Cd In Gills Research Articles

Ecological risk assessment of a contaminated stream using multi-level integrated biomarker response in Carassius auratus.

The goal of this study was to evaluate the adverse effects of wastewater effluents on freshwater crucian carp, Carassius auratus, inhabiting Sincheon stream using the integrated biomarker response (IBR) at the genotoxic (micronucleus [MN] test), oxidative stress (activity of catalase [CAT] and glutathione S-transferase [GST], and level of lipid peroxidation [LPO]), histopathological (degree of tissue changes [DTC]), and physiological (condition factor [CF] and liver somatic index [LSI]) levels. The CF and LSI were significantly (p<0.05) enhanced in fish from downstream sites (DS1 and DS2) as compared to that of upstream (US) fish samples. Moreover, a significant increase in morphometric indices (DTC) was observed in C.auratus collected from downstream sites (p<0.05) and histopathological responses showed the degree of pathogenicity in the order of liver>kidney>gills. The activities of CAT, GST, and LPO in fish from the DS1 and DS2 sites were notably increased in gills, liver, and kidney compared to that of fish from the US site. Additionally, the MN test level in C.auratus from the DS1 and DS2 were significantly increased (p<0.05) when compared with that of the US site. Considering the higher bioaccumulation of Cd, Co, Cr, Mn, Ni, and Pb in gills, liver, and kidney of C.auratus collected from downstream sites compared to that of the upstream site (p<0.05), the observed toxicity was likely attributable to metal accumulation. The multi-level IBR index was higher at the DS1 site (15.08) than at the DS2 (1.02) and the reference US (0.00) sites. Therefore, these findings demonstrated that wastewater effluent discharge induces significant DNA damage, oxidative stress, and tissue injuries in C.auratus and suggested that the multi-level IBR approach should be used to quantify these effects on fish in streams and rivers.

Metal concentrations in the mussel Bathymodiolus platifrons from a cold seep in the South China Sea

Data regarding the concentration and distribution of various metals in different tissues of mussels from the cold seep is scant. We aimed to quantify the presence of twenty elements (Ca, K, Mg, Sr, Ag, Al, As, Ba, Cd, Co, Cr, Cu, Li, Fe, Mn, Mo, Ni, Pb, V, and Zn) in gills, mantles and shells of Bathymodiolus platifrons, a common mussel species in deep-sea cold seep and hydrothermal vent communities. Specimens of B. platifrons were sampled from a cold seep at the northern continental slope of the South China Sea and the elemental contents in its tissues were quantified. Our findings were compared to data from taxonomically similar species at hydrothermal vents and coastal waters. We found that most elements were significantly enriched in the gills, which could be related to food uptake and the existence of endosymbionts. In shells and mantles, Mn was particularly rich, possibly due to its replacement of Ca in the carbonate structure. A significant positive correlation among Ca, Sr, and Mg was found in both gills and mantles, consistent with relationships observed in vent and littoral mussel species. Concentrations of metals were highest in the new-growth outer edges of shells in comparison to older shell material, which suggests that trace metals have become more abundant in the ambient seawater in recent years. Compared with other deep-sea environments and coastal areas, metal accumulation showed local variability but similar overall patterns of uptake and accumulation, indicating that essential elemental requirements in different mussel species may be similar across taxa. The high bioconcentration factor (BCF) values of Mn and Ag suggest that their particular functions and regulation mechanisms are related to specific adaptations and life cycle processes.

Bioaccumulation of heavy metals in some tissues of croaker fish from oil spilled rivers of Niger Delta region, Nigeria

ObjectiveTo investigate the level of heavy metals (Cu, Zn, Fe Mn Ni, Pb and Cd) in muscles, gills and liver tissue of Croaker fish from oil spilled rivers of Bonny and Finima, Niger Delta region, Nigeria. MethodsTwenty four Croacker fishes (Genyonemus lineatus) weighing between 250 and 260 g and 24–26 cm length were collected from each sampling sites (Bonny and finima rivers). The frozen fishes were thawed and dried at 105 °C until they reach a constant weight. The dried samples were homogenized and digested with 10 ml tri-acid mixture (HNO3: HClO4:H2SO4), and then the digested samples were diluted to 100 ml with deionized water. Heavy metals (Cu, Ni, Zn, Pb, Mn, Iron Fe, and Cd) concentrations were determined by atomic absorption spectrophotometer. ResultsOur results revealed that concentrations and distribution patterns of all heavy metals studied varied significantly (P < 0.05) amongst the fish tissues analyzed and sampling sites. Moreover, liver tissue of fish caught from Finima creek accumulated the highest concentrations of Cu (52.64 ± 3.01 μg/g dry wt), Zn (166.50 ± 6.45 μg/g dry wt) and Fe (801.50 ± 14.15 μg/g dry wt) in comparison to the liver of fish caught from Bonny river in which the levels of Cu, Zn and Fe were (45.00 ± 2.79), (49.90 ± 2.91) and (216 ± 6.11 μg/g dry wt), respectively. In addition, Mn, Ni, Pb and Cd exhibited their highest concentrations in gills from both locations. As expected, muscle tissue contained the least concentrations of all metals investigated from both sampling sites. Furthermore, all the metals investigated exhibited highest concentration in fish collected from Finima creek. These abnormal high level heavy metals accumulation observed in this location could be linked to the frequent crude oil spills as well as industrial activity around the area which might get discharged into Finima creek. In general, the mean concentrations of some toxic heavy metals investigated exceed the recommended maximum permissible limits set by the Joint FAO/WHO committee. However, some metals are within the acceptable limits. ConclusionsIn conclusion, our data showed the abnormal higher concentration of these metals and this might be toxic to the fish and other aquatic organisms directly or by extension to humans that frequently consumed such contaminated fishes.

Bioaccumulation of heavy metals in Nile tilapia Oreochromis niloticus (Linnaeus 1758) fed with commercial fish feeds

The study was carried out to determine the concentration of heavy metals in some commonly used commercial fish feeds and to observe the bioaccumulation of Cr, Cu, Cd and Ni in liver, muscle and gills of tilapia Oreochromis niloticus after culturing them for 60 days by feeding those commercial feeds. The study revealed that the concentration of Cu was the highest (65.08 mg/kg) in handmade feed (B1) among four heavy metals. The concentrations of Cr in collected feeds were 1.75 to 3.04 mg/kg, which exceeds the permissible limit set by FAO. In cultured tilapia, the concentrations of studied heavy metals were found higher than initial concentration in fish feeds and in tilapia fingerlings. Metal levels in cultured fish followed the ranking of Cu&gt;Cr&gt;Ni&gt;Cd and order in individual organs was liver&gt;gill&gt;muscle. The highest concentration of Cu (72.86 mg/kg) was found in liver given S feed and the lowest concentration (0.67 mg/kg) was in muscle receiving Q feed. Bioaccumulation of Cr was the highest (23.95 mg/kg) in liver taken B1 feed and the lowest (9.29 mg/kg) in muscle of tilapia cultured with C feed. Concentration of Cu exceeded the tolerable limit in fishes cultured with S and C feeds. But Cr concentration surpassed the allowable limit in every feed studied. The concentrations of Ni and Cd were below the permissible range approved by FAO. Considering the present study, tilapia cultured with these experimental feeds is not safe for human consumption. Higher concentration of these heavy metals exceeding allowable limit may cause harmful effect on human body after consumption of those fishes and can create cancer and other diseases in human body.Bangladesh J. Sci. Res. 29(2): 89-99, December-2016

Accumulation behavior and risk assessment of heavy metals and arsenic in tissues of white bream (Parabramis pekinensis) from the Xiang River, southern China.

Aquatic environment suffered from serious heavy metal and As pollutions due to rapid industrialization and urbanization in the last decades. In order to evaluate the heavy metal and As contamination in aquatic organism in southern China, the levels of As, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn in muscle, gill, and liver of white bream (Parabramis pekinensis) collected from Xiang River were analyzed. The statistically significant differences of the analyzed element concentration (wet weight) between tissues were determined through one-way analysis of variance (ANOVA). The liver presented high affinity for accumulation of Cd, Cu, and Zn due to the binding activity of metallothionein proteins. Mn and Pb mainly accumulated in the gill indicated the major uptake route through the gill. Lack of correlation between analyzed element and fish size might imply no or weak biomagnification of the analyzed elements in fish tissues. The potential health risk associated with exposure to heavy metals and As was evaluated. The uncertainty of target hazard quotient was calculated by Monte Carlo simulation. The results indicated that the analyzed element contentsin the white bream muscle posed relatively low-chronic toxic risk to consumers.

Assessment of Trace Elements in Tissues of Fish Species: Multivariate Study and Safety Evaluation

Levels of As, Cd, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sb and Se in muscle, gill, stomach, liver, kidney and gonad tissues of six different fish species (Caranx latus, Bagre marinus, Archosargus rhomboidalis, Lutjanus synagris, Scomberomorus cavalla and Sphyraena guachancho) from the Todos os Santos Bay (Bahia State, Brazil) were evaluated. The elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) after wet digestion using reflux system with a cold finger. The detected concentration ranges were as follows (mg kg-1 dry weight): < 0.49-27.31 for As, < 0.013-1.12 for Cd, 0.38-6.05 for Cr, 0.17-28.12 for Cu, < 0.092-1.19 for Li, 0.16-55.9 for Mn, < 0.034-1.24 for Mo, < 0.067-15.57 for Ni, < 0.013-0.60 for Pb, < 0.144 for Sb and 0.57-14.6 for Se. Highest concentrations of trace elements were observed in kidney, liver and gill tissues.

The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis)

This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18nM) in moderately hard water (120mgL−1 CaCO3) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (Ucrit) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the Ucrit of control fish, a 30min recovery period and finally a second swim challenge to determine Ucrit. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim Ucrit and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure where 31% and 38% reductions were observed for brown trout and lake whitefish respectively. Swimming to 85% Ucrit resulted in metabolic expenditure with little recovery after 30min. Few differences were observed between control and Cd exposed fish with the exception of a reduction in resting white muscle ATP stores of Cd exposed fish after 1 week of exposure. The results show that chronic sublethal Cd exposure results in an impairment of swimming ability in repeat swim challenges but this impairment is generally not related to metabolic processes in white muscle.

Validation of Methods Employing Fast Alkaline Solubilization to Determine Cadmium in Fish Liver, Spleen, Gills and Muscle by Graphite Furnace Atomic Absorption Spectrometry

The validations of analytical methods were performed to determine Cd in fish liver, spleen, gill, and muscle by graphite furnace atomic absorption spectrometry (GF AAS). The methods were based to alkaline solubilization of the samples with benzyltrimethylammonium hydroxide 40% v/v in water (Universol®), and when added to each sample, immediately solubilized the samples and formed an indefinitely stable and highly homogeneous solution, without a need for temperature, microwaves or any other apparatus. Ru was the best permanent modifier (500μg) for all samples except for liver, while permanent Ir (500μg) proved best for liver. The optimum pyrolysis temperatures were 450°C for liver and spleen, 500°C for gill, and 400°C for muscle, while for atomization, the optimum temperatures were 1800, 1100, 1600, and 900°C, respectively. No matrix effects were observed for liver and gill when external calibration was performed. For spleen and muscle, matrix effects were observed and matrix matching calibration was used. The limits of quantifications were 0.13, 1.20, 0.34, and 1.80μgg−1 for liver, spleen, gill, and muscle, respectively. The absorption signals obtained for each sample were symmetrical and returned to baseline in less than 5s. Recoveries levels (three levels of Cd for each matrix) ranged from 87.1 to 108.2. For the analysis of seven certified reference materials, the obtained values (n=5 samples of each material) were not statistically different from the certified values (95% of confidence). This reagent (Universol®) promoted an immediate solubilization of the samples, thus forming an indefinitely stable suspension which can be an alternative for fast solubilization of any biological sample, such as food and other organic material.

Determination of heavy metals in selected black sea fish species

Heavy metals can be accumulated by marine organisms thought a variety of pathways, including respiration, adsorption and ingestion. The levels of heavy metals are known to increase drastically in marine environment through mainly anthropogenic activities. Fish are good indicators for the long term monitoring of metal accumulation in the marine environment. The aim of this study was to determine the levels of Cd, As, Hg, Pb, Zn and Cu in edible part and gill of seven most consumed Bulgarian fish species collected from north-east coast of Black Sea. These fish species are sprat (Sprattus sprattus sulinus), Mediterranean horse mackerel (Trachurus mediterraneus ponticus), Black sea gobies (Neogobius melanostromus), shad (Alosa pontica), Atlantic bonito (Sarda sarda), bluefish (Pomatomus saltatrix) and grey mullet (Mugil cephalus). The fish samples were collected during 2010. The analytical determination of As, Cd, Pb, Zn and Cu were performed by using flame and graphite furnace atomic absorption spectrometry after microwave digestion procedure. The total mercury determination was determined using a direct mercury analyzer (DMA-80). The metal concentration of analyzed elements was highest in the gill for all fish species. The maximum metal concentration was measured for Cu (1.40 mg kg−1 w.w), Zn (11 mg kg−1 w.w) and Pb (0.08 mg kg−1 w.w) in muscle tissues of shad and sprat. The edible part of horse mackerel has the maximum value for Hg (0.12 mg kg−1 w.w) while Atlantic bonito predominantly accumulates As (1.10 mg kg−1 w.w). The analytical results obtained from this study were compared within acceptable limits for human consumption set by various health institutions.

Bioaccumulation of Heavy Metals and Microelements in Silver Bream (Brama brama L.), Northern Pike (Esox lucius L.), Sterlet (Acipenser ruthenus L.), and Common Carp (Cyprinus carpio L.) From Tisza River, Serbia

The aim of this study was to determine the concentrations of Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr, and Zn in liver, gills, gonads, and brain of four ecologically different fish species in Serbia: piscivorous northern pike, benthivorous sterlet and silver bream, and omnivorous common carp. Fish were caught at four sites along the stretch of the River Tisza in the Pannonian part of Serbia during October 2010. Results revealed that heavy metals and microelements with the highest values in fish samples were Fe, Al, and Zn. The highest concentration of heavy metals and microelements was recorded in omnivorous common carp, and organs that most intensively accumulated the greatest number of metals were liver and gills, whereas the locality did not exert a marked impact on level of bioaccumulation.

Interactive effects of waterborne metals in binary mixtures on short-term gill–metal binding and ion uptake in rainbow trout (Oncorhynchus mykiss)

Metal binding to fish gills forms the basis of the biotic ligand model (BLM) approach, which has emerged as a useful tool for conducting site-specific water quality assessments for metals. The current BLMs are designed to assess the toxicity of individual metals, and cannot account for the interactive effects of metal mixtures to aquatic organisms including fish. The present study was designed mainly to examine the interactive effects of waterborne metals (Cd, Zn, Cu, Ag, and Ni) in specific binary combinations on short-term (3h) gill–metal binding and essential ion (Ca2+ and Na+) uptake (a physiological index of toxicity) in fish, using juvenile freshwater rainbow trout (Oncorhynchus mykiss) as the model species. We hypothesized that binary mixtures of metals that share a common mode of uptake and toxicity (e.g., Cd and Zn – Ca2+ antagonists, Cu and Ag – Na+ antagonists) would reduce the gill binding of each other via competitive interactions and induce less than additive effects on ion transport. In addition, the mixture of metals that have different modes of uptake and toxicity (e.g., Cd and Cu, or Cd and Ni) would not exhibit any interactive effects either on gill–metal binding or ion transport. We found that both Zn and Cu reduced gill–Cd binding and vice versa, however, Ni did not influence gill–Cd binding in fish. Surprisingly, Ag was found to stimulate gill–Cu binding especially at high exposure concentrations, whereas, Cu had no effect on gill–Ag binding. The inhibitory effect of Cd and Zn in mixture on branchial Ca2+ uptake was significantly greater than that of Cd or Zn alone. Similarly, the inhibitory effect of Cu and Ag in mixture on branchial Na+ uptake was significantly greater than that of Cu or Ag alone. The inhibitory effects of Cd and Zn mixture on Ca2+ uptake as well as Cu and Ag mixture on Na+ uptake were found to follow the principles of simple additivity. In contrast, no significant additive effect on either Ca2+ or Na+ uptake was recorded in fish exposed to the mixture of Cd and Cu. Overall, we found that although the effects of metal mixture interactions on gill–metal binding did not always match with our original assumptions, the effects of metal mixtures on toxicity in fish were generally consistent with our predictions. The findings of the present study have important implications for improving the BLM approach to assess metal mixture toxicity in fish.

Titanium dioxide nanoparticles modulate the toxicological response to cadmium in the gills of Mytilus galloprovincialis

We investigated the influence of titanium dioxide nanoparticles (nano-TiO2) on the response to cadmium in the gills of the marine mussel Mytilus galloprovincialis in terms of accumulation and toxicity. Mussels were in vivo exposed to nano-TiO2, CdCl2, alone and in combination. Several cellular biomarkers were investigated in gills: ABC transport proteins and metallothioneins at gene/protein (abcb1, abcc-like and mt-20) and functional level, GST activity, NO production and DNA damage (Comet assay). Accumulation of total Cd and titanium in gills as in whole soft tissue was also investigated. Significant responses to Cd exposure were observed in mussel gills as up-regulation of abcb1 and mt-20 gene transcription, increases in total MT content, P-gp efflux and GST activity, DNA damage and NO production. Nano-TiO2 alone increased P-gp efflux activity and NO production. When combined with Cd, nano-TiO2 reduced the metal-induced effects by significantly lowering abcb1 gene transcription, GST activity, and DNA damage, whereas, additive effects were observed on NO production. A lower concentration of Cd was observed in the gills upon co-exposure, whereas, Ti levels were unaffected. A competitive effect in uptake/accumulation of nano-TiO2 and Cd seems to occur in gills. A confirmation is given by the observed absence of adsorption of Cd onto nano-TiO2 in sea water media.

Response of the hairy mussel Trichomya hirsuta to sediment-metal contamination in the presence of a bioturbator

The accumulation of metals in tissue compartments of bivalve biomonitors is expected to reflect the phases in which metals are most bioavailable. In concurrent field and laboratory experiments we measured Zn, Cd and Pb concentrations in the gills and digestive glands of mussels exposed to sediments from Lake Macquarie in NSW, Australia. Mussels in the laboratory were also exposed to the bioturbating gastropod Batillaria australis. Zn, Cd and Pb concentrations in gills and digestive glands of mussels from both experiments were accumulated in proportion with levels of metal contamination in the sediments. An interaction in the field between site and tissue type was found for Cd and Pb suggesting variation in the phases in which metals are most bioavailable. No effect of bioturbation on metal accumulation in the bivalve was detected and we conclude that it is unlikely to be a significant factor in metal uptake when these species interact.

Comparison of S, Se, and 210Po accumulation patterns in common squid Todarodes pacificus from the Yellow Sea and East/Japan Sea

Activities of 210Po and concentrations of the chalcogen elements S and Se, were measured in muscle, stomach, gill, and hepatopancreas tissues of two groups of the common squid, Todarodes pacificus, from common spawning grounds but different feeding grounds: The Yellow Sea and the East/Japan Sea. All elements displayed lowest concentrations in the muscle tissues, but while S was highest in stomach and gills tissues, Se and 210Po were highest in hepatopancreas tissues, probably due to compartmentalization based on their toxicity. Whole body burden calculations based on organ weight contributions confirmed that the majority of the squids total S is contributed by the muscle while the majority of 210Po is contributed by the hepatopancreas. Overall, squids from the East/Japan Sea displayed significantly higher 210Po activities than those from the Yellow Sea, in line with previous reports on higher activities of dissolved 210Po in the water column of the former compared to the latter, which likely affects bioaccumulation by the foodweb. Tissue-based correlation patterns of the three chalcogens with each other and with the toxic heavy metal Cd suggest S- and Se-containing detoxifying mechanisms for 210Po and Cd in stomach and gills, but not in the hepatopancreas, which supports previous hypotheses that both 210Po and Cd could be bound to S- and Se-depleted compounds in the squid hepatopancreas.

The Relationship Between Heavy Metal (Cd, Co, Cu, Ni and Pb) Levels and the Size of Benthic, Benthopelagic and Pelagic Fish Species, Persian Gulf

The concentration of heavy metals was determined in tissues of sole (Euryglossa orientalis), mullet (Liza abu) and croacker fish (Johnius belangerii) from Musa estuary. Generally, the highest concentration of the studied metals in the three species was found in the liver tissue. The levels of Cd and Cu in fish liver were J. belangerii = E. orientalis > L. abu and E. orientalis > L. abu > J. belangerii respectively. The concentrations of Cd and Cu in fish gills were E. orientalis > L. abu = J. belangerii and E. orientalis > L. abu > J. belangerii, respectively, and the level of Cu in muscle was E. orientalis > L. abu = J. belangerii. The results of linear regression analysis indicated that highly significant (p < 0.001) negative relationships were found between fish size and Cd concentrations in the liver of L. abu and Pb in the gills of J. belangerii.

Determination of Bioaccumulation of Heavy Metals and Selenium in Tissues of Brown Trout Salmo trutta macrostigma (Duméril, 1858) from Munzur Stream, Tunceli, Turkey

The objective of the present work was to determine the bioaccumulation of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), uranium (U) and selenium (Se) in gill, liver, and muscle tissues of the fresh water fish Salmo trutta macrostigma (Duméril, 1858) in Munzur Stream, Tunceli, Turkey. The highest concentrations of U (1.83 μg kg(-1)), Pb (119.84 μg kg(-1)) and Se (1.31 μg kg(-1)) were recorded in the gills of S. t. macrostigma. Concentrations of As (46.27 μg kg(-1)), Cd (109.19 μg kg(-1)), Hg (16.40 μg kg(-1)), Cu (18.19 μg kg(-1)) were recorded at highest levels in the liver. The results showed that there were significant differences in concentrations of As, Cd, Cu, Pb, Se, U and Hg in gill, liver and muscle tissue (p < 0.05). Heavy metals were within the edible parts of the investigated fish were in the permissible safety levels for human uses.

Contamination of Metals in Tissues of Ctenopharyngodon idella and Perca fluviatilis, from Anzali Wetland, Iran

The objective of the present study was to investigate the levels of metals (Cd, Cu, Zn, Pb and Cr) in muscle, gill, liver, kidney and intestine of two freshwater fish, Ctenopharyngodon idella and Perca fluviatilis, in Anzali Wetland, Iran. The concentrations were different between the fish species as well as among the tissues of fish. Results showed that the metal concentrations in both fish species were in descending order of Zn > Cu > Pb > Cr > Cd. Results also showed that the Cd, Cu, Zn, and Pb concentrations in the muscle of both fish from Anzali Wetland are below levels of concern for human consumption.

NILE TILAPIA AS BIO INDICATOR TO ESTIMATE THE CONTAMINATION OF WATER USING SDS-PAGE AND RAPDPCR TECHNIQUES

The present study used Nile tilapia (Oreochromis niloticus) as an biological marker to revealed the concentrations of some heavy metals (Cu, Pb and Cd) in water, gills and muscles of fish collected from four sites in Egypt {Maryuot Lake, Manzala Lake and the River Nile (Mansura)} which are polluted by industrial effluents, waste municipal and agricultural drainage water that is discharged directly into them in addition to Ismailia Canal (Abassa) as control. Analysis of water samples showed that Abassa site was the lowest concentration of copper, cadmium and lead (0.18, 0.0 and 0.2 ppm, respectively) while, Manzala Lake site showed the highest concentration (16.38, 2.87 and 10.1, respectively) and heavy metals in the water samples of Abassa site were within the permissible limits. Abassa site showed the lowest concentrations of the three heavy metals in gill and muscle while, Manzala Lake site indicated the highest concentrations. Copper and cadmium in gill and muscle samples of Abassa site and muscle samples of Mansoura site were within the permissible limits. Polyacrylamid gel electrophoresis was used to study protein banding pattern variation in tested fish and was showed variation in number of phenotypic bands and the variation between and within each site was clear. Protein locus (55 KDa) in 90% of Mansoura samples and also protein locus (32 KDa) in all samples were missed compared to control Site. Maryuot Lake samples demonstrated loss of protein loci (55 and 60 KDa) in 100% of samples and appeared a new protein locus (163 KDa) with ratio of 75%. Manzalla samples compared with control were missed protein locus (60 KDa) in all samples and appeared a new protein locus (163 KDa) in 25% of samples. Appear of a new protein locus (163 KDa) in Maryuot and Manzalla Lakes considered as a resistance protein for pollution. Results of RAPD with the five primers showed that the total No. of fragments were 55 with average 11 fragments which ranged from 140 to 2323 bp approximately. The total polymorphism was 87.27% and the total polymorphic fragments were 48 with average 9.6 fragments per primer. The different band profile (appearance/ disappearance) between polluted fishes and control fishes was shown. Results of RAPD and protein electrophoresis showed that heavy metals were genotoxic to Nile Tilapia fish.

Metal accumulation in sediment, water, and freshwater fish in a Dam Lake

Metal concentrations were determined in water, sediment, and freshwater fish samples (Squalus cephalus, Barbus esocinus, and Barbus xanthopterus) collected from Karakaya Dam Lake, Turkey, to estimate the risk of human consumption and pollution. Metal concentrations differed between the species (p < 0.05) even as they were living in similar habitats. Metal analyses were performed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Cd and Hg were not detected in water, sediment, and fish samples. Also, Mn, Ni, and Se were not determined in water. The accumulation order of the metals were found to be Fe > Zn = Cu in water and Fe > Zn > Mn > Ni > Cu in sediment. In general, the accumulation order of elements in the tissues all of the species sampled were found as Fe > Zn > Se > Mn > Cu > Ni > Cd in muscle, Zn > Fe > Mn > Se > Cu > Ni > Cd in gills, Fe > Zn > Se > Mn > Cu > Ni > Cd in liver and gonad, and Zn > Fe > Cu > Mn > Se > Ni > Cd in kidney. It was concluded that the fish from the dam lake are not heavily burdened with metals, but they should be controlled periodically to avoid excessive intake of trace metals by humans, and to monitoring the pollution of aquatic environment.

Assessing the impact of waterborne and dietborne cadmium toxicity on susceptibility risk for rainbow trout

The purpose of this study was to use a risk-based integrated-scale toxicological model to examine the impact of waterborne and dietborne cadmium (Cd) toxicity on rainbow trout ( Oncorhynchus mykiss) susceptibility appraised with recent published data. A probabilistic assessment model was performed to estimate Cd susceptibility risk. The dose–response models were constructed based on two endpoints of % Cd in metabolically active pool (MAP) and susceptibility time that causes 50% effect (ST50). We further constructed an elimination–detoxification–recovery scheme to enhance the model predictive ability. We found a 95% probability of % Cd in gill and liver MAP exceeding 47–49% and it was likely (70% probability) to have exceeded 52–55%, but it was unlikely (30% probability) to have exceeded 56–60%. In contrast to gill and liver, gut had a relative lower Cd susceptibility risk (15–17% Cd in MAP) with a longer ST50. We suggested that the proposed probabilistic risk assessment framework can incorporate the elimination–detoxification–recovery scheme to help government based biomonitoring and bioassessment programs to prevent potential aquatic ecosystems and human health consequences.