Metals In Fish Samples Research Articles

ASSESSMENT OF HEAVY METAL CONTAMINATION IN FISH AND WATER SAMPLES FROM BABBAN WUYA MADACHI RIVER: IMPLICATIONS FOR HUMAN HEALTH AND ENVIRONMENTAL SUSTAINABILITY

This manuscript investigates the presence and concentration of heavy metals, namely zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd), in water and two commonly consumed fish species (Tilapia and Catfish) from the Babban Wuya Madachi River. Heavy metal contamination poses significant risks to both human health and environmental sustainability. The study employs Atomic Absorption Spectroscopy (AAS) to analyze heavy metal concentrations in water and fish samples collected from ten different points along the river. The mean concentration of Zn, Cu, Pb, and Cd in the Tilapia fish, Catfish and water are 50.85 ± 0.22, 2.84 ± 0.27, 7.89 ± 0.78, 0.80 ± 0.02 mg/kg; 33.87 ± 1.08, 1.49 ± 0.10, 3.74 ± 0.42, 0.33 ± 0.01mg/kg; and 0.07 ± 0.00, 0.09 ± 0.00, 0.05 ± 0.02, BDL mg/L respectively. Results indicate that water concentrations generally fall below World Health Organization (WHO) standards, while the concentrations of certain heavy metals in fish samples exceed WHO limits, notably Zn, Pb, and Cd. Moreover, concentration of Cu in fish samples is within the standard WHO limit of 2.25 mg/kg and in water its concentration is below the standard limit of 2mg/L. It has been reported that, heavy metals such as Zinc, Cd and Pb has a unique behavior that once absorbed by man it retained in the body system for long and accumulate to cause kidney problems and born demineralization through direct bone damage or indirect through renal dysfunction. The findings underscore the necessity of continued monitoring...

INDUSTRIAL IMPACT ON SELECTED HEAVY METALS IN ECONOMIC FISH WITHIN THE RIVER IN NNEWI-NORTH LOCAL GOVERNMENT AREA, ANAMBRA STATE NIGERIA

This work was carried out to research on the Industrial impact of selected heavy metals in economic fish samples in Eze river of Nnewi-North, Anambra State, Nigeria. The levels of seven heavy metals (Pb, Mn, Zn, Ni, Cr, Cu, and Cd) in selected fish samples (Clariasgariepinus, Oreochromisneloticus, Pseudotolithus elongates) from the area were detected using Flame Atomic Absorption Spectrophotometric technique. The HN03-HCl method was used in the fish sample digestion. All the fish samples collected from the Eze river contained the six heavy metals analyzed. The mean concentrations(µg/g) of heavy metals in the fish samples from the studied area were 1.85 for Pb, 0.86 for Mn, 3.38 for Zn, 1.18 for Cr, 2.84 for Cu and 0.43 for Cd. With the exception of Pb and Cd most metals were within the acceptable levels in the fish. The target hazard quotient (THQ) and the hazard index (HI) values were evaluated in order to assess the health risk of the inhabitants of Nnewi-north and environs due to heavy metal intake from food crops. The values were less than 1 in all the fish samples; therefore, their consumption does not pose any health risk concern. Metal-metal correlation was carried out using Pearson’s product moments. Most elemental pairs show significant correlation with each other, this implies that each paired element has common pollution sources. In conclusion, the investigated area has been affected by the industrial activities. So control measures stated by regulatory authorities should be enforced in all the industries.

Evaluation of the ecological health and food chain on the shores of four River Nile Islands, Egypt

This study was conducted to evaluate the impact of human activities on the ecological health and food chain at the shores of four Nile Islands in Great Cairo including El-Qeratten, El-Waraq, El-Zamalek, and El-Manial. Water quality, bacteria, phytoplankton, benthic algae, zooplankton, macrobenthic invertebrates, and bony fishes were examined at each island shore over two seasons including the lowest and the highest flow (February and July 2020, respectively). The obtained results showed that the average values of most of the chemicals in Nile Island’s water were within the Egyptian water quality limits. Discriminant analysis of physicochemical factors revealed a similarity between El-Waraq and El-Qerateen and between El-Manial and El-Zamalek. El-Qeratten was the most polluted island. It has the highest total and fecal coliform bacteria count (3.155 and 3.050 Log MPN/100 mL, respectively). El-Zamalek shores have the highest phytoplankton (33,582 cells × 104 L−1) and zooplankton count (310,891 organisms × m−3) and phyto-biochemical values. Biochemical analysis of phytoplankton demonstrated the richness of the bulk by protein (> 85% of biomass), indicating that phytoplankton has a high nutritional value. Elevated zooplankton count was recorded at El-Zamalek, which coincided with the peak of phytoplankton abundance. Mollusca were the dominant macrobenthic invertebrates on most of the island’s shores. Bony fishes were represented by 27 species and two crustaceans. The levels of the metals in fish samples were compared with the food safety guideline endorsed by the World Health Organization and Food and Agriculture Organization (WHO/FAO) to evaluate the toxicity level.

Ecological Risk Assessment of Heavy Metals in Fish Samples from Donga River, Taraba State, Nigeria

Ecological Risk Assessment of Heavy Metals in Fish Samples from Donga River, Taraba State, Nigeria

Bioaccumulation of Toxic Metals in Commercially Valuable Fish from the Western Region of Ghana

Fish is an important source of protein, however as human impacts on the environment through industrialization, mining and farming among others is resulting in increased concentration of toxic metals in them. The levels of copper (Cu), arsenic (As), zinc (Zn), lead (Pb), cadmium (Cd), mercury (Hg), and selenium (Se) were analysed in fish samples from the southwestern coast of Ghana using acid digestion and atomic absorption spectrophotometer method. A total of 71 fish species were sampled where 35 species were collected in the wet season (October, 2014) whereas 36 species were collected in the dry season (March, 2015). The average levels of heavy metals detected in the wet season were 1.08 mg/kg for Cu, 9.79 mg/kg for Zn, 4.80 mg/kg for Se, 0.06 mg/kg for Pb, 0.03 mg/kg for Hg, 0.02 mg/kg for As, and 0.01 mg/kg for Cd. The average values of heavy metals in fish samples analysed in the dry season were 2.17 mg/kg for Cu, 4.55 mg/kg for Zn, 8.13 mg/kg for Se, 0.06 mg/kg for Pb, 0.03 mg/kg for Hg, 0.09 mg/kg for As, and 0.005 mg/kg for Cd. The results showed that the average levels of toxic metals analysed in the wet season increased in the order of Cd < As <Hg <Pb <Cu < Zn < Se whereas the dry season increased in the order of Cd < Hg < Pb < As <Cu < Zn < Se. The levels of all seven heavy metals were below the FAO/WHO Maximum Permissible Limits (MPL), Australia New Zealand Food Standards, EU, Australian National Health and Medical Research Council (ANHMRC) standards. Hence the consumption of these fish poses no public health concern. The estimated daily intake of the various toxic metals analysed were lower than the daily intake of their respective toxic metals. The non-carcinogenic health risk to adults and children showed that the Total Targeted Hazard Quotients (TTHQ) was less than 1 ( <1) hence poses no health risk to humans.

Potential health risk assessment of heavy metals contamination in Chelon Saliens highly consumed by residents around an international wetland, Gomishan, north of Iran

ABSTRACT The content of the prioritised heavy metals including lead (Pb), chromium (Cr), nickel (Ni), cadmium (Cd), and arsenic (As) was measured in water and tissues of ChelonSaliens- the most hunted and consumed fish- in an international wetland, Gomishan, located in Iran. Also, the health risk attributed to consuming the fish was assessed. The concentration of heavy metals in water and fish samples was obtained using inductively coupled plasma mass spectrometry (ICP-MS). The results were calculated in terms of mg/kg for fish and ppm for water samples, respectively. The concentration of the heavy metals in water decreased in the following order: Pb>Ni>As>Cr>Cd. The content of heavy metals in the fish tissues was 0.01–0.013 mg/kg, 0.005–0.01 mg/kg, 0.011–0.014 mg/kg, 0.004 mg/kg, and 1.5–1.6 mg/kg for As, Cd, Cr, Ni, and Pb, respectively. The estimated daily intake (EDI) for all the heavy metals in the fish samples were below the permissible range of EDI for foodstuffs. Concerning health risks related to consumingChelonSaliens by people living around the wetland, only the non-carcinogenic target hazard quotient (THQnon-carcinogenic) of Pb for children was more than one and THQnon-carcinogenic for other heavy metals was distinctly less than one. Similarly, THQcarcinogenic for Pb was remarkably more than the safe range, i.e. 10−6-10−4, and those of other heavy metals were acceptable. It seems that consuming thefish hunted from GomishanWetlandcan make a health effect, especially for children, since a regular monitoring programme is required for assessing the contamination of heavy metals in water, soil, and fish in GomishanWetland.

Determination of toxic heavy metals in fish samples using dispersive micro solid phase extraction combined with inductively coupled plasma optical emission spectroscopy

Monitoring of toxic heavy metals in fish samples is a matter of a great importance from the nutritional and toxicological points of view. A dispersive micro solid phase extraction (dµSPE) for preconcentration of trace Pb, Cd, Hg, Co, Ni ions using pectin coated magnetic graphene oxide (pectin/Fe3O4/GO) is presented. Inductively coupled plasma optical emission spectroscopy (ICP/OES) was utilized for analyzing the samples. The influence of parameters name as pH, extraction time, sample volume and amount of sorbent were optimized using central composite design (CCD) methodology. Detection and quantification limits were between 0.01 and 0.21 µg g−1 and 0.04–0.67 µg g−1 of fresh fish sample, respectively. Accuracy of the method verified using certified reference materials (NIST-SRM-1946). Concentration of the toxic heavy metals were successfully determined in 11 different fish samples using the proposed method.

Heavy metals in water, sediment, fish and associated risks from an endorheic lake located in Southern Africa

The study assessed heavy metals (Cd, Cu, Fe, Mn, Pb and Zn) and physico-chemical parameters in water, sediments and fish from an endorheic lake (Lake Chilwa) in Malawi. It was observed that pH (max. 9.7), EC (max. 2936 μS/cm), TDS (max. 2119 mg/L), NO3− (max. 6.6 mg/L) and PO43− (max. 1.3 mg/L) were higher in the dry season than in the rainy season. Pb was not detected in all samples. However, the rest of heavy metals were detected with significant values of Mn and Cu in fish (Mn: 0.015–1.18 mg/kg dry weight, dw; Cu: 0.41–0.92 mg/kg dw) and sediment (Mn: 2.25–10.66 mg/kg dw; Cu: n.d–1.63 mg/kg dw). The concentrations of heavy metals in fish samples were below the maximum limits for edible fish recommended by Food and Agriculture Organization/World Health Organization: Cd (0.1 mg/kg), Cu (3 mg/kg), Fe (43 mg/kg), Pb (0.2 mg/kg), Mn (2–9 mg/kg) and Zn (60 mg/kg). The calculated target hazard quotients (ranged from 0.001 to 1.07) indicated no human risks from fish consumption. Furthermore, dry season values for Mn, Cu and Zn in sediments were significantly higher (p < 0.05) than those of the rainy season. Conversely, Fe in sediments was significantly higher (p < 0.05) in the rainy season than in the dry season. The use of fertilizer and indiscriminate disposal of metal products contributes to the observed levels. This calls for reinforcement of suitable agricultural and waste management practices in the study area.

Heavy metal contamination of Pleuronectiformes species from Sinop coasts of the Black Sea

In the Turkish Black Sea coasts fish is particularly consumed because of high protein supplies, essential amino acids, vitamin, and mineral content. Fish are exposed to contaminants such as heavy metals in polluted waters. The aims of the study are to determine heavy metals in Pleuronectiformes species from Sinop coasts of the Black Sea and determine the health risks due to the consumption of contaminated fish. Pleuronectiformes species Scophthalmus maximus (Linnaeus, 1758) belonging to Scophthalmidae family, Arnoglossus laterna (Walbaum, 1792) belonging to Bothidae family and Pegusa lascaris (Risso, 1810) belonging to Soleidae family were collected from Sinop coasts of the Black Sea in fishing season of 2016. Heavy metals (Hg, Cd, Pb, Cu and Zn) in edible tissues were determined by ICP-MS (Agilent 7700x). The limit values given by the international and national organizations did not exceed in the muscle tissues of turbot, Mediterranean scald fish and sand sole. Overall Zn was detected in higher concentrations in all species followed by Cu, Pb, Hg and Cd. The results obtained from the analyses of the maximum levels of the metals except Hg were found in turbot. The highest Hg (0.021±0.007 µg g-1 wet wt.) was found in sand sole. However, the high amounts of Cd, Pb, Cu and Zn in turbot were 0.011±0.004, 0.07±0.005,1.32±0.28 and 14±3 µg g-1 wet wt., respectively. The EDIs and EWIs of the metals were estimated taking into account the mean of metal in all fish samples and the mean consumption of fish per day/week for adults. These results are normally significantly lower than the recommended values of FAO/WHO. Estimated HIs of all the considered metals were below the value of 1, therefore the metals in fish samples do not toxic any apparent threat to the population and these fishes are healthy for consumption.Keywords: Scophthalmus maximus, Arnoglossus laterna, Pegusa lascaris, heavy metals, Black Sea

Accumulation of Heavy Metals in Water and Some Fish Samples from Onuimo River, Imo State, Nigeria

Accumulation of some heavy metals (Cu, Zn, Cd and Cr) was determined in selected fish; Moon fish (Citharinus citharus), Tilapia fish (Oreochronus niloticus), Mud fish (Clarias anguillaris), Cat fish (Clarias gariepinus) and Carp fish (Labeo coulbie) and water samples from Onuimo River in Imo State in Nigeria. Accumulation order of heavy metals in fish samples comprised of Moon fish &gt; Cling fish &gt; Mud fish &gt; Tilapia fish &gt; Cat fish. Bioconcentration factor model used in the present study showed the following order; Moon fish = Carp fish &gt; Cat fish &gt; Mud fish &gt; Tilapia fish and Moon fish = Carp fish &gt; Tilapia &gt;Mud fish &gt; Cat fish for copper and zinc metals respectively. The concentration of cadmium and chromium in water samples were below detection limits of the Atomic Absorption Spectrophotometer (AAS) Machine. Concentrations of Cu, Cd, Zn and Cr were also below permissible limits of some international regulatory bodies.

Application of Cyanidin in Quantitative Estimation of Metals in Fish Samples

The use of cyanidin as a metallochromic agent in analyses of heavy metal is reported. Cyanidin is a ligand that was extracted from Gmelina arborea fruit and characterized. The cyanidin was used to form complexes with metals in five fish samples for the quantitative determination of Cu, Zn, Ca and Mg. The optimum pH for absorbances of the cyanidin-metal complexes was observed at 5. Experimental results obtained using cyanidin were compared with analyses results obtained by Atomic absorption spectrophotometry (AAS) and both methods were evaluated using paired T-test to ascertain the suitability of cyanidin as metallochromic agent for the quantitative determination of heavy metals in fish samples. A null hypothesis that cyanidin method is a good alternative to AAS was accepted for the analyses of Cu and Zn (p > 0.05). The paired T-test, however rejected the null hypothesis for the determination of Ca and Mg (p < 0.05). This study has provided a cheap, sensitive, rapid, simple and easy method for metal determination in analytical samples.

Determination of Some Selected Heavy Metals in Water, Oreochromis niloticus and Labeobarbus intermedius Samples from Abaya and Chamo Lakes

The fish organs and water was collected from three sampling sites of Lakes Chamo and Abaya. A procedure consuming 12 mL mixture of HNO 3 -H 2 O 2 for gill, kidney, liver and 1:2.5 mL mixture of HNO 3 -HCl for water samples for digestion of was developed. Concentrations of six metals in water and their accumulation in the edible tissue of Tilapia (Oreochromis niloticus) and Barbus (Labeobarbus intermedius) fish species were determined using Flame Atomic Absorption Spectroscopy. The results revealed that the average heavy metal concentrations in water samples were; Zn 0.017, Cu 0.077, Fe 7.50, Cr 0.033, Cd 0.264 and Pb 1.731 mg/L respectivelty. The highest concentrations of iron (Fe) and lead (Pb) were observed at Chamo Park and Sile sites, respectively. The average contents of heavy metals in fish samples were; Zn 0.062, Cu 0.047, Fe 2.270, Cr 0.041, Cd 0.045 and Pb1.78 mg/Kg in both fish species. The highest accumulations of iron (Fe) and lead (Pb) concentration were observed in liver and gill of Tilapia fish from Chamo Lake. There was no significant difference between the two lakes in accumulating trace metals. Keywords : Fish variety, Heavy metals, Lakes, ANOVA DOI : 10.7176/FSQM/83-05

Analysis of Heavy Metal Accumulation in Fish at Terengganu Coastal Area, Malaysia

Bioaccumulation of toxic metals in fish causes serious threats to human when they are consumed. Thus, the detection of toxic element concentration levels in aquatic component is important. The accumulation of some heavy metals such as Cd, Cu, Fe, Mn, Pb and Zn in fish were determined. Ten species (Selaroides leptolepis, Decapterus maraudsi, Epinephelus lanceolatus, Priacanthus tayenus, Rastrelliger, Megalaspis cordyla, Nibea soldado, Pristipomoides filamentosus, Bramidae and Siganus canaliculatus) were collected from Terengganu coastal area, Malaysia. The analysis was done using inductive coupled plasma-mass spectrometer (ICP-MS) technique. In general, the concentration levels of heavy metals in fish samples are lower than the previous study in various locations. The highest average level of heavy metal recorded in fish is Fe followed by Zn, Mn, Cu, Cd and Pb. The metal concentration found in this study was lower than the national and international recommended dietary allowance (RDA) for human consumption except Fe (52.33 × 10-2 ± 6.39 × 10-2 mg kg-1) which exceeded the limit of 0.3 mg kg-1. Long term monitoring system of metal bioaccumulation in fishes need to be done to provide useful information for the assessment of the potential health risks of metals in Malaysia.

Determination of Levels of Some Heavy Metals in Fish and Hens Eggs in Sudan

The concentration of the food stuffs by toxic metals is a threat and their exposure for long time has determinate effects on the health tutus of animals. Hen’s eggs and fish are one the main sources of protein but if contaminated by toxic heavy metals will cause a harmful effect on human health. This study aimed to assess the concentration of seven microelements performed by Atomic Absorption Spectrophotometer (AAS). Namely (Cadmium, Cobalt, Copper, Iron, Manganese, Lead, and Zinc) in tow samples of some animal products fresh (fish and hens egg) collected from the district popularly in Merowe-city-North Sudan. Heavy metals in hens eggs and fish samples were analyzed using (AAS) in accordance to standard analytical method data obtained were subjected to statistical analysis (ANOVA). To find out the significant difference of toxic heavy metals in fish sample the obtained results showed the average values Cd and Pb (0.100 and 0.720 mg/kg) respectively in fish sample were higher than permissible limits (p<0.05mg/kg) set by world health organization (WHO). The analysis of heavy metals in fish indicated among seven heavy metals tested, lead showed the highest concentration compered to levels essential elements followed by (0.170 for Co, 0.420 for Cu, 1.910 for Fe, 0.145 for Mn, and 2.685 mg/kg for Zn). Our results also showed that accumulation of heavy metals differed in the hens eggs sample recorded high levels of heavy metals found to Cd and Pb (0.070 and 0.305 mg/kg) respectively. The mean concentrations of essential elements followed (3.335 for Zn, 2.200 for Fe, 0.195 for Cu 0.090 for Co, and 0.070 mg/kg for Mn) respectively. Concentrations in sample of the studied fish showed that there were highly significant different between the Cd and Pb (0.100 and 0.720 m/kg) than hens eggs (0.070 and 0.305mg/kg).

Environmental assessment of Al-Hammar Marsh, Southern Iraq.

Aim(a) To determine the spatial distributions and levels of major and minor elements, as well as heavy metals, in water, sediment, and biota (plant and fish) in Al-Hammar Marsh, southern Iraq, and ultimately to supply more comprehensive information for policy-makers to manage the contaminants input into the marsh so that their concentrations do not reach toxic levels. (b) to characterize the seasonal changes in the marsh surface water quality. (c) to address the potential environmental risk of these elements by comparison with the historical levels and global quality guidelines (i.e., World Health Organization (WHO) standard limits). (d) to define the sources of these elements (i.e., natural and/or anthropogenic) using combined multivariate statistical techniques such as Principal Component Analysis (PCA) and Agglomerative Hierarchical Cluster Analysis (AHCA) along with pollution analysis (i.e., enrichment factor analysis)MethodsWater, sediment, plant, and fish samples were collected from the marsh, and analyzed for major and minor ions, as well as heavy metals, and then compared to historical levels and global quality guidelines (WHO guidelines). Then, multivariate statistical techniques, such as PCA and AHCA, were used to determine the element sourcing.ResultsWater analyses revealed unacceptable values for almost all physio-chemical and biological properties, according to WHO standard limits for drinking water. Almost all major ions and heavy metal concentrations in water showed a distinct decreasing trend at the marsh outlet station compared to other stations. In general, major and minor ions, as well as heavy metals exhibit higher concentrations in winter than in summer. Sediment analyses using multivariate statistical techniques revealed that Mg, Fe, S, P, V, Zn, As, Se, Mo, Co, Ni, Cu, Sr, Br, Cd, Ca, N, Mn, Cr, and Pb were derived from anthropogenic sources, while Al, Si, Ti, K, and Zr were primarily derived from natural sources. Enrichment factor analysis gave results compatible with multivariate statistical techniques findings. Analysis of heavy metals in plant samples revealed that there is no pollution in plants in Al-Hammar Marsh. However, the concentrations of heavy metals in fish samples showed that all samples were contaminated by Pb, Mn, and Ni, while some samples were contaminated by Pb, Mn, and Ni.Discussion and conclusionsDecreasing of Tigris and Euphrates discharges during the past decades due to drought conditions and upstream damming, as well as the increasing stress of wastewater effluents from anthropogenic activities, led to degradation of the downstream Al-Hammar Marsh water quality in terms of physical, chemical, and biological properties. As such properties were found to consistently exceed the historical and global quality objectives. However, element concentration decreasing trend at the marsh outlet station compared to other stations indicate that the marsh plays an important role as a natural filtration and bioremediation system. Higher element concentrations in winter were due to runoff from the washing of the surrounding Sabkha during flooding by winter rainstorms. Finally, the high concentrations of heavy metals in fish samples can be attributed to bioaccumulation and biomagnification processes.

Heavy metals in the common carp (Cyprinus carpio L.) from three reservoirs in the Czech Republic

Toxic metals (cadmium, lead, and mercury) in the tissues of common carp fished from three reservoirs (Pilská, Domaninský, and Matějovský) in the Bohemian-Moravian Highlands were measured in the period from April 2013 to September 2014 and the risk of consuming the fish from these localities was evaluated. During this project 25 fish specimens from each locality were analysed. The concentration of metals in muscle tissue and liver was determined by atomic absorption spectrometry. A variation in the content of heavy metals in fish samples and fish tissues was demonstrated and discussed. Higher concentrations of cadmium in the fish tissue were found in 50 samples of carp liver. Because the fish liver is not commonly consumed, common carp from the Moravian-Moravian Highlands does not pose any health risk for consumers. Concentrations of the other monitored toxic metals in fish tissue were low and were complying with the maximum residue limit in all cases.

Trace metal contamination in commercial fish and crustaceans collected from coastal area of Bangladesh and health risk assessment.

Trace metals contamination in commercial fish and crustaceans have become a great problem in Bangladesh. This study was conducted to determine seven trace metals concentration (Cr, Ni, Cu, Zn, As, Cd, and Pb) in some commercial fishes and crustaceans collected from coastal areas of Bangladesh. Trace metals in fish samples were in the range of Cr (0.15 - 2.2), Ni (0.1 - 0.56), Cu (1.3 - 1.4), Zn (31 - 138), As (0.76 - 13), Cd (0.033 - 0.075), and Pb (0.07 - 0.63mg/kg wet weight (ww)), respectively. Arsenic (13mg/kg ww) and Zn (138mg/kg ww) concentrations were remarkably high in fish of Cox's Bazar due to the interference of uncontrolled huge hatcheries and industrial activities. The elevated concentrations of Cu (400), Zn (1480), and As (53mg/kg ww) were also observed in crabs of Cox's Bazar which was considered as an absolutely discrepant aquatic species with totally different bioaccumulation pattern. Some metals in fish and crustaceans exceeded the international quality guidelines. Estimated daily intake (EDI) and target cancer risk (TR) revealed high dietary intake of As and Pb, which was obviously a matter of severe public health issue of Bangladeshi coastal people which should not be ignored and concentrate our views to solve this problem with an integrated approaches. Thus, continuous monitoring of these toxic trace elements in seafood and immediate control measure is recommended.

Analysis of Some Trace Metals in Fish Species after Preconcentration with Congo Red on Amberlite XAD-7 Resin by Flame Atomic Absorption Spectrometry

A new procedure for separation and preconcentration of trace amounts of Cu(II), Ni(II), Fe(III), Zn(II), Cr(III), Cd(II), and Pb(II) in fish samples was proposed. The procedure is based on the adsorption of these metal ions on the column of Amberlite XAD-7 as congo red complexes prior to their determination by flame atomic absorption spectrometry (FAAS). Several factors that can affect the sorption and elution efficiency of the metal ions were investigated and optimized. The sorption was quantitative in the pH range of 6.0–9.0 for Cu(II) and Ni(II), 5.5–8.0 for Fe(III), 6.0–8.5 for Zn(II) and Cd(II), and 7.0–8.5 for Cr(III) and Pb(II). The optimum pH for simultaneous retention was 7.5. The sorption capacity of the resin was found to be 0.89, 0.72, 0.82, 0.61, 0.53, 0.84, and 0.78 mg/g for Cu(II), Ni(II), Fe(III), Zn(II), Cr(III), Cd(II), and Pb(II), respectively. The precision of the method was evaluated as the relative standard deviation obtained by analyzing a series of six replicates and below 6% for all seven elements. The validation of the method was performed by the analysis of certified reference materials. The proposed method was successfully applied to separation/preconcentration and determination of these metals in fish samples.

Concentrations of heavy metals in muscle, liver and gill of Sardina pilchardus (Walbaum, 1792): Risk assessment for the consumers.

Present study was aimed at investigating the three heavy metals namely cadmium, lead and mercury in liver, gills and muscles of sardine fish (Sardina pilchardusWalbaum,1792) which was collected from five locations in south of Morocco. Mass fraction of heavy metals in fish samples were determined using graphite furnace and cold vapor atomic absorption spectrometry. Generally, the levels of Cd, Hg and Pb in muscle of sardine were lower than those in livers and gills. This study reveals that the concentrations of heavy metals in sardine are below the maximum acceptable concentrations for human consumption. Metal concentrations in the edible parts (muscle) of sardine were assessed for human uses according to provisional tolerable weekly and daily intake. The estimated values of all metals in muscle of fish in this study were below the established values. Therefore, it can be concluded that cadmium, lead and mercury in pilchard pose no health risk for consumers.

Bioaccumulation of Some Heavy Metals in Fish Samples from River Benue in Vinikilang, Adamawa State, Nigeria

This study was aim to determined the levels of some heavy metals in the gills, liver, stomach, kidney, bones and flesh of four fish species (Tilapia zilli, Clarias anguillaris, Synodentis budgetti and Oreochronmis niloticus) collected at River Benue in Vinikilang, Adamawa State, Nigeria for analysis of Cu, Zn, Co, Mn, Fe, Cr, Cd, Ni and Pb. These metals were chosen because at higher concentrations there might be toxic to the fish and by extension humans that depends on such fish as food. The concentrations of the metals were carried out using Flame Atomic Absorption Spectrophotometer (AAS, Unicam 969). Large differences in trace metal concentrations were observed between different tissues within each fish. The highest concentration of Fe (12.65 μg/g) was recorded in gill of Synodentis budgetti, while the lowest value of 0.68 μg/g was recorded in the flesh of Oreochronmis niloticus. The liver of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species; Fe and Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Cd and Co. The stomach of Synodentis budgetti accumulate significant higher levels of Fe than other species; Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Mn, Cr, Cu, Cd and Pb. Similarly, the bone of Synodentis budgettiaccumulates significant higher levels of Mn and Cd than other species; Zn and Fe were highest in the bone of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Ni, and Co. The highest levels of Fe (12.65 μg/g) observed in this study was recorded in the gill of Synodentis budgetti and it was below the high residue concentrations of Fe (34 - 107 ppm) in fish samples. Based on the above results, it can therefore be concluded that metals bioaccumulation in the entire fish species study did not exceeds the permissible limits set for heavy metals by FAO, FEPA and WHO.