JWSS - Journal of Water and Soil Science

Dust particles are suspended particles created from various natural and anthropogenic sources. Dust particles contain toxic metals, such as mercury (Hg), which can have harmful effects on the human health. In this study, to investigate the contamination level of Hg in the street dust in Ahvaz, 95 dust samples were collected from the pavements in the main streets. The concentration of Hg in the collected samples was determined by the atomic absorption method (ASS). The contamination level was estimated based on indicators such as contamination factor (Cf), enrichment factor (EF), geo-accumulation index (Igeo) and ecological risk index (Er). The concentration value of mercury ranged from 0.02 to 8.75 mg/kg with an average of 2.53 mg/kg. The results of pollution indicators showed that the level of Hg contamination in the street dust of Ahvaz was a high level of contamination. In addition, the results of ecological risk assessment indicated that the ecological risk of Hg in the study area was very high. Spatial distribution pattern of Hg concentration showed that in areas with high population density, high traffic volume and industrial activities, there was a high pollution level of Hg.

Soil pollution by heavy metals is a serious environmental problem that threatens the human health. The present study was carried out to investigate and detect the contamination of heavy metals of arsenic, copper, lead, zinc and iron due to human and natural activities in the sediment of lake bed and the surface soils of the eastern part of Urmia Province, West Azarbaijan Province. A total of 20 soil samples and surface deposition from the depths of 0 to 30 cm were collected randomly from the studied areas. After preparing the samples, extraction was carried out to determine the concentration of the heavy metals in the soil by using hydrochloric acid and nitric acid, and the total concentration of metals was measured using ICP-OES. The results of the calculation of the contamination factor showed that copper, iron, zinc and lead in the class of low and medium pollution and arsenic in 65.5% of the samples were very high in the class. The high concentrations of copper, lead and zinc contamination in the margin of the city and the contamination of arsenic in the lake bed were observed. The analysis of the contamination factor maps and contamination index with land use and geological map showed that copper, lead and zinc were mostly affected by human activities and arsenic influenced by the maternal materials in the region.

Dusts contain heavy metals such as Pb, Zn, Cu, Cr, Cd and As that can threat human's health and environment. Therefore, the spatial distribution of heavy metals concentration and soil pollution monitoring and environmental quality protection seem to be essential. To assess heavy metals pollution level in Ahvaz street dust, 115 street dust samples were collected from main pedestrians. The samples were analyzed by Atomic Absorption (AAS). The pollution level was estimated based on the geo-accumulation index (I_geo), contamination factor (CF) and the enrichment factor (EF). The average concentration values of Pb, Zn, Cu, Cr, Cd and As were found to be 197.6, 150.1, 179.7, 101, 5.6 and 14.2 mg/kg, respectively. Pearson's correlation coefficient also indicated that Pb, Zn, Cu and Cr had a significant correlation showing similar possible anthropogenic sources. On the other hand, Cd and As showed a lower correlation with other metals, indicating that they belonged to the geogenic sources. The results of contamination factor, enrichment factor and geo-accumulation index also indicated that Pb, Zn, Cu and Cd had a high contamination level.  Also, areas with high population density, heavy traffic volume, and industrial activities exhibited a high level of heavy metals contamination.