Geochemistry of street dust in Tyumen, Russia: influence of traffic load

Abstract

The article presents the results of studying the composition of road dust in Tyumen, a large city in Western Siberia. On roads with different tra c intensities, 50 dust samples were taken, in which the particle size distribution, pH, and organic carbon content were determined. The content of 62 major and trace elements was studied using atomic emission spectrometry (AES-MS) и inductively coupled plasma spectrometry (ICP-MS). It was revealed that the dust has an alkaline reaction pH = 7.4 -10.2, low organic carbon content (0.07 -2.9%). The particle size distribution is dominated by particles PM = 100-250. The content of small particles (PM <2 and PM2-10) representing the greatest environmental hazard is minimal on roads with an average tra c intensity. Studies have shown that the main road dust pollutants in Tyumen are Ni, Sb, Cr, Zn, Co. The average geoaccumulation index (Igeo) values are ranked as Ni (2.2) > Sb (1.5) > Cr (1.3) > Zn (0.4) > Co (0.4) > Cu (0.2). The contamination evaluation through enrichment factor (EF) calculation showed that road dust is highly enriched in Ni and signi cantly in Cr and Sb. More than 80% of Zn, Co, Cu and more than 90% of Ni, Sb, Cr come from anthropogenic sources. By the content of Ni and Cr, Tyumen surpasses all cities of the Earth where similar studies were carried out. The high Ni content is associated with the composition of local soils and roadways, increased content in vehicle exhaust gases, and abrasion of metal parts. Calculations of the total pollution indices (IPI and Zc) showed that the level of road dust pollution in most of Tyumen's territory is average, moderately hazardous.