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A B S T R A C T Wetlands hold a principal position in storing food for primary producers, so they are not able to bear the pressure. The slightest disturbance, hence, may harm wetlands and cause detrimental effects. The present study aims at monitoring heavy metals and evaluation of the sediment quality index of Shadegan wetland in Iran. Thus, a sampling of surface sediments of the wetland was performed at ten stations with three replications; after the preparation of samples with aqua regia, the concentrations of heavy metals were measured by atomic absorption spectroscopy. The quantification of sediment pollution using the contamination factor, contamination degree, pollution load index, ecological risk assessment index, and ecological toxicity of heavy metals in the region were all carried out. The results of Cf and Cd showed that the degree of zinc and copper contamination is low; however, the degree of lead contamination is moderate. Moreover, the obtained PLI was less than 1 indicating a lack of sediments contamination with heavy metals. The RI was less than 150 indicating a low risk of contamination. In addition, comparing the concentrations of elements with National Oceanic and Atmospheric Administration and Sediment Quality Guidelines showed slightly toxic and non-toxic sediments, respectively. Finally, based on a mixture of effect range median, all sediment samples are placed in the first category with less than 12% toxicity probability.

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Quality Evaluation and Study of Ecological Toxicity of Heavy Metals in Shadegan Wetland *Dr.Samar Mortazavi1, Dr.Mohsen Tizhoosh2, Dr.Zahra Cheraghi3 1, 2, 3Department of Environmental Science, Faculty of Natural Recourses and Environmental Science, Malayer University, Iran 1 E mail: mortazavi.s@gmail.com, 3 E mail: nejatsan@tums.sc.ir A B S T R A C T Wetlands hold a principal position in storing food for primary producers, so they are not able to bear the pressure. The slightest disturbance, hence, may harm wetlands and cause detrimental effects. The present study aims at monitoring heavy metals and evaluation of the sediment quality index of Shadegan wetland in Iran. Thus, a sampling of surface sediments of the wetland was performed at ten stations with three replications; after the preparation of samples with aqua regia, the concentrations of heavy metals were measured by atomic absorption spectroscopy. The quantification of sediment pollution using the contamination factor, contamination degree, pollution load index, ecological risk assessment index, and ecological toxicity of heavy metals in the region were all carried out. The results of Cf and Cd showed that the degree of zinc and copper contamination is low; however, the degree of lead contamination is moderate. Moreover, the obtained PLI was less than 1 indicating a lack of sediments contamination with heavy metals. The RI was less than 150 indicating a low risk of contamination. In addition, comparing the concentrations of elements with National Oceanic and Atmospheric Administration and Sediment Quality Guidelines showed slightly toxic and non-toxic sediments, respectively. Finally, based on a mixture of effect range median, all sediment samples are placed in the first category with less than 12% toxicity probability. CONTEMPORARY URBAN AFFAIRS (2017) 1(3), 66-72. https://doi.org/10.25034/ijcua.2018.3683 www.ijcua.com Copyright © 2017 Contemporary Urban Affairs. All rights reserved. 1. Introduction Aquatic ecosystems, as one of the main environmental features, are a key supplier of food and a roof over aquatic organism’s head; on the other hand, they are also large sources for a wide range of pollutants. Since these ecosystems withstand a high capacity for development, they are subject to more serious risk due to the pollutants. Domestic and industrial sewage discharges, the growth in urbanization, and industrial activities in coastal areas are severe threats to the safety of the coastal environment and aquatic ecosystems. Among the existing pollutants in the sewage, heavy metals can be mentioned, especially the ones that play important roles in society as the main raw materials for many industries.(Zhuang and Gao, 2014; Caerio,et l, 2005) Some, such as copper and zinc, play a vital role in the metabolism of the human body.However, in high concentrations, they turn into toxic substances.Being attributable to high persistence toxicity, solubility low absorption and accumulation in the bottom sediments, heavy metals cause contamination in aquatic environments.(Caerio,et al., 2005) The biological toxicity and bio-magnification in food chains have made the issue of heavy metals a significant global problem. (Förstner and Wittmann, 1983)the ways to clean up contaminated sediment are mostlycostly, and in some cases impossible.Hence, the evaluation of sediment contamination in the aquatic environment, identifying sources of pollution, applying management policies, and processes to reduce a number of pollutants into the aquatic environment is more important than focusing on clearing techniques. Many studies have been done in this regard, among which the one carried out by Zarezadeh and Rezai, (2014) can be mentioned through which they have investigated the heavy metals in the sediments bed of mangroves Khurgabrik in Jack Port involving Molar coefficient, the degree of reformed contamination, and ecological risk assessment index.Vaezietall,(2014) have investigated Mollar environmental index, pollution load, ecological toxicity in sedimentsin Mosa Firth, Persian Gulf. Chaiet al., (2016) explored heavy metal pollution in river sediments in Serbia by calculating the pollution load index and ecological risk assessment. Chai and et al. Sakan and Dordevic, (2015) examined the index of enrichment, molar and ecological risk assessment in XiangjiangRiver sediments. In the present study, the types of sediment geochemical index have been determined.Moreover, the ecological risks have been assessed, and ecological toxicity of sediments with heavy metals, namely lead, zinc and copper have been analyzed. The results have been compared with the standards of NOAA and SQG, respectively. 2. Materials and Methods 2.1Area of study The ShadeganWetland with an area of approximately 400,000 hectares in the range of coordinates 48 degrees 17 minutes and degrees 50 minutes east, 30 degrees 17 minutes 30 degrees and 58 minutes north is located in Khuzestan province, Iran, and has been recognized as an international wetland in the Ramsar Settlement in 1972.(Nasirianet al., 2015) Figure 1.The location of the Shadegan wetland (left) [Source: Google map], and the locations of the sampling stations within the wetland (right). 2.2 Sampling and Preparing Samples As per available access points, asampling of surface sediments was carried in 10 stations with three replications and recording the geographic coordinates (table 1). For the purpose of preparation, the sediment samples were dried in an oven at a temperature of 105° C.Then, they were crushed in a stone mortar and screened by a 63-micron sieve.

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Quality Evaluation and Study of Ecological Toxicity of Heavy Metals in Shadegan Wetland *Dr.Samar Mortazavi1, Dr.Mohsen Tizhoosh2, Dr.Zahra Cheraghi3 1, 2, 3Department of Environmental Science, Faculty of Natural Recourses and Environmental Science, Malayer University, Iran 1 E mail: mortazavi.s@gmail.com, 3 E mail: nejatsan@tums.sc.ir A B S T R A C T Wetlands hold a principal position in storing food for primary producers, so they are not able to bear the pressure. The slightest disturbance, hence, may harm wetlands and cause detrimental effects. The present study aims at monitoring heavy metals and evaluation of the sediment quality index of Shadegan wetland in Iran. Thus, a sampling of surface sediments of the wetland was performed at ten stations with three replications; after the preparation of samples with aqua regia, the concentrations of heavy metals were measured by atomic absorption spectroscopy. The quantification of sediment pollution using the contamination factor, contamination degree, pollution load index, ecological risk assessment index, and ecological toxicity of heavy metals in the region were all carried out. The results of Cf and Cd showed that the degree of zinc and copper contamination is low; however, the degree of lead contamination is moderate. Moreover, the obtained PLI was less than 1 indicating a lack of sediments contamination with heavy metals. The RI was less than 150 indicating a low risk of contamination. In addition, comparing the concentrations of elements with National Oceanic and Atmospheric Administration and Sediment Quality Guidelines showed slightly toxic and non-toxic sediments, respectively. Finally, based on a mixture of effect range median, all sediment samples are placed in the first category with less than 12% toxicity probability. CONTEMPORARY URBAN AFFAIRS (2017) 1(3), 66-72. https://doi.org/10.25034/ijcua.2018.3683 www.ijcua.com Copyright © 2017 Contemporary Urban Affairs. All rights reserved. 1. Introduction Aquatic ecosystems, as one of the main environmental features, are a key supplier of food and a roof over aquatic organism’s head; on the other hand, they are also large sources for a wide range of pollutants. Since these ecosystems withstand a high capacity for development, they are subject to more serious risk due to the pollutants. Domestic and industrial sewage discharges, the growth in urbanization, and industrial activities in coastal areas are severe threats to the safety of the coastal environment and aquatic ecosystems. Among the existing pollutants in the sewage, heavy metals can be mentioned, especially the ones that play important roles in society as the main raw materials for many industries.(Zhuang and Gao, 2014; Caerio,et l, 2005) Some, such as copper and zinc, play a vital role in the metabolism of the human body.However, in high concentrations, they turn into toxic substances.Being attributable to high persistence toxicity, solubility low absorption and accumulation in the bottom sediments, heavy metals cause contamination in aquatic environments.(Caerio,et al., 2005) The biological toxicity and bio-magnification in food chains have made the issue of heavy metals a significant global problem. (Förstner and Wittmann, 1983)the ways to clean up contaminated sediment are mostlycostly, and in some cases impossible.Hence, the evaluation of sediment contamination in the aquatic environment, identifying sources of pollution, applying management policies, and processes to reduce a number of pollutants into the aquatic environment is more important than focusing on clearing techniques. Many studies have been done in this regard, among which the one carried out by Zarezadeh and Rezai, (2014) can be mentioned through which they have investigated the heavy metals in the sediments bed of mangroves Khurgabrik in Jack Port involving Molar coefficient, the degree of reformed contamination, and ecological risk assessment index.Vaezietall,(2014) have investigated Mollar environmental index, pollution load, ecological toxicity in sedimentsin Mosa Firth, Persian Gulf. Chaiet al., (2016) explored heavy metal pollution in river sediments in Serbia by calculating the pollution load index and ecological risk assessment. Chai and et al. Sakan and Dordevic, (2015) examined the index of enrichment, molar and ecological risk assessment in XiangjiangRiver sediments. In the present study, the types of sediment geochemical index have been determined.Moreover, the ecological risks have been assessed, and ecological toxicity of sediments with heavy metals, namely lead, zinc and copper have been analyzed. The results have been compared with the standards of NOAA and SQG, respectively. 2. Materials and Methods 2.1Area of study The ShadeganWetland with an area of approximately 400,000 hectares in the range of coordinates 48 degrees 17 minutes and degrees 50 minutes east, 30 degrees 17 minutes 30 degrees and 58 minutes north is located in Khuzestan province, Iran, and has been recognized as an international wetland in the Ramsar Settlement in 1972.(Nasirianet al., 2015) Figure 1.The location of the Shadegan wetland (left) [Source: Google map], and the locations of the sampling stations within the wetland (right). 2.2 Sampling and Preparing Samples As per available access points, asampling of surface sediments was carried in 10 stations with three replications and recording the geographic coordinates (table 1). For the purpose of preparation, the sediment samples were dried in an oven at a temperature of 105° C.Then, they were crushed in a stone mortar and screened by a 63-micron sieve.

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This page is a summary of: Quality Evaluation and Study of Ecological Toxicity of Heavy Metals in Shadegan Wetland, Journal of Contemporary Urban Affairs, September 2017, Journal of Contemporary Urban Affairs (JCUA), DOI: 10.25034/ijcua.2018.3683.
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