Metals and arsenic in fish from a Ramsar site under past and present human pressures: Consumption risk factors to the local population

Metal contamination in mangrove crab (Ucides cordatus) and human risk assessment on the Brazilian Amazon coast

The mangrove crab, Ucides cordatus, plays a relevant role in nutrient cycling in mangroves and is a significant source of food security and income by sustaining the artisanal fishing economy in South America. However, increasing metal contamination threatens the coastal systems, mangrove crabs, and the human population depending on this resource. This study investigates the concentrations of five metals (Al, Co, Fe, Ni, Zn) in the muscle, gills, hepatopancreas, and carapace via metal transfer from the sediment to these crab tissues in "low" and "potentially impacted" areas in the states of Pará and Maranhão on the Brazilian Amazon coast. Our results indicate that Fe (2403.35 mg kg-1 ww) and Zn (65.94 ± 4.48 mg kg-1 ww) levels exceed the most conservative limits established for Fe (EU and FAO/WHO = 45.00 mg kg-1 ww) and Zn (EU and ANVISA = 50.00 mg kg-1 ww), particularly in the gills and hepatopancreas. Bioaccumulation of Zn was observed in all tissues, with this concentration being up to 7.76-fold higher in crab meat. Risk assessment analyses suggest that estimated daily intake values for muscle consumption alone pose no health risk. In contrast, PIS and SIS methods for consuming white and brown meat suggest potential risks. These findings reveal the urgent need for comprehensive assessments of metal contamination in different fish and shellfish species and for improved risk assessment protocols, which are crucial to supporting public health policies and mitigating the impacts of this kind of contamination in mangrove areas.

Arsenic Speciation, an Evaluation of Health Risk Due to the Consumption of Two Fishes from Coastal Marine Areas of the Southwestern Atlantic Ocean (SWAO)

Arsenic (As) is naturally occurring and is found in different forms, some of which are considered toxic to human health and frequently present in fishery resources. The aim of this work was to determine the contribution of toxic As species to the total As in muscle of two commercial fish species (Micropogonias furnieri and Urophycis brasiliensis) and to assess the toxicological risk associated with their consumption, considering different exposed groups. The total As concentrations found exceeded local guideline recommendations (> 1 mg kg-1 wet weight), but the concentrations of the toxic As species were below this threshold. The inorganic As levels do not exceed the international guideline recommendations (0.03-0.15 μg kg-1 bw per day of iAs). Both interspecific and intraspecific differences in As concentrations were found. Non-carcinogenic and carcinogenic risk values indicated that the exposed groups would not experience health risks through consumption of either fish species. However, due to the lack of an established safe consumption limit for iAs or As species worldwide, there are currently no legal tools to ensure that these fish species are safe for human consumption.

Poison in the water: Arsenic's silent assault on fish health

Arsenic occurs across the world in freshwater and marine environments, menacing the survival of aquatic organisms. Organic and inorganic forms of this substance can be found, in which the inorganic form is more hazardous than the organic form. Most aquatic bodies contain inorganic arsenic species, but organic species are believed to be the dominant form of arsenic in the majority of fish. Natural and anthropogenic both are the sources of water contamination with arsenic. Its bioaccumulation and transfer from one trophic level to another in the aquatic food chain make arsenic a vital environmental issue. Continuous exposure to low concentrations of arsenic in aquatic organisms including fish leads to its bioaccumulation, which may affect organisms of higher trophic levels including large fishes or humans. Humans can be exposed to arsenic through the consumption of fish contaminated with arsenic. Hence, the present review facilitates our understanding about sources of arsenic, its bioaccumulation, food chain transfer, and its effect on the fish health. Also, "Poison in the Water: Arsenic's Silent Assault on Fish Health" serves as a wake-up call to recognize the pressing need to address arsenic contamination in water bodies. By understanding its devastating impact on fish health, we can strive to implement sustainable practices and policies that safeguard our precious aquatic environments and ensure the well-being of both wildlife and human communities that depend on them.

Introducing bio-indicator fish of the Persian Gulf based on health risk assessment of 27 commercial species

BACKGROUND

The increasing consumption of seafood may bring health risks. It will be especially important for the people living along the coasts who are highly dependent on seafood for food and income.

METHODS

In this research, a comprehensive health risk assessment was performed on 27 species of high-consumption commercial fish sampled from stations located in Hormozgan province within the Northeast Persian Gulf. Concentrations of trace metals and their health risk were investigated.

RESULTS

Spatial distribution of trace metals in commercial fish showed central stations including Kong and Greater Tonb have higher concentrations of all trace metals except Pb. Some metals showed a significant correlation between concentrations. Our finding indicated the average concentration of all trace metals except Ni in all species was below the concentrations proposed by WHO/FAO/USEPA. EDI for all metals in all species in both adult and child age groups was lower than its RfD (oral reference dose of trace metal) showing the daily consumption of these fish does not pose any health risk and implicates seafood consumption guidelines or policies. Values of THQ for each metal and HI for all metals were lower than 1 in all commercial fish indicating the lack of non-cancerous health risk through the long-term consumption of these fish. The research found potential health risks associated with the consumption of these fish, specifically related to the metals Cr, Ni, and Cd.

CONCLUSION

In total, health risk indices proposed eight fish as bio-indicator species of the Persian Gulf. The findings emphasize the risk management of commercial fish consumption, especially bio-indicator species, in Hormozgan province, the Northeast Persian Gulf.

Multiple biomarkers in pufferfish as a proxy of environmental health in brazilian marine protected areas

Marine Protected Areas (MPAs) are designed to conserve biodiversity and vulnerable ecosystems. This study aimed to assess the environmental quality of three Brazilian MPAs, based on the integrated analysis of biomarkers in pufferfish. The MPAs are differentiated by the degree of anthropogenic influences. The Barra do Una Estuary sustainable reserve (JUR) is a reference area due to its low levels of contamination and species diversity. The Cananéia Estuarine System (CAN) has been recognized as a biosphere reserve by UNESCO, as well as a Ramsar wetland. This MPA was influenced by upstream mining activities, resulting in the introduction of metals in the estuarine waters and the discharge of untreated urban sewage. The São Vicente estuary (SSV) lacks proper sanitation infrastructure. All collections were conducted during winter season, and, after collection, the animals were euthanized, their soft tissues were removed, and multiple biomarkers were analyzed in the gills and liver, as biometric, genotoxic, biochemical, and morphological. A one-factor multivariate analysis was applied to evaluate the differences between the data sets, and the matrices were analyzed using PERMANOVA to evaluate the "estuary" factor. The results were integrated using PCA with a 0.4 cut value and an Enhanced Integrated Biomarker Response (EIBR) was calculated. PCA was correlated with biochemical, genotoxic, and morphological biomarkers. In general, SVV differed from CAN and JUR as shown by both univariate and multivariate analyses. SVV also showed the highest EIBR, followed by CAN. Organisms from SSV showed greater gill pathology, elevated AChE activity and lipoperoxidation (LPO), and micronuclei frequency. CAN present intermediate EIBR, with severe pathologies in the liver. CAN seems to present an intermediate environmental quality between SSV and JUR indicating the importance of the existence of MPAs for environmental conservation and the need to monitor such areas, to maintain their suitable environmental quality.

Pollutant bioaccumulation in sentinel fish chronically exposed in Iguaçu river reservoirs (Southern Brazil) and human health risk of fish consumption

Bioaccumulation studies in fish mark the initial phase of assessing the risk of chemical exposure to biota and human populations. The Iguaçu River boasting a diverse endemic ichthyofauna, is grappling with the repercussions of human activities. This study delved into the bioaccumulation of micropollutants, the early-warning effects on Rhamdia quelen and Oreochomis niloticus in the Segredo Reservoir (HRS) and the potential risk of human exposure. Two groups of caged fish in three sites of the reservoir were exposed during the autumn-winter and spring-summer, while a third group (O. niloticus) underwent a twelve-month exposure, and inorganic and organic chemicals analysis in water, sediment, and biota. Additionally, metallothionein expression and genotoxicity were employed as biomarkers. PAHs, PCBs, Al, Cu, Fe, and As in water and DDTs, Cu, Zn, and As in sediment surpassed the thresholds set by Brazilian regulations, where DDT exhibited bioaccumulation in muscle, alongside metals in liver, kidney, gills, and muscle tissues. R. quelen showed metallothionein expression whereas DNA damage and NMA frequencies were elevated in target organs and in brain and erythrocytes of O. niloticus during summer. In this species the DNA damage in liver was remarkable after twelve months. Target Hazard Quotients and Cancer Risk values shedding light on the vulnerability of both children and adults. The reservoir's conditions led to heightened sensitivity to micropollutants for R. quelen species. The data presented herein provides decision-makers with pertinent insights to facilitate effective management and conservation initiatives within the Iguaçu Basin.

Trophic transfer patterns of arsenic in freshwater ecosystem layers in arsenic-endemic Ganges Delta and its potential human health risk

Arsenic (As) is a toxic environmental contaminant with global public health concern. In aquatic ecosystems, the quantification of total As is restricted chiefly to the individual organisms. The present study has quantified the total As in different trophic layers (sediment-water-phytoplankton-periphyton-zooplankton-fish-gastropod-hydrophytes) of lentic freshwater ecosystems. As transfer pathways quantifying the transmission rate across trophic-level compartmental route were delineated using a novel model-based approach along with its potential contamination risk to humans. Lentic water bodies from Indo-Gangetic region, a core area of groundwater As, were selected for the present investigation. The study revealed that among the lower biota, zooplankton were the highest accumulator of total As (5554-11,564 µg kg-1) with magnification (rate = 1.129) of the metalloid, followed by phytoplankton (2579-6865 µg kg-1) and periphytic biofilm (1075 to 4382 µg kg -1). Muscle tissue of zooplanktivore Labeo catla is found to store higher As (80-115 µg kg-1 w.w.) compared to bottom-dwelling omnivore Cirrhinus mrigala (58-92 µg kg-1 w.w.). Whereas, Amblypharyngodon mola has accumulated higher As (203-319 µg kg-1 w.w.) than Puntius sophore (30-98 µg kg-1 w.w.) that raised further concern. The hepatic concentration indicated arsenic-mediated stress based on As stress index (threshold value = 1). Mrigal and Mola showed significant biomagnification among fishes while biodiminution was observed in Catla, Bata, Rohu and Punti. All the studied fishes were under the arsenic mediated stress. In the 'sediment-water-periphytic biofilm-gastropod' compartment, the direct grazing accumulation was higher (rate = 0.618) than the indirect path (rate = 0.587). Stems of edible freshwater macrophytes accumulated lesser As (32-190 µg kg-1 d.w.) than roots (292-946 µg kg-1 d.w.) and leaves (62-231 µg kg-1 d.w.). The target cancer risk (TCR) revealed a greater concern for adults consuming edible macrophyte regularly. Similarly, the varied level of target hazard quotient and TCR for adults consuming fishes from these waterbodies further speculated significant health concerns. The trophic transfer rate of environmental As in soil-water-biota level at an increasing trophic guild and consumer risk analysis have been unravelled for the first time in the Indo-Gangetic plains, which will be helpful for the strategic mitigation of As contamination.

A systematic review on metal contamination due to mining activities in the Amazon basin and associated environmental hazards

Metal contamination associated with mining activities has been considered one of the main environmental pollution problems in the Amazon region. Understanding the levels of metal contamination from mining activities requires a good understanding of background metal concentrations, which may vary notably according to the geology/lithology characteristics of the region, soil type, and predominant biogeochemical processes. This review assessed 50 papers and reports published between 1989 and 2020 describing environmental concentrations of different metals and metalloids (As, Hg, Mn, Fe, Cd, Cu, Cr, Pb, Ni, and Zn) in water and sediments of mining and non-mining areas in five geographic regions of the Amazon basin. Metal enrichment caused by mining activities was calculated and exposure concentrations were compared with sediment and water quality standards set for the protection of aquatic life. Significant enrichments of Cd, Cu, Cr, Fe, Hg, Mn, Ni and Zn were observed in mining areas in both sediment and water. Regarding background levels in the different geographic regions, the highest prevalence of metal enrichment (i.e., concentrations 10 to 100-fold higher than mean background values) in sediment samples was found for Fe (100% of samples), Ni (90%), and Mn (69%). For water, high prevalence of metal enrichment occurred for Zn, Mn, and Fe (100% of samples), and for Hg (86%). Hg, Fe, Pb, Cu, Cd, Ni and Zn exceeded water and/or sediment quality standards in a significant number of samples in the proximity of mining areas. This study indicates that mining activities significantly contribute to water and sediment contamination across the Amazon basin, posing hazards for freshwater ecosystems and potentially having human health implications.

Essential and toxic elements in juvenile migratory commercial fish species in the Paraná River alluvial valley (South America): an approach for aquatic environmental monitoring

The Paraná River is the sixth largest in the world, and the lower section of the river is one of the largest and most productive floodplain wetlands in South America. The alluvial plain is an important habitat for nursery and feeding areas for commercial fish; however, it has been heavily anthropized due to industries, agricultural activities, and the growth and expansion of metropolitan areas. The aim of this study was to determine element accumulation (As, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) in young-of-the-year fish muscle from a floodplain lagoon of the lower Paraná River (Argentina) during summer and winter seasons, in relation with abiotic matrices (water and sediment). Four commercial fish species were assessed: sábalo (Prochilodus lineatus), boga (Megaleporinus obtusidens), dorado (Salminus brasiliensis), and pirapitá (Brycon orbignyanus). The concentrations of eight elements were detected by quadrupole inductively coupled plasma mass spectrometry. In water samples, Cd, Cr, Mn, Fe, and Zn levels were under the permissible limits for aquatic biota protection in both seasons, except for Pb (> 1 μg L-1) and Cu (> 2 μg L-1). In sediment, the average concentrations of all elements were under the limits set by national and international regulatory authorities. Differences in elemental concentrations between species and seasons were found. In general, the levels of elements in water were higher in summer than in winter, while in sediment, the lowest concentrations of elements were detected during the summer. The order of element concentration in fish muscle was Cd (0.01-0.04 μg g-1) < As (0.02-0.16 μg g-1) < Pb (0.03-0.23 μg g-1) < Mn (0.77-4.32 μg g-1) < Cu (1.01-4.07 μg g-1) < Cr (1.09-4.30 μg g-1) < Zn (15.8-31.7 μg g -1) < Fe (12.6-49.7 μg g-1). The accumulation assessment showed that the four fish species significantly accumulate Cr, Cu and Zn, and As and Zn from water and sediment, respectively. The correlation analysis showed a relationship between fish size and As, Cr, Cu, Fe, Mn, and Zn concentrations. Similarly, the highest values of element concentrations in muscle were detected during the summer when the fishes are early juveniles. The level of As, Cd, and Pb detected in B. orbignyanus, M. obtusidens, and P. lineatus juveniles suggested that these species had the potential to be used as biomarkers for assessing accumulation of toxic elements in the environment. Also, this study reveals that the accumulation patterns differ between size and fish species, which should be a considered insight at the moment of selecting a bioindicator to monitor pollution in the ecosystem.

Health risk assessment and differential distribution of Arsenic and metals in organs of Urophycis brasiliensis a commercial fish from Southwestern Atlantic coast

The concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, and Zn were analyzed in muscle, gills, and liver of Urophycis brasiliensis from two Southwestern Atlantic catch areas (Brazil and Argentina). Additionally, the health risk of general and fishermen populations through fish consumption was estimated. The gills showed the highest concentrations of most of the elements, followed by the liver. With the exception of As, the muscle was the organ with the lowest concentrations of most elements. Levels of arsenic in muscle of U. brasiliensis were exceeded the maximum permissible levels for human consumption recommended by local and international guidelines. The target hazard quotients (THQs) and the carcinogenic risk (CR) showed no risk for individual and all elements. These results highlight the importance of arsenic speciation in U. brasiliensis muscle in order to generate more reliable risk estimates.

Trace elements in edible tissues of elasmobranchs from the North Aegean Sea (Eastern Mediterranean) and potential risks from consumption

Trace elements have the potential to bioaccumulate in marine organisms and to biomagnify towards the upper levels of marine trophic webs, resulting in a range of negative effects on organisms. Elasmobranchs are highly susceptible to bioaccumulation of trace metals, while their consumption by humans is increasing worldwide. Therefore, it is important to monitor the trace metal content in the edible tissues of elasmobranchs. This work reveals the content of 12 trace metals in the edible tissues of 10 elasmobranch species caught in Greek waters. Levels above the permissible limits for Hg and Pb were found in some species, while analysis of the lifetime consumption risk for adults and children using the Target Hazard Quotient (THQ), revealed a high risk for two of the most toxic substances on the priority list for substances, namely As and Hg. These are preliminary results, and further research is required to understand better the issue.

Bioaccumulation of selected trace elements in some aquatic organisms from the proximity of Qeshm Island ecosystems: Human health perspective

In this study selected marine species from north Persian Gulf ecosystems were collected to investigate the concentration of 15 trace elements (Al, As, Co, Cr, Cu, Fe, Li, Mo, Ni, Pb, Se, Sr, V, Zn and Hg) in muscle and liver tissues for the purpose of evaluating potential health risks for human consumers. The results indicated that Fe, Zn, Sr, Cu and As are the most abundant TEs in the tissues of the species. The concentration of Cu in P. semisulcatus and As in most investigated species pose the highest risk of exposure. The carcinogenic risk values indicate that As and Ni concentrations in the species are above the acceptable lifetime risk for adults and children in most of the species. The margin of exposure risk approach indicated that the risk of detrimental effects due to dietary Pb intake for age groups is low, except for consumers of T. tonggol.

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.

Temporal and spatial variations in metals and arsenic contamination in water, sediment and biota of freshwater, marine and coastal environments after the Fundão dam failure

Temporal and spatial variabilities in concentrations of metals (Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) and metalloid (As) associated with the Fundão dam tailings were evaluated in water, sediment and biota from freshwater (tributary, river, lakes and lagoons), marine and coastal (mangroves and beaches) ecosystems affected by the Mariana dam disaster (southeastern Brazil). In freshwater shrimps and fishes, temporal increases in the concentrations of most elements analyzed were observed. This finding was clearly associated with temporal increases in the concentrations of As and metals observed in both water and sediment. In turn, freshwater plankton showed only a temporal increase in Hg concentration, which was also associated with an increased concentration of this metal in the abiotic matrices. In marine fishes, temporal increases were only observed for Cu, Fe and Pb concentrations. Also, temporal increase was observed for Fe concentration in marine plankton (phytoplankton and zooplankton) and shrimps. Marine phytoplankton also showed a temporal increase in Hg concentration. All these findings were clearly associated with temporal increases in the concentrations of these metals in marine sediments. Mangrove crabs showed temporal increases in Hg and Cd, which were associated with temporal increases in water Hg and sediment Cd concentrations, respectively. In turn, beach crabs displayed temporal increases in Mn and Zn, which were associated with temporal increases in the concentrations of these metals in sediments, especially for Mn. In summary, all environmental matrices evaluated in the present study were shown to be contaminated with metals and metalloid associated with the Fundão dam tailings. Additionally, findings reported in the present study relative to the spatial variabilities observed in the whole aquatic area affected by the Fundão dam failure clearly reinforce the need of incorporating biological diversity in monitoring programs aiming to assess environmental health of aquatic systems, considering that patterns of metals and metalloid contamination levels may vary among taxa.

Tracing the heavy metals zinc, lead and nickel in banana shrimp (Penaeus merguiensis) from the Persian Gulf and human health risk assessment

Seafood has long been considered a unique source of nutrition. However, increasing trends in consumption of marine products must be considered, especially in potentially polluted environments such as the Persian Gulf. This study was undertaken to analyse the level of heavy metal contamination of nickel (Ni), zinc (Zn), and lead (Pb) in shrimp (Penaeus merguiensis) captured from the northern Persian Gulf. The concentration of heavy metals in the muscle of shrimp followed the order Zn > Ni > Pb. The content of Zn and Ni was higher than recommended standard limits by the FAO/WHO. The combined impact of all metals was lower than the acceptable limit of 1 in shrimp. The carcinogenic risk for Ni was higher than the unacceptable value. In total, our finding indicated no potential health risk from the daily consumption of this species. However, long-term consumption of shrimp can pose a risk of carcinogenic effects of nickel. Continuous monitoring of these trace metals in seafood is necessary to ensure the quality of seafood and food safety.

The concentration of the potentially toxic elements (PTEs) in the muscle of fishes collected from Caspian Sea: A health risk assessment study

In the present study, the concentration of (potentially toxic element) PTEs in the five fish species from the Caspian Sea (from five coastal areas) was measured and compared. The target hazard quotient (THQ) and total THQ (TTHQ) were calculated using Monte Carlo simulations to determine the non-carcinogenic risk in both children and adults consumers. The highest concentration of PTEs was associated with chromium (Cr) measured in Cyprinus carpio, sampled from Bandar Anzali (1.56 ± 0.14 μg/g dw), and the minimum PTEs level was nickel (Ni) in Vimba from Astara (0.02 ± 0.01 μg/g d w). The rank order for PTEs based on THQ was mercury (Hg) > cadmium (Cd) > lead (Pb)> Ni > tin (Sn) > Total Cr. For adults, the fishes rank order based on TTHQ was: Cyprinus carpio (3.268) > Chelon saliens (2.89) > Rutilus frisii kutum kanesky (2.28) > Oncorhynchus mykis (1.39) > Vimba (0.25); and for children was Cyprinus carpio (15.25) > Chelon saliens (13.47) > Rutilus frisii kutum kanesky (10.63) > Oncorhynchus mykis (6.48) > Vimba (1.16). Overall this study showed that the levels of PTEs in investigated fish species had a potential non-carcinogenic risk for both children and adults (TTHQ>1).

Sediment contamination and toxic effects on Violet Goby fish (Gobioides broussonnetii - Gobiidae) from a marine protected area in South Atlantic

The Estuarine-Lagoon Complex of Iguape-Cananéia (ELCIC), a Marine Protected Area (MPA) in Brazil, was the focus of this study that aimed to relate external levels of exposure to contaminants to toxic effects on Gobioides broussonnetii fish. Different anthropogenic contaminants such as metals, polycyclic aromatic hydrocarbons (PAHs) and pharmaceuticals and personal care products (PPCPs) were analyzed in the sediments; and biochemical, histopathological and genotoxicity biomarkers evaluated in fish; in two different seasons at three sites of the estuarine region. Higher contamination of the sediments was observed near the main urban center (Iguape city - IG). Metal concentrations were considered low to moderate, while PAHs concentrations were considered low. The concentrations of PPCPs increased due to the anthropogenic presence and were higher near IG and the Cananéia Island (CI). Contributions from historical mining, agriculture, nautical activities, oil, sewage and waste disposal, biomass and fossil fuels combustion were identified. Higher concentrations of metals and PPCPs were observed during the cold-dry season, suggesting influences of the lower hydrodynamics during the season of lower precipitation. Higher PAHs concentrations occurred in the hot-rainy season, indicating influences of greater human presence in summer. In fish, biological responses followed the same spatial and seasonal pattern. More pronounced changes in antioxidant, biotransformation, histopathological and genotoxic biomarkers were observed in IG and CI. The multivariate analysis and the integrated biomarkers response index (IBR) also evidenced worse environmental conditions in these sites. This result can indicate a negative influence of anthropogenic activities on the contamination of sediments and on the biological responses of fish. This study presented the first ecotoxicological data for the species and suggested that these chronic exposures can cause adverse effects on this fish population. The data contribute to the understanding of local environmental quality and can be applied in the future to the environmental and social management of marine protected areas.

Trace metals in estuarine organisms from a port region in southern Brazil: consumption risk to the local population

Metal contamination is a threat to estuarine environments. They can accumulate in the food chain and cause toxic effects on aquatic organisms and human health. This study evaluated the concentrations of metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn) in aquatic organisms of Antonina Bay (southern Brazil) to analyze whether the metal concentrations were in accordance with Brazilian food legislation and estimate the human risk of local seafood consumption. All analyzed organisms (Centropomus parallelus, Mugil curema, Genidens genidens, Crassostrea brasiliana, and Xiphopenaeus kroyeri) showed traces of metals in their tissues with different metal concentrations among species. Metal concentrations were generally higher in oyster C. brasiliana, and biomagnification was not observed. Cr and Zn concentrations were above the limits established by legislation for all species in at least one sample. The concentrations of the other metals were within permitted levels. However, concentrations of Cd, Cr, Fe, and Zn posed a human consumption risk. In general, the C. brasiliana oyster presented the highest risk for human consumption, probably due to its filtering habit. Thus, the results indicated that metal concentrations in the tissues of the Antonina Bay seafood can pose a risk to human health, and this chronic exposure to metals also can cause toxic effects on local aquatic biota.

Use of an Integrated Geochemical and Ecotoxicological Approach to Evaluate Sediment Metal Contamination in Three Protected Estuarine Areas Along the Coast of São Paulo State, Brazil

We compared sediment quality in estuaries at three locations along the coast of São Paulo State, Brazil, using geochemical analyses and whole sediment toxicity tests, during the southern summer and winter of 2013. Each locality is afforded a distinct degree of legal protection, and exhibits a different level of metal pollution: overall, Rio Diana (RD, the most polluted, a Permanent Protection Area) > Rio Itapanhaú (RI, intermediate contamination, an Environmental Protection Area) > Rio Picinguaba (RP, pristine, a State Park). Chronic sediment toxicity tests evaluated reproductive rates of the copepod Nitokra sp. RI sediments showed the highest metal concentrations and toxicity in both seasons. Metal concentrations at RD were low but toxic in summer. RP sediments were not contaminated, suggesting effective legal protection from pollution at this locality. RI and RD, although provided some legal protection, showed clear signs of environmental degradation, emphasizing the need for more effective pollution control.

Marine protected areas in Latin America and Caribbean threatened by polycyclic aromatic hydrocarbons

The present study is a literature-based analysis investigating occurrence and the possible consequences of polycyclic aromatic hydrocarbons (PAH) in marine protected areas (MPAs) of Latin America and Caribbean. The approach using overlapping of georeferenced MPA polygons with data compiled from peer-reviewed literature, published during the last 15 years, showed 341 records of PAH in 9 countries. PAH was reported to occur within the boundaries of 36 MPAs located in Argentina, Brazil, Colombia, Mexico, Nicaragua and Uruguay. According to quality guidelines, low to moderate impacts are expected in MPAs categorized in different management classes. Considering sediment samples, 13% of the records presented concentrations enough to cause occasional toxicity. Such level of risk was also seen in Ramsar sites and in Amazonian MPAs. In addition, based on concentrations reported in biota, occasional deleterious effects on organisms from Biosphere Reserves might occur. Diagnostic ratios pointed out petrogenic and pyrolytic processes as PAH predominant sources, and were mainly attributed to the proximity to ports, industries and urban areas. MPAs located in the vicinity of impact-generating areas may be under threat and require government attention and action, mainly through implementation of contamination monitoring programs.

Bioaccumulation of 10 trace elements in juvenile fishes of the Lower Paraná River, Argentina: implications associated with essential fish growing habitat

This study assessed the concentration, bioconcentration, and bioaccumulation of As, Cd, Co, Cr, Cu, Mg, Mn, Ni, Pb, and Zn in juvenile fishes (Acestrorynchus pantaneiro, Brycon orbygnianus, Cyphocharax voga, Megaleporinus obtusidens, Odontesthes bonariensis, Pimelodus maculatus, Prochilodus lineatus, Salminus brasiliensis, and Schizodon borelli) in the Lower Paraná River (Argentina), the most extensive floodplain from the Plata Basin. The floodplain is crucial for the reproduction and growth of various species such as P. lineatus, M. obtusidens, and S. brasiliensis, which complete their life cycle in this environment. In total, 90 individuals were sampled for nitrogen stable isotope, and trace element analysis in muscle tissue, water, and sediment was analyzed. The results show that all the studied species bioaccumulate Cr, Mg, Ni, and Zn. In particular, B. orbygnianus and P. maculatus presented the highest bioaccumulation factor for Cr. A biodilution of Co through the food chain was observed. No positive correlation was found between element concentration and trophic level, but we observed significant differences between trophic guilds (herbivorous, omnivorous, and carnivorous). Our findings suggest that feeding habits determine trace element concentrations. To establish differential behavior between different species within the aquatic web further studies are necessary, particularly in the floodplain of the Paraná, which is a crucial nursery area for most commercially important fishes from the Plata Basin. Graphical abstract.

Manganese: The overlooked contaminant in the world largest mine tailings dam collapse

Manganese (Mn) is an abundant element in terrestrial and coastal ecosystems and an essential micronutrient in the metabolic processes of plants and animals. Mn is generally not considered a potentially toxic element due to its low content in both soil and water. However, in coastal ecosystems, the Mn dynamic (commonly associated with the Fe cycle) is mostly controlled by redox processes. Here, we assessed the potential contamination of the Rio Doce estuary (SE Brazil) by Mn after the world's largest mine tailings dam collapse, potentially resulting in chronic exposure to local wildlife and humans. Estuarine soils, water, and fish were collected and analyzed seven days after the arrival of the tailings in 2015 and again two years after the dam collapse in 2017. Using a suite of solid-phase analyses including X-ray absorption spectroscopy and sequential extractions, our results indicated that a large quantity of Mn^II arrived in the estuary in 2015 bound to Fe oxyhydroxides. Over time, dissolved Mn and Fe were released from soils when Fe^III oxyhydroxides underwent reductive dissolution. Due to seasonal redox oscillations, both Fe and Mn were then re-oxidized to Fe^III, Mn^III, and Mn^IV and re-precipitated as poorly crystalline Fe oxyhydroxides and poorly crystalline Mn oxides. In 2017, redox conditions (Eh: -47 ± 83 mV; pH: 6.7 ± 0.5) favorable to both Fe and Mn reduction led to an increase (~880%) of dissolved Mn (average for 2015: 66 ± 130 µg L^-1; 2017: 582 ± 626 µg L^-1) in water and a decrease (~75%, 2015: 547 ± 498 mg kg^-1; 2017: 135 ± 80 mg kg^-1) in the total Mn content in soils. The crystalline Fe oxyhydroxides content significantly decreased while the fraction of poorly ordered Fe oxides increased in the soils limiting the role of Fe in Mn retention. The high concentration of dissolved Mn found within the estuary two years after the arrival of mine tailings indicates a possible chronic contamination scenario, which is supported by the high levels of Mn in two species of fish living in the estuary. Our work suggests a high risk to estuarine biota and human health due to the rapid Fe and Mn biogeochemical dynamic within the impacted estuary.

Contamination and oxidative stress biomarkers in estuarine fish following a mine tailing disaster

BACKGROUND

The Rio Doce estuary, in Brazil, was impacted by the deposition of iron mine tailings, caused by the collapse of a dam in 2015. Based on published baseline datasets, the estuary has been experiencing chronic trace metal contamination effects since 2017, with potential bioaccumulation in fishes and human health risks. As metal and metalloid concentrations in aquatic ecosystems pose severe threats to the aquatic biota, we hypothesized that the trace metals in estuarine sediments nearly two years after the disaster would lead to bioaccumulation in demersal fishes and result in the biosynthesis of metal-responsive proteins.

METHODS

We measured As, Cd, Cr, Cu, Fe, Mn, Pb, Se and Zn concentrations in sediment samples in August 2017 and compared to published baseline levels. Also, trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn) and protein (metallothionein and reduced glutathione) concentrations were quantified in the liver and muscle tissues of five fish species (Cathorops spixii, Genidens genidens, Eugerres brasilianus, Diapterus rhombeus and Mugil sp.) from the estuary, commonly used as food sources by local populations.

RESULTS

Our results revealed high trace metal concentrations in estuarine sediments, when compared to published baseline values for the same estuary. The demersal fish species C. spixii and G. genidens had the highest concentrations of As, Cr, Mn, Hg, and Se in both, hepatic and muscle, tissues. Trace metal bioaccumulation in fish was correlated with the biosynthesis of metallothionein and reduced glutathione in both, liver and muscle, tissues, suggesting active physiological responses to contamination sources. The trace metal concentrations determined in fish tissues were also present in the estuarine sediments at the time of this study. Some elements had concentrations above the maximum permissible limits for human consumption in fish muscles (e.g., As, Cr, Mn, Se and Zn), suggesting potential human health risks that require further studies. Our study supports the high biogeochemical mobility of toxic elements between sediments and the bottom-dwelling biota in estuarine ecosystems.

Pharmaceuticals and personal care products in a Brazilian wetland of international importance: Occurrence and environmental risk assessment

Despite the fact that the occurrence of emerging contaminants in the environment has become frequent in recent decades, the seasonal dynamics of contaminants in different environmental compartments are little studied in protected areas influenced by effluent discharges. In this study, the seasonal and spatial occurrence of 33 pharmaceuticals and personal care products (PPCPs) was investigated in surface waters and sediments from Anil and Bacanga rivers (northeast of Brazil). The studied area is located within a Wetland of International Importance by Ramsar Convention (Amazon Estuary and its Mangroves). Sample preparation was carried out using solid-phase extraction and QuEChERS, for water and sediment samples, respectively and all determinations were performed by liquid chromatography tandem mass spectrometry. Eleven PPCPs were detected in water samples and 14 in sediments. In aqueous samples, caffeine was the most occurring compound reaching 13,798 ng L^-1. In addition, high levels of acetaminophen, ibuprofen, sulfamethoxazole, carbamazepine and diclofenac were also observed. In the sediment samples, triclocarban, benzophenone-3, ketoconazole and methylparaben were also detected. The spatial and temporal distribution of the assessed molecules indicates urbanization and anthropic activities as relevant sources of PPCPs in the region. Moreover, the levels of acetaminophen, caffeine, diclofenac, ibuprofen, benzophenone-3, triclosan and triclocarban measured within the Ramsar site pose a high risk to aquatic and terrestrial organisms. These findings indicate potential threats to the allegedly protected biodiversity and, therefore, urgent actions are needed to effectively protect this unique and vulnerable area.

Arsenic contamination assessment in Brazil - Past, present and future concerns: A historical and critical review

This paper presents a summary of some relevant documents published during the last decades regarding arsenic contamination in Brazil until December 2018, including scientific papers, reports and regulatory documents. Natural and anthropogenic arsenic sources were covered, excluding those related to agriculture. International "key" documents related to arsenic contamination were used to support the discussion and comparative analysis. This paper aims: (a) to summarize and discuss some available data (including Portuguese written documents) concerning arsenic contamination in Brazil, mainly geographical, geological, geochemical, environmental and health studies; (b) to critically review the published studies comparing their main findings; (c) to describe and compare ancient and recent contamination events; and (d) to highlight key knowledge gaps, and identify promising areas for future researches. The arsenic contamination scenario in Brazil results not only from mining. Natural or anthropogenic emissions caused by great magnitude phenomena as flooding, erosion, landslide and, water scarcity equally impact arsenic mobilization/immobilization equilibria. Our literature review demonstrates that arsenic contamination of soils, sediments and water sources is observed at least at three of the five geographically defined Brazilian regions (Northern, Southern and, Southeastern regions). Arsenic enriched soils, and waters naturally occur all around the country and anthropogenic activities have been the main contributory factor to the environmental contamination since the 18th Century. Geogenic materials (topsoil and mining tailings), and water samples could contain extremely high arsenic concentrations, i.e. 21,000 mg kg^-1 or 1,700,000 μg L^-1, respectively, have been found mainly at the "Iron Quadrangle". Moreover, if we consider both the Brazilian and international parameters, the health risks associated with the human exposition to arsenic are of significant concern. For those reasons, constant monitoring of As contaminated areas in Brazil is mandatory. Furthermore, it is necessary to learn from the mistakes made in the past in order to prevent or minimize future problems.

Health Risk Assessment for Human Exposure to Trace Metals Via Bushmeat in Ghana

Consumption and trade in bushmeat are entrenched in sub-Saharan Africa amid growing land degradation and environmental pollution that raise safety concerns, yet sustainability of bushmeat extraction and zoonoses considerations have been the focus of bushmeat research. Here, we evaluated the health risk of trace metals in the skeletal muscle, bone, liver, and skin of the black duiker (Cephalophus niger), brush-tailed porcupine (Atherurus africanus), bushbuck (Tragelaphus scriptus), cane rat (Thryonomys swinderianus), and Maxwell's duiker (Cephalophus maxwelli) being the five most hunted and consumed species of bushmeat in Ghana. Sample tissues of the five species were analyzed for Cu, Zn, Se, Cd, As, Pb, and Hg. Targeted hazard quotient (THQ) of Se for black duiker, bushback, and Maxwell's duiker as well as that of Pb for black duiker, Brush-tailed porcupine, and Maxwell's duiker were concerning (> 1) for individuals foraging daily on bushmeat. Thus, cane rat was the only species that recorded both estimated daily intake (EDI) and THQ of Se and Pb within safe limits for daily consumption. In respect of Cu, Zn, Cd, As, and Hg, EDI and THQ values indicated no perceived risk to consumers for all five species. Lifetime cancer risk (CR) of As was negligible for all species. At the rate of bushmeat consumption in sub-Saharan Africa (0.104 kg per day), the cane rat was the only species considered safe for daily consumption among the five species.

Metal-Associated Biomarker Responses in Crabs from a Marine Protected Area in Southeastern Brazil

The environmental quality of a Ramsar wetland site located at the Cananéia-Iguape-Peruíbe Protected Area (CIP-PA), in São Paulo, Brazil, was assessed by geochemical analyses and biomarker assessments (GPx, GST, GSH, GST, MT, LPO, DNA damage) performed in swimming crab Callinectes danae Smith, 1869 organs (posterior and anterior gills and hepatopancreas) to estimate sediment contaminant bioavailability. The results indicated that two sampling stations, PT and PM, exhibited the worst environmental conditions, as sediments collected at both points contained metal contamination, while crabs exhibited significant responses for GPx, GST, and LPO (mostly during winter). Sediment contamination tended to be associated to fine sediments (both seasons) and organic matter (winter). During the summer survey, Pb concentrations in sediments of station PT exceeded the Brazilian Sediment Quality Guidelines (SQGs) and the Canadian Interim Marine Sediment Quality Guidelines. Metal concentrations in sediments sampled in winter were higher compared with summer, with Co, Ni, and Pb exceeding SQGs levels at PT, whereas Co, Ni, Hg, Zn, and Pb exceeded SQGs at PM. Biomarker induction during summer appeared to be caused by natural variables (water salinity and temperature, and molting cycle), whereas oxidative stress and tissue damage during winter appeared to be more clearly linked to metal contamination. Anterior gills presented the clearest signs of seasonal variability, being more responsive to sediment contamination. The results suggest that metals originated from the upper Ribeira de Iguape River are transported toward the estuarine system, causing effects on C. danae individuals. Additionally, seasonality is a strong factor concerning CIP-PA toxicity, since the rainfall regime significantly modifies the freshwater flow and, consequently, estuarine water salinity, suspended particle and metal inputs, as well as the location of depositional areas. Thus, efforts to mitigate CIP-PA contamination should be based on the control of upstream pollution sources.

Food safety risk assessment of metal pollution in crayfish from two historical mining areas: Accounting for bioavailability and cooking extractability

Here we characterize the bioaccumulation of mercury (Hg) and lead (Pb) in red swamp crayfish (Procambarus clarkii) from two river courses in Central Spain that are impacted by historical Hg and Pb mining activities, respectively. We estimate the absolute oral bioavailability of metals in crayfish tissues by means of in vitro bioaccessibility simulations, and assess whether their consumption may imply a health risk for humans by estimating target hazard quotients and safe consumption rates. We also study the effect of cooking crayfish on the mobilization of the metal body burden in the context of the traditional Spanish cuisine. The results showed that crayfish from the mining districts accumulated a high level of Hg and Pb pollution in both the tail muscle and the carcass. The in vitro bioaccessibility of Hg and Pb in the edible part was 27.86 ± 4.05 and 33.73 ± 5.91%, respectively. Absolute bioavailability was estimated to be 38.31 for Hg, and 20.21 (adults) and 67.35% (children) for Pb. Risk indices indicated that, even after adjusting for bioavailability, it is not safe to consume crayfish from the mining-impacted rivers because of their high levels of Hg and Pb. Using the carcass as a condiment for flavouring should also be avoided. The cooking procedure extracted relatively small amounts of the total Hg (8.92 ± 2.13%) and Pb (1.68 ± 0.29%) body burden. Further research that will support human and ecological risk assessment, along with the implementation of advisory measures for the local population as regards crayfish consumption, are recommended.

Adaptative responses of myenteric neurons of Sphoeroides testudineus to environmental pollution

Contamination in estuarine regions affects the local biota damaging the ecosystems and reaching humans. The gastrointestinal tract is a dynamic environment capable of obtaining nutrients and energy from food while it protects the host against harmful toxins and pathogens from the external environment. These functions are modulated by the enteric nervous system and changes in its structure can result in gastrointestinal disorders. The objective of this study was to evaluate if the environmental contaminants have effects on the myenteric neuronal plasticity of pufferfish Sphoeroides testudineus. Animals were collected in Barra do Una River, located at Jureia-Itatins Mosaic of Protected Areas (reference area - RA) and in the Santos Estuarine System (impacted area - IA). Morpho-quantitative analyses of the general and metabolically active myenteric neuronal populations of the proximal and distal intestine were made. Disarrangement was observed in the general organization of the myenteric plexus, with an expressive reduction of the neuronal groups (nodes) in the animals of IA. The vulnerability of the myenteric plexus was evidenced by a decrease in density and cellular profile of the general neuronal population, followed by an increase of the metabolism of the remaining neurons, which in turn was verified by a growth of the area of the cellular and nuclear profiles of the metabolically active neuronal population. Through these analyses, we concluded that animals inhabiting polluted regions present alterations in the myenteric neuronal plasticity, as a way of maintaining the functions of the gastrointestinal tract.

Impacts of suspended sediment and metal pollution from mining activities on riverine fish population-a review

Mining activities are responsible for the elevated input levels of suspended sediment and hazardous metals into the riverine ecosystem. These have been shown to threaten the riverine fish populations and can even lead to localized population extinction. To date, research on the effects of mining activities on fish has been focused within metal contamination and bioaccumulation and its threat to human consumption, neglecting the effects of suspended sediment. This paper reviews the effects of suspended sediment and metal pollution on riverine ecosystem and fish population by examining the possibilities of genetic changes and population extinction. In addition, possible assessments and studies of the riverine fish population are discussed to cope with the risks from mining activities and fish population declines.

Potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) in fish and prawn in the Persian Gulf, Iran

This study aimed to speciate and quantify potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs), in addition to estimate potential human health risk of PTEs (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se, V, and Zn) through the consumption of three edible fish species (Leuciscus vorax, Liza abu, and Coptodon zillii) and two prawn species (Metapenaeus affinis and Penaeus semisulcatus) collected from Arvand River and Musa Estuary in the Persian Gulf. The concentration of As in prawn species exceeded permissible limit set by international organizations. PAHs were dominated by low molecular weight species such as naphthalene, phenanthrene, and, fluorene but generally exhibited low mean concentrations in fish and prawn samples. The human health hazard posed by PTEs was assessed using methods that consider estimated daily intake (EDI), estimated weekly intake (EWI), target hazard quotients (THQ), and combined THQ. The results suggested that elevated As concentrations in almost all prawn samples may pose a probable health hazard to local inhabitants.

Mercurio, metilmercurio y otros metales pesados en peces de Colombia: riesgo por ingesta

En 2013 el pescado proporcionó a más de 3100 millones de personas casi el 20 % de la ingesta promedio de proteínas de origen animal per cápita (FAO, 2016). De acuerdo con el Programa de las Naciones Unidas para el Desarrollo (PNUD), en Colombia y, particularmente en las poblaciones ribereñas y costeras, el 90 % del consumo de proteína de origen animal proviene del pescado, como resultado de un acceso muy bajo a otro tipo de proteínas. Colombia enfrenta uno de los mayores problemas por contaminación ambiental a nivel mundial, generado en gran parte por el abuso de sustancias químicas para el aprovechamiento de minerales, mala disposición de aguas servidas y prácticas industriales y agrícolas inadecuadas, en cuerpos de aguas fundamentales para la dinámica poblacional de animales, vegetales y humanos. Como estrategia mundial para reducir los riesgos a la salud humana por consumo de pescado contaminado con metales pesados, se han considerado límites máximos permisibles, propuestos por diferentes entidades; sin embargo, el 31,5 % de los resultados de estudios publicados para Colombia, son superiores al límite permisible recomendado por la OMS (0,5 μg/g). Los resultados presentados en esta revisión evidencian la urgente necesidad de realizar estudios que evalúen el riesgo a la salud que enfrentan pobladores de zonas mineras y no mineras de Colombia, aportará también fundamentos científicos y bases para el establecimiento de ejes estratégicos que permitan la puesta en marcha de nuevos proyectos productivos que ofrezcan el acceso de la población a diversas fuentes de alimentación.

Assessment of metal contamination in fish from estuaries of southern and southeastern Brazil

Historically, the Brazilian coast has been impacted by urban, industrial, and port activities that have increased the input of chemical contaminants, such as heavy metals, to the ecosystem. The Paranaguá estuarine complex (PEC), Cananéia-Iguape estuarine-lagoon complex (CIELC), and Santos-São Vicente estuarine complex (SSVEC) (S-SE Brazil) are surrounded by urbanized cities and port areas characterized by various anthropogenic discharges comprising several potential pollutants, including heavy metals. Concerns about such contamination are paramount because these estuaries are important for traditional fishing communities and are categorized as World Heritage sites and biodiversity hotspots by UNESCO. In this study, metals (Cu, Cr, Ni, Pb, Zn, and Hg) and metalloids (As and Se) known to affect the health of marine life were evaluated in regional fishes. Muscle and liver tissues from three demersal teleosts (Stellifer rastrifer, Paralonchurus brasiliensis, and Isopisthus parvipinnis) were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES), with a coupled vapor generated accessory (VGA). Irrespective of species, metal bioconcentration was significantly greater in fishes from the PEC and CIELC, which had higher As, Cu, and Zn concentrations, while Se levels were higher in fish from the PEC and SSVEC estuaries. Seasonality, fish species and maturation stage affected the accumulation of metals. Some metal levels, including As, Cr, Pb, and Se in all species across all estuaries, and Zn in the PEC, exceeded the maximum permitted level for seafood and might present a risk for daily human consumption. The results provide reference points for existing chemical contamination and should be used to guide monitoring programs and the sustainable development of these coastal regions, within a broader objective of maintaining public health.

High arsenic and low lead concentrations in fish and reptiles from Taim wetlands, a Ramsar site in southern Brazil

The pollution caused by heavy metals and metalloids represent an emerging threat to wetlands worldwide. Herein we examined the concentrations of arsenic (As) and lead (Pb) in fish and aquatic/semi-aquatic reptiles from Taim wetlands, a Ramsar site located at the southernmost Brazilian coastal plain. A total of 82 individuals from six fish and three reptile species from varied trophic levels were analysed through furnace graphite atomic absorption spectrophotometry. Mean As concentrations (μg·g^-1 dry weight) were markedly high, ranging from 13.06 ± 3.18 to 19.4 ± 4.04 in fish and 3.51 ± 2.36 to 19.00 ± 10.45 in reptiles. Mean Pb concentrations were low, ranging from 0.00067 ± 0.00060 to 0.0040 ± 0.00045 in fishes and 0.00103 ± 0.0011 to 0.0271 ± 0.0353 in reptiles. The highest As mean level was detected in the herbivore-insectivore fish Astyanax aff. fasciatus, a species of low trophic level among the analysed taxa. The highest Pb mean level was found in the broad-snouted caiman Caiman latirostris, the highest trophic level species analysed. The present study warns for the contamination of As especially in edible fish, which constitute a threat to the communities that use this resource in systems connected to Taim wetlands. As concentrations in reptiles were also higher than those reported in previous studies concerning the groups herein addressed. It is possible that the high As burdens found in the analysed species could be attributed to the use of fertilizers and pesticides in extensive irrigated rice areas located in Taim wetlands surroundings, but natural sources cannot be dismissed.

Heavy metal accumulation in and food safety of shark meat from Jeju island, Republic of Korea

Shark meat is consumed as a food source worldwide, especially in Asian countries. However, since sharks are apex predators in the ocean food chain, they are prone to bioaccumulation of heavy metals. More than 100 million sharks are caught annually for human consumption, and the safety of shark meat cannot be overemphasized. Here, we examined heavy metal concentration in the muscle tissue of 6 shark species including 3 migratory species (Carcharhinus brachyurus, Carcharhinus obscurus, and Isurus oxyrinchus) and 3 local species (Triakis scyllium, Mustelus manazo, and Cephaloscyllium umbratile) from fish markets in Jeju Island, Republic of Korea. The concentrations of 11 heavy metals (Cr, Fe, Cu, Zn, As, Se, Cd, Sn, Sb, Pb, and Hg) and MeHg were analyzed. The result showed that the average concentrations of all metals, except for that of As, were below the regulatory maximum limits of many organizations, including the Codex standard. Hg and MeHg were significantly correlated with body length, body weight, and age, and the concentration of Hg was expected to exceed the limit in C. brachyurus with a body length or weight of over 130 cm or 25 kg, respectively. Our results indicate that shark meat can expose consumers to a high level of As and that copper sharks bigger than the predicted size should be avoided for excessive Hg. Considering these findings, a detailed guideline on consumption of meat of different shark species should be suggested based on further investigation.

Integrated assessment of sediment contaminant levels and biological responses in sentinel fish species Atherinella brasiliensis from a sub-tropical estuary in south Atlantic

This study combined data of the concentrations of metals, polycyclic aromatic hydrocarbons (PAHs) and pharmaceuticals and personal hygiene products (PPCPs) in the sediments and the biological responses of the Atherinella brasiliensis fish in two different sites and climate seasons in the Estuarine-Lagoon Complex of Iguape-Cananéia, Southeast Brazil. The presence of metals, PAHs, and PPCPs were observed in the sediments demonstrating the contamination throughout the system with contributions of sewage and residues disposal, oil and combustion of biomass and fossil fuels. Higher contaminations were identified in the point of greater human presence (C - Cananéia City), especially during the cold-dry season. The influence of anthropic activities and variations in the estuarine conditions, such as lower hydrodynamics during the lower rainfall period, were observed. In fish, spatial and seasonal changes in the parameters of oxidative stress and biotransformation, genotoxicity and histopathological alterations followed the same trend, with more pronounced responses in C in the cold-dry season. The biological responses of the fish revealed adverse effects in the local species population and indicated the presence of metals, PAHs and PPCPs as stressors. The multivariate analysis and the integrated biomarker response index (IBR) corroborated with these results, also indicating that site C had the worst environmental quality. The present study provides new information about the contamination of the sediments of Estuarine-Lagoon Complex of Iguape-Cananéia and the chronic exposure to contaminants in A. brasiliensis. Therefore, contributing to a better understanding of the local environmental quality with data that can support protective management of the area.

Bioaccumulation and morphological traits in a multi-generation test with two Daphnia species exposed to lead

Anthropic pressure negatively affects natural environments. Lead (Pb) is a non-essential highly toxic metal that is present in aquatic ecosystems. Two daphnid species from two different latitudes, the temperate Daphnia magna and the tropical Daphnia similis were used as test-organisms to evaluate a long-term Pb exposure. Both species were exposed for nine generations to a chronic concentration of Pb (50 μg/L) and the effects were explored, considering some endpoints not commonly used in toxicity tests: body burden of Pb and presence of granules in the dorsal region of neonates, hemoglobin contents, carapace deformation and morphology, production of males and ephippia (or dormant haploid egg), changes in the eggs' colour and eggs abortion. This multi-generation test was conducted under two food regimes, the usual (3 × 10⁵ cells/mL) and the restricted (1.5 × 10⁵ cells/mL) regime. On generation F6, Pb acclimated neonates were changed to a clean media for three generations, to evaluate exposure retrieval (recovery period). Negative and adverse effects occurred through generations, but no disparity was shown between D. magna and D. similis. The D. magna Pb accumulation showed different patterns regarding food regime. Bioaccumulation was faster under usual food, rapidly reaching a saturation point, whereas a gradual increase occurred under food restriction. A successful retrieval happened regarding Pb in D. magna, since no difference between control and recovering organisms was evidenced regarding their Pb body burdens. Generational Pb exposure led to carapace malformations, Pb aggregation in neonates' dorsal region, reddish extremities, production of males, ephippia (or dormant haploid egg), and aborted eggs, and changes in the eggs' colour (green and white). Food restriction also induced the production of males. Reddish extremities disappeared in recovering organisms and ephippia (or dormant haploid egg) did not occurred during the recovery period. Existent males revealed a shorter lifespan than females (under stress). D. magna and D. similis presented similar responses, for the endpoints analysed; however, it does not mean that this lack of sensitivity difference will be observed when other endpoints (e.g. survival, reproduction) are considered. Bioaccumulation of Pb and adverse effects occurred at the tested concentration of 50μg/L, although higher Pb levels are allowed in the environment as safe concentrations, as reported by the Brazilian legislation and the literature where effects are evidences above 400 μg/L of Pb. Pb effects on reproduction, respiration, malformation, and other adverse effects suggest that a chronic generational exposure can be harmful to both D. magna and D. similis, and that such chronic contaminated environments should not be disregarded when it comes to environmental monitoring.

Proximate, fatty acids and metals in edible marine bivalves from Italian market: Beneficial and risk for consumers health

Seafood is recognized as a healthy food choice due to high contents of essential nutrients, including polyunsaturated fatty acids (PUFAs) of the n-3 family. However, seafood is often contaminated by toxic compounds, which have adverse effects on human health. The aim of this study was to provide information about the percentage of edible part, condition index and the benefit and risk for human consumers health associated to the consumption of eight bivalve species (Flexopecten glaber, Mimachlamys varia, Modiolus barbatus, Mytilus galloprovincialis, Ostrea edulis, Ruditapes philippinarum, Solen marginatus and Venus verrucosa) of high commercial value, purchased from Taranto local fish markets. High percentage of edibility and condition index were found in all analysed species. The relatively high protein content, low levels of lipid and high percentage of healthy n-3 PUFAs make M. varia, O. edulis, S. marginatus, M. galloprovincialis, M. barbatus more suitable for benefit to consumers. Provisional tolerable weekly intake and hazard index calculated on the basis of trace metals in edible tissues, indicated specific recommendations for a responsible daily consumption of shellfish. For the most part of studied species, the estimated balance between beneficial and risk for consumers recommend a daily portion (RDP) lesser of 60 g/person/day than M. galloprovincialis, O. edulis and R. philippinarum (≥60 g/person/day). Careful risk-benefit considerations should promote seafood consumption while minimizing exposure to toxic contaminants.