Evaluating the rate of atmospheric dust deposition in Isfahan city

Abstract

Dust deposition occurs extensively in arid and semi-arid areas. Dust particles have a high adsorption capacity and therefore high pollution potential. The present study investigates seasonal and spatial variations in atmospheric dust deposition rate (DDR) and the concentration of dust-borne heavy metals in the eastern part of Isfahan as well as Segzi plain located in the central part of Iran. Dust samples were collected from nine different sites on a monthly basis from December 2016 to September 2017 using glass trays. The total concentrations of Pb and Zn were measured. The lowest concentrations of Pb with 16.95 ± 25.21 mg kg^–1 and Zn with 2.34 ± 0.80 mg kg^–1 were recorded. The lowest value of seasonal DDR (0.7 ± 0.1 ton km^–2 season^–1) was observed in the winter due to low amount of precipitation, and the highest value (40.8 ± 0.1 ton km^–2 season^–1) was recorded in the summer. Spatial distribution of dust-borne Pb and Zn followed almost the same trend and the highest concentrations were observed in the western parts of the study area. It seems that fossil fuel, traffic, and industrial activities are the most important anthropogenic factors contributing to dust-borne heavy metals in the study area.