16 research outputs found
Quality Evaluation and Study of Ecological Toxicity of Heavy Metals in Shadegan Wetland
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.
Copyright © 2017 Journal of Contemporary Urban Affairs
Quality Evaluation and Study of Ecological Toxicity of Heavy Metals in Shadegan Wetland
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
Ecological Risk Assessment, Interpolation, and Pollution Source Identification of Toxic Elements in Soils and Leaves of the Vineyard of Malayer County
Grape is a strategic product in the county of Malayer. Despite the great importance and existence of polluted resources in the vicinity of vineyards in Malayer, there are few studies conducted in this regard. To evaluate the pollution level of toxic elements in these vineyards, 20 sampling stations were selected randomly and samples of garden soil and leaves of grapevine species were collected. After the acidic digestion of the samples, the concentrations of the heavy metals were measured using atomic absorption spectrometer. Then, the indices of contamination factor (Cf), geo-accumulation index (Igeo), biological accumulation coefficient (BAC), and ecological risk index (RI) were calculated. According to the results obtained for Igeo and Cf indices, the soil in the study region was moderately contaminated with copper. However, the ecological risk index and BAC of the studied region were low. To investigate the spatial distribution of copper in the studied region, the spatial distribution map was prepared. To locate the source of copper contamination and investigate the effect of various land uses on the amount of contamination, land use map (LUM) of vineyards was generated. To this end, images were downloaded from Landsat Satellite, and after the exertion of various corrections on the images based on the supervised classification method, the LUM with agricultural, residential, vineyard, brick furnace and pasture classes was prepared. The comparison of the LUM and the copper contamination map illustrated that the copper contamination was higher in the places with urban and adobe furnace land-use types
The risk assessment of Lead, Cadmium and Zinc in the two edible fishe species (Carcharhinus limbatus) and (Epinephelus coioides) of Persian Gulf in 2016
Abstract Background and aim:With the development of coastal industries and cities, aquatic ecosystems and organisms are exposed to contaminants, especially heavy metals. Heavy metals accumulate in aquatic tissues and eventually enter the food chain and human body. The aim of this study was to investigate the concentrations of lead, cadmium and zinc in muscle of two fish species (Cicharhinuslimbatus) and (Epinepheluscoioides) from the Persian Gulf. Materials and Methods:For this purpose, 15 samples of muscle were takenfrom each fish, and by wet digestion method, the concentration of Lead, Cadmium and Zinc were measured by atomic absorption device. Statistical analysis of the obtained results was carried out by SPSS software (v.20) using Shapiro-Wilk, One Sample T-Test and Binomial Test. Results:According to the results, the mean concentrations of lead, zinc and cadmium were 5.55, 8.40, 0.202 mg/kg and 14.9, 13.54, 277.0 mg/kg, in Cicharhinuslimbatus and Epinepheluscoioides respectively. The mean concentration of lead in both fisheswashigher than the WHO standard. The HI index for Cicharhinuslimbatus and Epinepheluscoioides is less than 1. Conclusion:With respect to the obtained results, the absorption of these metals does not threaten consumers. However, the proportions of condition factor for Cicharhinuslimbatus and Epinepheluscoioides are not within the standard range and indicate the inappropriate conditions of this habitat for aquatic health and environmental stresses
Spatiotemporal variation analysis of water quality using multivariate statistical methods, Case study: Koohsar Lake, Western Iran
The study of water resources and reviewing periodic and spatial changes in the quality of water in aquatic ecosystems are of important necessity due to the reasons including, climate change, water resource constraints, and increased human water requirements. Given the fact that Koohsar Lake water in Zanjan Province is one of the sources of drinking water in the region, the present study aimed to measure the values of 19 parameters of water quality in two seasons of summer and spring at four stations. The samples were transferred to a laboratory under steady-state and sunlight conditions and analyzed according to the standard methods. Statistical analyses were performed using SPSS software. Moreover, the study applied factor analysis using principle components to analyze the variance of data. In addition, the values of the parameters were compared with the permissible limits of drinking water of national standard. The results indicated a significant difference between the parameters studied at stations and different sampling times by repeated measurements. The results of factor analysis also showed that the total of three main components in the summer and spring were 96.573% and 98.581% of the variance of data respectively. The main parameters in the summer included Chlorophyll-a, Na, DO, pH, BOD, COD, TDS, EC, and nitrate. Also, EC, TDS, alkalinity, pH, COD, BOD, Ca, and ammonia were found as the main parameters in the spring. Also, it was found that except for the pH in the spring and at stations 3 and 4 which were below the standard minimum, the lake water in both seasons and all stations, in terms of parameters, was within the standard range and exhibited a good quality for drinking. Implications are discussed in light of the study findings
Survey of Modified Hazard Quotient, Potential Ecological Risk Factor and Toxicity Units of Heavy Metals in Surface Sediments of Some Wetlands of Iran
Background & Aims of the Study: The present research aims to use sediment quality indices in the assessment of toxicity and ecological risk factors of heavy metals Pb, Cu and Zn in Anzali, Meighan, Shadegan and Hashilan wetlands.
Material & Methods: Given the environmental conditions, surface sediments in 71 diverse stations were sampled in three replications. Having preparation and subjected to acid digestion of sediment samples, 0.5 g of each sample was digested with a mixture of nitric acid and super-pure ratio of 4 to 1 perchloric acid. Finally the concentration of these metals was determined using the contrAA 700 Analytic Jena Atomic absorption spectroscopy.
Results: The results of the potential acute toxicity and the ecological risk of the considered metals indicated low toxicity and risk. Also, the outcomes of Modified Hazard Quotient (mHQ) indicated a low to moderate pollution risk in Anzali wetland, very low pollution in Shadegan wetland, and in Meighan wetland for Pb and Cu, low pollution to very low and for Zn metal it showed low to high pollution. In Hashilan wetland Modified Hazard Quotient for Pb and Zn showed very low pollution and for Cu it was negligible to moderate among others.
Conclusion: However, the growth of urbanization and the increase of various anthropogenic activities such as agriculture, urban, industrial ... within the wetland basin (draining area) and entry of untreated urban and rural sewage requires urgently continuous monitoring of wetlands as well as the assessment of their health risks and ecological risk among others
Assessment of Ecological Hazard of Heavy Metals (Cr, Zn, Cu, Pb) in Surface Sediments of The Bashar River, Yasouj, Iran
Background & Aims of the Study: Heavy metals pollution in aquatic ecosystems threats living organisms' health and environment. Hence, the present study aims to assess concentration of lead, chromium, copper, zinc and their ecological risk in the surface sediments of the Bashar River during the summer and winter seasons.
Materials & Methods: This is a field study; sampling of surface sediment was done in 8 stations in 2016. The samples were digested by the composition of ratio of 1:4 Percholoric acid and Nitric acid and then were analyzed by atomic absorption spectrophotometry. Statistical analysis of all data was also done using SPSS 21 and various criteria were used to fine the amount of contamination of heavy metals.
Results: The results showed that the average total concentration of Zn, Cu, Pb and Cr in the summer were (48.16, 39.2, 14.45 and 10.35) and as for winter was (39.88, 26.93, 12.23 and 10.301) mg/kg respectively. In addition, evaluating geo-accumulation indexes, pollution load and pollution factor indicated the low pollution status of the area in both seasons.
Conclusions: According to the results, pollution status and the RI level of heavy metals in the Bashar River is low and similar in summer and winter. Also, the sources and changes in elements concentration in different stations and seasons may be as a result of the institution of various urban and industrial contamination sources along the river, and its physical and geo-biochemical changes in water flow volume entering the river, especially in winter
Determination of Heavy Metals Pollution Load Index in Sediments and Aquatic Plant (Nasturtium microphyllum) in Bashar River, Yasuj
Background: Pollution of aquatic ecosystems to heavy metals is one of the most important threats of human health and its food chain. Thus, in this study the concentration of heavy metals (lead, chromium, copper, and zinc) in Surface sediments and Nasturtium microphyllum was investigated in order to assessment their effects and ecological risk.
Methods: In order to assess the concentration of metals, 8 stations along the river were selected and in each station two samples of sediment and plant were taken. After preparinng and digesting the samples, the concentrations of these metals were determined using Atomic absorbtion.
Results: The average of total concentration of detected metals Cr, Pb, Cu and Zn in sediment (10.33 ± 0. 02 > 13.35±1.10 > 33.07 ±6.13 > 44.02± 4.13) mg/kg respectively. In addition, evaluation indicators such as; Pollution Load Index (PLI) and ecological risk represents less pollution in the region. Also, the environmental risk of metals in the region was evaluated as (Cu> Pb> Zn> Cr). The results of concentration of metals in different organs of root, stem and leaf of Nasturtium microphyllum showed that the highest average accumulated concentration for each metal was obtained in stem, root and leaf, respectively.
Conclusion: According to the results, the pollution and ecological risk of metals in the region is low evaluated. The results of this study confirm the use of Nasturtium microphyllum as a heavy metals accumulation species and a suitable indicator for their biomonitoring
Risk Assessment of Non-Carcinogenic Effects of Heavy Metals from Dez River Fish
Background and purpose: Considering the many benefits of fish in the food basket, it is essential to assess its health risk. The purpose of this study was to examine the risk assessment effects of heavy metals from Dez river fish.
Materials and Methods: In order to determine the concentration of heavy metals in the edible parts of fish, 80 samples were caught from the local species of Dez River, and after the bioassay, they were digested using the combination of 1:4 perchloric acid and nitric acid; afterwards, the concentration of heavy metals was measured by means of atomic absorption spectrometry.
Results: The results showed that there was a positive correlation between accumulating metals and condition factor, especially with regard to zinc and cadmium; this correlation was more likely to be observed for the Capoeta trutta species. Also, comparing the daily and weekly intake of heavy metals with the rate limits of PTDI and PTWI has shown that the absorption value of metals were considerably lower than the specified limit.
Conclusion: The high level of CRlim showed safe consumption of fish in Dez River considering the potential health risk. Zinc and cadmium had also the highest share percent in finding out the TTHQ index. Also, the Target Hazard Quotient and Total Target Hazard Quotient were not higher than the one for all of the studied metals and species. The Capoeta trutta and Carasobarbus luteus species had the most and least amounts of TTHQ index. Finally, comparing the means of metal concentrations with standard ones has shown that the concentrations of zinc and cadmium were higher than the United Kingdom Ministry of Agriculture Fisheries and Food, Food and Drug Administer, Food and Agriculture Organization, FAO/WH limits and the international standards of European Commission and National Health and Medical Research Council, respectively.
 
Human Health Risk of Some Heavy Metals in the Surface Soil of Arak Plain
Background & Aims: Soil contamination with heavy metals is becoming a major environmental concern today. Therefore, the present study was conducted to evaluate the health risks of heavy metals in the surface soil of Arak plain.
Materials and Methods: Soil samples were collected by random sampling from 30 stations with three replications from a depth of 0-20 cm. After acidic digestion of the samples (HNO3: HclO4: HF = 3: 2: 1), the concentrations of lead (Pb), zinc (Zn), copper (Cu), nickel (Ni), and cadmium (Cd) were determined by atomic absorption spectrometry. Finally, the carcinogenic and non-carcinogenic hazards of heavy metals in surface soils for human health were assessed through ingestion, inhalation, and dermal absorption using the method recommended by the EPA for children and adults.
Results: The results indicated that the average total concentrations of heavy metals of Pb, Zn, Cu, Ni, and Cd in the study area are 10.01, 13.83, 39.82, 43.41, and 11.9 mg/kg, respectively. The highest and lowest average daily dose (ADD) of elements in both age groups were related to Ni metal from the ingestion route and Cd metal from the inhalation tract, respectively. Further, the non-carcinogenic risk hazard quotient (HQ) of heavy metals in all three paths was less than 1. The results of the non-carcinogenic hazard index (HI) risk assessment of all three pathways separately for each metal and for both groups of children and adults showed metal values as Cu > Cd > Zn > Pb > Ni, respectively. In addition, the results of the carcinogenic risk index (RI) in the surface soil of Arak plain revealed that Ni and Pb have the highest and the lowest carcinogenic risk, respectively.
Conclusion: Finally, considering the size of the study area and proving the carcinogenic hazards and risks in the area, it is necessary and important to pay attention to health and environmental principles