Potential Ecological Risk Assessment of Arsenic and Some Heavy Metals in Street Dusts Collected from Industrial, Commercial and Residential Areas of City of Hamedan in 2019 Using the Ecotoxicological Criteria

Trace elements are the common pollutants of soils, sediments and street dust in the urban environment, which pose a potential threat to public health. Therefore, this study was conducted to potential ecological risk assessment of As, Cd, Cr, Cu, Pb, Ni and Zn in street dust collected from industrial, commercial and residential areas of city of Hamedan in 2019 using ecotoxicological criteria.

In this descriptive study, a total of 378 street dust specimens were collected from 18 sampling sites. After acid digestion of dust specimens, the element contents were determined using ICP-OES. Also, potential ecological risk factor (Er), risk index (RI) and the ecotoxicological criteria were calculated. All statistical analyses were done by SPSS software.

Based on the results obtained, the mean contents of the examined elements in dust specimens (mg/kg) were 2.31, 0.225, 41.3, 48.8, 65.2, 79.2 and 211 for As, Cd, Cr, Cu, Pb, Ni and Zn, respectively. The computed values of Er showed that, factor values were decreased in the order Cd > As > Pb > Ni > Cu > Zn > Cr. Also, the mean values of RI with 77 represented that, all the examined elements have the "low potential ecological risk". Moreover, the computed values of the ecotoxicological criteria showed that the street dust specimens of the study area were non-polluted with trace elements.

Although the examined elements have been shown the low potential ecological risk, Cd with 38.2% of the mean values of RI showed significant potential to occurrence the ecological risk, therefore, source identification and sources control of this element and also periodic monitoring of contaminated soils are recommended for maintenance of public health.