JWSS - Journal of Water and Soil Science

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.

Drilling material from the tunnel of the Tehran-Shomal highway was estimated to be about 2.5 Million Cubic Meters by the project authorities. Sadly, from the beginning, the drilling materials had been deposited on the open space in the floodplain of the Chaloos river with slightest environmental considerations. During the previous years, weathering and leaching from the drilled materials besides the discharge of drain water from the tunnel had led to seriouse contaminations and the deterioration of the water quality of the Chaloos river. In this paper, the ecological risk of nonorganic pollutants due to drilled materials was investigated. The sampling was done from the excavated materials and river sediment in five different locations throughout a complete year. From the many pollutants, Nickel, Cadmium and Copper were chosen to be investigated. The results showed that almost 15 percent of the samples had a high degree of pollution, while 60 percent of them were clean and the other 25 percent included the highly contaminated ones. All samples were also estimated to have a low to high ecological risk.