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Fish is a cheap source of omega-3 polyunsaturated fatty acids for humans. However, the presence of toxic heavy metals in water can be detrimental to both fish and humans. The aim of this study was to investigate the levels of heavy metals in the liver, kidney and gills of cat fish obtained from Kwalkwalawa River, Sokoto. Water, sediments, blood and tissue samples of (10) cat fish (Clarias gariepinus) species caught from Kwalkwalawa river were analysed quantitatively for the presence of zinc, copper, lead, chromium and cadmium using atomic absorption spectrophotometer. Bioaccumulation of these heavy metals was estimated in these organs. Results showed that lead concentrations in the water was significantly higher (p < 0.05) compared to the sediment sample. Also, copper and lead accumulated most in the liver and kidney when compared with that observed for the gills. In conclusion, lead and cadmium levels in the samples were above WHO certified limits hence the concentration of metals in this water should be monitored periodically. [ABSTRACT FROM AUTHOR]

There is a dearth of data about public health in the regular evaluation of heavy metal levels in seafood obtained from public market. This study aimed to examine the levels of essential (copper, zinc) and nonessential metals (cadmium, lead) in the tissues of cultured seabream (Sparus aurata), which was in public market. For this purpose, seabream samples were collected from the public market. And then, copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) metal accumulation levels in tissues of the dissected gill, liver, kidney, and muscle were measured by inductively coupled plasma mass spectrometry (ICP-MS). In order to understand whether the fish posed a risk to public health, risk evaluation formulations (estimated daily intake: EDI, hazard coefficients: HQ, hazard index: HI) were calculated for the muscle tissue. The data showed that Zn, Cd and Pb concentrations were maximal in the kidney tissue of S. aurata and Cu concentration were in the liver tissue, while the minimum heavy metal levels were in the muscle tissue. As a result, the maximum levels of heavy metals in the edible tissue of seabream were found as 0.11 mg Cu/kg wet weight, 0.72 mg Zn/kg wet weight, 0.12 mg Cd/kg wet weight, and 0.34 mg Pb/kg wet weight. Maximum values of them do not indicate any health risks as they are lower than the allowable tolerable levels specified by the international EDI estimation committees. The examined HQ and HI indicators were observed below 1 in all seasons. However, it is always possible for heavy metal intake to pose potential risks. For this reason, it is essential that the results of the study be interpreted from different perspectives and taken into consideration by other scientists. [ABSTRACT FROM AUTHOR]

This research studied the levels of cadmium, chromium, copper, cobalt, Iron, lead, nickel and zinc in the gill, liver, bone, and muscle of Tilapia zilli, Oreochromis niloticus and Clarias gariepenus and its associated water and sediment from Egbe dam in Ekiti - State. The levels of the metals in water were much lower than their corresponding concentrations in the sediment. Also, concentrations of the metals in the fish organs were higher than those recorded for the water except Cu, Zn and Fe in Oreochromis niloticus. It was observed that the mean concentrations of the metals in Tilapia zilli and Clarias gariepinus followed the order Muscle < Bone < Gills < Liver, while the order in Oreochromis niloticus was Muscle < Bone < Liver < Gills that showed that muscle possessed the lowest concentration of all the metals and that the metals varied among fish species and organs. Also, the highly toxic metals (Pb, Cd) detected fell below the Maximum Allowed Limit by Median International Standard. The result of this study, however, established the presence and bioaccumulation of these heavy metals in fish organs from water and sediment column hence, the need for continuous monitoring of the dam. [ABSTRACT FROM AUTHOR]

The fingerlings of Cyprinus carpio exposed to heavy metals Nickel, Copper and their mixture with reference to histopathological changes were observed. Histopathological observation were made in liver, stomach and gonad (ovary). The tissues of the fingerlings treated with the mixture showed remarkable changes in the structure when compared with the individual metal Nickel and Copper treatments. In all the above mentioned parameters, mixture treatment was more effective that too in the 30 days exposure than individual metal treatments. So the following sequence of toxicity is inferred from the present study in all the periods of exposure. Mixture> Copper> Nickel and the joint action of the metals is synergistic. This indicates Nickel and copper acted synergistically at sublethal levels in combination. [ABSTRACT FROM AUTHOR]

The goal of this study is to assess the concentrations of selected heavy metals (Pb, Cd, As, Cr, Hg) in the water and fish of the artificial lakes in Heipang (Latitude 9o 41' N and Longitude 8o 51' E) and Rayfield (Latitude 9o 50' N and Longitude 8o 55' E). Two methods namely: Atomic Absorption Spectroscopy (AAS) and Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) were used to determine the level of heavy metals in Tilapia zilli from the lake at Heipang and Clarias gariepinus from the lake at Rayfield. Determination of heavy metals in water was carried using AAS. The result show that Pb, As and Hg were above the limit of Nigerian Standard for drinking water quality. Percentage composition of heavy metals in the fish organs were muscle 40.6 %, intestine 35.4 % and gills 20.0 for Tilapia zilli, while Clarias gariepinus contained muscle 39.8 %, gills 33.5 % and intestine 26.7 %. The study revealed the bioaccumulation factors of 339, 302, 20.0, 2.30 and 0.320 for Cr, Cd, As, Hg and Pb respectively in Clarias gariepinus. While Tilapia zilli had 142, 137, 1.70, 1.03 and 0.690 for Cr, Cd, As, Hg and Pb, respectively. This study concludes that the two lakes were contaminated with Pb. [ABSTRACT FROM AUTHOR]

The study, aimed at assessing comparative concentration of heavy metals at the shoreline and about 70 km offshore, determined levels of heavy metals (Pb, Cd, As, Cr and Hg) in water and Tilapia bravemanus at the shoreline of Ilaje Local Government Area of Ondo State, Nigeria (SP1) using AAS technique. Same metals were assessed in water and Euthynnus alleteratus at Oyo Oil Field, about 70 km offshore of Ondo State (SP2). Trends of heavy metals in water and fish at SP1 were Hg > Cd > Cr > As > Pb and Hg > Cd > Cr > As > Pb respectively. While trends in water and fish at SP2 were Cr > Hg > Cd > As > Pb and Cr > Cd > As > Hg > Pb respectively. Bioaccumulation factor (BAF) in SP1 ranged from 217.43 to 1773. In SP2 it ranged from 31.34 to 331. Heavy metal contamination in water at SP1 was higher than at SP2. Similarly, heavy metal bioaccumulation in Tilapia brevimanus was higher than in Euthynnus alleteratus. Based on the outcome of the study, Tilapia brevimanus and Euthynnus alleteratus can be used as bio-indicators of heavy metal contamination in SP1 and SP2 respectively. [ABSTRACT FROM AUTHOR]

Abstract Aluminium and cadmium are biologically non-essential metals with a role in neurodegenerative and neuromuscular diseases. As an attractive model for neurobehavioural studies, zebrafish at 6 h post fertilization were exposed to 9, 18, 36 and 72 μM CdCl 2 and 50, 100 and 200 μM AlCl 3 , respectively, for 72 h, and motility such as distance moved, mean velocity, cumulative movement, meander and heading were measured by DanioVision equipment. The hatching time was also analysed. A delay in the exit from the chorion was observed in all treated larvae with respect to the controls. CdCl 2 acted on the exit from the chorion of larvae with a dose-dependent delay. By contrast, the delay caused by AlCl 3 was greater at low concentrations. A dose-dependent reduction in swimming performance was observed in the larvae exposed to CdCl 2. Instead, for those exposed to AlCl 3 , swimming performance improved at higher concentrations although values were in general lower than those of control. All the parameters had a similar trend except the meander parameter which showed a dose-dependent reduction. These data show that cadmium and aluminium can delay hatching and alter swimming ability in the early developmental stages of zebrafish, albeit with different effects, suggesting that exposure to sublethal concentrations of both metals can change behavioural parameters. Graphical abstract Image 101 Highlights • Aluminium and cadmium are toxic metals for developing zebrafish. • Exposure to CdCl 2 induces delay in hatching and in swimming dose-dependent. • Exposure to AlCl 3 increases swimming ability at increasing dose. [ABSTRACT FROM AUTHOR]

While ecotoxicology has long recognised the importance of identifying levels at which contaminants pose threats to biota, most estimates of species responses to toxicants are derived from controlled laboratory studies and may hold limited relevance to natural systems. However, designing appropriate field‐based studies investigating contaminant induced changes in assemblages has been challenging, partially due to the difficulty in identifying comparable uncontaminated reference sites. The aim of this study is to characterise the effects of heavy metal contamination on natural fish assemblages using an ecologically relevant catchment‐scale design. We hypothesise that environmental variables, including discharge, sediment, and landscape variables, can be used to characterise differences in fish species richness and abundances between sites contaminated with heavy metals and uncontaminated reference sites.We apply a geographic information systems approach that uses assemblage–environment relationships developed using hydrologic model outputs, land cover, and topographic data from uncontaminated reference sites to predict expected fish species richness and abundance at sites contaminated with heavy‐metals within the Big River catchment in south‐eastern Missouri, U.S.A. These predicted levels of richness and abundance are then compared to observed assemblages at contaminated sites to estimate the potential impacts of historical lead mining activities on freshwater taxa.We developed models that characterised variation in Centrarchidae (bass and sunfish) richness and abundance, Cyprinidae (minnows) abundance, and Percidae (darters) richness using variables including streamflow regime, suspended sediment concentration, and land cover at uncontaminated sites. Using these relationships, we predicted expected fish species richness and abundance at heavy metal contaminated sites across the Big River catchment and found a significant reduction in centrarchid abundance from field‐collected data compared to predicted estimates.Our results suggest that centrarchids, which tend to occupy a higher trophic level than cyprinids and percids, have lower abundances at sites contaminated with heavy metals than predicted by assemblage–environment relationships. These decreases in abundance are not associated with decreases in centrarchid species richness, cyprinid abundance, or percid richness.This geographic information systems‐based approach provides a useful and ecologically relevant framework for understanding the response of taxa to the presence of contaminants without assuming habitat equivalence across sites. Our findings also suggest the need for further research regarding how heavy metals impact fishes of varying trophic levels in natural settings. [ABSTRACT FROM AUTHOR]

Abstract Species – specific differences in the levels of 26 metals and elements in sardine and anchovy are investigated and the factors of proximate composition (proteins, lipids, ash) and body size (length, weight) that may affect the metal and elemental concentrations in fish are explored. Statistical analysis revealed that levels of metals and elements in fish seem to strongly depend on species. Significantly higher levels of most of the metals and elements studied have been observed in anchovy compared to sardine at each of six different sites. The observed species-specific differences in metal content could be attributed to different proximate composition and size among other factors. The significant (positive or negative) correlations found between lipids, proteins, ash, weight, length and metals or elements, suggest that higher levels of most of the metals and elements studied can be associated with lower lipid content, greater protein and ash content and smaller size. Graphical abstract Unlabelled Image Highlights • Metal and elemental content depends on fish species, proximate composition and size. • Higher levels of most metals were observed in anchovy compared to sardine. • Higher levels of metals and elements can be associated with lower lipid content. • Higher levels of metals and elements can be associated with greater protein content. • Higher levels of metals and elements can be associated with smaller fish size. [ABSTRACT FROM AUTHOR]

Keban Dam Reservoir (KDR), located on the Euphrates River (Turkey), is an internationally important reservoir. In this study, levels of ten metals in 220 muscle samples of five fish species (mangar, common carp, Tigris scraper, Euphrates barbell and trout barb) taken from 11 sampling sites in the KDR were determined and compared with the results of previous studies carried out in other countries and Turkey. In addition, multiple approaches were used to assess human health risks from fish consumption. The significant spatial differences in concentrations of studied metals except As and Ni in Euphrates barbell were not found. However, concentrations of all metals except Cd showed significant seasonal differences. The concentrations of ten metals in fish species were lower than or comparable to those in fish species from other freshwater bodies. The metal concentrations in all fish species were found below the maximeavyum permissible concentrations. No health risks of studied heavy metals on human were found by daily fish intake. The target hazard quotient (THQ) and total THQ values were below 1, which suggests there are no significant non-carcinogenic health risks for fish consumers. The cancer risk values calculated for inorganic arsenic in all fish species except Euphrates barbell did not exceed the 10 −6 threshold. The allowable number of fish meals per month can be categorized as safe fish consumption. The results of this study revealed that the consumption of the examined fish species does not pose a significant risk to human health. [ABSTRACT FROM AUTHOR]

The distribution and potential health risks of eight heavy metals (Copper (Cu), Chromium (Cr), Zinc (Zn), Lead (Pb), Arsenic (As), Cadmium (Cd), Manganese (Mn), Nickel (Ni)) in 16 freshwater systems from central and eastern North China, were investigated. The fish were divided as wild fish, which grew naturally without artificially feeding, and farmed fish. The total concentrations of the eight heavy metals ranged from 82.9 to 226 μg/L in the surface water samples and 3.32–27.6 mg/kg dw in the fish samples. There was no significant difference in the heavy metal concentrations between natural and farmed water systems. The concentrations of toxic metals, including Pb, As, Cd, Cr, are similar in all kinds of fish. However, the essential metals (Zn, Cu, Mn, Ni) in crucian carp (15.9 mg/kg) was much higher than other kinds of fish. Comparing the wild and farmed fish, the average concentrations of each heavy metal in wild crucian carp, bighead carp, grass carp were higher than those in farmed fish. The average log BCFs (bioconcentration factor) of Zn, Cr and Cu were the highest (2.14, 2.04, 2.00 L/kg) while that of Cd (0.65 L/kg) was the lowest. The non-carcinogenic and carcinogenic health risks to adults and children resulting from consuming the fish were assessed based on the target hazard quotients (THQ). The results indicated that the non-carcinogenic health risk to humans by consuming fish products, no matter wild or farmed fish, was relatively low. The carcinogenic risk of inorganic As was 5.11 × 10 −6 –1.95 × 10 −4 for children and 2.71 × 10 −6 –1.04 × 10 −4 for adult, which are within the acceptable range. The results indicated that the concentrations of heavy metals in the freshwater fish in central and eastern North China were relatively low, and did not cause considerable human health risks. [ABSTRACT FROM AUTHOR]

While fish is considered a healthy component of the human diet, consumption of fish with high levels of trace metals in their flesh constitutes a public health risk as trace metals have been proven to be toxic. We investigated the concentrations of toxic elements in seawater and also in different body parts of the fish Trachurus capensis caught near Durban, South Africa, using inductively coupled plasma-atomic emission spectrometry (ICP-AES). The highest metal concentration in fish body parts was observed for Pb, followed by Zn. Significantly higher levels of Mn were observed in fish gills as compared to the tissue (muscle) and fish frame. With respect to bioaccumulation, significantly higher Pb levels were observed in fish tissues compared to As, Cr, and Mn. In the frame, significantly higher Pb levels were observed compared to all other metals except Ba. There were no significant differences in the concentrations of different metals in fish gills. Overall, the toxic metal concentrations in the muscle of cape horse mackerel were below levels of concern for human consumption as defined by the FAO and WHO. [ABSTRACT FROM AUTHOR]

The study explored (I) the concentration of heavy metals in water samples (II) their bioaccumulation in common carp Cyprinus carpio (III) and the subsequent genotoxicity in the selected organs of carp; from river Kabul, Khyber Pakhtunkhwa Pakistan. Except for Mercury (Hg) the water samples had all the heavy metals within permissible limits of recommended dietary allowance (RDA). Nonetheless a number of heavy metals (Zn, Ni, Cr, Cd, Pb and Hg) showed bioaccumulation at levels higher than permissible. Zinc (Zn) was the most while Cadmium (Cd) was the least accumulated metal in all tissue samples analyzed. The metal burden in different organs of C. carpio was in sequence of intestine > skin > liver > gills > muscle. The Comet assay established DNA damage in selected organs to be in accordance with metal burden; the most to least damage being in sequence of blood > intestine > skin > liver > gills > muscle. In conclusion assessment of DNA damage in the organs of C. carpio appears to be a useful bio-marker to evaluate genotoxic effects of heavy metal pollution. [ABSTRACT FROM AUTHOR]

The present study assessed the impact of metal pollution on two widely consumed types of wild fish Sardinella aurita and Mugil cephalus captured from the Gulf of Gabes (Tunisia) which is currently experiencing acute environmental problems. A study of the Cd, Cu, Zn, and Pb levels present in the studied site and vital in fish tissues (gills, liver, gonad, and muscle) was undertaken. As expected, muscle, liver, and gonad tissues contained the highest concentrations of all metals except for Zn. The metal levels showed a significant variation of accumulation between species with overall effects of the tested tissues. In addition, the results address the significant effects of the species/tissue interaction. Liver sections showed structural alterations consisting mainly of a significant desquamation of the tissue, a fibroblast proliferation, and a lipid droplet accumulation in both species. Additionally, the presence of skeletal abnormalities affecting the vertebral column was observed in the M. cephalus specimens. As a whole, our data provide the first evidence of distinctive metal accumulation patterns in vital fish tissues as well as the interspecific difference that can be correlated with the biological habits of the two selected models, S. aurita and M. cephalus, known respectively as pelagic and benthopelagic species. [ABSTRACT FROM AUTHOR]

Bream, anchovy, horse mackerel, sea bass, sardine, and whiting that are commonly consumed by the Turkish community were collected from the Marmara Sea in September and March and were analyzed for trace elements and for fat content. The total concentrations of some metals in these fish were determined using ICP-MS in acid extracts obtained after microwave digestion. The seasonal fat contents of the fish samples were determined gravimetrically following a Soxhlet extraction method. Experimental results were evaluated statistically using t tests and principal component analyses. This enabled the comparison of the elements' contents in the fish samples in March and September and also led to an investigation into whether or not there is a relationship between the elements' contents and the fat amount. The results of this work showed that a significant temporal difference was observed. This difference was not related to the seasonal variation in fat concentrations. [ABSTRACT FROM AUTHOR]

The increases in urbanization, demography and industrial activity, along with growing human needs which exploit the resources of the planet, have exponentially exacerbated pollution. In particular, the discharge of heavy metals into the marine ecosystem is a problem of global magnitude, as this may damage the diversity of marine species and ecosystems because of their toxicity, long persistence and bioaccumulation. Consequently, it is necessary to carry out an assessment of the risk of human exposure from the consumption of marine species potentially exposed to this type of pollutants. In the present study, the levels of toxic heavy metals (Cd, Pb and Al) as well as trace and essential metals (B, Ba, Co, Cu, Cr, Fe, Li, Mn, Mo, Ni, Sr, V and Zn) and macronutrients (Ca, K, Mg, Na) have been quantified in two species of fish for human consumption. In order to do this, a total of 80 muscle samples and 80 liver samples, belonging to two species of osteichthyes (bony fish), Diplodus sargus cadenati and Sparisoma cretense, were analyzed. The specimens studied were captured on the north coast of Gran Canaria (Canary Islands) using recreational fishing techniques. As they caught from the shore, the data obtained respond to the need to assess the toxic levels in two representative species of artisanal and recreational fishing in the area. The risk assessment indicated that these two fish species are safe for the average consumer; however, if the livers are frequently consumed, there may be potential risks because they exceed the Admissible Daily Intakes for Pb and Cd. [ABSTRACT FROM AUTHOR]

The objective of this research is to reveal the pollution level and its impact on fresh water fish and finally, to estimate the concentration (ppm) of toxic metals chromium (Cr) (53.9 ppm) and lead (Pb) (13.2 ppm) in raw waste water (100%) and in fish (heteropneustes fossilis) (Cr 3.4 ppm, and Pb 2.0 ppm) by Atomic Absorption Spectrometry (AAS). Fresh tannery effluent is collected from Hazaribag-Dhaka and as early as possible some physicochemical parameters of that effluent such as Electrical Conductivity (EC) (535 ms/cm) and pH (6.1), Total Dissolved Solids (TDS) (30336 ppm), Dissolved Oxygen (DO) (2.0 ppm), Chemical Oxygen Demand (COD) (9480 ppm) are determined. Pisi-culture is done by constructing some pilot base fresh water systems in the laboratory and it has been found that in raw waste water (100%), the fish survival rate is only a few hours (5h), where in rest of others such as 75%, 50%, 25% and 5% waste water systems, the survival rate of fishes is longer than a week after increasing the amount of DO artificially. So, if fishes are eaten from nearby fresh water bodies of Hazaribag-Dhaka, ultimately it may harm the normal physiology of human. [ABSTRACT FROM AUTHOR]

Concentrations of heavy metals arsenic, cadmium, lead and mercury and trace elements chromium, copper, nickel and zinc were tested in the muscle tissue of four commercial edible lethrinids fish species from different region of Mauritius. Sky emperor (Lethrinus mahsena) was collected from coastal regions as well as offshore regions (banks) for this study. Blackspot emperor (Lethrinus harak) and spangled emperor (Lethrinus nebulosus) were also studied for their popularity in the fish market. Condition factor was calculated for each fish and the highest value obtained was in Lethrinus mahsena collected from offshore regions (2.598 cm/g). Flame atomic absorption spectrometry was used to analyse copper, nickel and zinc while, graphite furnace technique was used for cadmium, chromium and lead. Mercury levels were evaluated with the cold vapour technique and arsenic with the thermal hydride cell. The level of lead, mercury, copper, nickel and zinc ranged from 0.0011-0.0024 mg/L, 0.0016-0.0036 mg/L, 0.080-0.389 mg/L, 0.566-1.192 mg/L and 0.219-0.422 respectively in wet weight. Interspecies variations in levels of heavy metals and trace elements were observed for nickel and no significant variations occurred for mercury, lead and zinc. Concentrations of heavy metals and trace elements were all within the permissible level except for nickel. As per this study, the Food Act 1998 of Mauritius must be reviewed in order to incorporate the Maximum Permissible Level for nickel. [ABSTRACT FROM AUTHOR]

Fish are exposed to different heavy metals that may induce numerous physiological changes. In the present study, we examined the redox state in response to a severe stress resulting from two heavy metals (Zinc and Lead) contamination in carp Cirrhinus cirrhosus. Fish were exposed to 1/10th of LC50 of the respective metals [zinc chloride (2.72 mg/L) and lead acetate (2.53 mg/L)] for 30 days and allowed to recover for another 30 days without any metal exposure. Concentration of metals, different enzymatic and non-enzymatic antioxidant agents and expression levels of heat shock protein (HSP) 70 and 90 were measured in the liver and the kidney of fish. The lipid peroxide levels in fish tissues gradually increased with duration of treatment for both metals. After 15 days of treatment, glutathione (GSH) levels had increased, but decreased as the treatment continued for 30 days and returned to basal levels after a 30-day recovery period. Activities of all the anti-oxidant enzymes, except glutathione peroxidase, in stressed fish were significantly increased compared to those in the control at 15 days and continued till the 30th day of treatment, showing a tendency to return to basal levels after the recovery period. Expression levels of HSP70 and HSP90 gradually increased after zinc and lead treatment, respectively. The expression of HSP was higher in the liver. The results suggest that different heavy metals may have differential effects on the redox state and induction of oxidative stress in carp, in vivo. [ABSTRACT FROM AUTHOR]

The potential for metals to bioaccumulate in aquatic species, such as fish, via trophic level transfer was investigated. An in vivo experiment was set up in a flow-through system in which juvenile rainbow trout were fed blue mussels collected from a Class A pristine site and an effluent-impacted river estuary, over a period of 28 days. Selected elements (As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Mo, Ni, Se, Sn, V, Zn) were determined in the mussels and fish tissues (muscle and skin) collected at 0, 14 and 28 days. This study reveals the occurrence of metals in mussels sampled in the Irish marine environment and highlights the bioaccumulation potential of metals in fish tissues via trophic transfer. All 14 monitored metals were determined in the mussels collected from both sites and mussels collected from the effluent-impacted site contained three times more Co, Mo, Sn and V than the mussels collected from the Class A site. Following a 28-day dietary exposure, concentrations of As and Se (fish muscle), and Pb, Se and Zn (fish skin), were significantly greater in fish feeding on contaminated mussels compared to those with a regular fish feed diet. The significance of metal detection and bioaccumulation in the mussel and fish tissues, highlights the potential for metal exposure to humans through the food chain. As fish are recommended as a healthy and nutritious food source, it is important to fully understand metal bioaccumulation in commercially important aquatic species and ensure the safety of human consumers. [ABSTRACT FROM AUTHOR]

Fluoroquinolone antibiotics are widely used in the production of aquatic products and considered to be a significant contributing factor to the burden of both natural and aquaculture environments. However, the main types of fluoroquinolones present in aquaculture systems have not been determined. The objectives of the present study were to explore the occurrence of residual fluoroquinolone antibiotics in fish muscle tissues sampled from across the entire aquaculture season in the Tai Lake basin in China and to assess the dietary risks associated with the upcoming vendible fish in the last month of the aquaculture season. Fluoroquinolones were detected in 95.69% of all fish samples, and the concentrations ranged from the limit of quantification (LOQ) to 47 108.00 μg · kg−1. Enrofloxacin contributed the most among the 9 fluoroquinolone antibiotics tested. Of the 4 fish species studied, enrofloxacin was present in bream at significant ( p < 0.05) concentrations in August, with an average value of 321.45 μg · kg−1, while enrofloxacin concentrations peaked in crab and shrimp in September, with average values of 6949.60 and 460.82 μg · kg−1, respectively. However, different patterns were observed in perch, suggesting that other categories of antibiotics may be used in the production of this fish. Dietary risk assessment showed that the residual levels and estimated daily intake in bream, perch, and shrimp were far below the maximum residual level and acceptable daily intake. However, the average residual level in crab exceeded the maximum residual level, and the estimated daily intake value accounted for 78.49% of the acceptable daily intake, indicating potential consumption risk. In summary, the present study aims to guide the production and consumption of aquatic products. Environ Toxicol Chem 2017;36:2899-2905. © 2017 SETAC [ABSTRACT FROM AUTHOR]

Cadmium (Cd) has proved to be associated with numerous toxic effects in aquatic organisms via waterborne exposure. With a view to investigate Cd toxicity along a broad spectrum of exposures reaching from environmental to toxic, we employed adult zebrafish ( Danio rerio ) for an in vivo study. A number of 10 fish per tank were placed in 40 L tanks and were exposed for 30 days to 0.0, 5.0, 25, 50, 75, 100 and 1000 μg Cd per liter. There were 2 tanks for each Cd exposure (duplicate experiment). Mortality was recorded daily, dead fish were collected and tissue samples were obtained for histologic observation, whereas remaining tissues were stored for Cd burden determination. Surviving fish were collected at the end of the experiment. Median overall survival (OS) in days was found to be 9.0, 11.0, 8.0 and 7.0 for 25 μg/L, 50 μg/L, 75 μg/L and 100 μg/L respectively, with all of them showing mortality greater than 50%. Remarkably, fish exposed to the highest Cd concentration (1000 μg/L) survived the longest exhibiting a mean OS of 29.2 days. Cd determination in fish tissue was conducted with an in house ICP-MS method and levels ranged from 3.1 to 29.1 ng/mg. Log Cd tissue levels were significantly correlated with the log Cd exposure levels (r = 0.535, p < 0.001). The highest Cd burden was determined for fish exposed to 1000 μg Cd /L (mean = 12.2 ng/mg). Histopathology supported these results. Our findings disclose a deviation in toxic responses through the range of Cd concentrations, leading to nonlinear responses. These differentiated responses, could be linked to hormesis phenomena. [ABSTRACT FROM AUTHOR]

Edible muscle tissues of Solea solea, Mullus barbatus, and Sardina pilchardus marketed in Mersin were analyzed for their Cr (total), Mn, Fe, Ni, Cu, Zn, As (total), Cd, Sn, and Pb levels. Metal levels of the tissues were determined using inductively coupled plasma-mass spectrophotometric (ICP-MS) methods. Muscle levels of Cr, Mn, Fe, Ni, Cu, Zn, As, Sn, and Pb were determined as 0.19-2.80, 0.08-3.88, 0.93-25.76, 0.03-0.63, 0.01-1.96, 1.28-45.95, 0.49-25.26, 0.14-4.03, and 0.02-1.37 mg kg w.w., respectively. Cadmium levels were below detection limits in all the muscle samples taken. Mean metal levels of the tissues were compared with the provisional tolerable daily (PTDs) and weekly (PTWIs) intake limits. Mean metal levels taken by the consumption of analyzed tissues were below PTDs and PTWIs; hence, the fish species studied do not pose any risk for human consumption from the point of heavy metals. [ABSTRACT FROM AUTHOR]

The present study was designed to evaluate the interactive effects of chronic waterborne cadmium (Cd) and zinc (Zn) on tissue-specific metal accumulation and reproduction in fathead minnow ( Pimephales promelas ). Trios (1 male: 2 female; n=6–7) of fish were exposed for 21 days to: (i) control (no added Cd or Zn), (ii) waterborne Cd (7 µg/L), (iii) waterborne Zn (170 µg/L), and (iv) Cd and Zn in mixture (7 and 170 µg/L, respectively). Exposure to Cd or Zn alone did not elicit any significant effect on reproductive output (cumulative egg production) relative to the control, however exposure to Cd and Zn in mixture resulted in a ~50% decrease in fish fecundity. Plasma estradiol in females was reduced by Cd and Zn exposures, both individually and in mixture, with the maximum reduction in the metal mixture exposure. The expression of hepatic estrogen receptor genes (ER-α and ER-β) in females was affected by exposure to Zn, alone and in mixture with Cd, but not to Cd alone, whereas hepatic vitellogenin gene expression was downregulated across all treatments. Increased follicular atresia in the ovary was also recorded, but only in fish exposed to Cd and Zn in mixture. The interactions of Cd and Zn in mixture decreased Cd accumulation in tissues (gill and liver), however no reciprocal reduction in tissue Zn accumulation was observed. In addition, the expression of the hepatic metallothionein gene was upregulated following exposure to Zn, alone and in combination with Cd, with no additive effects in the latter treatment. Overall, our findings suggest that chronic exposure to waterborne Cd and Zn in mixture may induce additive reproductive toxicity, essentially by disrupting estrogen-mediated functions in fish. [ABSTRACT FROM AUTHOR]

Presence of heavy metals at high concentrations in edible fish might lead to some health issues for consumers. The current work determined the concentrations of four heavy metals Cd, Pb, Zn and Cu in seawater, gills and muscles of two common fishes, Mugil cephalus and Lethrinus miniatus, collected in summer 2014 from two different areas of Red Sea, Jazan, Saudi Arabia, using ICP-AES after microwave digestion procedure. The concentrations of investigated metals were higher in the gills than in muscles for the two fish species. However, the concentration of zinc was higher than other metals in all samples, in the following order Zn>Cu>Pb>Cd. The average of maximum metal concentration was measured for Zn (11.087 ± 1.672 mg kg-1w.w) in the gills of Lethrinus miniatus, Cu (0.548 ± 0.249 mg kg-1w.w) in the gills of Mugilcephalu, Pb (0.131 ± 0.092 mg kg-1w.w) in the gills of Mugilcephalu, and Cd (0.064 ± 0.017 mg kg-1w.w) in the gills of Lethrinus miniatus. Concentration of investigated metals in water was following the same order in the fish tissues Zn>Cu>Pb>Cd, with a maximum detected concentrations of 0.0233, 0.0085, 0.0059, and 0.0023 mg L-1, respectively. Despite the detection of heavy metals in the edible tissues of investigated fish, the concentrations were within the recommended maximum residual level of FAO/WHO and EU. Therefore, the investigated fish might be considered safe for human consumption. More extended investigations are highly recommended. [ABSTRACT FROM AUTHOR]

The present study focuses on bacterial and selected heavy metal contaminations of economically important mullet fish ( Mugil cephalus) collected from West coast of Gujarat, India. Molecular identification using 16S rRNA sequencing revealed the presence of Aeromonas veronii, A. mollusorum, A. cavae, A. bivalvum, and V.alginolyticus in the gill and the intestine along with some other non-pathogenic bacteria. Pathogenicity of different Aeromonas species was confirmed by hemolysin assay. Apart from pathogenicity, multidrug resistance pattern was also reported against some commonly used antibiotics. Heavy metal analysis of different parts such as ventral and dorsal muscles as well as gills of M. cephalus revealed maximum concentration of Pb (24.08 ± 4.40 mg/kg), Cd (8.25 ± 3.04 mg/kg), and Cu (33.67 ± 5.34 mg/kg), which were higher than the permissible limit. To the best of our knowledge, this is the first study analyzing different heavy metals and associated bacteria in M. cephalus fish in India. Further, the distribution of heavy metals in M. cephalus fish from other countries was also compared. [ABSTRACT FROM AUTHOR]

Three fish species ( Carassius auratus, Pelteobagrus fulvidraco, and Squaliobarbus curriculus) were collected from Xiang River near Changsha City, Southern China. The concentrations of heavy metals including arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn) in the muscle, gill, and liver of three species were determined by the inductively coupled plasma mass spectrometry method. One-way analysis of variance (ANOVA) was introduced to determine the significant variations ( p < 0.05) of heavy metals. Livers were found to accumulate Cd and Cu due to the metallothionein proteins. High levels of Mn and Pb in the gills indicated that the main uptake pathway of these heavy metals was from the water. The carnivorous species, P. fulvidraco, was found to accumulate the highest levels of toxic elements (As, Cd, and Pb), while relatively high concentrations of nutrient elements (Cu, Fe, Mn, and Zn) were accumulated in omnivorous species ( C. auratus and S. curriculus). According to the results of Pearson's correlation analysis, there were few significant relationships at p < 0.01 level between the concentrations of the analyzed elements and the fish sizes. The results of risk assessment indicated that exposure to the toxic heavy metals from fish muscle consumption posed no non-carcinogenic health risk to local inhabitants. [ABSTRACT FROM AUTHOR]

Mercury (Hg) exposure represents a significant public health concern at a global level. This study aims at assessing Hg exposure and risk among Lebanese young adults based on Hg biomonitoring and seafood intake. A group of 166 young adults were administered a questionnaire to assess Hg exposure and were asked to provide a hair sample. Risk assessment was performed: (1) using the US Environmental Protection Agency Hazard Quotient (HQ) model based on fish intake and previously studied local fish Hg concentrations, and (2) by determining the total hair Hg concentration (THHg) using continuous flow-chemical vapor generation atomic absorption spectrometry. Differences in THHg across demographic and exposure subgroups were tested using t test or ANOVA. Correlations between THHg concentrations, fish consumption, and HQ were determined by computing Pearson's r. Higher THHg correlated with higher consumption of Mediterranean rabbitfish/spinefoots ( r = 0.27; p = 0.001) and geographical location ( p < 0.001) in the bivariate analysis, and remained significant in the adjusted multivariable linear regression model (geographical location: ß = 0.255, 95%CI 0.121-0.388; rabbitfish/spinefoots consumption: ß = 0.016, 95%CI 0.004-0.027). No significant correlations were found between HQ and THHg. In conclusion, this is the first study examining hair Hg levels and fish consumption in a young adult Lebanese population. Our findings constitute valuable baseline data for a local fish advisory and Hg monitoring. [ABSTRACT FROM AUTHOR]

In this study, metal concentration levels (Cd, Co, Cr, Ni, and Pb) were investigated in the gill, hepatopancreas, ovary, testis, and mantle of the male and female cuttlefish Sepia officinalis in various stations (Iskenderun, Antalya, Kas, Gazipasa, and Anamur) in Mediterranean coasts of Turkey. Hepatopancreas tissue was a better indicator in terms of heavy metal concentration compared to the other tissues. In general, Cd, Co, Cr, Ni, and Pb accumulation for the male was found more than that of the female, whereas Cd and Ni accumulation was found higher in the female. There was a relationship among the metals in the form of Co > Pb > Ni > Cd > Cr in the mantle tissue. The Pb concentration over the recommended limits was found in cuttlefish of Anamur, Antalya, and Iskenderun stations. [ABSTRACT FROM AUTHOR]

The anthropogenic activities in the Black Sea area are responsible for toxic metal contamination of sea food products. In this study, several toxic metals: cadmium, lead, nickel, chromium, and copper were quantified in different tissues (digestive tract, muscle, skeleton, skin) of nine fish species ( Neogobius melanostomus, Belone belone, Solea solea, Trachurus mediterraneus ponticus, Sardina pilchardus, Engraulis encrasicolus, Pomatomus saltatrix, Sprattus sprattus, Scorpaena porcus) by using atomic absorption spectrometer with a high-resolution continuum source and graphite furnace technique (HR-CS GF-AAS), and the risk of fish meat consumption by the young human population was evaluated. These metals are used in high amounts in industries located near the coastline such as shipyard construction and industrial plants. Toxic metal accumulation depends on fish feeding behavior, abiotic conditions, metal chemistry, and animal physiology. For instance, cadmium was measured in the muscle of the investigated species and average values of 0.0008-0.0338 mg kg were obtained. The lowest average value of this metal was measured at benthic species N. melanostomus and the highest at the pelagic predator T. mediterraneus ponticus. Generally, the highest metal concentration was measured in the digestive tract that has the role of biofilter for these contaminants. The risk of contamination is significantly reduced by avoiding the consumption of certain fish tissues (digestive tract and skin for copper and skeleton for nickel). An estimation of the dietary metal intake to young consumers was realized for each of the studied species of fish from Romanian, Bulgarian, and Turkish waters, during the period 2001-2014 in order to evaluate the risks of chronic exposure in time due to metal toxicity. This estimation is important for the prevention of chronic exposure due to metal toxicity. Food exposure to studied metals showed a negative trend for Romania, Turkey, and Bulgaria based on the data provided by this study. The young consumers were highly exposed to these elements during the 2001-2006 period as proven by the results from this study. [ABSTRACT FROM AUTHOR]

This study measured the elemental and species concentrations of arsenic (As) in the water, sediments and food webs of two shallow Chinese freshwater lakes. Organic As species were widely detected in various organisms from the two lakes (60%-100% of the total). Among these organisms, dimethylarsinic acid (DMA) was predominant in most of the samples. The average concentrations and corresponding proportions were 0.59 mg/kg, 81% in fish; 3.24 mg/kg, 70.63% in zoobenthos; and 1.34 mg/kg, 79% in plants. The average concentrations and corresponding proportions of monomethylarsonic acid (MMA) and inorganic As were much lower, ranging from n.d. (not detected) to 1.94 mg/kg and from n.d. to 1.54 mg/kg, with an average proportion of 14 and 7.4%, respectively. In Lake Taihu, the mean As concentrations in different fish tissues were generally low and in the following order: eggs (0.47) < skin (0.62) < muscles (0.91) < gills (1.65) < livers (5.47) mg/kg. DMA occupied 75%-100% of the total As species, while MMA and inorganic As were much less prevalent. [ABSTRACT FROM AUTHOR]

This study was carried out to assess the effect of smoking methods on quality and safety of traditional smoked of fish from Lagos State, Nigeria. Five types of fresh fish (40) samples each were obtained from 20 different fish processing centers. The fresh fish samples were divided into two batches. The first batch was smoked with drum kiln and second batch was smoked with convective kiln. Laboratory analyses were carried out on the two batches for proximate, rancidity indices (PV, TBA, TVBN, TMA, and pH), heavy metals and microbiological (coliform, fungi,Listeria monocytogenes, Salmonella paratyphi, andStaphylococcus aureus). The results revealed that the mean MC of fresh fish samples ranged from 73.48%–75.94% and that of drum-smoked fish samples ranged from 11.86%–13.41% and 8.56%–9.36% for convective smoked fish samples. The mean PC of fresh fish samples ranged from 15.18%–17.96% and that of drum-smoked fish samples ranged from 54.80%–59.35% and 57.45%–66.23% for convective-smoked fish samples. The results of the proximate, quality, and microbiological analyses revealed that there was significant variations (p < 0.05) due to smoking methods. The study showed that the levels of the four heavy metals investigated in the fish samples are generally below the maximum permissible levels set by WHO for Pb (0.3 ppm); Cd (0.2 ppm), Hg (0.2 ppm) and Cr (0.5 ppm) and hence pose no risk to smoked fish consumers. The study concluded that traditional drum-smoked fish needs further cooking or heat treatment before it can be included in the menu, as non-heat treatment may pose higher microbiological risks to the consumers due to the presence ofListeria monocytogenesin some of the traditional drum-smoked fish samples which may constitute a threat to public health. [ABSTRACT FROM PUBLISHER]

Barium is generally considered a nonessential element with low toxicity, and with uptake from food sources balanced by excretion. Investigations into the dynamics of Ba in freshwater ecosystems have been limited. I show a 3-fold, trophic level-related decline in Ba in a freshwater ecosystem from a high of 60.9 µg/g for crayfish (Crustacea Orconectes virilis) to 0.438 µg/g for the largest individuals of a top predator (walleye Sander vitreus >3 kg). Barium concentrations were significantly higher in organisms (invertebrates and fish) associated with benthic substrates compared with those associated with pelagic environments. Thus, the concentration of Ba in muscle of 12 fish species was generally aligned along a pelagic to benthic food source gradient. These patterns may be related to relatively low concentration of Ba in water (77 µg/l) compared to the concentration of Ba in lake sediment (679 µg/g). Species level Ba assessments may provide a practical tool to assist with the identification of food web links and species specific routes of energy transfer in freshwater ecosystems. [ABSTRACT FROM AUTHOR]

The aims of the present work were (1) to evaluate oxidative stress biomarkers and AChE in two tissues of wild mussel ( Mytilus galloprovincialis) of high biochemical activity and accumulation capacity (gills and digestive gland) and (2) to study the behaviour of these biomarkers in presence of heavy metals. For this, EA, TOS, TAC and AChE were measured in tissues of mussels exposed to binary combination of Pb, Cd and Cu. Mussels ( n = 36) were exposed to one of the binary mixtures of Pb (1000 μg L), Cd (100 μg L) and Cu (100 μg L) for 7 days, under controlled conditions. Gills and digestive gland were extracted and frozen at −80 °C until analysis. The automatic methods employed for the measurement of EA, TAC, TOS and AChE in M. galloprovincialis revealed higher levels of these biomarkers in digestive gland than gills. Study results suggest that gills would be the tissue of election for study oxidative stress markers, whereas digestive tissue should be selected for AChE measurements in case of evaluation of combined metal toxicity in mussels. [ABSTRACT FROM AUTHOR]

To assess stress level induced by multiple stressors in aquatic organism, biomarkers have been adopted as early warning indicator due to their high accuracy, rapidity, and sensitivity. We investigated the effects of ectoparasitic isopod infection on heavy metal bioaccumulation (Fe, Cu, Zn, and Cd) in the fish Nemipterus furcosus and profiled the expression of metallothionein (MT) and heat shock proteins 70 (HSP70) genes of the fish host. Sixty individuals (parasitized and nonparasitized with Cymothoa truncata) were collected from three sites differing in the levels of anthropogenic activities off the South China Sea. Our results revealed no significant difference in heavy metal concentrations between infected and nonparasitized fish. We observed a positive correlation between heavy metal bioaccumulation in the fish host and anthropogenic activities. Accordingly, expression analysis of MT genes in fish liver showed significant differences in expression level between sampling sites, with lowest level in the least exploited site (Batu Rakit). A reverse pattern in HSP70 gene expression was demonstrated in fish muscle, showing the highest expression at Batu Rakit. While cymothoid infection in N. furcosus had no significant impact on fish MT gene expression, it resulted in a reduction of HSP70 level in liver of parasitized fish. These findings highlight the putative roles of MT in heavy metal assessment. Future studies should determine the kinetics of cymothoid infection and other potential stressors in characterizing the HSP70 gene expression profile. [ABSTRACT FROM AUTHOR]

The antimicrobial activity of silver nanoparticles (AgNP) makes them useful in a wide range of products although their environmental impact is still uncertain. The main goal of this study was to evaluate short-term effects induced by AgNP on gills oxidative status and bacterial communities living at the skin mucus of zebrafish. Both the number of bacteria colony forming units and bacteria growth obtained from skin mucus were lower in all concentrations tested (25, 50 and 100 µg nAg/L). Besides, AgNP exposure caused a significant decrease in bacteria growth in zebrafish exposed to 100 µg nAg/L. AgNP accumulated in zebrafish gills at both highest concentrations tested, but this accumulation did not appear to result in oxidative stress. Overall the results indicated toxicological effects of AgNP on bacteria communities living at the zebrafish mucus surface. Although silver accumulation was verified in gills, no evidence of toxicity in terms of oxidative stress was found. [ABSTRACT FROM AUTHOR]

Concentrations of Cu, Zn, Cr, As, Cd, Pb and Hg were determined in 153 samples covering 18 fish species collected from Heilongjiang River, China, and the potential health risks to local residents through fish consumption were estimated. Results revealed that all metals were detected with Cd and Pb having considerably lower detection rate. There were 28.6 % of Lethenteron camtschaticum samples exceeding the limit of inorganic As content established by Chinese legislation. Metal bioaccumulation in fish were poorly correlated with fish sizes, and generally tended to increase with trophic levels. The hazard quotient values of all fish species were far below 1 for general population and fishermen. The carcinogenic risk of As in L. camtschaticum for the local fishermen exceeded the acceptable level of 10 rise in cancer rates, but was considered safe given the migratory habits of the fish. [ABSTRACT FROM AUTHOR]

Effects of acute exposure to sublethal waterborne cadmium (Cd) on energy homeostasis in filter-feeding fishes have rarely been studied. The response patterns of energy substances were investigated in juvenile silver carp ( Hypophthalmichthys molitrix) exposed to sublethal waterborne Cd for 96 h. The results showed the 96hLC of Cd on juvenile silver carp was 1.723 mg/L. Sublethal acute exposure of Cd significantly affected the energy homeostasis of juvenile silver carp, including increase in plasma glucose and lactate, and decrease in plasma triglyceride, muscle glycogen and triglyceride and liver glycogen. The results indicated that glycogen and triglyceride prior to protein were mobilized to meet the increased demands for detoxication and repair mechanism to sublethal waterborne Cd exposure, and glycogen level depleted faster and restored slower in the liver than in the white muscle in juvenile silver carp. [ABSTRACT FROM AUTHOR]

Accumulation of copper (Cu), applied singly and in mixture with chitosan (CT), in gill, liver, spleen, kidney and muscle tissues of Clarias gariepinus was studied after exposing the fish to no Cu (control), 5 ppm Cu, 5 ppm Cu + 75 ppm CT mixture over 1, 7 and 15 days. Metal levels in tissues were determined using an ICP-AES spectrophotometer. No mortality was observed during the experiments. Highest accumulation of Cu was observed in liver while lowest accumulation was observed in muscle tissue. Exposure to Cu-CT mixture decreased Cu accumulation in liver at all exposure periods and in kidney on the 15th day compared to Cu alone. Exposure to Cu alone and Cu-CT mixture had no effect on Cu accumulation in spleen or muscle tissue. Copper accumulation increased in gill tissue compared to control when exposed to Cu alone at all exposure periods, and exposure to the Cu-CT mixture significantly increased Cu accumulation in this tissue at all exposure periods compared to Cu alone. [ABSTRACT FROM AUTHOR]

The development of a fast, effective, simple and low-cost procedure for chromium speciation is an analytical challenge. In this work, a new and simple method for speciation and determination of chromium species in different matrices was developed. Sepia pharaonis endoskeleton nano-powder was used as an adsorbent for the dispersive micro-solid-phase extraction. Finally, the desorbed chromium was determined using a graphite furnace atomic absorption spectrometer. The experimental results showed that Cr(III) could be quantitatively extracted by the adsorbent, while Cr(VI) adsorption was negligible. Concentrated HSO and ethanol reduced Cr(VI)-Cr(III), and total chromium content was assessed as Cr(III). Then, the Cr(VI) concentration in the sample was calculated as the difference. The optimum conditions were obtained in terms of pH, adsorbent amount, contact time, and type, concentration and volume of eluent. Under the optimum conditions that involved the speciation of chromium ions from 25 mL of the water samples at pH 7.0 using 0.025 g of the adsorbent with contact time of 5 min, the method was validated in terms of linearity, precision and accuracy. The calibration curve was linear over the concentration range of 0.01-25.00 μg L for Cr(III). The obtained limit of detection for the proposed method was 0.003 µg L. The maximum adsorption capacity of the adsorbent was found to be 995.57 mg g. The proposed method was validated by the speciation of Cr(III) and Cr(VI) in different real water and wastewater samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The present study investigates the concentrations of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), chromium (Cr), aluminum (Al), and iron (Fe) in the carapace meat of female and male blue swimming crabs (Portunus segnis) from the northeastern Mediterranean Sea in the Gulf of Mersin, Turkey. The order of average heavy metal concentrations in carapace meat samples in both male and female species was Zn>Fe >Cu>Al>Mn>Cr>Pb. From the obtained results, the levels of some metals such as Cu, Zn, and Fe were higher than the acceptable values for human consumption designated by various health organizations. The comparison of our results with previous studies showed that blue swimming crab (Portunus segnis) have been contaminated with heavy metals. The occurrence of high levels of Cu, Zn, and Fe in the aquatic environment is thought to be a result of industrial and maritime traffic activities in Mersin Bay. [ABSTRACT FROM AUTHOR]

This research was conducted to assess the water quality and the contamination of heavy metals in water, sediment, fish, and frogs, as well as bioaccumulation factors (BAFs) in fish and frogs around the gold mine area. The water samples were analyzed for water quality (temperature, pH, and dissolved oxygen). The samples were analyzed for heavy metals by inductively coupled plasma optical emission spectrometry. The water quality was within the standard. The concentrations of heavy metals, including As, Cr, Cd, Pb, Ni, Zn, Fe, Mn, and Cu, in water and sediment samples were measured. Three species of fish were collected:Rasbora tornieri, Brachydanio albolineata,andSystomus rubripinnis. The mean heavy metal concentrations of fish were as follows: Fe>Zn>Mn>Cr>Ni>Cu>As>Pb>Cd. The As, Cr, and Pb concentrations in all the fish species exceeded the standard levels. Five species of frogs were collected:Kaloula pulchra,Microhyla heymonsi,Fejervarya limnocharis, Hoplobatrachus rugulosus,andMicrohyla pulchra. The mean heavy metal concentrations of frog were as follows: Fe>Cu>Mn>Zn>Cr>Ni>Pb>Cd>As. The Cr, Cd, and Cu concentrations exceeded the standard levels. The BAFs in fish were in order of Cr>Zn>Ni>Cu>Pb>Fe>Cd>As. The BAFs in frogs were Cr>Zn>Ni>Cu>Fe>Pb>Cd>As. The accumulation of heavy metals was higher in the sediment than in the water. Many aquatic organisms take up heavy metals directly from the environment around the gold mine. [ABSTRACT FROM PUBLISHER]

The influence of salinity on Ag toxicity was investigated in Atlantic killifish ( Fundulus heteroclitus) early life-stages. Embryo mortality was significantly reduced as salinity increased and Ag was converted to AgCl. However, as salinity continued to rise (>5 ‰), toxicity increased to a level at least as high as observed for Ag in deionized water. Rather than correlating with Ag, Fundulus embryo toxicity was better explained (R = 0.96) by total dissolved Ag (Ag, AgCl, AgCl, AgCl). Complementary experiments were conducted with medaka ( Oryzias latipes) embryos to determine if this pattern was consistent among evolutionarily divergent euryhaline species. Contrary to Fundulus data, medaka toxicity data were best explained by Ag concentrations (R = 0.94), suggesting that differing ionoregulatory physiology may drive observed differences. Fundulus larvae were also tested, and toxicity did increase at higher salinities, but did not track predicted silver speciation. Alternatively, toxicity began to increase only at salinities above the isosmotic point, suggesting that shifts in osmoregulatory strategy at higher salinities might be an important factor. Na dysregulation was confirmed as the mechanism of toxicity in Ag-exposed Fundulus larvae at both low and high salinities. While Ag uptake was highest at low salinities for both Fundulus embryos and larvae, uptake was not predictive of toxicity. [ABSTRACT FROM AUTHOR]

Waterborne and dietborne exposures of freshwater fish to mercury (Hg) in the forms of inorganic (Hg(II)) and organic (methylmercury or MeHg) affect their growth, development, and reproduction. However, an integrated mechanistic risk model framework to predict the impact of Hg(II)/MeHg on freshwater fish is lacking. Here, we integrated biokinetic, physiological and biogeographic data to calibrate and then establish key risk indices-hazardous quotient and exceedance risk-for freshwater tilapia species across geographic ranges of several major rivers in Taiwan. We found that Hg(II) burden was highest in kidney followed by gill, intestine, liver, blood, and muscle. Our results showed that Hg was less likely to pose mortality risk (mortality rate less than 5 %) for freshwater tilapia species. However, Hg is likely to pose the potential hazard to aquatic environments constrained by safety levels for aquatic organisms. Sensitivity analysis showed that amount of Hg accumulated in tilapia was most influenced by sediment uptake rate. Our approach opens up new possibilities for predicting future fish population health with the impacts of continued Hg exposure to provide information on which fish are deemed safe for human consumption. [ABSTRACT FROM AUTHOR]

This study aims to determine heavy metal accumulation levels in the muscles tissues of two economically most important demersal fish species in the Eastern Black Sea, Turkey, red mullet (Mullus barbatus) and whiting (Merlangius merlangus), and evaluate the effects of fish species, sampling locations, fishing season and size groups on heavy metal accumulation levels. Chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) concentrations in fish muscle samples were measured with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Co, Zn, As and Cd accumulation levels in both species differed significantly (P<0.05). The metal concentrations of muscle tissues of both species, in general, were higher during summer and autumn. In the study, the differences in concentrations levels of As and Pb in whiting, Co, Cu, and Pb in red mullet muscle tissues were significantly related to fishing locations. The results of metal concentrations were compared with various legal limits such as Turkish Food Codex (TFC 2011), European Communities Commission Regulation (EC 2006) and Food and Agriculture Organization (FAO 1983) and the obtained metal levels of fish muscle tissues of both species were found to be below the limit values which are a threat to human health. [ABSTRACT FROM AUTHOR]

The present study was undertaken to examine the DNA damage induced by binary metal mixture (cadmium-lead) in peripheral blood erythrocytes of freshwater carp, Cyprinus carpio by using Comet bioassay. The 96-hr LC50 value of mixture was estimated for 180-old fingerlings of Cyprinus carpio in a static system and then four sub-lethal concentrations viz. SL-I (10.42mgL-1), SL-II (7.81mgL-1), SL-III (6.25mgL-1) and SL-IV (5.21mgL-1) were calculated and fish were exposed to these concentrations, separately in glass aquaria for 30 days along with negative and positive control at constant water temperature (30°C), pH (7.75) and total hardness (225mgL-1). Peripheral erythrocytes were sampled after 30 day exposure for DNA damage assessment. Statistically significant effects were observed at sub-lethal concentrations in-terms of percentage of DNA damage, cumulative tail lengths (μm) and genetic damage index. Concentration dependent response was observed in fish erythrocytes with induction of maximum DNA damage, due to positive control, followed by at highest concentration (SL-I) of mixture. This study also concluded that comet bioassay can be used for in-vivo experiments, using fish as a model for the screening of genotoxic and mutagenic pollutants in aquatic environment. [ABSTRACT FROM AUTHOR]

The effects of different doses of date palm (Phoenix dactylifera) seed (DPS) extract on heavy metals (Pb, Cd, As, Hg) concentrations of common carp (Cyprinus carpio) were evaluated. The fi sh (31.6±3.7 g) were assigned to five treatments of three replications each. Five treatments were held using five different DPS extracts at doses of 0% (control), 0.5%, 1%, 2%, and 4%. The results revealed that heavy metals concentrations of fish decreased in the 0.5% and 1% treatments (P<0.05). Hg and Cd concentrations in muscle decreased in all treatments (P<0.05). The results of this research clearly show that the addition of DPS extract to a fish diet has a significant effect on heavy metals concentrations (P<0.05). DPS extracts were shown to be rich in phenolics and flavonoids. Therefore, they have also been discussed as protectants against heavy metal stress. It could be concluded that feeding common carp a diet enriched with DPS extract could decrease heavy metals concentrations that can cause cancer. [ABSTRACT FROM AUTHOR]

Bakun Hydroelectric Dam in Sarawak is one of the world highest concrete rock filled dams. This paper reports the heavy metals concentrations in water, sediment, and fishes of Bakun Dam. Water and sediment samples were collected from 11 stations and 6 fish species were caught. The samples were digested with open acid digestion and the metals contents were analysed using an atomic absorption spectrophotometer and mercury analyser. The method was validated based on certified reference materials. A higher concentration of Fe and Mn was detected in downstream water with significant longitudinal variation. Cu, Zn, and Hg were present in trace amount. All elements analysed were consistently found in sediment with no risk of contamination. For fish, Hemibagrus planiceps was characterised by higher affinity for Hg accumulation. The concentrations detected in all fish species were within the permissible guideline of 0.5 mg/kg. The health risk assessment suggested that Barbonymus schwanenfeldii, Puntioplites waandersii, Cyclocheilichthys apogon, and Hemibagrus planiceps were characterised by hazard index > 1 implying possible adverse effects. The amount of fish recommended for adults and children was in the range of 500–775 g/week and 33–135 g/week, respectively. [ABSTRACT FROM AUTHOR]

Food quality and safety are the major problems of the food industry. Currently the focus is on investigating the presence of contaminants that can be transferred from the environment, particularly heavy metals in fish and other marine products, with serious implications for public health. Nowadays, a significant contribution to the diet is brought by the fish products coming from the sweet or salty water. The aim of this study was to follow the heavy metal contamination of four species of fish, two predators (zander and tuna) and two freshwater fish (crucian and trout). The research goal was to detect the possible presence of lead and cadmium, near other metallic elements. For experimental analyses it was used a mass spectrometer with inductively coupled plasma, ICP-MS AGILENT SERIA 7500ce, witch could measure trace elements up to parts per trillion (ppt) or quickly scan for more than 70 elements to determine the composition of unknown samples. The experimental results showed that of the four species evaluated, zander contains the highest amount of Pb and crucian contains an insignificant amount of Pb. Zander not contain Zn while tuna has a significant amount (7.85 mg / kg) which is recommended for consumers with zinc deficiency. Sample crucian was the only uncontaminated with Cd. [ABSTRACT FROM AUTHOR]

Juvenile rockfish (mean length 13.7 ± 1.7 cm, and mean weight 55.6 ± 4.8 g) were exposed for 4 weeks with the different levels of dietary chromium (Cr 6+ ) at 0, 30, 60, 120 and 240 mg/kg. The profile of chromium in the tissues of rockfish is dependent on the exposure periods and chromium concentration. After 4 weeks, the order of chromium accumulation in tissues was liver > kidney > spleen > intestine > gill > muscle. The dietary chromium exposure decreased the growth rate and hepatosomatic index of rockfish. The major hematological findings were significant decrease in the red blood cell (RBC) count, hematocrit (Ht) value, and hemoglobin (Hb) concentration exposed to ≥120 mg/kg chromium concentrations. The dietary chromium exposure (≥120 mg/kg) led to notable increase in glucose, cholesterol, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) in plasma, whereas there was no considerable change in calcium, magnesium, total protein, and alkaline phosphatase (ALP). The results indicated that the dietary chromium exposure to rockfish can induce significant chromium accumulation in the specific tissues, inhibition of growth, and hematological alterations. [ABSTRACT FROM AUTHOR]