd, Cu, and Al respectively), except for Zn which exhibited similar concentrations in crabs harvested from both lagoons. The recorded concentrations of all TE measured in both lagoons were within acceptable limits per the recommended standards. The highest TE concentrations in P. segnis muscle tissue of crabs from both lagoons were recorded during the summer. The analysis of trace element (TE) levels in P. segnis and the assessment parameters, including estimated daily intake (EDI), target hazard quotient (THQ), and target cancer risk (TCr), revealed values below the acceptable limits for human health. THQ and TCr are commonly utilized in environmental and health risk assessments to gauge the potential impact of contaminants on human health. As a result, we can affirm that the invasive crab P. segnis figures as a secure shellfish product suitable for human consumption in Tunisia. This study provides an opportunity to assess the health risks of consuming blue crabs, with the toxicity risk index aiding decision-making for consumers, policymakers, and stakeholders focused on safety and sustainability. Additionally, it offers fundamental insights to lay the groundwork for forthcoming studies on environmental assessments.

Monitoring and Assessment of Heavy Metal Concentrations in Two Black Fish Species, Capoeta saadii (Heckel, 1847) and Capoeta trutta (Heckel, 1843), in Western Iran

Contamination of aquatic ecosystems with heavy metals poses a significant global issue due to its hazardous effects and persistent accumulation in living organisms. This study analyzed 51 fish samples from two species of Black Fish, Capoeta saadii and Capoeta trutta, collected from Iran's Khorramroud River during the summer and fall of 2022 to assess heavy metal accumulation in their gill, liver, and muscle tissues. After biometry, the studied tissues of each fish were isolated to measure the concentration of heavy metals (cadmium (Cd), zinc (Zn), chromium (Cr), lead (Pb), copper (Cu), and nickel (Ni)). The tissue concentration of the studied metals was obtained by measuring in the inductively coupled plasma optical emission spectroscopy (ICP-OES) device after chemical digestion. Based on the results of this study, muscle and liver tissues had the lowest and highest accumulation of heavy metals, respectively, with zinc concentration in the liver of C. saadii reaching 118.557 mg/kg, which exceeds the permissible limit of 75 mg/kg. Also, there was no significant correlation between the amount of absorption of heavy elements and the biometric indicators of body weight and length. Although C. saadii accumulated higher levels of Zn, Cu, Cd, and Cr than C. trutta, statistical analysis (ANOVA and PCA) revealed no significant differences in heavy metal accumulation between the two species (P > 0.05). Comparisons with international standards indicated that chromium (2.10-9.97 mg/kg) and zinc concentrations (41.72-118.557 mg/kg) exceeded permissible limits, while Ni, Cu, Pb, and Cr levels remained below the allowable thresholds. These findings underscore the need for strategic planning, management, and continuous environmental monitoring to mitigate heavy metal pollution in aquatic ecosystems and safeguard the health of fish populations in the Khorramroud River.

The impact of feeding pattern on heavy metal accumulation and associated health risks in fishes from the Dhaleshwari River Bangladesh

Heavy metals in aquatic ecosystems accumulate in fish tissues, posing significant ecological and health hazards due to their toxic effects on both the environment and human consumers. The purpose of the study was to assess the potential hazards associated with consuming carnivorous, omnivorous, and herbivorous fish species from the Dhaleshwari River in Bangladesh. The study focused on the seasonal variation and accumulation pattern of toxic heavy metals in these fish species. For this, four fish species (Wallagu attu, Ompak bimaculatus, Labeo calbasu, Cirrhinus mrigala were sampled during the dry and wet seasons from the contiguity of the industrial outlet from Dhaleshwari River. The amount of accumulation of Cr, Pb, Cd, Cu and As in the muscles of the samples were analyzed using spectrophotometry. Heavy metal concentrations were observed to be in the following descending order: Cu (1.99) > Cr (1.92) > Pb (1.42) > Cd (0.31) > As (≤0.0002) (mg/kg, wet weight). Cr, Cd and Pb concentrations exceeded some international food safety guidelines for fish muscles. Carnivorous species exhibited higher metal accumulation than omnivores and herbivores. Statistical analysis revealed significant variations among seasons (p < 0.001), species (p < 0.05) and strong correlation among metals (except As) with p < 0.01. Risk assessment suggested carnivorous species might pose noncarcinogenic risks to both of its child and adult consumers. Despite the potential noncarcinogenic risks, the alarming levels of chromium in these fish indicate a substantial cancer risk for both adults and children, raising concerns about the safety of consuming fish from the Dhaleshwari River. These findings strongly emphasize the importance of implementing enhanced regulatory monitoring to mitigate health risks associated with contaminated fish consumption.

Exploring the efficacy of Cystoseira sedoide alga for cadmium and copper biosorption: an integrated experimental and computational study

Pollution by heavy metals is a major global issue. The biosorptive removal of Cd2+ and Cu2+ by Cystoseira sedoide (C. sedoide) was evaluated in this work. FTIR and XRD analysis were performed to determine the characteristics of the biosorbent. In batch biosorption studies, several operating parameters such as solution pH and concentration, contact time, biosorbent dose and temperature were tested and optimized for the effective elimination of cadmium and copper ions. Results were further compared to industrial activated carbon (Ac.C). The biosorption capacities for Cd2+ and Cu2+ were 23.78 and 14.66 mg g-1, respectively. Excellent removal rates were achieved for both Cd2+ and Cu2+ by C. sedoide. In experiments with varying temperature, biosorbent dose, and heavy metal ions concentration, almost steady states were observed whatever the operating conditions and no notable differences were observed within the studied range of conditions. However, Ac.C performance was dependent on the operating conditions. Moreover, cadmium ion removal by C. sedoide was efficient even in the presence of copper ions. Based on the density functional theory (DFT) computations, it can be stated that the attraction forces between the heavy metal ion and the biosorbent depend on the considered structure and arrangement of the proposed complex models. Besides the revealed benefits of using C. sedoide for the removal of heavy metals, the biomass can be reused as a feedstock for the production of biochar or bioethanol, leading to economic and environmental sustainability when implemented on a large scale.

Effects of antimony on antioxidant system, damage indexes of blood-brain barrier and ultrastructure of zebrafish (Danio rerio)

Antimony (Sb) and its compounds can be harmful to people and are known to cause cancer, so they are a key pollutant to control. This study investigated the influence of antimony on non-enzymatic antioxidants and the blood-brain barrier (BBB) in zebrafish(Danio rerio), a model organism that shares a high degree of genetic similarity with humans. Zebrafish were exposed to different doses of antimony in water for 7, 18, and 30 days. The results indicated that antimony accumulated most in the liver, followed by the gills, flesh, and brain, with the accumulation increasing as the exposure duration extends. Additionally, under identical antimony concentrations, the buildup in the four tissues was positively correlated with the duration of exposure. After 18 days of exposure, the total antioxidant capacity (T-AOC) and endogenous non-enzymatic antioxidants vitamin C (VC) and vitamin E (VE) decreased as a result of antimony ingestion in zebrafish, although cysteine secretion was increased in the liver, gills, and brain. The structural integrity of the BBB was compromised by the elevation of ApoE4 and MMP-9 levels as a result of antimony exposure, which led to the breakdown of the basal lamina, tight junctions, and nerve fibers in the brain. At this injured region, 5-HT and MBP were also able to easily enter and leave the BBB, albeit at variable rates. Additionally, when the antimony exposure level reached 16.58 mg·L-1, antimony penetrated the BBB and bound to erythrocytes, causing their lysis.

Exposure assessment of pesticide residues, heavy metals, and veterinary drugs through consumption of Egyptian fish samples

Environmental contaminants may enter seafood products either through water and sediments or via feed and feed additives or may be introduced during fish processing and storage. The study focused on the nutritional and toxicological significance of heavy metals, antibiotics, and pesticide residues in 48 fish samples collected from the Kafr-ElSheikh governorate in Egypt. Various analytical instruments are used to determine and detect heavy metals, antibiotics, and pesticides. These include Liquid Chromatography Tandem Mass Spectrometer (LC-MS/MS), Inductively Coupled Plasma Mass Spectrometer (ICP-MS), and Gas Chromatography-Mass Spectrometer (GC-MS). The following metals were discovered in fish species: arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), and zinc (Zn). Each of these metals was detected 47 times. Chromium (Cr) was detected 40 times, nickel (Ni) was detected 27 times, and lead (Pb) was detected 6 times. The mean concentrations of As, Cd, Cr, Co, Cu, Fe, Ni, Mn, Hg, Pb, and Zn were determined to be 0.025, 0.02, 0.501, 0.50, 0.81, 12.56, 0.5, 0.689, 0.051, 0.031, and 5.78 mg/kg, respectively. All levels of cadmium, mercury, and lead detected in fish samples were significantly lower than the maximum permissible limits set by Egyptian and European standards. Furthermore, in this study, antibiotics and pesticide residues were found to be not detected in all analyzed fish samples. Based on the estimated daily intake and hazard quotient values, the concentration levels of metals found in fish samples seem to pose no significant threat to public health.

Assessing the risk of consuming fish from Kanyakumari (Tamil Nadu), India: An evaluative study on bioaccumulated heavy metals in different fish species using inductively coupled plasma mass spectrometry

Environmental pollutants which are developing an alarming situation in the contemporary world captured attention in the present research. When it comes to food safety and security concerns it becomes an important field to be studied rigorously as food contributes majorly to human and animal health. The pollution of aquatic ecosystems by heavy metals (HMs) ultimately results in adverse effect on the food chain, which is covered in the current study. Fish is considered to be one of the main components of a balanced diet plate due to its high-quality protein, which sets it apart from other dietary sources. On the other hand, it is also susceptible to the absorption and bioaccumulation of HMs at toxic levels. In our study, we have considered three different species (Nemipterus japonicus, Oreochromis mossambicus, and Lates calcarifer) of fish collected from Kanyakumari, Tamil Nadu (India). Three organs namely liver, gill, and muscle were taken into consideration for the HM profiling using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg) and Lead (Pb) were found to be in varied concentrations ranging from 0.1 to 1.13, 0.89-1.45, 9.95-30.66, 0.14-1.62, and 24.69-189.5 µg/kg respectively, in the studied organs of fish. Carcinogenic and noncarcinogenic risk assessments were also done indicating a notable level of Pb and Cr in selected fish species. The Hazard Index (HI) for Oreochromis mossambicus was >1 for adults and children, indicating future possibility of probable health hazards on daily consumption of these fish. In Oreochromis mossambicus, the cancer risk (CR) values for Cr and As were significantly high, particularly for children, indicating a possible occurrence of acute health risk as it exceeded the threshold of 1 × 10-3 and suggesting a significant concern. Though consumption of fish on daily basis in such significant quantity is practically impossible both for adult and children, rendering these species safe.

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).

Metal distribution in three organs and edibility assessment on Coptodon rendalli from the Umgeni River impacted by metallurgic industrial activities

Fish is among the most affordable and readily available protein sources for communities residing near water bodies. However, the recent pollution status of aquatic ecosystems has rendered fish consumption risky for human health. The study evaluated metal levels in the liver, gill, and muscle tissues of Redbreast tilapia (Coptodon rendalli) from Inanda and Nagle dams in the uMgeni River system. Metals, Al, Sb, Cd, Cr, Fe, Mn, Mo, Pb, and Zn were analysed using ICP-OES. Fish size showed no significant difference between the two dams (p > 0.05) whereas a descending trend liver > gill > muscle was observed for most metal levels at both dams. Moreover, there was a clear separation for metal levels in the liver, gill, and muscle between the two dams (p < 0.001) and a similar trend was observed for organs in each dam (p < 0.001). No relationship was observed between fish length and metal levels and no definite trend was observed for inter-metal relationships. Antimony, Cr, and Pb showed THQs greater than 1 at both dams which suggests health risks for consumers. Molybdenum has also shown a concerning THQs with some individuals exhibiting values ranging from 0.5 - 0.9. These findings suggest that consuming C. rendalli from the Inanda and Nagle dams could result in adverse health effects from Sb, Cr and Pb.

Bioaccumulation of Cadmium in Muscle and Liver Tissues of Juvenile Yellowfin Tuna (Thunnus albacares) from the Indian Ocean

The present study evaluated the cadmium (Cd) levels and temporal variation of Cd in dark muscle, white muscle, and liver of juvenile Thunnus albacares. 72 individuals (Standard length: 50-67 cm; weight: 0.8-2.5 kg) were collected from Indian Oceanic water around Sri Lanka during the period between April 2021 to May 2022. Total Cd levels were analyzed using an Inductively Coupled Plasma Mass Spectrophotometer. The mean Cd levels (mean ± SD mg kg-1 dry weight) in different tissues varied with significantly higher levels in the liver (13.62 ± 0.98, p < 0.05), compared to dark muscle (0.52 ± 0.05), and white muscle (0.42 ± 0.04). Cd levels in liver tissues were positively correlated (p < 0.05) with the fish weight. The Cd levels reported in dark muscles, white muscles, and liver tissues were significantly higher (p < 0.05) during 2nd inter-monsoon than in the other monsoonal regimes and exceeded the maximum permissible level (0.1 mg kg-1 wet weight) set by the European Union (EU). However, the measured Cd levels in white and dark muscles were below the maximum permissible level (0.2 mg kg-1 wet weight) set by FAO/WHO. The Cd levels in all the liver tissues were above the levels set by the EU and FAO/WHO. Accordingly, people should avoid the consumption of liver tissues of T. albacares from the Indian Ocean. A human with a body weight of 60 kg can consume white muscles up to 4.667 kg per week without exceeding the Provisional Tolerable Weekly Intake.

Health risk assessment of heavy metal toxicity in the aquatic environment of the Persian Gulf

This study aims to explore the potential health risks linked to four heavy metals/metalloids (Pb, Cd, As, Hg) present in four commercially important fish species (Scombromorus commerson, Pseudorhombus elevatus, Thunnus tonggol and Otolithes ruber) in the Persian Gulf. Metals in fish muscle tissue were analyzed via ICP-MS. The analysis revealed that Scombromorus commerson (except for Pb) and Thunnus tonggol (except for As) exhibited the highest and lowest contamination levels, respectively. The Hazard Index findings highlighted arsenic and mercury as the most hazardous elements. However, the Target Hazard Quotient values for each metal and fish species remained within safe thresholds. The highest and lowest Total Carcinogenic Risk was concerning Pseudorhombus elevates (As: 7.41-E05), and Thunnus thonggol (Pb: 3.21-E07), respectively. TCR analysis suggests that the cancer risk of studied metals was below the negligible level (TCR < 10-6) or within the acceptable level (10-6 < TCR < 10-4), potentially not posing carcinogenic risks through extended consumption.

Lead and cadmium in blood and tissues of Atlantic bluefin tuna (Thunnus thynnus L., 1758)

Cadmium (Cd) and lead (Pb) levels in blood and tissues of Atlantic bluefin tuna were analysed to gather information regarding their distribution, accumulation and inter-relationships, as well as to examine how sex affects them. In the whole population, the concentration range was from below the detection limit (bone) to 8.512 μg g-1 (liver) for Cd, and from below detection limit (bone and gills) to 0.063 μg g-1 (kidney) for Pb. The median concentration in the muscles (0.008 and 0.029 μg g-1 for Cd and Pb, respectively) was 10 times less than the maximum permitted for consumption. Sex was shown to be an important variable affecting concentrations of Cd in both liver and kidneys, so taking into account sex when interpreting results is highly recommended. The importance of Cd and Pb bioaccumulation in fishery by-products, increasingly important in commercial circuits, is also highlighted.

Microplastic pollution and heavy metal risk assessment in Perca fluviatilis from Anzali wetland: Implications for environmental health and human consumption

The worldwide increase of anthropogenic contaminants in aquatic ecosystems has raised concerns, particularly heavy metals and microplastics (MPs), posing potential health risks for aquatic organisms. Therefore, this study aimed to investigate the presence of heavy metals (Cu, Ni, Pb, Cd, Hg, Zn, Mn, As, V, Co, Cr, Fe, and Se) and MPs in the muscle, liver, and gills of Perca fluviatilis Linnaeus 1758 from Anzali Wetland during the autumn-winter 2021 and spring-summer 2022 periods. The mean concentration of metals in the muscle was lower than that in the liver and gills. The highest level of metal in the liver, gills, and muscle was related to Fe (4.049 ± 1.192, 3.605 ± 0.878, and 3.459 ± 0.895 μg/g, respectively), while the lowest concentration in the muscle was related to Co (0.011 ± 0.004 μg/g), and in the liver and gills was related to Se (0.013 ± 0.004 and 0.012 ± 0.003 μg/g, respectively) and As (0.013 ± 0.004 and 0.012 ± 0.004 μg/g, respectively). The concentration of metals in summer was higher than in other seasons. The Hazard Index (HI) and Target Hazard Quotient (THQ) values below 1 indicate that consuming this fish does not pose any risk to consumers in terms of metal contamination. Moreover, MPs were identified in the gills of all fish, while no MPs were found in the muscle and liver. The mean number of MPs in the gills was 3.5 ± 1.02 item/individual, and the number of MPs in spring (4.6 ± 0.84 item/individual) was higher than in autumn, winter and summer (4.2 ± 1.22, 3 ± 1.63, and 2.4 ± 0.51 item/individual, respectively). The MPs were dominated by fiber in shape, black in color, 300-1000 μm in size, and nylon in polymer. No significant correlation was found between metal concentrations and MPs, except for Co.

The Concentration and Risk Assessment of Potentially Toxic Elements (PTEs) in Farmed and Wild Carps (Cyprinus carpio) in Hamadan Province of Iran

This study focuses on measuring potentially toxic elements (PTEs) including mercury (Hg), lead (Pb), cadmium (Cd), arsenic (As), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn) in farmed and wild carp by inductively coupled plasma-optical emission spectrometry (ICP-OES) and their intake amount and risk assessment. Estimated Daily Intake (EDI), Target Hazard Quotient (THQ) and the total THQ (TTHQ) were calculated for each element. In the present research, the concentration of As in farmed and wild carp samples was below the detection limit of ICP-OES (< 0.005 mg/kg). The mean concentrations of Pb, Cd, Fe, and Cu in farmed carp samples were significantly higher than that in wild carp samples, while Zn level was higher in the wild carp samples (P < 0.05). There is no significant difference between Hg and Mn in both fish (P > 0.05). The Monte Carlo simulation (MCS) results showed that the ranking order of PTEs based on their THQ was Hg > Pb > Zn > Cu > Fe > Cd > Mn. In the worst-case scenario (in the top 95 percentile) for both wild and farmed carp, the THQ of measured metals was less than one except Hg in children. Overall, this study demonstrated that the levels of PTEs in farmed and wild common carp had a potential non-carcinogenic risk for children (TTHQ > 1).

Bioaccumulation, Bioindication and Health Risk Assessment of Heavy Metals in Cape Horse Mackerel (Trachurus trachurus) and Slinger Seabream (Chrysoblephus puniceus) in the Durban Basin and Cape Vidal, South Africa

The bioaccumulation of heavy metals (HMs) in marine fish is a growing global concern due to potential human health risks. The study analyzed HM in the muscle tissue, gills, and gut of adult male and female cape horse mackerel and slinger seabream caught in the polluted Durban Basin and pristine Cape Vidal from April 2018 to February 2019. Results revealed interspecific, spatial, and organ-specific variability in HM levels. In the Durban Basin, slinger seabream had bioaccumulation (in mg/kg) of As (2.3 ± 0.2), Cr (2.6 ± 0.2), Ni (2.0 ± 0.1), and Pb (4.1 ± 0.3) while cape horse mackerel had Ni (1.6 ± 0.2), Pb (4.7 ± 0.6), and Zn (52 ± 3.01) exceeding World Health Organization (WHO) regulatory limits. Metal pollution index (MPI) values were also higher in Durban Basin (> 5.13) than Cape Vidal (< 3.32) for both species' muscles. Liver and gills of slinger seabream and gut of cape horse mackerel exhibited higher HM accumulation patterns proportionate to the environmental concentrations, indicating the bioindicative potential of HM pollution by the two species. Risk assessment indicated that both fish species had target hazard quotient > 1 for Cr, and target cancer risk < 10-4 for Pb, implying significant potential non-carcinogenic and carcinogenic health risks associated with fish consumption from the Durban Basin. The study recommends daily consumption limits of 16 g/day for slinger seabream and 14 g/day for cape horse mackerel to ensure health safety. The findings contribute to the understanding of HM pollution in the Durban Basin and provide important information for decision-makers and policymakers in developing effective strategies to mitigate and manage HM contamination in fish populations.

Health risk assessment of heavy metals in Coptodon zillii and Parachanna obscura from a tropical reservoir

In this study, the concentrations of trace metals were examined in commercially important fish, Coptodon zillii and Parachanna obscura from Osu reservoir. These were with a view to providing baseline information on the levels of heavy metals and its associated risks to human health through fish consumption. Fish samples were collected fortnightly for five months using fish traps and gill nets with the assistance of local fisherman. They were brought into the laboratory in an ice chest for identification. The fish samples were dissected and the gills, fillet and liver kept in freezer and later analyzed for heavy metals based on Atomic Absorption Spectrophotometric (AAS) method. The data collected were subjected to appropriate statistical software packages. The results revealed that the concentration of the heavy metals in P. obscura and C. zillii across the tissues were not significantly different (p > 0.05) from each other. Also, the mean concentration of heavy metals in the fish were below the recommended limits of FAO and WHO. The target hazard quotient (THQ) for each heavy metals were below one (1) while the estimated hazard index (HI) for C. zillii and P. obscura showed no threat to human health risk through the consumption of the fish species. However, continuous consumption of the fish could probably cause health risk to the consumers of the fish. According to the study's findings, human consumption of fish species with low concentration of heavy metals at the current accumulating level is safe.

Health Risk Assessment and Comparative Studies on Some Fish Species Cultured in Traditional and Biofloc Fish Farms

The present study aimed at (a) determining the concentration of macro-minerals and toxic metals in fish species collected from biofloc and traditional fish farms; (b) assessing the contribution of macro-minerals to our daily diet; and (c) evaluating the health risks of children and adults based on the US Environmental Protection Agency (USEPA) deterministic model. Significantly higher concentrations of macro-minerals and significantly lower levels of toxic metals (at < 0.05 level) were found in most of the biofloc fish species compared to the market fish samples. The values of the target hazard quotient (THQ) were less than 1.0 for all individual trace metals in all species, which indicated that there were no noncarcinogenic health risks. Furthermore, the value of the hazard index (HI) in three samples of Tilapia from the market exceeded the recommended value of 1.0, while all samples from the biofloc fish tank were within the maximum tolerable limit, which suggested that the daily consumption of Tilapia fishes from the market may result in considerable harmful effects. Target cancer risk (TCR) for Pb in all of the studied samples was within the range of 10^-6 and 10^-4, hence the adults and children would not experience any kinds of carcinogenic effects. The result obtained from this comparative study revealed that the consumption of fish species from both local market and biofloc fish farms was almost safe, but the value of TCR in Pb was higher in traditional fish samples than that of biofloc tanks, hence fish samples from biofloc farms were more suitable for consumption.

A Probabilistic-Deterministic Approach Towards Human Health Risk Assessment and Source Apportionment of Potentially Toxic Elements (PTEs) in Some Contaminated Fish Species

Contamination of fish species with potential toxic elements (PTEs) has caught the prime attention globally including Bangladesh. The present study enlightened on the accumulation, origin, and associated health implications of Mn, Fe, Cu, Zn, As, Hg, Pb, and Cr in ten varieties of fish species collected from the heavily polluted river Buriganga. Levels of PTEs in the studied fish species were found within the legislative value suggested by the World Health Organization (WHO) and Federal Environmental Protection Agency (FEPA) except for Fe, Cu, Zn, and Hg and can be assembled as Zn > Fe > Cu > Mn > Cr > Hg > As > Pb. The origin of PTEs in fish species apportioned mostly anthropogenic coupled with natural sources. Among the anthropogenic sources, industrial wastewater, recycling of leaded and lithium-ion batteries, metallurgical industries, shipyards, tannery, cosmetics, and chemical industries are the major contributors. This study identified children are exposed to As and Zn as their estimated targeted hazard quotient (THQ) value exceeded the threshold limit of safety, whereas adults are exposed to As only. The estimated, hazard index (HI) for children was found more than four times of adults; however, both the population groups are in vulnerable situation considering HI value (HI > 1), indicating possible non-carcinogenic health risk. Moreover, cumulative cancer risk TCR appraised that all the fish species exceeded the threshold limit of > 1E-03 for children and > 1E-04 for adults, which are level VII and level V contamination state for child and adult, respectively, and manifested consumption of the studied fishes arises a high probability for lifetime cancer risk.

Heavy metals content in fresh tuna and swordfish caught from Hindian and Pacific Oceans: Health risk assessment of dietary exposure

Background and Aim

Yellowfin tuna and swordfish are seafood commodities commonly caught from deep oceans worldwide. Therefore, this study aimed to assess the levels of three heavy metals, namely, cadmium (Cd), lead (Pb), and mercury (Hg) in yellowfin tuna and swordfish. The results are expected to provide consumers with information on the safety of consuming or exporting these fishes caught in the Hindian and Pacific Oceans.

Materials and Methods

Fresh yellowfin and swordfish were obtained from fishermen's catches in FAO Fishing Zone 57 (Indian Ocean) and 71 (Pacific Ocean) and then collected at Benoa Harbor, Bali Province. The comparative method was to evaluate the levels of heavy metals in each fish. Furthermore, heavy metal concentrations, including Pb, Cd, and Hg, were determined using atomic absorption spectroscopy analysis. These results were then used to assess the safety of these fishes by calculating the estimated daily intake (EDI) and target hazard quotients-total target hazard quotients (THQs-TTHQs).

Results

The analysis showed that none of the samples exceeded the threshold levels for the three heavy metals, which was specified by the Indonesian National Standard (SNI) and European Commission Regulation (CR) No. 1881/2006. The EDI and provisional tolerable weekly index (PTWI) obtained in this study were still in the safe range. However, the PTWI values for Pb in yellowfin tuna product from the Indian Ocean were higher (0.0038 mg/kg) compared to the recommended standard for the adult population. The THQ-TTHQ values of fish caught from these oceans were also within the acceptable range specified by the two agencies, indicating that they are safe for consumption by people with various age groups and for export purposes.

Conclusion

The average levels of three heavy metals (Cd, Pb, and Hg) in muscle samples of yellowfin tuna and swordfish caught from the Pacific and Hindian Oceans were within the acceptable range as specified by the SNI and CR No. 1881/2006. Furthermore, the EDI and THQs values indicated that fishes caught from the Pacific and Hindian Oceans were safe for consumption. This research is still limited to assessing two capture fisheries commodities. Further research is needed on the assessment of heavy metal levels in other capture fisheries commodities in this capture zone.

Fish liver damage related to the wastewater treatment plant effluents

Wastewater treatment plants (WWTPs) continuously release a complex mixture of municipal, hospital, industrial, and runoff chemicals into the aquatic environment. These contaminants are both legacy contaminants and emerging-concern contaminants, affecting all tissues in a fish body, particularly the liver. The fish liver is the principal detoxifying organ and effects of consistent pollutant exposure can be evident on its cellular and tissue level. The objective of this paper is thus to provide an in-depth analysis of the WWTP contaminants' impact on the fish liver structure, physiology, and metabolism. The paper also gives an overview of the fish liver biotransformation enzymes, antioxidant enzymes, and non-enzymatic antioxidants, their role in metabolizing xenobiotic compounds and coping with oxidative damage. Emphasis has been placed on highlighting the vulnerability of fish to xenobiotic compounds, and on biomonitoring of exposed fish, generally involving observation of biomarkers in caged or native fish. Furthermore, the paper systematically assesses the most common contaminants with the potential to affect fish liver tissue.

Metal Biological Enrichment Capacities, Distribution Patterns, and Health Risk Implications in Sea Bass (Lateolabrax japonicus)

Seabass (Lateolabrax japonicus) is a major aquacultured fish species worldwide. The bioconcentration, bioaccumulation, and biomagnification of metals in water, sediments, and commercial feed were investigated in L. japonicus from an aquaculture pond in the Pearl River Delta of South China. Aluminum (Al), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), and lead (Pb) were determined in the dorsal muscle, viscera, backbone, gill, and stomach contents of L. japonicus. The gill and stomach contents had higher levels of bioconcentration of most metals than other parts of fish. Based on the bioaccumulation factor, the gill and backbone exhibited the highest accumulation of Zn, while the viscera had the highest capacity to accumulate Cu. The mean biomagnification factor values exceeded for As in dorsal muscle, for Cu in the viscera, for Cr and Pb in the gill, and for Al, Cr, Fe, Cu, and Pb in the stomach contents, indicating efficient bioaccumulation from commercial feed and their habitat. Non-metric multidimensional scaling analysis revealed two groups that resulted from the accumulation of metals in various parts of L. japonicus. Moreover, health risk assessment indicated that no notable adverse health effects occurred from the ingestion of L. japonicus.

Heavy metal exposure risk associated with ingestion of Oreochromis niloticus and Coptodon kottae harvested from a lacustrine ecosystem

Lacustrine ecosystems have not been widely assessed for heavy metal contamination and associated health risks; yet, they could be accumulating these contaminants to the detriment of aquatic organisms and communities relying on them for various aspects. The water quality index (WQI) and concentrations of heavy metals including As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn in water, sediment, Oreochromis niloticus, and in the endemic and endangered Coptodon kottae in Lake Barombi Kotto in Cameroon were determined to evaluate fish heavy metal bioaccumulation, and heavy metal exposure risk posed to communities consuming these fish species. The WQI of the lake was found to be excellent with heavy metal concentrations that were lower than what was obtained in the sediments and fish samples. Mean heavy metal concentrations in sediment ranged from 0.86 ± 0.03 mg/kg for Cd to 560.1 ± 11.15 mg/kg for Fe. In both fish species, Fe, Mn, and Cu had the highest concentrations. Though the heavy metal concentrations in the lake water were low, heavy metal bioconcentration factors for both fish species were very high ranging from 1.6 for Fe to 1568 for Mn. The concentration patterns of heavy metals in the organs of both fish species followed the order bones > gut > muscle. Consumption of these two fish species contributes less than 1.0% of the permissible tolerable daily intake (PTDI) and provisional tolerable weekly intake (PTWI) of these metals with lead (Pb) having the potential to exceed permissible exposure levels when high amounts of these fish are consumed by adults.

Health risk assessment of some heavy metals detected in edible fishes of Gorgan Bay, Caspian Sea (Iran), for human

Just recently, heavy metals have been dramatically detected in aquatic animals, especially in fishes; hence, documented method to assess their health risks for humans who eat these contaminated fishes could be helpful. For the sake of this aim, the health risk assessment of four heavy metals including arsenic, cadmium, lead, and copper in three main edible fishes caught from Gorgan bay was studied. Mullet, roach, and common carp have been caught randomly in winter and spring of 2021 from three different fishing sites of Gorgan bay, including Miankaleh wetland, estuary of Qaresu River, and mouth of Chapaghli canal. Heavy metal measurement has been done with MOOPAM method, and risk assessment of fish consumption was assessed by estimated daily (EDI) and weekly intakes (EWI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) indices. In this study, estimated daily intake (EDI) was much lower than the tolerable daily intake. Although TCR of cadmium within all fishes and arsenic in two fishes were more than acceptable value, THQ and HI values were less than one, and TCR of lead as well as copper was lower than the critical values, which suggests heavy metals of the Gorgan bay have no serious risks to consumer health.

Accumulation of Heavy Metals in Long-Evans Rat Through Feeding Fishes of Buriganga River and Their Histopathological Evaluation

The study was conducted to evaluate the impacts of industrial discharges, including from tanneries, in terms of heavy metal loads in fin-fish of the Buriganga river, Dhaka, Bangladesh, and to find out the ultimate effects of feeding those heavy metal-contaminated fishes to Long-Evans rats to examine rats' heavy metal accumulation along with viable architectural alterations on various organs through histopathological screenings. Being the most edible by the populace, Labeo rohita was chosen for this purpose. Labeo rohita was collected from five different spots in the river close to the industrial outlets, covering three seasons: monsoon, winter, and summer throughout the year. Experiments unearthed that the deposition of heavy metals inside fishes always surpassed the standard margin, implying a pernicious aquatic milieu. The empirical data suggests that the mean concentrations of Cu, Pb, Cr, and Cd were higher than the permissible limits of WHO and FAO after feeding heavy metal-contaminated fishes for a period of 120 days. Seasonal variations were also taken into account, and it was noticed that rats fed with fish collected in winter had the highest heavy metal concentrations (P < 0.05). Significant architectural changes were observed during histopathological screening of rats' livers and kidneys characterized by necrosis, inflammation, and congestion. After gauging the obtained data, it might be concluded that consumption of heavy metal-contaminated fish entails accumulation of heavy metals, which causes histopathological changes in rats' livers and kidneys, including necrosis and severe structural deformational changes compared to those of control groups.

Antimony accumulation in zebrafish (Danio rerio) and its effect on genotoxicity, histopathology, and ultrastructure

Antimony (Sb) is a toxic metal in aquatic ecosystems. In this study, the accumulation of aqueous Sb in the liver, brain, gills and muscle of zebrafish (Danio rerio) and its effect on genotoxicity, histopathology and ultrastructure alterations were evaluated. The fishes were exposed to different concentrations (0, 8.29, 16.58, 33.16 mg L^-1) of aqueous Sb for 18 days. The results showed that the order of Sb accumulation in different tissues was liver > gill > muscle > brain, and the accumulation increased with increasing Sb stress concentration. The mRNA expression levels of Nrf2, Cu/Zn-SOD, Mn-SOD, CAT and GPx genes showed different trends. In addition, significant histopathology and ultrastructure alterations were observed in the liver and gills exposed to Sb. Sb could accumulate in different tissues of zebrafish, inducing the expression of oxidative stress genes and activating antioxidant defense systems. Histological and ultrastructural changes could be used as valid biomarkers for the assessment of aqueous Sb contamination.

Determination of the Heavy Metal Bioaccumulation Patterns in Muscles of Two Species of Mullets from the Southern Caspian Sea

Simple Summary

Fish are an important source of proteins of a high biological value, of some vitamins and minerals, and of polyunsaturated omega-3 fatty acids. However, fish products can also allow harmful substances, like heavy metals, to enter the diet. Such substances are recognized as being the most serious contaminants for aquatic ecosystems at the present time. Their non-biodegradability allows them to accumulate in fish tissues, and then pass into human diets. Therefore, our study aimed to determine the concentrations of heavy metals (As, Cd, Cu, Hg, Ni, Pb, and Zn), and to evaluate the bioaccumulation patterns in the different types of musculature in two species of fish of commercial interest, Chelon auratus and Chelon saliens, from the south coast of the Caspian Sea. The results obtained emphasize the need to continue to monitor and evaluate the degree of pollution in the sampled area, both in fish and other species and also in the environment, as well as recommending prevention measures orientated towards limiting and/or reducing the excessive exposure of the human population to heavy metal contamination.

Abstract

Although fish is a food that supplies nutrients of a high biological value, they can also be a source of some harmful substances, such as heavy metals. In the same context, some human activities in the Caspian Sea have contaminated this ecosystem during the past few years. For those reasons, our objective consisted of determining the concentrations of heavy metals and evaluating their bioaccumulation patterns in the different types of musculature in two species of mullets of commercial interest, Chelon auratus and Chelon saliens, from the southern coast of this sea. For this purpose, 20 C. auratus and 29 C. saliens were caught off this coastline and the metal concentrations in 3 different muscle locations were analyzed: the ventral, dorsal and caudal muscles of each fish. The caudal muscle had higher concentrations of Cd, Cu, Pb, and Zn, whereas As, Hg and Ni accumulation seemed to be independent of the musculature type. Overall, the Cd, Hg, and Pb concentrations exceeded the maximum levels permitted in fish by the European Union. In addition, the relationships between pairs of metals were positive and elevated in all the cases, which could be a sign of heavy metal pollution in the region sampled. Therefore, it will be necessary to continue monitoring and evaluating the degree of pollution in the Caspian Sea.

Distribution of metals in water, sediment and fish tissue. Consequences for human health risks due to fish consumption in Lake Hawassa, Ethiopia

Water pollution may be a serious environmental problem for Lake Hawassa, an important fishing and recreational site as well as a drinking-water source in Ethiopia. The present study aims at determining the distribution of metals and metalloids in the lake's water, sediment and fish tissues and assessing the resulting human health and ecological risks. Metals were detected in both abiotic and biotic samples. In water, only the Hg concentration was significantly different among sampling sites. The average concentration of As, Cd, Cr, Cu, Ni, Pb, and Zn in water were below the environmental quality thresholds, thus not having potentially adverse effect on aquatic life. In sediment, significant differences in metals concentration among sites were found for As, Cd, Pb, Co, Zn and Hg (p < 0.05). Exceedances of As, Cr, Cu, Hg, Ni and Zn were found in sediment, with Cr, Ni and Zn above the probable effect concentration and being potentially toxic to aquatic life. Fish stored more metals in their liver than in their muscle. The concentration of metals in carnivorous fish (Barbus intermedius) was not higher in muscle and liver than those in herbivores fish (Oreochromis niloticus). The Bioaccumulation Factor of Cr in all fish species muscle was >1. The Biota-Sediment Accumulation Factor of all metals in all fish species muscle were <1. Positive correlations among metals in water and correlations among metals in sediment were found, indicating a potential common pollution source. Positive correlation of total organic carbon with Cd, Co and Se and clay content with Pb, As and Hg was found and may imply that metals are easily adsorbed by the organic matter and fine sediment. With respect to the measured metals no potential health risk due to consumption of fish from Lake Hawassa was observed.

Comparative Study on the Distribution of Essential, Non-Essential Toxic, and Other Elements across Trophic Levels in Various Edible Aquatic Organisms in Sri Lanka and Dietary Human Risk Assessment

Thirty-six elements are categorized as essential but toxic in excess amount (EBTEs), non-essential toxic (NETs), and Other in 29 different edible aquatic species dwelling in offshore pelagic, and coastal and estuarine (CE) ecosystems were investigated in Sri Lanka. Elements were analyzed using an energy-dispersive X-ray fluorescence (EDXRF) spectrometer, and an NIC MA-3000 Mercury Analyzer. EBTEs showed a negative relationship, whereas NETs showed a positive relationship between the concentration (mg/kg wet weight) and trophic levels in both ecosystems. EBTEs showed trophic dilution, whereas NETs showed trophic magnification. Some elements in a few organisms exceeded the maximum allowable limit which is safe for human consumption. There was a positive relationship (R² = 0.85) between the concentration of mercury and body weight of yellowfin tuna (YFT). For the widely consumed YFT, the calculated hazard index (HI) for the non-carcinogenic health and exposure daily intake of NETs for adults were 0.27 and 9.38 × 10^-5 mg/kg bw/day, respectively. The estimated provisional tolerable weekly intake (PTWI) (μg/kg bw/w) was 0.47 for arsenic and 0.05 for antimony, cadmium, mercury, and lead. The HI and PTWI values were below the recommended limits; thus, consumption of YFT does not pose any health risk for Sri Lankan adults.

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.

Cadmium and zinc accumulation and depuration in tilapia (Oreochromis niloticus) tissues following sub-lethal exposure

Oreochromis niloticus was subjected to sub-lethal Cd and Zn concentrations for 14 days in order to evaluate their accumulation in the gills, liver, and muscle. Following that, the fish were placed to uncontaminated water for 7 days to allow the metals to be removed from the tissues. The gills had the highest bio-concentration factor for Cd and Zn. The gills showed the highest Cd accumulation rate, and the muscle showed the lowest. The muscle had the highest Cd depuration rate, while the liver had the lowest. The liver exhibited the highest Zn accumulation rate, while the gills and muscle had nearly similar values. Zn depuration rates were very consistent across all tissues.

Content of Pb and Zn in Sediments and Hydrobionts as Ecological Markers for Pollution Assessment of Freshwater Objects in Bulgaria-A Review

The purpose of this review is to describe the contents of Pb and Zn in sediments and hydrobionts as ecological markers for the pollution assessment of freshwater objects in Bulgaria, and the data are compared with other countries and regions. Symmetry was found regarding the levels of Zn in the sediment of the Ovcharitsa and Zhrebchevo dams, which were twice the MAC for arable land (Regulation № 3 of Bulgarian legislation). Symmetry was also observed between the results for Zn and Pb in the studied sediments, and the "favorites" in terms of content were the samples from Zhrebchevo Dam and, especially, from Ovcharitsa Dam. Asymmetry was established in the accumulation of Zn in the livers of carps inhabiting Topolnitsa Dam in comparison with these in Ovcharitsa Dam. A similar asymmetry was observed for lead. The analysis of the muscles and livers of the studied fish showed an asymmetry in the accumulation of zinc, and this process was more intense in the liver. Symmetry was found in the accumulation of Pb in the liver and muscle tissues of the carp from the studied water bodies.

Toxicokinetics of silver in the goldfish Carassius auratus under simultaneous waterborne and diet-borne exposures to silver nanoparticles

Silver nanoparticles (AgNPs) are applied in many products as antimicrobial agents and can be found in the environment. In this study, the uptake and elimination kinetics of silver nanoparticles in fish (Carassius auratus), via simultaneous water and dietary exposure, was investigated and compared with ionic silver (AgNO₃). Silver concentration in the tissues of C. auratus after the uptake phase was similar between nanoparticles and ionic treatments. Upon exposure to nanoparticles, Ag concentration in the different tissues of C. auratus was significantly different (Ag[liver] > Ag[intestine] > Ag[gill] > Ag[muscle]). The liver presented the highest amount of Ag among all organs, and no elimination was detected throughout the elimination period. Our results suggest that once uptake of Ag occurs in fish, the elimination takes very long which may pose ecological implications for bioaccumulation.

Heavy Metals Accumulation in Tissues of Wild and Farmed Barramundi from the Northern Bay of Bengal Coast, and Its Estimated Human Health Risks

Globally, both natural water bodies and aquaculture systems are being severely contaminated by heavy metals due to rising anthropogenic activities. Fish living in aquatic environments can easily accumulate metals in their bodies, which can then be transferred to consumers and put them at risk. In this study, metal concentrations (Pb, Cd, Cr, As, Mn, Cu, Zn) in different organs (gill, liver, and muscle) of farmed and wild Barramundi (Lates calcarifer) fish from the northern Bay of Bengal were evaluated to quantify and compare contamination levels and related human health risk. Heavy metal concentrations were higher in liver tissues of farmed Barramundi than in wild Barramundi, with the following relative mean values in the liver, gills, and muscle: Zn > Cu > Pb > Mn > Cd > Cr > As; Zn > Cr > Cu > Pb > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; and Zn > Pb > Cu > Cr > Mn > Cd > As, respectively. The differences in heavy metal accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations. However, ANOVA indicated that the variation of metals in wild and Barramundi was not statically significant. Pb concentrations in the liver tissue of farmed Barramundi exceeded the national and international threshold limits, whereas concentrations of other metals were within the limit. Among the examined organs in both fish species (wild and farmed), muscle had the lowest concentration compared to others, and liver was the target organ for Pb, Cu, and Cd accumulations. Metals such as Zn and Mn exhibited higher concentration in the gills. However, all the studied heavy metals were below the maximum permissible limits of national and international standards, but the mean concentrations of Pb and Cd values in the liver of farmed Barramundi exceeded all international and national guidelines. Based on the contamination factors (CF) and pollution indices (PLI and MPI), the degree of contamination in the fish organs was as follows: gills > liver > muscle. The major accumulation tissues for both farmed and wild fish were found to be the gills (MPI = 0.970) and the liver (MPI = 0.692). Based on the estimated daily intake (EDI), the fish samples examined in this study are safe for human consumption as within the recommended daily allowance (RDA) range established by various authorities. According to the Target Hazard Quotient (THQ) and Carcinogenic Risk (CR) calculations, though the Barramundi fishes depicted no potential hazard to humans, farmed fish posed a higher health risk than wild fish.

Distribution and Bioaccumulation of Essential and Toxic Metals in Tissues of Thaila (Catla catla) from a Natural Lake, Pakistan and Its Possible Health Impact on Consumers

Although fish are often recommended as a component of a healthy diet, the environmental accumulation of heavy metals in many fish species has been of considerable concern for those weighing the nutritional health benefits against adverse toxic outcome of excess intake of toxic metals. This study aimed to determine the concentration of essential and toxic metals in the tissues of Catla catla in Mangla Lake and to assess the possible risk to the consumers. Fifty samples of Catla catla were collected from Mangla Lake, Mirpur, Azad Jammu and Kashmir, Pakistan and analyzed for eighteen metals including essential and trace metals. The measured range concentrations (µg/g, wet weight) in muscle tissues, in decreasing order, were: K (955–1632), Ca (550–2081), Na (449–896), Mg (129–312), Zn (61.2–215), Fe (11.6–26.8), Sr (2.60–9.27), Pb (1.72–7.81), Se (1.55–3.55), Co (0.12–4.08), Mn (1.04–4.33), Ni (0.69–3.06), Cu (0.88–2.78), Cr (0.45–1.88), As (0.67–1.58), Cd (0.28–0.56), Hg (0.17–0.57) and Li (0.12–0.38). The metal concentrations found in this study were comparatively higher than those reported in literature. A majority of the metals exhibited higher accumulation in gills compared with those in scales and muscles. Mean levels of Pb, As, Co, Mn, Cd, Cr and Zn in Catla catla muscle were found to be exceeding the international permissible limits for the safe human consumption. The condition factor (K), as an indicator of fish health status, indicated that Catla catla of Mangla Lake are in good health condition. The metal pollution index (MPI) of gills (27.9), scales (12.5) and muscle (7.57) indicated low contamination. Moreover, human health risk was evaluated using estimated weekly intake (EWI) and daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and target cancer risk (TCR). Estimated weekly and daily intake values for As, Cd, Cr, Hg, Ni and Pb were higher than provisional permissible tolerable weekly intake and permissible tolerable daily intake while THQ for As, Cd, Cr, Hg, Pb, Se and Zn was higher than 1. The THQ for As, Hg and Pb was several folds higher than 1, indicative of lifetime non-carcinogenic health risks to the consumers. The hazard index indicated cumulative risk, which greatly increased with increasing fish consumption. Target cancer risk indicated that the people eating the Catla catla from Mangla Lake were exposed to As, Cd, Cr, Ni and Pb with a significant lifetime carcinogenic risk. In summary, consumption of Catla catla from this lake was found to be associated with an increased lifetime risk to the general health of the consumers.

Unraveling the hazardous impact of diverse contaminants in the marine environment: Detection and remedial approach through nanomaterials and nano-biosensors

Marine pollution is one of the most underlooked forms of pollution as it affects most aquatic lives and public health in the coastal area. The diverse form of the hazardous pollutant in the marine ecosystem leads the serious genetic level disorders and diseases which include cancer, diabetes, arthritis, reproductive, and neurological diseases such as Parkinson's, Alzheimer's, and several microbial infections. Therefore, a recent alarming study on these pollutants, the microplastics have been voiced out in many countries worldwide, it was even found to be in the human placenta. In recent times, nanomaterials have demonstrated their potential in the detection and remediation of sensitive contaminants. In this review, we presented a comprehensive overview of the source, and distribution of diverse marine pollution on both aquatic and human health by summarizing the concentration of diverse pollutions (heavy metals, pesticides, microbial toxins, and micro/nano plastics) in marine samples such as soil, water, and seafood. Followed by emphasizing its ecotoxicological impact on aquatic animal life and coastal public health. Also discussed are the applicability and advancements of nanomaterials and nano-based biosensors in the detection, prevention, and remediation of diverse pollution in the marine ecosystem.

The health risk assessment of heavy metals to human health through the consumption of Tilapia spp and catfish caught from Lake Mariut, Egypt

This work assesses the concentration of As, Cd, Pb, Hg, and Al in three of Tilapia species and catfish caught from Lake Mariut. As well as the human health risk and muscle biochemical composition. Besides, the antioxidant responses of different species. The average metal concentration order was Pb> As> Cd> Al> Hg. The Cd and Pb levels in all species; besides, the Hg levels in Oreochromis niloticus and Oreochromis aureus exceeded the maximum limits set by FAO, European legislation, and FAO/WHO. The human health risk was assessed using estimated dietary intakes, the target hazard quotient (THQ), and the carcinogenic risk (CR). THQAs was >1 in all examined fishes and closer to 1 in THQCd, Hg. As well, CR level for As was higher than the permissible value. Tilapia zillii showed significant decreases in carbohydrates compared to Clarias gariepinus; also, ash content compared to C. gariepinus, O. niloticus, and O. aureus. Furthermore, water content compared to O. aureus. In contrast, significant increases of SOD in O. niloticus compared to C. gariepinus. In addition, CAT and GPx in O. aureus compared to C. gariepinus. Also, GR in both O. niloticus and O. aureus compared to C. gariepinus, and GSH in all of Tilapia spp. compared to C. gariepinus. Data obtained provide evidence of health risks to the consumers. Therefore, more caution is required.

Pollution and risk assessment of heavy metals in water, sediment and fish (Clarias gariepinus) in a fish farm cluster in Niger Delta region, Nigeria

The study determined the following heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) concentrations in surface water and in fish pond (water, sediments and farmed fish (Clarias gariepinus)) from a fish farm cluster with the view of assessing its pollution level and associated human health exposure risk to these heavy metals through fish consumption. Samples were digested with aqua regia and metal concentrations were determined with an atomic absorption spectrophotometer equipped with an air acetylene flame. Mean concentrations of the heavy metals (ppm) in surface and pond water ranged as follows: cadmium (below detection limit (bdl): 0.298); chromium (bdl: 0.257); copper (bdl: 0.067); manganese (bdl: 0.163); lead (bdl: 0.736) and zinc (bdl: 0.078) while in sediment, the ranges (mg/kg dry weight) were as follows: cadmium (1.156-3.329); chromium (9.439-14.373); copper (26.710-121.819); manganese (3.143-37.202); lead (0.340-1.537) and zinc (87.681-371.060). The mean concentrations of the metals in surface water were significantly different (p < 0.05) from those in sediment in all the sampling sites. The mean metal concentrations (mg/kg dry weight) in C. gariepnus were in the following ranges: cadmium (0.733-1.405); chromium (0.593-1.692); copper (175.882-245.321); manganese (bdl: 3.326); lead (0.221-0.263) and zinc (248.191-292.333). Some of the heavy metal concentrations obtained in water, sediment and catfish analyzed were above the permissible limit set by some National (DPR) and International organisations (WHO, FEPA and FAO). The pollution studies showed that lead, cadmium and chromium contaminated the surface water samples. Sediment from all sites showed low to considerable contamination by the heavy metals. The human exposure risk assessment of the metals showed that the total hazard index was less than one which indicates no probable adverse health effect from the consumption of fish from the ponds, although this case is different for Pb since there is no estimation of oral reference dose (RfDo) for lead according to EPA.

Trophodynamics of trace elements in marine organisms from cold and remote regions of southern hemisphere

Trace metals bioaccumulate in aquatic organisms and some of them biomagnify through food webs, posing a threat to the organisms or their human consumers. Although the trophodynamics of many trace metals is well known in the northern hemisphere, much less is known about metals in aquatic food webs from cold and remote coastal zones of the southern hemisphere. To fill this gap, we investigated the trophodynamics of Al, Co, Cr, Li, Mo, Ni, Sr, and V, which were measured in marine macroinvertebrates and fishes from inshore and offshore locations in each of the Chilean Patagonia and the Antarctic Peninsula area. In Patagonia, there was biodilution of these metals across the whole food web, while biomagnification of Li and Ni was significantly found across the lower food web at the offshore site. In Antarctica, significant biodilution of Al, Li, Ni, Mo, Sr and V occurred through the whole food web for the inshore site, but no tendency (biodilution or biomagnification) was found (p > 0.05) across the organisms at lower trophic levels for the offshore site. Our data suggest that the geographic location and species influences the trophodynamics of these trace elements and expand our understanding of metal fate in remote locations of the southern hemisphere.

Genotoxicity and Trace Elements Contents Analysis in Nile Tilapia (Oreochromis niloticus) Indicated the Levels of Aquatic Contamination at Three Egyptian Areas

The toxic waste and pollutants of heavy metals continuously pollute freshwater aquatic reservoirs, which have severe implications on aquatic life and human health. The present work aims to evaluate trace elements (Zn, Mn, Cu, Cd, and Pb) along with three sites, Mariout Lake, Abbassa, and River Nile Aswan in Egypt, using Nile tilapia (Oreochromis niloticus) as bioindicator. The quality assurance, health-risk assessment, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), quantitative polymerase chain reaction (qPCR), and micronucleus test were performed to investigate the effect of different trace elements on Hsp70 gene level and micronuclei formation. We observed the highest expression of Hsp70 protein band of 70 KD and stress-responsive Hsp70 gene in the liver followed by gills of Nile tilapia caught from Mariout and Abbassa, but the lowest expression was in Nile tilapia caught from Aswan. Obvious micronuclei were observed under the microscope in erythrocytes, and their number was gradually decreased in the following manner: Mariout > Abbassa > Aswan. Noticeably, Cu, Zn, and Mn contents were low. Still, Pb and Cd contents were higher than the toxicity level recommended by the Food and Agriculture Organization (FAO), The World Health Organization (WHO), and the European Commission (EC). These results showed that Hsp70's appearance at the two levels of mRNA and protein is an effective indicator for aquatic pollution besides the aberration at the chromosome level represented in the micronucleus test. Furthermore, these results showed that Nile tilapia of the Aswan region had comparatively low trace elements contamination and were suitable for consumption.

Strongly Basic Anion Exchange Resin Based on a Cross-Linked Polyacrylate for Simultaneous C.I. Acid Green 16, Zn(II), Cu(II), Ni(II) and Phenol Removal

The adsorption ability of Lewatit S5528 (S5528) resin for C.I. Acid Green 16 (AG16), heavy metals (Zn(II), Cu(II) and Ni(II)) and phenol removal from single-component aqueous solutions is presented in this study to assess its suitability for wastewater treatment. Kinetic and equilibrium studies were carried out in order to determine adsorption capacities, taking into account phase contact time, adsorbates’ initial concentration, and auxiliary presence (NaCl, Na2SO4, anionic (SDS) and non-ionic (Triton X100) surfactants). The pseudo-second-order kinetic model described experimental data better than pseudo-first-order or intraparticle diffusion models. The adsorption of AG16 (538 mg/g), phenol (14.5 mg/g) and Cu(II) (5.8 mg/g) followed the Langmuir isotherm equation, while the uptake of Zn(II) (0.179 mg1−1/nL1/n/g) and Ni(II) (0.048 mg1−1/nL1/n/g) was better described by the Freundlich model. The auxiliary’s presence significantly reduced AG16 removal efficiency, whereas in the case of heavy metals the changes were negligible. The column studies proved the good adsorption ability of Lewatit S5528 towards AG16 and Zn(II). The desorption was the most effective for AG16 (>90% of dye was eluted using 1 mol/L HCl + 50% v/v MeOH and 1 mol/L NaCl + 50% v/v MeOH solutions).

Bioaccumulation and potential human health risks of metals in commercially important fishes and shellfishes from Hangzhou Bay, China

Hangzhou Bay is facing severe anthropogenic perturbation because of its geographic position. We studied species-specific bioaccumulation of metals in commercially important fishes and shellfishes, and calculated the potential human health hazards through their consumption, which has not been reported earlier from this area. The hierarchy of metal concentration in organisms was in the decreasing order of Zn (10.32 ± 7.13) > Cu (2.40 ± 2.66) > As (0.42 ± 0.26) > Cr (0.11 ± 0.08) > Cd (0.07 ± 0.07) > Pb (0.05 ± 0.02) > Hg (0.012 ± 0.009). Except for Cd and As concentrations in fishes, metal concentrations have not exceeded the national and international guideline values. P. laevis and P. trituberculatus were the most bioaccumulative of the species studied. According to the non-carcinogenic risk assessment, children were more susceptible to metal contamination than adults. The carcinogenic risk (CR) values indicated that children were likely to experience carcinogenic threats for taking cancer-causing agents As and Cd through fish consumption. In terms of organisms, intake of two crab species, P. trituberculatus and E. sinensis, as well as the oyster species P. laevis, could be detrimental to consumers.

A Brief Review on Heavy Metal Bioaccumulation Studies from Red Sea

The Red Sea forms an important marine ecosystem with its rich species diversity and the different ecosystems, including the coral reefs. The region has received relatively less heavy metal pollution owing to comparatively lesser industrial pollution. This study attempts to review the records of heavy metal bioaccumulation reported in the last two decades. This review is an endeavour to audit the heavy metal bioaccumulation, revealed over the past twenty years, such as As, Cr, Cu, Fe, Cd, Hg, Mn, Zn Ni, Co, Se, and Pb, as reported from various regions of the Red Sea in organisms such as plankton, molluscs, crustaceans, and fish. Though the results of various studies reviewed here are not comparable to each other due to differences in organisms, types of tissues studied, and different methods of analysis as well as nature of their inhabiting sites, this review will be a baseline data of the heavy metal bioaccumulation, which can help in future evaluation in the context of the rapid developmental activity prevalent in the coasts of the Red Sea. The findings compiled emphasize the need for a comprehensive biomonitoring program that can conserve the unique biodiversity of the Red Sea.

Potentially toxic elements and microplastics in muscle tissues of different marine species from the Persian Gulf: Levels, associated risks, and trophic transfer

Selected potentially toxic elements (PTEs), including As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, and Zn, along with microplastic particles (MPs) were characterized in the muscle of seafood species in order to study potential health risk and also investigate biomagnification of the contaminants. The results revealed high levels of the analyzed PTEs and MPs in crustaceans. The cancer risk among the consumer population (adult and children) posed by As is higher than the acceptable lifetime risk of 10^-4. Portunus plagicus and Platycephalus indicus had the highest and lowest amount of MP particles in their muscles, respectively, among investigated species. Finally, PTEs (except Hg) and MPs are not biomagnified in the collected species. The results of this research emphasize the importance of accounting for health risks posed by potential pollutants via consumption of contaminated seafood.

Metal Bioaccumulation and Potential Health Risk Assessment in Different Tissues of Three Commercial Fish Species (Merluccius merluccius, Mullus barbatus, and Pagellus erythrinus) from Edremit Bay (Aegean Sea), Turkey

Metal levels and potential health risk assessment in muscle, liver, and gills of three fish species (Merluccius merluccius, Mullus barbatus, and Pagellus erythrinus) from the Edremit Bay were investigated in spring and autumn 2015. Metal concentrations (Hg, Cd, Pb, Cr, Cu, Zn, Mn, and Fe), metal pollution index, and bioaccumulation factors in P. erythrinus were observed to be generally higher than those in M. barbatus and M. merluccius. Tissue was the main factor that might be responsible from the variations of metals in fish species according to ANOVA and PCA. Hg concentrations in M. barbatus and P. erythrinus were greater than threshold limits defined by international authorities; however, no carcinogenic risks were found for Cd and Pb levels. According to the results, the bay has been negatively influenced by human activities, and further research on monitoring of the biota and sediments is recommended for Edremit Bay and similar coastal areas under human pressure.

Copper and Zinc Levels in Commercial Marine Fish from Setiu, East Coast of Peninsular Malaysia

Potentially toxic metals (PTMs) in edible marine fish have been widely reported from at least 15 different regions or countries in the literature. This evidently demonstrates the importance of monitoring the PTMs in fish fillets from a human health risk (HHR) point of view. This study aims to assess the HHR of Cu and Zn in 19 species of marine fish from popular marine fish loading sites at Setiu in Terengganu, on the east coast of Peninsular Malaysia, collected between August 2016 and February 2017. With overall ranges of concentrations (mg/kg dry weight) of Cu (1.50–7.83), and Zn (24.1–80.5), the 19 species of marine fishes from Setiu are good sources of these essential elements because they are below the maximum permissible limits set by seafood safety guidelines. The target hazard quotient values of Cu and Zn were lower than one, indicating non-carcinogenic risks of Cu and Zn in fish consumption. It was also found that the calculated values of the estimated weekly intake were below the established provisional tolerable weekly intake of Cu and Zn. It can be concluded that the consumption of fish from Setiu would not pose adverse effects from the PTMs to consumers. Nonetheless, continuous monitoring is necessary to ensure the safety of consumers who rely heavily on marine fish in Setiu coastal waters.

Stress response markers in the blood of São Tomé green sea turtles (Chelonia mydas) and their relation with accumulated metal levels

Metals are persistent worldwide being harmful for diverse organisms and having complex and combined effects with other contaminants in the environment. Sea turtles accumulate these contaminants being considered good bioindicator species for marine pollution. However, very little is known on how this is affecting these charismatic animals. São Tomé and Príncipe archipelago harbours important green sea turtle (Chelonia mydas) nesting and feeding grounds. The main goal of this study was to determine metal and metalloid accumulation in the blood of females C. mydas nesting in São Tomé Island, and evaluate the possible impacts of this contamination by addressing molecular stress responses. Gene expression analysis was performed in blood targeting genes involved in detoxification/sequestration and metal transport (mt, mtf and fer), and in antioxidant and oxidative stress responses (cat, sod, gr, tdx, txrd, selp and gclc). Micronuclei analysis in blood was also addressed as a biomarker of genotoxicity. Present results showed significant correlations between different gene expressions with the metals evaluated. The best GLM models and significant relationships were found for mt expression, for which 78% of the variability was attributed to metal levels (Al, Cu, Fe, Hg, Pb and Zn), followed by micronuclei count (65% - Cr, Cu, Fe, Hg, Mn and Zn), tdx expression (52% - Cd, Fe, Mn, Pb and Se), and cat expression (52% - As, Fe, Se and Cd x Hg). Overall, this study demonstrates that these green sea turtles are trying to adapt to the oxidative stress and damage produced by metals through the increased expression of antioxidants and other protectors, which raises concerns about the impacts on these endangered organisms' fitness. Furthermore, promising biomarker candidates associated to metal stress were identified in this species that may be used in future biomonitoring studies using C. mydas' blood, allowing for a temporal follow-up of the organisms.

Determination of Mercury, Methylmercury and Selenium Concentrations in Elasmobranch Meat: Fish Consumption Safety

This study measures total mercury (THg), methylmercury (MeHg) and selenium (Se) concentrations in elasmobranch fish from an Italian market with the aim of evaluating the risk-benefit associated with their consumption, using estimated weekly intake (EWI), permissible safety level (MeHg_PSL), selenium health benefit value (HBV_Se) and monthly consumption rate limit (CR_mm) for each species. THg and Se were analysed by atomic absorption spectrometry, while MeHg was determined by HrGc/Ms. THg and MeHg concentrations ranged from 0.61 to 1.25 μg g^-1 w.w. and from 0.57 to 0.97 μg g^-1 w.w., respectively, whereas Se levels were 0.49-0.65 μg g^-1 w.w. In most samples European Community limits for THg were surpassed, while for MeHg none of the fish had levels above the limit adopted by FAO/WHO. EWIs for THg and MeHg in many cases were above the provisional tolerable weekly intakes (PTWIs). MeHg_PSL estimate showed that fish should contain approximately 50% of the concentration measured to avoid exceeding the PTWI. Nevertheless, the HBV_Se index indicated that solely skates were safe for human consumption (HBV_Se = 3.57-6.22). Our results highlight the importance of a constant monitoring of THg and MeHg level in fish, especially in apex predators, to avoid the risk of overexposure for consumers.

Risk assessment of trace element accumulation in two species of edible commercial fish Scomberoides commersonnianus and Cynoglossus arel from the northern waters of the Oman Sea

Concentrations of heavy metals, namely, cadmium, copper, zinc, lead, and chromium were measured in the muscle tissue of Scomberoides commersonnianus and Cynoglossus arel from the northern waters of the Oman Sea. Human health risk assessment for Iranian child and adult consumers were also evaluated. The mean concentration of zinc and copper were lower than international standards of maximum permissible limits (MPL). The estimated daily and weekly intakes (EDI and EWI) of all metals were lower than permissible tolerable daily intake (PTDI). The permissible frequency of fish consumption (CRmm) of S. commersonnianus and C. arel showed that they are safe for both children and adults even at a high meal frequency (>16 meals/month). Target hazard quotient (THQ) and risk index (HI) values were higher than 1 for Cu in adults, Cu and Zn in children with consumption rate of 7 times per week. Therefore, consumption of these spices of Oman Sea more than 7 times per week can threaten the health of consumers.