Environmental Risk Assessment of Heavy Metals in Road Dust of Isfahan Metropolitan

Heavy metals (HMs) are one of the main pollutants in the environment, which have adverse environmental and health effects. Therefore, their risk assessment is an important environmental issue. In this study, the environmental risk of ۶ HMs including Pb, Co, As, Ni, Cr and Cd in road dusts of ۴ sampling stations (Jomhori Square, Azadi Square, Segzi and Gavkhuoni Wetland) was investigated. The ecological risk of metals was assessed using the pollution index (PI), enrichment factor (EF) and geo-accumulation index (Igeo) as well as pollution load index (PLI). The health risk of each metal was assessed separately in two cases of carcinogenic risk and non-carcinogenic risk for adults and children. The mobility of each metal was calculated using the Mobility Factor (MF) index. The results of PI, EF and Igeo indices showed that Cr and Ni had the highest and lowest risk, respectively. Besides, the results of PLI showed that Jomhori Square and Azadi Square stations were more polluted than the other stations. According to the results of health risk assessment, Cr and Cd showed the highest non-carcinogenic risk, whereas among the elements, the carcinogenic risk of Cr exceeded the carcinogenic risk limit. The mobility of elements followed the decreasing trend of Pb> Ni> Co> As> Cd> Cr. Considering the results, management and prevention of road dusts and particles are highly recommended.