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Showing 3 results for Toxic Elements
Spatial Variability Analysis of Heavy Metals in Street Dusts of Kashan City
Q Moradi, R Mirzaei,
Volume 9, Issue 4 (3-2017)
Abstract

Background and Objective: Street dust is consisting of solid particles with complex compositions which can be an appropriate indicator to determine urban environmental contamination. Therefore, the purpose of this study was to determine spatial patterns and heavy metals contamination in the street dusts of Kashan.   

Materials and Methods: A total of 48 urban street dust samples were collected and total concentrations of Pb, Cu, Zn, Fe, Cr, Ni, and Cd were determined in the dust samples. The geoaccumulation index was applied to assess heavy metals contamination. In addition, the spatial patterns of heavy metals concentrations in the street dust were determined using GIS.

Results: The results showed that the average concentrations of Zn, Cd, Cr, Fe, Ni, Pb and Cu in the street dust samples were 237.21, 0.43, 37.12, 16589.77, 13.62, 45.18 and 45.58 mg/kg, respectively. The average concentrations of Pb, Cu, Zn, and Fe were higher than their local background values. Based on geoaccumulation index, the heavy metals in the street dust were in the following decreasing order: Pb > Zn > Cu > Ni > Cd > Cr.  According to the spatial analysis results, higher concentrations of heavy metals were observed in the city center and Kashan-Qom highway; whereas, lower concentrations were found in the residential regions.

Conclusion: Based on the obtained results, it seems the high concentrations of Pb, Zn and Cu and to a lesser extent Fe and Cd concentrations in the dust samples was derived from anthropogenic activities; whereas the concentration of Cr and Ni has been mostly affected by natural sources. The high concentrations of heavy metals in the street dusts of Kashan could be attributed to vehicle emissions and industrial activities.


Evaluation of contamination of Qeshm island coastal sediments with Cu, Pb, Zn, Cd, Ni, Cr using sediment quality indices
P Nourozifard, S Mortazavi, S Asad, N Hassanzadeh,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Marine sediments are the most important component of monitoring the health of aquatic ecosystems. The present study uses sediment quality indices to determine the contamination status in Qeshm ecosystems and to evaluate the toxicity of the elements studied for its organisms.
Materials and Methods: Sampling of surface sediments of seven stations was carried out on Qeshm coastal areas. The samples were digested by a combination of nitric acid and perchloric acid, and the concentration of metals was measured by atomic absorption spectrometry.
Results: The results of modified Hazard Quotient indicated a high pollution rate for copper and nickel metals in most stations, which was consistent with the results of the Potential Contamination Index in relation to nickel metal. Additionally, the results of the Potential Contamination Index and Contamination Factor agreed with the amount of lead element. According to the results, the pollution index of Hamoon Lake and Zakeri pier was highly contaminated and Modified Pollution Index demonstrated a contamination in Romacha, Hamoon Lake, Zakeri pier and Nazes areas. The enrichment factor associated with contamination regarding most of the heavy metals confirmed the indices used to evaluate the comtamination in the study area.
Conclusion: Due to the higher concentrations of the heavy metals in the sediments than that of the quality guidelines, the high toxicity of sediments for the aquatic ecosystems was confirmed. The Romachah, Hamoon, Zakeri stations showed higher pollution levels and sever toxicity for aquatic life. Copper, nickel and in some cases lead, were the main heavy metals that contaminated the sediments in the region.
 

Investigating the amount of heavy metals in compost produced in the compost industries of Mazandaran province
Mohammadali Zazouli, Samaneh Dehghan, Mahdieh Mohammadi Alashti, Afsaneh Fendereski, Reza Dehbandi,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: One of the main limitations of using compost is the possibility of heavy metals with high concentrations. Unlike organic contaminants, these elements resist decomposition by microorganisms and, when present at elevated levels, pose a toxicity risk to soil, plants, aquatic ecosystems, and human health.
Materials and Methods: This study was a descriptive cross-sectional study conducted in 2021-2022w. Samples were collected from three compost factories in Mazandaran (Babol, Behshahr, and Tonekabon) using random sampling methods and prepared according to the acid digestion method (National Standard Institute 5615). The concentration of heavy metals in the samples was measured using an ICP-OES.
Results: The average concentration of arsenic, zinc, lead, cadmium, cobalt, chromium, copper, and nickel in the analyzed samples were 1.38±3.47, 490±151.5, 74±12, 2.56±0.65, 4.5±1.46, 31.72±16.47, 186.11±49.9, 22.72±4.2 mg/kg dry weight of compost, respectively. The average concentration of heavy metals in different cities was compared using the Kruskal-Wallis test, based on which the concentration of heavy metals in none of the cities was significantly different from each other (p>0.05).
Conclusion: The concentration of heavy metals in the investigated compost samples was lower than the limits specified in both domestic and international standards. Therefore, the final product of the examined compost factories meets the health standards for heavy metals and is safe for use in environmental applications.
 

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