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The effect of cadmium on hematological and biochemical indices of silver carp (Hypophthalmichthys molitrix) exposed to subacute (0.65ppm) and acute (3.25ppm) concentrations for 96-h test period was assessed. The results showed that Hb, Hct, RBC and MCV significantly decreased in low concentration of cadmium (p<0/05), while MCH, MCHC, WBC, glucose and cortisol were significantly (p<0/05) higher than control group in both low and high concentrations. This study reveals that some hematological and biochemical indices of silver carp, such as cortisol, can be used as suitable biomarkers in tracing Cd²⁺ contamination within water bodies.

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In a completely randomized design, the effects of heavy metals of Cd, Cu, Pb and Ni at concentrations of 0, 5, 50 and 100 mg/l on chlorophyll a and biomass in green algae Scenedesmus quadricauda were investigated for 14 days under laboratory conditions of 23 °C, 12 h light: 12 hours light and light intensity of 60 mol photons/m²/s. The lowest density, chlorophyll a and dry biomass obtained at 100 mg/l in all of the heavy metals. The mean (±SE) highest increasing rates of chlorophyll a were 24.2±1.1, 23.1±0.8, 36.7±1.4 and 35.5±1.2% for Cd, Cu, Pb and Ni, respectively. Correspondingly, the reduction rates based on dry biomass were 51.5±3.1, 35.2±1.1, 47.9±1.6 and 56.6±2.8% for Cd, Cu, Ni and Pb, respectively. The results showed that heavy metals made significant reduction on chlorophyll a and dry biomass in S. quadricauda.

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Pot experiment was carried out to investigate the effects of ethylenediaminetetraacetic acid (EDTA) on some morphological characteristics of Thlaspi caerulescens L., and also on the accumulation of lead (Pb) and zinc (Zn) in roots and shoots of T. caerulescens L.. Experiments were then set up in three treated pots with doses of 3, 6 and 9 mmol kg^-1 of EDTA and control pots (C: uncontaminated soil and W: contaminated soil). The results indicated the significant effect of EDTA on morphological characteristics and accumulation of heavy metals in the plant (P<0.05). Data revealed that the maximum of germination (99.11 and 96.00%), maximum of root length (73.31 and 70.14 mm) and maximum of shoot length (51.64 and 44.14 mm) and maximum of biomass weight (61.31 and 52.18 mg) were achieved by C treatment followed by W treatment. The maximum bioconcentration factor (3.57) and translocation factor (0.89) was observed on 9 mmol kg^-1 EDTA. In addition, the effect of EDTA on Tolerance Index (TI) showed that the TI decreased with increasing doses of EDTA. The findings indicated that the study species tolerated heavy metals concentration. EDTA had potential to promote the uptake of heavy metals for T. caerulescens L., butwith respect to non-significant differences between 6 mmol kg^-1 EDTA and 9 mmol kg^-1 EDTA treatments. Thereore, low dose of EDTA suggested to be applied because of its environmental risk.

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The total concentration and percentage of heavy metals content in the sediment of Hashilan wetland, Kermanshah province, was assessed in summer 2015. The total concentrations of Cu, Pb, and Fe were around 18.57, 6.95 and 379.24 μg g^-1, respectively. Successive extractions of the samples showed a decreasing trend as follows: residual>organic matter>iron and manganese oxides>exchangeable parts. The comparison of the total metal concentrations and SQGs and NOAA standards proposed high concentrations of Pb and Fe contents, while RAC suggested that Cu, Pb, and Fe had posed a low-moderate risk, low risk and no risk to the system, respectively. Furthermore, the results showed that the most common sources of Pb and Fe were natural while sources of Cu was anthropogenic. Continuous monitoring of the wetlands, particularly water inputs are recommended.

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  Natural Waters are normally Considered as Healthy, and most of the sources of pollution such as heavy metals, get Through the water, during the passage to reach the consumption aera. Therefore to search the total pollution, sampling was performed from the tap water (7 stations in Tehran). Samples were analyzed to determine the concentration of the elements such as Pb, Cd, Ni, Zn and Cr. Comparison of the results with that of the EPA Standard values showed that the concentration of Pb were much higher in few stations. Considering the canceriogenic effects of Pb, this can be very hazardous. There were no problems due to the other elements, One of the sources of Pb uptake is the piping network system, sharing 29% which seems to be the main source. However reduction and removal of heavy metals were examined by the Reverse Osmiss method at the second step. The results showed high reduction and removal of Pb by this method, so the method looks to be very applicable./s

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  Effect of two storage temperatures -14±2˚c and -28±2˚c was investigated on distribution and redistribution of Fe, Cu, Zn, Mg, Mn, Hg, Pb and Cd metals in tissue and viscera of green back mullet. Statical results showed that average amount of Fe metal in tissue of mature and immature fish stored at -14˚c (respectively 77.1 ppm and 166.6 ppm ) was more than both fresh mature and immature fish (28.5 ppm and 88.1 ppm) and fish stored at -28˚c ( 26 ppm and 109.1ppm). Amount of Zn metal in the viscera of mature fish stored at -28˚c (56.8 ppm) was more than fresh fish (43.5 ppm) and fish stored at -14˚c (43.5 ppm). Likewise amount of Pb metal in the viscera of immature fish (59.9 ppm) and fish stored at -14˚c (58.3 ppm) was less than immature fish stored at -28˚c (110.2 ppm). Considering that the amount of other metal did not show significant changes during frozen storage, it seems that -28˚c temperatures provides better quality from the view point of distribution and redistribution of heavy metals, and fish tissues stored at this temperature have more food immunity and health for consumers.    

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Aims: Karun River, which is the largest river in Iran, represents a unique ecosystem. However, increased anthropogenic activities result in the formation of this river is seriously affected by a large range of pollutants especially the heavy metal pollutants which may be toxic to human and aquatic fauna. Therefore, there is a need for continuous monitoring of pollution levels in the river.
Materials & Methods: In this study, water, sediment, and algae samples were collected from six different stations along the course of the river in September 2015 to investigate the quality of Karun’s River in terms of heavy metals (Pb, Zn, Cr, and Cd) at the basin of drinking water treatment in Ahwaz and Mollasani cities. After drying and digestion of samples, heavy metal concentrations were determined using an atomic absorption spectrophotometry (Perkin Elmer-Analyst 300).
Findings: The highest concentration of trace metals was found in sediment samples with Zn having the highest mean concentration values in all stations. The heavy metal concentrations in the downstream indicated an increase in the pollution load due to the flow of water from upstream to downstream of the river resulted in the movement and accumulation of all contaminants to the river in the downstream; hence, there was the highest concentration
of metals in basin of the Kut Abdollah treatment (downstream) and the lowest in Mollasani (upstream).
Conclusion: Comparison of the concentration of metals in the sediments with some universal standards including EPA3050 and the criterion of sediments quality standard from NOAA and Canadian Environment Agency showed that the concentration of chromium and cadmium in stations was higher than the allowable limit of EPA3050 standards and some environmental standards of Canada among all metals. Since algae samples have been able to accumulate a significant amount of heavy metals, therefore, these are suitable bio-indicators to determine the concentration of heavy metals in this aquatic ecosystems.

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Aims: Cement industry is considered as one of the major consuming energies, producing large amounts of environmental contaminants. The aim of this study was to examine the extent of metals Cadmium (Cd), Zinc (Zn), Lead (Pb), and Manganese (Mn) in the soil and leaves of planted around the cement factory in Pinus eldarica, Ulmus umbraculifera, and Quercus brantii naturally grown there.
Materials and Methods: In the present experimental study, to perform this, the level of elements was examined in the leaves as well as depths of 0-10 and 10-20cm of soil across the three studied species using atomic absorption device. The extent of elements sequestrated in the factory’s electro filter was also measured. One-way ANOVA test, Duncan’s test, and SPSS 20 software were used for Statistical analysis.
Findings: Cadmium was sequestrated in the electro filter was almost close to the level of cadmium in the leaf and soil samples. The level of lead, zinc, and manganese in the electro filter of the factory were higher than the extent of sequestration of these three elements in the leaf of three tree species and the soil below them. Across the three species, with increased depth of soil, the extent of lead sequestration declined. Pinus eldarica had the minimum extent of sequestration for the four studied elements both in the soil and leaf across the three studied species.
Conclusion: Quercus brantii and Ulmus umbraculifera have a greater potential in sequestration of heavy metals in comparison with Pinus eldarica.

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Research subject: The presence of heavy metal ions in surface and underground water, followed by their infiltration into drinking water at high concentrations, poses irreparable risks to human health and the environment. In this context, solid-phase extraction (SPE) has recently been recognized as a routine and practical method for removing heavy metals from water and wastewater samples. Consequently, the development of selective adsorbents for application in the SPE method is of significant importance in environmental studies.
Research Approach: In the present study, polyvinyl alcohol (PVA) molecules were functionalized onto Fe₃O₄@SiO₂ core-shell nanoparticles using cyanuric chloride and triethoxysilyl propylamine compounds. The synthesized nanoparticles were then employed as an effective adsorbent for the removal of Pb²⁺ ions from aqueous solutions. The structural characteristics, morphology, and particle size were analyzed using Fourier-transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Furthermore, the key operational parameters affecting adsorption performance were evaluated to optimize the adsorption capacity for the effective removal of heavy metal contaminants.
 

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  Cultivated mushrooms are considered as a popular delicacy and have an important role in daily intake due to essential Amino Acids, elements and vitamins. Based on Several Studies, mushrooms can accumulate great concentrations of toxic metallic elements like lead and cadmium in Comparative to other Fruits and vegetables. This study has conducted due to following reasons: - Lead and Cadmium have Considerable toxic effects even in low Concentrations. - There is no reports about these elements contents in mushrooms cultivated in Iran. - There is no Proper strategy for this infection control Material and Method: 8 mushroom Samples were collected randomatically from mushroom sale centres in Tehran, and delivered to laboratory. Then they were sorted, cut, washed, and dried at 80°c for 20h. Dried Samples were homogenized and laid in ash. Then they were Solved in Nitric Acid and finally analysed by Atomic Absorption Spectrometer. Results: Cadmium Content was lower than acceptable level (EU 466/2001) (2.0 mg/kg dry weight) in all samples. Lead content was generally lower than acceptable level (3.0 mg/kg dry weight) except for 2 Samples which have 5.35 mg/kg and 3.71 mg/kg Lead Content. Conclusion: Analysed Samples have low content of cadmium due to cultivating environment, good quality of Compost and irrigation with deep underground water. Geographical Condition of Cultivation may cause high content of lead in two Samples. It is recommended to investigate the main reason of this infection.  

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Aims: Heavy metals are one of the most important pollutants in earth and water environments due to long-term durability. The aim of this study was to isolate phosphate solubilizing bacteria from metal waste, investigate the amount of resistance, remove the metal by it and the effect of phosphatase on removal of metals.
Materials & Methods: In this experimental study, the isolation of phosphate solubilizing bacteria and detection of isolates were carried out, using biochemical and molecular tests. The phosphatase was measured by colorimetric method, the resistance of the separated to the metals with the minimum inhibitory concentration (MIC₅₀), minimum bactericidal concentration (MBC) and the rate of removal of metals by atomic absorption was measured. The surface changes of the exposed metal cells were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and the effect of phosphatase on metal removal. Data analysis was done with Duncan's test, using Excel 2013 and SPSS 20 software.
Findings: Serratia proteamaculans was identified as producer of the acid phosphatase. The highest MIC and MBC were obtained for Nickel (Ni) and Lead (Pb), respectively. The most metal removal was for Pb. MIC₅₀ of Chrome and Cadmium were obtained less than 0.1mM and 1mM, and their removal percentage by the isolate were 18% and 48%, respectively. According to the FTIR, 988.339cm^-1 wavelength was observed in the cells treated by 5mM Pb that is related to the Pb₃(PO₄)₂. The isolate showed the highest resistance and removal of Pb. The mechanism of Ni removal was associated to the cell surface, while Pb was removed by both of the cells and supernatant containing phosphatase.
Conclusion: Serratia proteamaculans is the phosphate solubilizing bacterium in metal waste. This bacterium produces an enzyme called phosphatase, which is a cause of lead removal.

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 The aim of this study was to compare the accumulation of heavy metals copper, zinc and cadmium and to investigate the changes of metallothionein as a biomarker of contamination in the gill tissue of the ghost crab Ocypode saratan in the two time periods before Monsoon (May) and after Monsoon (November) in mongrove forests. Chabahar and Gwater Bay was done in 2019. The results of the study showed that in both pre-Monsoon and post-Monsoon seasons the pattern of metal accumulation in the gill tissue of the ghost crab is zinc, copper, cadmium.The mean concentrations of copper, zinc and cadmium were obtained in the pre-monsoon and post-monsoon seasons at Chabahar station, 173.6 ± 3.83, 186.43 ± 3.1, 0.095 ± 0.008, respectively and 156.7±4.15 ،175.13 ± 2.8, 0.026 ±0.003 and in Gwater station the average concentrations of copper, zinc, cadmium in the two pre-Monsoon and post-Monsoon seasons were respectively 237.03 ± 6.4, 231.8 ± 1.8, 0.048 ± 0.003 and 205.9 ± 6.34, 253.2 ±  2.13, 0.037 ± 0.015 μg/g dry weight. The mean levels of metallothionein in pre-monsoon and post-monsoon season in Chabahar station were 2.02 ± 0.01 and 0.1 ± 0.06, respectively, and in goiter station were 2 ± 0.02 and 0.12 ± 0.02, respectively. Comparison of metallothionein levels between Chabahar and Gwater stations was not significant (P<0.05). But in both stations separately between the two pre-Monsoon and post-Monsoon seasons, there was a significant difference (P<0.05). Correlation between metallothionein and metals showed that there was no correlation between metallothionein and the studied metals. Therefore, according to the observations, changes in the concentration of metallothionein in this species are not affected by heavy metals and can be due to changes in the environmental conditions of the seasons.

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Status of heavy metal contamination of foods with animal  and aquatic animal origin in Iran The status of heavy metals contamination in foods with animal and aquatic animal origin was studied. In spite of limited studies about foods (except fish and edible marine foods), data shows low contamination of milk with lead but relatively high level of cadmium in this product. Iron contamination was found in high level in milk in the industrial areas. Concentrations of lead and copper were found relatively high in some imported infant milk powder. In some fishing areas in Khazar, the concentrations of lead and cadmium were higher than international standards. The same situation is seen in south sea’s fishery products for lead ,cadmium and nickel.  In a survey in 2005, mercury level was found higher than permitted level in white fish hunted from central Khazar’s fishing area. Shrimp was found relatively free and safe for heavy metal contamination. Other marine foods such as oyster contamination with nickel and vanadium were observed. The sole study about red meat shows lead contamination in low percentage of studied samples.  

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Aims: There is a relationship between environmental pollutants, particularly heavy metals, the risk of water pollution, and diseases in numerous areas. This study aimed to assess the water quality by measuring physio-chemical properties and heavy metals contents at two water stations in Basra city, Iraq.
Materials & Methods: The water samples were collected from two main water stations of Al-Baradi’yah and Al-Jubaila. The pH values, turbidity, and TDS of the water samples were measured, and the heavy metals analysis of Cd, Cr, and Cu was done by the direct extraction/air acetylene flame method using a flame atomic absorption spectrometer. The results of the parameters were compared with the safe limits of WHO.
Findings: The turbidity and total TDS for both stations showed a significant difference, whereas the pH values were not, referring to the raw and tap water at both stations being acidic (pH<7). A significant difference was observed between the level of Cr and Cd in the raw and tap water samples within the acceptable levels of WHO. A significant difference was observed in the Cu levels in Al-Bharatiya (p<0.05). Whereas, no significant difference was observed between the chromium level in the water samples of the Al-Jubaila station (p>0.05). The amount of the Pb was shown a slight increase from the acceptable levels in the tap water at Al-Baradi’yah station and the raw and tap water at the Al-Jubaila site. 
Conclusion: A part of the chemical parameters is within the WHO acceptable limits, except water turbidity and Pb levels.

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Fish are among the organisms that have the ability to bioaccumulate these metals. The aim of this study was to investigate the concentrations of aluminum, vanadium, tin and chromium in the muscle tissue of tapeworm and assess its potential risk. For this purpose, 30 pieces of fish were caught in July 2017 from Bushehr port, Persian Gulf. Samples were prepared according to standard laboratory methods and the concentration of heavy metals was measured using ICP-OES. The concentration of elements in the muscle tissue of fish for human consumption was compared with international standards, as well as the estimated daily, weekly absorption in children and adults, their permissible consumption and risk indicators of consumption of this fish against carcinogenic diseases. The results showed that the mean concentrations of aluminum (23.9 ±10.3), vanadium (0.15 ±0.07), tin (5.41 ±2.2) and chromium (0.34 ±0.12), based on micrograms per gram, fresh weight was observed in muscle tissue.  The absorption of the studied metals in the muscle tissue of fish was Al> Sn> Cr> V. The results showed that the permissible consumption of heavy metals with the exception of aluminum was lower than the standard of the World Health Organization. The calculation of the risk index showed that aluminum in both groups of adults and children and chromium in children have values ​​of more than one, in this regard, with continuous monitoring of heavy metal surfaces in fish offered in the market

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In this study, coastal sediments of Qeshm, Bandar Khamir and Bandar Laft regions in Hormozgan province were studied to determine the level of contamination of heavy metals lead, nickel, zinc, iron and copper by natural processes or human activities. In order to identify environmental pollutants caused by heavy metals, shovel sampling was performed from the sediments of these areas to measure the concentration of heavy metals and determine the enrichment index. The location of the samples was determined using a GPS device and sampling of surface sediments (tidal zone) was performed at 30 stations in the study areas. Atomic absorption of flame spectrometry was used to determine the concentration of heavy metals. The results showed that the mean concentrations of heavy elements lead, nickel, zinc, iron and copper in all sampling stations showed a significant difference (p<0.05). In terms of concentration of studied elements in Qeshm region (copper: 33.76 ± 1.88, zinc: 85.44 ± 2.75, lead: 31.79±  1.23, nickel: 34.17 ± 2.29 and Iron: 38000±691.21 μg/g) compared to Bandar Khamir (copper: 26.84 ± 2.30, zinc: 77.54 ± 2.12, lead: 24.71±  1.37, nickel:25.82± 1.30 and iron: 36810± 482.882 μg/g) and Bandar Laft (copper: 22.74± 2.42, zinc: 65.22±2.61, lead: 19.93± 1.32, nickel: 21.70±2.06 and iron: 35560±1014.56 μg/g) had higher contamination. The results also showed that the metal enrichment factor is low in all sediment samples and in terms of Müller geochemical index, the degree of soil contamination is in the category of non-contaminated soils.