Distribution and relationships of As, Cd, Pb and Hg in freshwater fish from five French fishing areas

Mercury bioaccumulation and trophic transfer in Pacific Saury from the North Pacific Ocean

This study investigates mercury (Hg) dynamics in Pacific Saury (Cololabis saira) across the North Pacific Ocean, specifically off East Japan in 2018. Saury traits vary with total mercury (THg) concentrations in muscle tissues ranging from 0.017 to 0.082 μg g-1 w. w., averaging of 0.042 (n = 46). A positive correlation between THg and saury length (Knob length, 270-319 mm) indicates increased Hg concentration with size. Stable isotopic tracers suggest Pacific Euphausiids (Krill) are significant contributors to the saury diet (>70% of total). Significant correlations between logarithm THg concentration (Log THg) and δ15N (‰) (R2 = 0.70) demonstrate Hg trophic biomagnification, with regional variations. Comparative analysis between the eastern (ENPO) and western North Pacific Ocean (WNPO) indicates differences, with WNPO saury exhibiting lower δ15N values and higher THg levels than ENPO saury. This suggests that the WNPO, located near East Asia, the world's largest Hg emitter, experiences elevated Hg levels in seawater due to anthropogenic release. Overall, this study advances understanding of Pacific Saury's ecological interactions and Hg bioaccumulations, emphasizing the importance of species-specific behaviors and regional influences in ecological studies.

Bioaccumulation of chemical elements in fish from areas affected by oil on the coast of Bahia, Brazil

In 2019, the Brazilian coast was affected by the largest oil spill in its history. We assessed the levels of chemical elements in Lutjanus synagris and Haemulon aurolienatum fish from Itacaré (least affected area), Tinharé-Boipeba (most affected area) and Madre de Deus (chronically affected area). The level of metals differed between species, tissues, life cycle phases, maturation stages and between sampled locations, indicating the influence of biological and environmental aspects on bioaccumulation. Only fish in Madre de Deus showed lead contamination, while arsenic concentrations in the three areas exceeded the maximum value acceptable by Anvisa (National Health Surveillance Agency). It is suggested that the oil spill may have impacted species differently, also having an impact in fish from less affected areas. However, metal concentrations in fish in Madre de Deus stood out when compared to populations in other studied areas.

Invasive Round Goby (Neogobius melanostomus) Fish from the Southern Baltic as a Source of Arsenic and Selenium-Food Safety Aspects

Minimizing human exposure to arsenic (As) and ensuring an adequate dietary intake of selenium (Se) are significant issues in research on food sources. This study measured the content of As and Se in the muscles, gills, liver, and gonads of the fish round goby (Neogobius melanostomus) to assess the benefits and risks associated with their consumption. This was achieved by using dietary reference intake (DRI), estimated daily intake (EDI), target hazard quotient (THQ), and carcinogenic risk (CR). The elements were analyzed by atomic absorption spectrometry. The mean concentrations of As and Se (in μg kg-1 wet weight) were 25.1 and 161.4 in muscle, 58.8 and 367.4 in liver, 47.4 and 635.3 in gonads, and 16.4 and 228.5 in gills, respectively. Arsenic in the muscle portion of fish accounted for up to 0.5% of the DRI, while Se constituted approximately 30% of the DRI. The EDI values were below the reference oral dose (RfD). The THQ were much below the permissible levels (THQ < 1), and the CR were at least within the permissible limit (CR < 10-4). With regard to the As content, round goby muscles can be deemed safe for consumers. They may also be a valuable source of Se in the human diet. However, round goby consumption should be monitored for the proper and safe intake of these elements.

Risk Assessment and Sources Apportionment of Toxic Metals in Two Commonly Consumed Fishes from a Subtropical Estuarine Wetland System

The widespread occurrence of heavy metals in aquatic environments, resulting in their bioaccumulation within aquatic organisms like fish, presents potential hazards to human health. This study investigates the concentrations of five toxic heavy metals (Pb, Hg, Zn, Cu, and Cr) and their potential health implications in two economically important fish species (Otolithoides pama and Labeo bata) from a subtropical estuarine wetland system (Feni estuary, Bangladesh). Muscle and gill samples from 36 individual fish were analyzed using energy dispersive X-ray fluorescence (EDXRF). The results revealed that the average quantities of heavy metals in both fishes' muscle followed the declining order of Zn (109.41-119.93 mg/kg) > Cu (45.52-65.43 mg/kg) > Hg (1.25-1.39 mg/kg) > Pb (0.68-1.12 mg/kg) > Cr (0.31-5.82 mg/kg). Furthermore, Zn was found to be present in the highest concentration within the gills of both species. While the levels of Cu, Zn, and Cr in the fish muscle were deemed acceptable for human consumption, the concentrations of Pb and Hg exceeded the permissible limits (>0.5 mg/kg) for human consumption. Different risk indices, including estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic or target risk (TR), revealed mixed and varying degrees of potential threat to human health. According to the EDI values, individuals consuming these fish may face health risks as the levels of Zn, Cu, and Cr in the muscle are either very close to or exceed the maximum tolerable daily intake (MTDI) threshold. Nevertheless, the THQ and HI values suggested that both species remained suitable for human consumption, as indicated by THQ (<1) and HI (<1) values. Carcinogenic risk values for Pb, Cr, and Zn all remained within permissible limits, with TR values falling below the range of (10-6 to 10-4), except for Zn, which exceeded it (>10-4). The correlation matrix and multivariate principal component analysis (PCA) findings revealed that Pb and Cr primarily stemmed from natural geological backgrounds, whereas Zn, Cu, and Hg were attributed to human-induced sources such as agricultural chemicals, silver nanoparticles, antimicrobial substances, and metallic plating. Given the significance of fish as a crucial and nutritious element of a balanced diet, it is essential to maintain consistent monitoring and regulation of the levels and origins of heavy metals found within it.

Differential accumulation of metals in the lacustrine and fluvial Alpine bullheads (Cottus poecilopus) and recovery of fish from metal contamination after a flash flood

The spatiotemporal distribution and transport of mercury, zinc, molybdenum, rubidium, and strontium from alpine terrestrial ecosystems to alpine lake and mountain stream populations of Cottus poecilopus were investigated. Metals were measured for 66 wild fish collected from different lakes and Javorinka stream across. Mercury was measured in the pectoral fins, other elements in the skull. Bullheads contained more metals in the alpine lakes than in the mountain stream. In particular, mercury and zinc concentrations in lake bullheads were 6 and 2.5 times higher, respectively, than those of stream-dwelling fish. New data were generated on metal bioaccumulation in fish of understudied West Carpathian alpine lake environments. In July 2018, a major flood occurred in the area of the Javorinka. Already then, the mercury content in bullheads increased significantly. Bioaccumulation of mercury in fish occurred very quickly after the flood and was also significant in the following 2019. Then, the concentrations of mercury quickly decreased up to 70% in 2021-2022. Average concentrations of molybdenum and rubidium in bullheads in the stream rapidly declined in the year following the flood disturbance, but within less than 2 years, the metal levels stabilized at about the same level as in 2017 prior the flood. Strontium concentrations in fish dropped rapidly immediately after the flood, increased in the following years, and dropped again after 4 years, suggesting that many more factors are influencing strontium bioaccumulation in fish that are comparable in magnitude to the flood. The most serious warning seems to be the absence of biogenic zinc. The average concentration in the Alpine bullheads population in the stream has declined by 70% in less than 5 years and is steadily declining. An important result of this study is the demonstration that disturbance by a single factor (heavy rainfall and flooding) has a clear and timely effect on average metal concentrations in the fish population.

Heavy metal concentrations in various tissues of two fish species from Damsa Dam Lake (Turkey) and associated health risk assessment

PURPOSE OF REVIEW AND METHOD

In this study, indicate the average or range of 10 heavy metal concentrations in muscle, gills and liver of two fish species (Squalius pursakensis and Cyprinus carpio) living in the Damsa Dam Lake (Turkey) was examined in relation to fish gender and size. Inductively coupled plasma-tandem mass spectrometry was used to evaluate the concentrations of heavy metals. The average contents of the metals in S. pursakensis muscle samples were 0.877, 9.285, 0.614, 0.488, 8.190, 0.155, 0.015, 0.010, 0.218, 0.009 mg/kg for Cu, Fe, Mn, Ni, Zn, As, Cd, Co, Cr and Pb respectively. On the other hand, the average contents of the metals in C. carpio muscle samples were 0.673, 8.001, 0.367, 0.435, 6.107, 0.188, 0.007, 0.007, 0.371, 0.012 mg/kg for Cu, Fe, Mn, Ni, Zn, As, Cd, Co, Cr and Pb respectively. In addition, human health risks were evaluated considering the estimated daily intake of heavy metals in adults. The target hazard quotient, hazard index and carcinogenic risk values were determined based on the frequency of fish consumption for the population living in the region.

RESULT AND CONCLUSION

The highest quantities of all heavy metals were determined in the gills and liver of the fish species. The levels of most heavy metals in tissues did not differ significantly between both fish species. Only a few heavy metals in the tissues of both fish species demonstrated significant associations with fish length or weight. In terms of the levels of most of the heavy metals in the tissues, there weren't any significant differences between the male and the female fish. The estimated daily intakes of all of the heavy metals were lower than the reference doses. The values of the target hazard quotient and the hazard index were found to be below 1 and the values regarding carcinogenic risk were assessed to be within or lower than the permissible levels. Cr, Cu, Zn, Cd, Pb and inorganic As values assessed in the muscle tissues of fish were found below the values acceptable by national and international institutions. These results proved that the examined fish species can be consumed safely.

Heavy metal bioaccumulation and risk assessment in fishery resources from the Gulf of Thailand

The muscle tissues of 19 fish species, two crab species, and one shrimp species collected from the Gulf of Thailand (GoT) were analyzed to determine the levels of heavy metals, including Cu, Zn, Fe, Mn, Ni, Pb, Cd, and Hg. The results revealed that the mean concentrations of the heavy metals, in descending order, were Zn > Cu > Fe > Cd > Hg > Mn > Pb > Ni. Among the examined metals, zinc was found to be the most prevalent in fish tissues. Based on the risk assessment indices, the estimated average daily doses (ADD) of the heavy metals were found to be below the provisional tolerable daily intake (PTDI) recommended by the joint Committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) on food contaminants. The results of the target cancer risk analysis revealed no related cancer risk from the consumption of the fishes considered for the study. However, the target hazard quotient (THQ) values exceeded the threshold of 1 (THQ > 1) specifically for mercury in Gymnothorax spp. and Terapon spp. Furthermore, the calculated hazard index (HI) values for fish muscles were all below 1, indicating that there is no significant health risk for humans at the current consumption rates, except in Terapon species for both normal and habitual consumers. Notably, habitual consumers of Gymnothorax species showed the highest HI value (>1), suggesting potential long-term effects on human health when consuming larger quantities of these fishes.

The Paraíba do Sul River Basin and its coastal area as a study model of the mercury cycle: A meta-analytical review of three decades of research

The Paraíba do Sul River (PSR) Basin is a crucial drainage basin in Southeast Brazil, being the most industrialized and densely populated region in the country. Over the last three decades, the basin has been the subject of numerous studies due to its long history of mercury (Hg) contamination. This makes the PSR Basin an excellent model to evaluate Hg cycling, which is a priority for signatory countries of the Minamata Convention, which includes Brazil. This review compiled data on Hg from five environmental compartments (animals, plants, sediment, suspended particulate matter (SPM), and water), three different sectors (upper, middle, and lower) and five different ecosystems (reservoir, mangrove, fluvial, estuarine, and coastal) from 60 published studies, aiming to understand the Hg cycling through meta-analyses. The highest concentrations of Hg were observed in the upper and middle sectors of the basin, which are areas with high industrialization and urbanization levels. Among the evaluated ecosystems, hydropower reservoirs showed the highest medians and were also frequent in the upper and middle portions of the PSR basin. Over the years, all environmental compartments showed a decline in Hg concentrations due to the implementation of federal and state environmental policies. The main source of Hg for the basin was Hg-rich soils from past activities (such as artisanal small-scale gold mining and the use of organomercurial fungicides in sugarcane plantations). These results can assist decision-makers in the management of the basin's ecosystems and can also be used to evaluate the effectiveness of implementing the Minamata Convention in the region.

Arsenic speciation in freshwater fish: challenges and research needs

Food and water are the main sources of human exposure to arsenic. It is important to determine arsenic species in food because the toxicities of arsenic vary greatly with its chemical speciation. Extensive research has focused on high concentrations of arsenic species in marine organisms. The concentrations of arsenic species in freshwater fish are much lower, and their determination presents analytical challenges. In this review, we summarize the current state of knowledge on arsenic speciation in freshwater fish and discuss challenges and research needs. Fish samples are typically homogenized, and arsenic species are extracted using water/methanol with the assistance of sonication and enzyme treatment. Arsenic species in the extracts are commonly separated using high-performance liquid chromatography (HPLC) and detected using inductively coupled plasma mass spectrometry (ICPMS). Electrospray ionization tandem mass spectrometry, used in combination with HPLC and ICPMS, provides complementary information for the identification and characterization of arsenic species. The methods and perspectives discussed in this review, covering sample preparation, chromatography separation, and mass spectrometry detection, are directed to arsenic speciation in freshwater fish and applicable to studies of other food items. Despite progress made in arsenic speciation analysis, a large fraction of the total arsenic in freshwater fish remains unidentified. It is challenging to identify and quantify arsenic species present in complex sample matrices at very low concentrations. Further research is needed to improve the extraction efficiency, chromatographic resolution, detection sensitivity, and characterization capability.

Toxicity risks associated with trace metals call for conservation of threatened fish species in heavily sediment-laden Yellow River

Trace metals and metalloids in aquatic ecosystems may lead to adverse effects on the survival of fish, especially in the sensitive life stages of vulnerable species. It is still unknown whether threatened fish species in the heavily sediment-laden Yellow River are exposed to toxicity risks associated with multiple trace metals. Herein, we analyzed the concentrations of trace metals in aquatic environmental media and fish tissues across the Yellow River mainstream and assessed the level of metal toxicity to threatened fish. Significantly different concentrations of trace metals in fish tissues were measured between at least two categories among near-threatened, vulnerable, endangered, and critically endangered fish. No metal showed a higher concentration in demersal fish than in pelagic fish. Substantially low metal toxicity was observed for the gill of Rhinogobio nasutus (near-threatened) in the upper reaches, as well as for the gill and liver of Silurus lanzhouensis (endangered) in the middle reaches. High contents of suspended sediment in water and high metal concentrations in sediment and suspended matter could influence the survival and reproduction of fish, especially those already with threatened status.

Microplastics in different fish and shellfish species in the mangrove estuary of Bangladesh and evaluation of human exposure

The water bodies in Bangladesh thrive from plastic pollution. Estuaries are pools of environmental contaminants, and the world's largest mangrove forest, Sundarbans' estuary, is no exception. Thus, for the first time, we investigate MPs abundance in the muscle and gastrointestinal tract (GIT) of twenty estuarine species of fish and shellfish of the Sundarbans, as well as the human health risk. MPs abundance was evident in all the samples ranging from 5.37 ± 1.07 to 54.30 ± 16.53 MP items/g wet body weight (dw) in muscle samples and 7.33 ± 1.89 to 205.61 ± 136.88 MP items/g (dw) in GIT samples. The estimated health risk from MPs is substantial, where the average human intake will be 85,710.08 items of MPs per year per capita for the population of Bangladesh. The dominant polymer types observed using ATR-FTIR are PP and PE (17.5 %), PA (17.5 %) in the muscle tissues, and PP and PE (11.11 %), and EVA (11.11 %) in the GITs. Bottom-feeding species, such as demersal and benthic species, are more contaminated. However, the level of MPs in the species shows a negative correlation with the length and weight of the species. This study reveals that MP pollution is widespread and concerning in Bangladesh's Sundarban mangrove estuarine zone.

Metal(loid)s and persistent organic pollutants in yellow European eel from the Raša River, Croatia

The anthropogenic impact on the aquatic environment of the Raša River (Croatia) was investigated through the analysis of seven polybrominated diphenyl ethers (PBDEs), seven polychlorinated biphenyls (PCBs), three DDT isomers, and 22 major and trace elements using yellow European eel (Anguilla anguilla L.) as a biological indicator of contamination. The obtained data indicated generally low contamination status in the surrounding area. Levels of all organic contaminants in muscle significantly increased with lipid content, length, weight and body condition. In both muscle and liver, most metal(loid)s decreased or remained unchanged with increasing size, while at downstream location only several elements (Cd, Cu, Fe, Na, Se, U, V, Zn) accumulated in the liver with fish growth. Spatial analysis revealed higher pressure of Ag, Cd, Cr, Mo, Tl, U, and V at the downstream location, revealing the potentially limited impact of historical coal mining industry on the lower reaches of the Raša River.

Metals bioaccumulation, possible sources and consumption risk assessment in five Sillaginid species, a case study: Bandar Abbas (Persian Gulf) and Chabahar Bay (Oman Sea), Iran

In this study, the concentrations of 10 metals (As, Al, Cd, Cr, Cu, Fe, Hg, Ni, Pb and Zn) in different tissues (gill, muscle and otolith) of five sillaginid species (Sillago arabica, S. attenuata and S. sihama from the Persian Gulf and S. indica, S. sihama and Sillaginopodys chondropus from the Oman Sea) were analyzed using ICP-MS, and the potential human health risk assessment for local consumers was also conducted using standard indices. The concentration of trace metals (μg g^-1 dw) in fish ranged from 0.24 to 16.09 (As), 7.88 to 167.51 (Al), 0.005 > -0.866 (Cd), 0.006 > -7.95 (Cr), 1.02-5.58 (Cu), 24.86 to 390.85 (Fe), 0.005 > -1.93 (Hg), 0.021 > -7.80 (Ni), 0.33-4.41 (Pb) and 4.78-170.43 (Zn). The levels of trace metals varied significantly among sampling sites, fish species and their tissues. Gill tissues accumulate higher concentrations of the analyzed elements, except for As and Hg, whose higher concentrations were found in muscle tissues. Among the species, S. sihama in the Persian Gulf showed the highest levels of toxic metals compared to the other species. The dendrogram of metal association in fish muscle tissues revealed that Ni, Cr, Cd, Pb and Hg in muscles mainly originated from anthropogenic sources, especially petroleum activities. A second dendrogram based on the association of these five metals in the muscle tissue separated the sillaginid species of the Persian Gulf from the Oman Sea. The mean concentrations of the analyzed metals in the edible tissues were lower than international standards of maximum permissible limits (MPL), except for inorganic As (_iAs) and Pb. The index of estimated daily intake (EDI) for Cr and Hg in all sillaginid species, and _iAs, Pb and Ni only in the Persian Gulf's sillaginid species was higher than the recommended values. The value of the target hazard quotient (THQ) indicated that the intake of individual heavy metals due to the consumption of sillaginid species was safe for human health (except Hg in S. arabica) whereas combined heavy metals' intake revealed potential health problems in the case of increased consumption for all three sillaginids in the Persian Gulf. Target cancer risk (TR) for _iAs in all species and Cd, Cr and Ni in Persian Gulf species was higher than the acceptable range. The results indicated the health issues associated with high consumption, especially for sillaginids in the Persian Gulf, which should be considered in food safety monitoring for local people in the area.

Evaluation of Chemical Elements, Lipid Profiles, Nutritional Indices and Health Risk Assessment of European Eel (Anguilla anguilla L.)

The concentrations of ten elements (K, Na, Ca, Mg, Zn, Fe, Hg, Cu, Mn, and Cd) and fatty acids were analyzed in muscles of the European eel (Anguilla anguilla Linnaeus, 1758). The eels were caught in freshwater lakes connected with the Sawica River (north-eastern Poland). On this basis, it was determined whether the consumption of the fish is beneficial and safe for the health of the consumer. The results showed that the metal concentrations followed this order: K > Na > Ca > Mg > Zn > Fe > Hg > Cu > Mn > Cd. The fatty acids gave rise to the following sequence: MUFAs > SFAs > n-3 PUFAs > n-6 PUFAs. The target hazard quotient (THQ) value was below 1.0. The hazard quotient for the benefit-risk ratio HQ_EFA (0.39) also was below one, indicating that the intake of the recommended dose of EPA + DHA (250 mg/day) and the intake of mercury (0.415 mg/kg) for a person weighing 70 kg does not pose an obvious risk for human health. The lipid quality indices were OFA: 24.69, DFA: 74.36, AI: 0.55, and TI: 0.41. Based on the above statements, the consumption of eel meat is safe from a health point of view. However, the levels of toxic metals in the muscles of eels and their environment should continue to be monitored, as eels occupy a high position in the food chain.

Potentially Toxic Elements in Water, Sediments and Fish from the Karstic River (Raša River, Croatia) Located in the Former Coal-Mining Area

The assessment of the environmental quality of a sensitive karst aquatic system under the centuries-long anthropogenic influence of the coal mining industry is important for both improving the quality of water resources and protecting aquatic wildlife and human health. In this study, we investigated the anthropogenic impact on the aquatic environment of the upper and middle course of the Raša River through the analysis of a suite of metal(loid)s in three aquatic compartments (water, sediment, fish) using inductively coupled plasma mass spectrometry (ICP-MS). Concentrations of inorganic constituents in water were low, while the chemical composition of stream sediments mainly reflected the geological background of the area, indicating the origin of metal(loid)s from predominantly natural sources. Although comparison with PEC-Q values indicated that existing sediment quality conditions could pose a threat to benthic organisms with regard to Cr and Ni, the constant vertical profiles of these elements suggested their natural origin from the weathering of flysch. Element levels in the muscle of targeted fish species were in accordance with the values typical for low-contaminated freshwater systems, while levels of Cd, Pb and Hg were mostly below the European regulatory limits for toxic elements in foods, indicating that the low concentrations of most contaminants in muscles of fish from the Raša River do not present a risk to humans or other consumers. The obtained data indicated a generally low contamination status of the western part of the Raša River basin with regard to the analyzed inorganic elements.

Heavy metals in Chinese freshwater fish: Levels, regional distribution, sources and health risk assessment

China is a major producer and consumer of freshwater fish, which can provide nutrients to the human body but is also of great concern because of the bioaccumulation and amplification of heavy metals that are directly related to human health. In this paper, we reviewed the accumulation and distribution patterns of lead (Pb), arsenic (As), mercury (Hg), cadmium (Cd), and chromium (Cr) in freshwater fish from 2010 to 2020 in nine basins of China (Yangtze River, Pearl River, Yellow River, Haihe River, Huaihe River, Songhua and Liaohe River, Continental, Southeast, and Southwest basins), assessed the health risks, and compared them with those in Chinese marine fish, international freshwater fish, Chinese wild freshwater fish, and artificially cultured freshwater fish. The results showed that 1) the pollution status of the five heavy metals in freshwater fish from nine basins in China is at an intermediate level internationally; 2) the magnitude of heavy metal concentration in four types of artificially farmed freshwater fish and wild freshwater fish is ranked as follows: rice-farmed fish < cage-farmed fish < pond-farmed fish < lake-farmed fish < wild fish; 3) the noncarcinogenic risk factors for heavy metals in freshwater fish in the nine major basins in China were <1 for adults, but the noncarcinogenic risk factors for heavy metals in freshwater fish in the Yellow River, Yangtze River, Pearl River, Songhua and Liaohe River, and Huaihe River basins were all >1 for children.

Determination of heavy metals from Aloe vera by- product in golden mullet (Liza aurata); A consumer health risk assessment

Heavy metals have become subject of concern in the recent years because of its potency to cause cardiovascular diseases and other toxic health effects. Therefore, this research was assumed to investigate the level of toxicity in terms of heavy metals accumulation in the fish samples and its benefits and risk for human consumers health and also evaluate the partial replacement of plant sources by canarian Aloe vera diets as a pure product or like a by-product on toxicological effects on the golden mullet (Liza aurata) fillet and whole body. In this study risks arising from fish metal content has been measured using various parameters as Estimated Daily Intake (EDI), Maximum Safe Consumption (MSC_A), Target Hazard quotient (THQ), Hazard Index (HI) Carcinogenic risk of As (As- CR), the Value Selenium Health Benefit (Se HBV) and also the Nutritional Values has been evaluated. The results showed that all heavy metal levels in the fish tissue and diets were below the confirmed safe limits for consumption. In case of diets, it is obvious that with the exception of As, Hg, and Se, the presence of heavy or essential metals in both whole fish and raw fillet in golden grey mullet given experimental diets revealed that the whole fish had the highest concentration. Thus, it can be concluded that Aloe vera product and byproduct were in safety limits for fish and also for humans through food chain. Various risk and benefit assessment measures established by national and international authorities concluded that Liza aurata use was mostly safe.

Residual Levels of Mercury, Cadmium, Lead and Arsenic in Some Commercially Key Species from Italian Coasts (Adriatic Sea): Focus on Human Health

This study provides information on the potential human health risk of Hg, Cd, Pb and As exposure from consumption of two fish species (Umbrina cirrosa and Sciaena umbra) in the general population and in high-level fish consumers. The concentrations did not show significant differences between the two species, and no fish length element level–body-length relationship was observed, except for Hg. The average metal(loid) levels, irrespective of species, varied in the following ranges: Hg = 0.18–0.19, Cd = 0.07–0.10, Pb = 0.10–0.12, As = 0.59–0.69 μg g⁻¹ w.w. The concentrations remained below the maximum permissible limits (MPLs) for human consumption, except for Cd. The estimated intakes of Hg, Cd and Pb in both consumption scenarios were lower than the respective PTWI/PTMIs, as well as those of inorganic As, which were even lower than the BMDL₀₁. The non-carcinogenic risk (THQ) did not reveal any concerns, except for Hg. The lifetime health cancer risk (ILCR) suggested hazard exclusively from Cd, although for high-level fish consumers, even the ILCR of inorganic As was, in some cases, above the acceptable range. Continuous monitoring of metal(loid) levels in these fish is strongly recommended because the results demonstrate the occurrence of potential health risks, especially in high-level fish consumers, due to the presence of Hg and Cd.

Unexpected pathways of mercury in an alkaline, biologically productive, saline lake: A mesocosm approach

Mercury (Hg), as one of the most frequently and globally occurring pollutants, is of major public health concern. Aquatic environments are the key compartment for Hg methylation as well as for its consequent bioaccumulation and biomagnification. This mesocosm study investigated the differences in Hg turnover, Hg distribution and bioaccumulation in two contrasting waterbodies: Panozzalacke (PL), an "average", oligotrophic European freshwater body and Lake Neusiedl (LN), an alkaline, saline, eutrophic, biologically highly productive lake. Mesocosm experiments were carried out with either water, water and sediment, and finally water, sediment and the macrophyte Ceratophyllum demersum from the respective waterbody. Hg²⁺ was added to the water phase and the Hg distribution over time was monitored in the compartments air, water, suspended particles, sediment and plants. The results show a much faster Hg turnover in LN compared to PL. Most striking is the significantly higher mercury bioaccumulation in macrophytes from LN and the significantly lower sedimentation rates there. We conclude that the specific physico-chemical and biological conditions in LN, e.g., alkalinity, sulfate content, dissolved carbon and high amount of particulate matter, lead to a rapid conversion of incoming mercury, accelerating bioaccumulation and potentially leading to unexpected mercury biomagnification in this lake. This has implications for other comparable waterbodies around the globe.

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

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

Trophic transfer, bioaccumulation, and health risk assessment of heavy metals in Aras River: case study-Amphipoda- zander - human

Heavy metals (As, Pb, Cd, and Cu) were traced in a model of the aqueous food chain in the Aras River, located in northwest of Iran. The selected model included the zander (Sander lucioperca L.) and crustacean species known as amphipods (Gammarus sp.) which belong to the food chain of this ray-finned fish. A total of 172 samples (70 fish and 102 amphipods) were collected randomly and analyzed for heavy metals using atomic absorption spectrophotometry (AAS). The results showed that the accumulation of heavy metals in both taxa are in the order of As > Pb > Cd > Cu, and concentrations of heavy metals in fish muscle are higher than Gammarus sp. in all stations in different seasons. Specimens of station (1) displayed the highest heavy metal content due to local industrial activities. The recorded concentrations of As, Pb, and Cd exceed the permissible limits. There is a close correlation between the concentrations of heavy metals in the amphipods and zanders. Target hazard quotient (THQ), total target hazard quotient (TTHQ), and carcinogenic risk (CR) were calculated to assess risks to human health. The average of THQ for As (1.43) exceeded the international standards and presenting health risks to the consumers of this fish species. The TTHQ for heavy metals was estimated higher than 1. At all stations, the value of CR_Cd > 1 × 10^-3 indicating the degree of carcinogenicity of this metal in all parts of the Aras River. Therefore, according to our results, efficient control measures and regular biomonitoring should be established in this region.

The Impact of Pb from Ammunition on the Vegetation of a Bird Shooting Range

Hunting with lead ammunition represents a source of heavy metal pollution to the environment that can be potentially high at the local scale. Intensive hunting of small game species can concentrate high levels of ammunition discharging in small areas. This type of hunting is a relevant economic resource for private landowners in some regions of Spain, and current legislation allows the use of lead ammunition in these scenarios. It becomes, therefore, highly relevant to study whether this activity may pose concerns to the conservation of the environment in the areas where it takes place. Using a red-legged partridge (Alectoris rufa) shooting range as a study area, we examined the effect of intensive hunting on this species on the vegetation present. We found significantly higher lead levels in the sprouts of plants of shooting areas related to control sites of the same property where partridge shooting does not occur. We found differences in the presence of lead between sprouts of different plant species. In addition, old sprouts of existing vegetation in shooting areas also showed higher lead levels than newly emerged sprouts of the same plants. These results demonstrate the impact of lead ammunition on vegetation in terms of persistence over time and differences between species. Further analyses using chemical and ecotoxicological data are necessary to evaluate the extent of environmental pollution risks. Our results provide new support in favor of the use of alternative ammunition, with particular emphasis on scenarios where hunting activity is intensive.

Mercury content in fish from drinking-water reservoirs in the Morava River Basin (Czech Republic)

This study focused on the total mercury content in fish from seven drinking-water reservoirs located in the Morava River Basin: Bojkovice, Boskovice, Hubenov, Karolinka, Landstejn, Ludkovice and Nova Rise in the Czech Republic. A total of 308 fish were collected for the analysis. The content of total mercury was measured in the muscle tissue of bream, roach and perch using atomic absorption spectrometry and varied from 0.057±0.009 to 0.440 mg kg^-1 in bream, from 0.030±0.005 to 0.393±0.138 mg kg^-1 in roach and from 0.092±0.007 to 0.638±0.042 mg kg^-1 in perch. The highest total mercury content was found in perch from Landstejn and the lowest was measured in roach from Ludkovice. A positive statistically significant relationship was found between fish weight and total mercury content in fish muscle for almost all species and all sampling sites, except for roach from Ludkovice. A total of 19 samples exceeded the maximum mercury level set by legislation on food contaminants-0.5 mg kg^-1 in freshwater fish.

Metal-associated human health risk assessment due to consumption of pelagic and benthic ichthyofaunal resources from the highly contaminated Cuddalore coast in Southern India

We present seasonal variation of four metals (Cd, Cu, Pb, and Zn) in nine pelagic and three benthic fish species from the highly polluted Cuddalore coast in Tamil Nadu, India. Metals were assessed using atomic absorption spectrometry and detected in all fish species, in at least one season, except Iniistius cyanifrons where cadmium was not detected throughout. In both benthic and pelagic fish, order of metal concentration was Zn > Cu > Pb > Cd. Multivariate statistical analysis revealed that metals may have originated from both natural and anthropogenic sources. Health risk assessment revealed that consumption of fish from Cuddalore coast does not pose health risk for now; however, hazard index values (pelagic = 0.97; benthic = 0.90) are in borderline. Even a slight increase in metal concentration in fish can prove hazardous for human consumption. Sooner or later, eating fish from Cuddalore coast may pose a considerable health risk to humans if metal pollution is not held at Bay.

Mercury accumulation in muscle and liver tissue and human health risk assessment of two resident freshwater fish species in Flanders (Belgium): a multilocation approach

Detrimental effects of chemical pollution-primarily caused by human activities-on aquatic ecosystems have increasingly gained attention. Because of its hydrophobic qualities, mercury is prone to easily bioaccumulate and biomagnify through the food chain, decreasing biodiversity and eventually also affecting humans. In the present study, accumulated mercury concentrations were measured in muscle and liver tissue of perch (Perca fluviatilis) and European eel (Anguilla anguilla) collected at 26 sampling locations in Flemish (Belgian) waterbodies, allowing a comparison of these species within a variety of environmental situations. Furthermore, effects of size and weight have been assessed, expected to influence accumulation and storage of pollutants. Mercury concentrations in perch ranged up to 1.7 μg g^-1 dw (median: 0.29 μg g^-1 dw) in muscle and from 0.02 to 0.77 μg g^-1 dw (median: 0.11 μg g^-1 dw) in liver tissue. For eel, these concentrations were between 0.07 and 1.3 μg g^-1 dw (median: 0.39 μg g^-1 dw) and between 0.08 and 1.4 μg g^-1 dw (median: 0.55 μg g^-1 dw) respectively. We found a correlation of accumulated mercury with length in perch, independent of location. Furthermore, a significant difference in accumulated mercury concentrations between the targeted species was measured, with the highest mean concentrations per dry weight in eel liver and muscle tissue. In perch, higher concentrations were found in muscle compared to liver tissue, while in eel, liver tissue showed the highest concentrations. These findings were further considered with concentrations corrected for lipid content, excluding the fat compartment, which is known to a hold negligible portion of the total and methyl mercury concentrations. This confirmed our previous conclusions, except for mercury concentrations in eel. Here there was no longer a significant difference between muscle and liver concentrations. Finally, health risk analyses revealed that only frequent consumption of local eel (> 71 g day^-1) could pose risks to humans.

Health risk assessment and heavy metal accumulation in fish species (Clarias gariepinus and Sarotherodon melanotheron) from industrially polluted Ogun and Eleyele Rivers, Nigeria

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Concentration of Arsenic and Cadmium in the fish tissues exceed the limits set by the European Union.

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THQ values indicated likely adverse effects during a person’s lifetime with continuous exposure to Arsenic and Cadmium.

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As, Cd, and Nickel may pose cancer risk to consumer of fish from the two rivers over longtime exposure.

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Cancer risk due to long time consumption of fish from the rivers can be a major concern.

Ogun and Eleyele Rivers are in the Western part of Nigeria with a potential risk of heavy metal pollution because of many industrial wastes channeling through their courses. Therefore, in this study, the concentration of heavy metals and the possible human health risk of consuming Clarias gariepinus and Sarotherodon melanotheron collected from industrially polluted Ogun and Eleyele Rivers in Nigeria were evaluated.

The concentration of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), manganese (Mn), nickel (Ni), and lead (Pb) in tissues (gill, muscle, and liver) of fish was measured using Atomic Absorption Spectroscopy (AAS) and compared with the maximum permissible. The Estimated Daily Intake (EDI), Targeted Hazard Quotient (THQ), and Carcinogenic Risk (CR) of the metals were estimated for the determination of human health risk. Probabilistic predictions of the health risk were performed with Oracle Crystal Ball software.

Results of this study showed that the dry weight concentrations of the metals in the gills, liver, and muscle of the two fish species from the two sites were well below the permissible limits set by the joint FAO/WHO Expert Committee. Only the EDI for arsenic in gills of C. gariepinus obtained from the Ogun River exceeded the set limit. The THQ was >1 for As in the gills and liver of C. gariepinus and S. melanotheron obtained from the Ogun river suggesting non-carcinogenic risk to the consumers. The carcinogenic risk above 10⁻⁶ obtained for As, Cd, and Ni in the tissues of the two fish species suggested cancer risk to the consumers of fish from the two rivers. Consequent to our observation, consumption of fish from the study site presents some public health concerns. Therefore, this study advises routine heavy metal monitoring of fish along these rivers to implement regulatory standards by the government environmental health management agencies.

Dietary nutrients and health risks from exposure to some heavy metals through the consumption of the farmed common carp (CYPRINUS CARPIO)

Common carp (Cyprinus carpio) is one of the most important cultured fish species in Poland. The aims of our study were to determine the concentration of essential minerals in the muscle tissue of carp obtained from a pond culture and to compare the content of these minerals with the physiological norms of nutrition for the Polish population, Recommended Dietary Allowances (RDA), and Estimated Average Requirements (EAR). The non-carcinogenic and carcinogenic risk by assessment of the Estimated target hazard quotients (THQ), total target hazard quotients (ΣTHQ), and carcinogenic risk were also studied. The muscle tissue of the carp was rich in macroelements. The pattern significance gradation of element concentrations was as follows: Na > K > Ca > P > Mg > Al > Zn > Fe > Cu > Mn > Cr > Se > Co. The concentration of toxic heavy metals in the samples was lower than the maximum allowable level of metals in food products. The risk of consumption of toxicants by an adult at a daily intake of 100 g of fish was 1.45% for Pb, 0.1% for Hg, 0.02% for Cd, and 0.02% for As, compared to the allowable daily intake for each toxicant. The value of the target hazard quotients of each metal was less than 1, indicating that the intake of a single metal through the consumption of carp meat does not pose a considerable health hazard. The total value of the target hazard quotients was also less than 1, indicating the safety of the combined effects of the chemicals. The major risk contributor was Pb with 82.9%, followed by Hg (9.38%), As (6.43%), and Cd (1.29%).

Comparison of trace element concentrations in freshwater fish and marine fish consumed in Shandong Province, China, and their potential risks to human health

This study provides the primary data of ten trace element concentrations from four highly consumed cultured freshwater fish species in comparison to six marine fish collected from markets of the Shandong province, China, and evaluates the potential human health risks from consuming these fish. A significant difference in five metal concentrations (Cr, As, Se, Cd, Pb) was found between freshwater and marine fish. With the exception of chromium, the other four element contents in marine fish were higher than those in freshwater fish. According to estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ), and the permissible safety limits prescribed by various agencies, consumption of the examined fish species is safe for human health. However, chromium in freshwater fish and arsenic in marine fish should still be a cause for concern in terms of human health, especially for fisher folk communities and populations that frequently consume fish.

Drivers of variability in mercury and methylmercury bioaccumulation and biomagnification in temperate freshwater lakes

The four largest freshwater lakes in southwestern France are of both ecological and economic importance. However, some of them are subjected to mercury (Hg) contamination, resulting in the ban of human consumption of piscivorous fish. Moreover, beyond predatory fish, little information exist regarding Hg levels in other species of these ecosystems. In this context, we used a food web analytical approach to investigate Hg bioaccumulation and biomagnification in relation to the trophic structure of these four lakes. More specifically, various organisms (macrophytes, epiphyton, invertebrates and fish) were collected at the four lakes and analysed for carbon and nitrogen stable isotopes as well as for total Hg (THg) and methylmercury (MeHg). A spatial variability of bioaccumulation in organisms was observed, particularly in carnivorous fish, with higher Hg levels being found in the two more northern lakes (median±SE: 3491 ± 474 and 1113 ± 209 ng THg.g^-1 dw in lakes HC and L, respectively) than in the southern pair (600 ± 117 and 911 ± 117 ng THg.g^-1 dw in lakes CS and PB, respectively). Methylmercury biomagnification was observed through the food webs of all four lakes, with different trophic magnification slopes (HC = 0.16; L = 0.33; CS = 0.27; PB = 0.27), even though the length of the food chains was similar between the lakes. Our results suggest that rather than the food web structure, anthropogenic inputs (sulfate in northern lakes and phosphorus inputs in southern ones) may have a strong impact, more or less directly, on Hg methylation in freshwater environments, and lead to concentrations exceeding environmental recommendations despite low Hg backgrounds in sediment and water.

Brominated flame retardants and heavy metals in common aquatic products from the pearl river delta, south china: Bioaccessibility assessment and human health implications

Aquatic products are an important source of environmental pollutants to humans. This study was conducted to assess the bioaccessibility of selected brominated flame retardants and heavy metals in common aquatic products from the Pearl River Delta, South China, as well as associated human health risks. Based on a questionnaire survey, ten of the most consumed aquatic products were collected from local markets. The bioaccessibility of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDDs), and heavy metals was assessed using an in vitro gastrointestinal model. Bioaccessibility of heavy metals (33.0-84.0%) and HBCDDs (38.5-68.4%) was significantly higher than that of PBDEs (13.4-65.4%). Total non-carcinogenic and carcinogenic risks from heavy metal consumption were much higher than the threshold values due to excessive abundances of arsenic in shellfish (HQ = 2.45, CR = 1.1 ×10^-3). Furthermore, middle-aged populations and females were subjected to greater health risks due to different intakes of aquatic products among age and gender groups. Significant difference in bioaccessibility among analytes indicated that bioaccessibility of pollutants is non-negligible in health risk assessment. This is the first study systematically investigating health risks of aquatic products consumption and concludes that shellfish is a great cause for concern for the PRD residents.

Metals and metalloids in freshwater fish from the floodplain of Tablas de Daimiel National Park, Spain

The Tablas de Daimiel National Park (TDNP) is a floodplain ecosystem in central Spain with a potential risk of heavy metal and metalloid pollution. The objective of this study was to know the accumulation of arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), and selenium (Se) in muscle of six species of freshwater fish from the floodplain of TDNP. We obtained muscle samples of Cyprinus carpio (n = 89); Squalius pyrenaicus (n = 16); Ameiurus melas (n = 9); Lepomis gibbosus (n = 8); Micropterus salmoides (n = 6) and Carassius auratus (n = 5). A. melas, which is a predatory species, had significantly higher Hg concentrations than omnivorous or herbivorous species (i.e. C. carpio). On the contrary, A. melas showed lower concentrations of As, Pb and Se than omnivorous species (i.e. S. pyrenaicus and L. gibbosus ). The concentration of Hg was positively associated with fish size in C. carpio and A. melas. Some individuals of C. carpio (5.7%) and S. pyrenaicus (12.5%) showed Pb muscle concentrations above the maximum residue levels established by the European legislation for human consumers. The observed muscle Se concentrations can be associated with adverse effects on fish such as blood changes, reduced growth, mortality of juveniles and reproductive failure. The accumulation of Se in this floodplain located in a seleniferous area and the contamination produced by spent Pb shot pellets used for hunting in the past are discussed as potential sources of the elevated levels of these two elements in fish from this floodplain wetland.

Mercury, Lead, and Cadmium in the Muscles of Five Fish Species from the Mechraâ-Hammadi Dam in Morocco and Health Risks for Their Consumers

This study aims to assess the degree of metal contamination (mercury (Hg), cadmium (Cd), and lead (Pb)) in the muscles of five species of fish Esox lucius, Sander lucioperca, Micropterus salmoides, Lepomis macrochirus, and Scardinius erythrophthalmus, from the Mechraâ-Hammadi Dam between July 2017 and May 2018, and to conduct a risk assessment for human consumers. Trace metals were determined by Graphite Furnace Atomic Absorption Spectrometry for the Pb and the Cd and by Cold Vapor Atomic Absorption Spectrometry for the Hg. The results gotten from the study of the muscles of the different fish species show that the higher mean amounts of Cd and Hg were determined in E. lucius, and the maximum mean levels of Pb were detected in S. erythrophthalmus. Results suggested that demersal fishes inhabiting near the sediments and piscivorous fishes with higher trophic level were likely to accumulate higher trace metal concentrations. The general order of bioaccumulation of the trace metals measured in the muscles of the fish species is as follows: Hg > Pb > Cd. Therefore, the bioaccumulation of Hg in fish studied is more important than that of Cd and Pb. Furthermore, these concentrations are higher in summer than in winter for all trace metals. All the values of the trace metals in the muscle tissues are below the maximum limits recommended by the European Community (EC) N° 1881/2006. However, estimation of noncarcinogenic health risks by the target hazard quotient indicated no obvious noncarcinogenic risks to humans that consume those fishes (THQ < 1). Results of THQ and maximum safe consumption indicated that Hg may cause more harm to human by fish consumption especially for E. lucius and S. lucioperca. Therefore, reduced intake of carnivorous fishes should be promoted as part of a healthier diet.

Accumulation of trace elements in selected fish and shellfish species from the largest natural carp fish breeding basin in Asia: a probabilistic human health risk implication

Intake of fish contaminated with non-essential hazardous trace elements poses a significant risk to human health. In this study, trace elements (As, Pb, Cd, Cu, Ni, and Zn) were measured in edible tissues of seven commercially important fish and shellfish species (Otolithoides pama, Pseudapocryptes elongatus, Macrobrachium rosenbergii, Liza parse, Notropis atherinoides, Apocryptes bato, and Rhinomugil corsula) from a natural carp breeding basin, Halda river, Bangladesh. The elements were detected by inductively coupled plasma-mass spectrometry (ICP-MS), and the hierarchy of elemental levels (mg/kg) was Zn (61.56) > Pb (30.45) > Ni (26.81) > Cu (21.09) > As (1.49) > Cd (0.24). Among the analyzed elements, Pb, Ni, and Zn for some fish species exceeded the permissible dietary limit, suggested by national and international agencies. In addition, results of bioaccumulation factor (BAF) indicated that most of the studied species were bioaccumulative in nature (BAFs > 1000), and the mean BAF of elements were found in the following order: Zn (3156.74) > Ni (1629.30) > Cu (1566.77) > As (997.14) > Pb (259.98) > Cd (216.52). However, the species, L. parse being omnivorous represented the highest BAF (stored higher concentrations of metals) as compared to other species. The growth pattern of all the species was negatively allometric, and the health condition of the species varied from poor to good state revealed from the estimated Fulton's condition factor (FC). For the evaluation of health hazards, estimated weekly (EWI), target hazard quotient (THQ), and carcinogenic risk (CR) were calculated for both adults and children. Results of EWI showed As, Pb, and Ni surpassed provisional tolerable weekly intake (PTWI)-recommended guidelines. The non-carcinogenic health effect (TTHQ) might not appear for both types of consumers (as TTHQ < 1), and CRs of all consumers were also in acceptable range (10^-6 to 10^-4). However, the probabilistic distribution through Monte Carlo simulation revealed that children were more vulnerable to non-carcinogenic (67.3%) and carcinogenic risk effect (47.3%) for Pb. Meanwhile, adults obtained the probability of 0.7% and 36% for THQ and CR effect, respectively, interpreting less vulnerable.

European eels and heavy metals from the Mar Menor lagoon (SE Spain)

Heavy metal pollution is related to the fall in European eel (Anguilla anguilla) populations. The Mar Menor lagoon (SE Spain) is home to an endangered population of this species, which is still caught for human consumption. The presence of Pb, Cd and Hg in the livers and muscles and the Se:Hg ratio in muscle of 150 eels from this lagoon were determined. Pb concentrations were higher than those reported from other populations in the world, while Cd and Hg concentrations in the tissues analysed were lower. In terms of food safety, Se concentrations play an important role in sequestering Hg in eels from this lagoon.

Accumulation of trace elements in muscle, gill and liver of fish species (Capoeta umbla and Luciobarbus mystaceus) in the Tigris River (Turkey), and health risk assessment

Two fish species (Capoeta umbla and Luciobarbus mystaceus) were collected from the Tigris River (Turkey), and tissues (gill, muscle and liver) of fish samples were analyzed for Cd, As, Mn, Cr, Cu, Co and Ni using the inductively coupled plasma-tandem mass spectrometry. Significant differences were present between fish species in regard to trace element (TE) concentrations in muscle for Mn, in liver for Cu, Cd and Mn, and in gill for As, Co, Cu and Cd (p < 0.05). Liver had the highest total TE concentration, followed by gill and muscle. Significant negative correlations were recorded between fish size (length and weight) and TE concentrations in the tissues. Both fish species showed no gender differences in TE accumulation in muscle, gill and liver (p > 0.05). The estimated daily intakes for all TEs were much lower than the tolerable daily intakes. The target hazard quotient (THQ) and total THQ values of all TEs did not exceed 1, which means that non-carcinogenic health effects are not expected for the consumers. Arsenic carcinogenic risk values were within acceptable range. Mean Cd concentrations in muscle tissue of both fish species exceeded the maximum permissible limit set by the European Commission Regulation, while mean concentrations of As, Cr and Cu were below the legislated limits.

Metal concentrations in fish from nine lakes of Anhui Province and the health risk assessment

In the present study, to comprehensively investigate the metal contamination in the fish of Anhui Province, four fish species, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, and Hypophthalmichthys nobilis, were collected from nine lakes, and the levels of Zn, Pb, Cr, Cu, Ni, As, Hg, and Cd in the fish muscle were determined. The results showed that the highest concentrations of Zn (7.791 mg/kg), Pb (0.522 mg/kg), Cr (0.030 mg/kg), and Cu (0.767 mg/kg) were found in Tiangang Lake, Xifei Lake, Tiangang Lake and Baidang Lake, respectively. However, metals Ni, As, Hg, and Cd were not detected in all fish samples. In the fish species, the metal bioaccumulation ability was decreased with the following order: C. idellus > H. molitrix > H. nobilis > C. carpio. Furthermore, the target hazard quotient (THQ) was used to assess the health risk via fish consumption. The results indicated for co-exposure; C. idellus would pose a health risk to children at high exposure level (95th) as THQ value was higher than 1. It should be pointed out that Pb contributes most to the total THQs (the ratio was 88%); thus, the contamination of Pb should be paid more attention. This field investigation combined with health risk assessment would provide useful information on the heavy metal pollution in Anhui Province.

Macroelements and toxic trace elements in muscle and liver of fish species from the largest three reservoirs in Turkey and human risk assessment based on the worst-case scenarios

Macroelement (Na, K, Ca, Mg and P) and toxic trace element (As, Cd and Pb) contents were investigated in muscle and liver of the two fish species (common carp and trout barb) from the largest three reservoirs (Atatürk, Keban and Karakaya) in Turkey. Also, human health risks for consumers using the worst-case scenarios were assessed. Potassium was the most abundant macroelement in muscle of both fish species in all reservoirs, whereas phosphorus was the most abundant in liver. Toxic trace element contents in the liver of the two fish species from the three reservoirs were higher than those in muscle. The mean levels of As and Pb in muscle and liver of fish species from the Karakaya Reservoir were higher than those from the other two reservoirs. Three-way ANOVA showed that the interaction between fish species, reservoir and fish tissue was significant for only Cd (p < 0.01). The maximum levels of As, Cd and Pb in muscle and liver of fish species from the three reservoirs were below permissible limits. The estimated daily intakes of toxic trace elements in fish species were much lower than their corresponding tolerable daily intakes. The target hazard quotient (THQ) and total THQ values in fish species were below 1, which indicated that non-carcinogenic health effects are not expected. The carcinogenic risk values for inorganic arsenic were within acceptable range. The results revealed that toxic trace elements in common carp and trout barb from the Atatürk, Keban and Karakaya reservoirs do not pose a significant health risk to consumers.

Biotic and Abiotic Factors Influencing Arsenic Biogeochemistry and Toxicity in Fluvial Ecosystems: A Review

This review is focused on the biogeochemistry of arsenic in freshwaters and, especially, on the key role that benthic microalgae and prokaryotic communities from biofilms play together in through speciation, distribution, and cycling. These microorganisms incorporate the dominant iAs (inorganic arsenic) form and may transform it to other arsenic forms through metabolic or detoxifying processes. These transformations have a big impact on the environmental behavior of arsenic because different chemical forms exhibit differences in mobility and toxicity. Moreover, exposure to toxicants may alter the physiology and structure of biofilms, leading to changes in ecosystem function and trophic relations. In this review we also explain how microorganisms (i.e., biofilms) can influence the effects of arsenic exposure on other key constituents of aquatic ecosystems such as fish. At the end, we present two real cases of fluvial systems with different origins of arsenic exposure (natural vs. anthropogenic) that have improved our comprehension of arsenic biogeochemistry and toxicity in freshwaters, the Pampean streams (Argentina) and the Anllóns River (Galicia, Spain). We finish with a briefly discussion of what we consider as future research needs on this topic. This work especially contributes to the general understanding of biofilms influencing arsenic biogeochemistry and highlights the strong impact of nutrient availability on arsenic toxicity for freshwater (micro) organisms.

Evaluation of health risks from exposure to arsenic and heavy metals through consumption of ten fish species

In this study, the levels of 11 heavy metal(loid)s (HMs) were determined in ten different fish species (wild, farmed, freshwater, and marine) frequently consumed in Turkey and compared with the maximum permissible limits (MPLs) established by international standards. Also, human health risks for the consumers were assessed. Among 11 HMs, only Al and Cr levels did not show significant differences among fish species. The highest concentrations of As were found in red mullet, which is a demersal fish. The average concentrations of Cd, Cr, Cu, and Pb in all fish species were below the MPLs, whereas those of Zn in European anchovy and Mediterranean horse mackerel, and that of inorganic As in red mullet exceeded the MPLs. The highest and lowest toxic metal contents (Al, As, Cd, and Pb) were recorded in red mullet and farmed rainbow trout, respectively. The estimated daily intakes of HMs in each fish species were very lower than their corresponding tolerable daily intakes, suggesting the daily intake of HMs through fish consumption would not pose health risks for the consumers. The target hazard quotient for individual HMs and hazard index for combined HMs in fish species were below 1, which indicated that non-carcinogenic health effects are not expected. The carcinogenic risk results revealed that there was a carcinogenic risk from exposure to inorganic As via the consumption of red mullet. Among all investigated fish species, rainbow trout and common carp were safer in terms of both non-carcinogenic and carcinogenic risks from exposure to HMs.

Evaluation of heavy metals and radionuclides in fish and seafood products

Despite the existence of a legislation regarding food contaminants, food safety control in Serbia is a matter of great concern. This study investigates the radioactivity levels and heavy metal concentrations in fish and seafood commercially available in Serbian markets. Domestic fish species (caught in the Danube River) and fishery products imported from Europe, Asia and America were analyzed. The content of natural radionuclides and ¹³⁷Cs were investigated by gamma spectrometry. Activity concentration of ⁴⁰ K was measured in the range of 44-165 Bq kg^-1; low levels of ¹³⁷Cs were detected in two samples (2.8 and 3.0 Bq kg^-1), while concentrations of ²²⁶Ra and ²³²Th were below minimal detectable values. Concentrations of heavy metals (Cd, Hg and Pb) were determined using ICP-OES method. Cd concentration ranged from 0.01 to 0.81 mg kg^-1 in sea fish and from 0.01 to 0.03 mg kg^-1 in freshwater fish. Hg concentrations were in the range of 0.01-1.47 mg kg^-1; the highest value was measured in the predator fish - shark. The highest level of Pb (6.56 mg kg^-1) was detected in a blue sea fish (Atlantic mackerel). The health risks associated with the intake of heavy metals and radionuclides via fish consumption were evaluated. The results indicate that fish and seafood consumption do not pose a significant health concern in the case of the usual consumption rate which is typical for the population of Serbia. However, a highly frequent consumption of fishery products can have adverse health effects, especially due to Hg and Pb contamination.

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.

Mercury, silver, selenium and other trace elements in three cyprinid fish species from the Vaal Dam, South Africa, including implications for fish consumers

The levels of Cr, Cu, Zn, Se, Ag, Cd, Hg, and Pb were determined in muscle and liver samples from 30 specimens of fish belonging to the species Labeobarbus aeneus, Labeobarbus kimberleyensis, and Labeo umbratus from the Vaal Dam. Health risks for human fish consumers were estimated using the target hazard quotient (THQ), the Se:Hg-ratio, and Se health benefit value (Se HBV). This is the first comprehensive report on Hg levels in fish from this lake. Mean concentrations ranging from 0.247-0.481 mg/kg dw in muscle and from 0.170-0.363 mg/kg dw in liver clearly show a contamination with this element. Although levels in muscle did not exceed maximum allowances for human consumption, a calculated THQ of 0.12 and 0.14 for the two Labeobarbus species, respectively, showed a potential risk due to additive effects. All Se:Hg-ratios as well as Se HBVs clearly suggested positive effects for fish consumers. Levels of Cu were remarkably high in the liver of L. umbratus, calling for further investigation on this species. Cadmium levels were above the maximum allowances for fish consumption in the liver of all three species (means between 0.190 and 0.460 mg/kg dw), but below the LOD in all muscle and intestine samples. This is also the first report of Ag in fish from South Africa. Levels were below the LOD in muscle, but well detectable in liver; they varied significantly between the two Labeobarbus species (0.054 ± 0.030 and 0.037 ± 0.016 mg/kg dw) compared to L. umbratus (1.92 ± 0.83 mg/kg dw) and showed a positive correlation with Cu levels (63.7 ± 17.0; 70.3 ± 9.0 and 1300 ± 823 mg/kg dw), possibly due to similar chemical affinities to metallothioneins. The detected Ag levels can serve as a basis to monitor the development of this new pollutant in aquatic environments in South Africa and worldwide.

Heavy metals concentrations in some commercially key species from Sicilian coasts (Mediterranean Sea): Potential human health risk estimation

Trace elements were measured in the edible tissues of target marine species (Sardina pilchardus, Mullus barbatus, Mullus surmuletus, Merluccius merluccius and Parapenaeus longirostris) collected in some of the main ports of the Sicilian coast (southern Italy) in order to evaluate the potential human health risk associated to their consumption. Cadmium, Pb and Hg were below the tolerable limits reported by the European Union in foodstuffs (Commission Regulation (EC) 1881/2006) except for Hg in P. longirostris from one sampling site. The health risk for consumers was assessed both for adults and children calculating the estimated weekly intake (EWI), the target hazard quotient (THQ) and the lifetime cancer risk (CR) for each element. The EWI did not exceed the provisional tolerable weekly intake (PTWI) recommended by the European Food Safety Authority and THQs were < 1 in most cases. Further, the probabilistic distributions of health hazard were evaluated through Monte-Carlo simulation which confirmed a non-carcinogenic risk. With some exceptions related to As exposure, the results obtained definitively confirm the goodness of the fishery commercial resources in one of the most important seafood market of the central Mediterranean Sea and represent a positive data for the assessment of the good environmental status for descriptor 9 of the Marine Strategy Framework Directive in this area of the basin.

Potentially toxic elements in water, sediments and fish of the Evrotas River under variable water discharges

Among different stressors like drought, hydro-morphological alterations, and pollution from agricultural activities, nutrients, organic compounds and discharges from wastewater treatment plants (WWTPs), potentially toxic elements (PTE) may also contribute to the overall pollution of the Evrotas River, Greece. Nevertheless, information on pollution of elements in water and sediments in this river is scarcely documented. There is also no information available on the impact of elemental pollution from the aquatic environmental compartments on biota. To fill these gaps, in this study, water, sediment and fish samples were collected from four sampling sites along the Evrotas River under variable flow regimes (July 2015, higher discharge; June 2016, low discharge and September 2016, minimum discharge). Total and dissolved element concentrations in water samples, total and acetic acid extractable contents in sediments, and element concentrations in fish samples were determined by inductively coupled plasma mass spectrometry and significant relationships between samples were established using correlation analysis. The concentrations of PTE (Ni, Cr, Cd, As, Pb, Zn and Cu) in water were generally low, while elevated Ni and Cr contents were found in sediments (up to 150 and 300 mg/kg, respectively), with total Cr concentration in water and sediment being positively correlated. The ecological risk posed by the simultaneous presence of PTE in sediments evaluated by calculating the Probable Effect Concentration Coefficient (PEC-Q), demonstrated that PEC-Qs, which were above the critical value of 0.34, derived mostly from Cr and Ni inputs. Since their mobile sediment fraction was extremely low, Cr and Ni origin is most probably geogenic. The analysis of elements in the target fish species, the Evrotas chub, showed low to moderate PTE concentrations, with Pb being positively correlated with total Pb concentration in water. Moderate Zn concentrations found in fish samples from the Evrotas are possibly derived from pesticides and fertilizers.

Potentially toxic elements in freshwater (Alburnus spp.) and marine (Sardina pilchardus) sardines from the Western Balkan Peninsula: An assessment of human health risk and management

The concentrations of 14 potentially toxic elements in freshwater and marine sardines from the Western Balkan Peninsula were determined. In Prespa Lake, a natural lake, the concentrations of toxic Pb and Cd were above the maximum permissible concentrations in freshwater sardines. The As concentrations were elevated in sardines from Boka Kotorska Bay. The Target Hazard Quotient (THQ) and Hazard index (HI) were above their defined limits in Boka Kotorska Bay and Skadar Lake, indicating a health risk for Montenegrin consumers. The results of this study set apart Zavoj, Vlasina and Međuvršje artificial reservoirs as potential ecosystems for developing commercial fishing and for the safe use of freshwater sardines for human consumption. Constant monitoring of Ohrid, Prespa and Dojran natural lakes, as well as Boka Kotorska Bay, may be implemented in the interest of public health.

Human health risks of Hg, As, Mn, and Cr through consumption of fish, Ticto barb (Puntius ticto) from a tropical river, Bangladesh

Metals tend to accumulate in higher organisms, e.g., fish and human through biomagnification effects in food chain. So, their presence in any component of the environment has become a global ecosystem and health concern. Here, we measured four health concerned metals like As, Cr, Mn, and Hg via inductively coupled plasma-mass spectrometry (ICP-MS) and analyzed applying some chemometrics for the assessment of human health risk through consumption of Puntius ticto, a very commonly consumed small fish in Bangladesh. The average concentration (wet weight) of metals was in the following descending order: Hg (0.006 mg/kg) > Cr (0.004 mg/kg) > Mn (0.003 mg/kg) > As (0.002 mg/kg). Hg level exceeded the provisional tolerable weekly intake (PTWI), and all other metals were within the permissible limit. The estimated daily intake (EDI) index of heavy metals showed that all the concentration levels were under the recommended daily intake (RDA) except Hg. Increased level of Hg is of particular concern to human health due to its biomagnification nature and can cause several neurological and physiological disorders including kidney failure. The total target hazard quotients (TTHQs) and carcinogenic risk (CR) matrices revealed that the intakes of Hg and As through fish consumption were higher than the recommended values, indicating consumers' remain non-carcinogenic and carcinogenic (THQ > 1; CR > 10^-5) health risks for lifetime consumption. Multivariate analyses (cluster and principal component) explained the sources of heavy metals in the study area originating from both anthropogenic and geological origin.