To investigate the atmospheric dust characteristics and the possibility of tree leaves as a biomonitor of dust pollution, this study was carried out in Isfahan city and its surrounding desert areas. Dust samples were collected monthly from June 2012 to May 2013, from 67 sites using flat glass surfaces placed on the roof of one-floor buildings. Surface soils were also collected from the same sites. Plane tree leaves were sampled monthly from May to Nov. 2012 from 21 sites in Isfahan city. Spatial and temporal variations of dust characteristics such as deposition rate, physicochemical, mineralogical and magnetic properties and heavy metal geochemistry were analyzed. Our results showed dust deposition rate varied in time and space depending on climatic parameters and distance from desert areas. The dominant particle size was silt and particle size distribution and dust mineralogy showed similar trend in different seasons. Dust heavy metal concentration, its flux and also their temporal and spatial distribution were affected by different anthropogenic activities and climatic parameters in the area. Based on our results, the eastern desert areas of the study region seem to be the major dust production source. The correlation between heavy metals deposited on the leaf surfaces and that of atmospheric dust showed that plane tree can be used as an appropriate bioindicator of atmospheric dust heavy metal concentration. Biomagnetic method was also effective in identifying Cu, Zn, Pb and Fe contamination in atmospheric dust and their hot spots in the area. Keywords: Dust, heavy metals, physicochemical properties, mineralogy, spatial and temporal distribution, biomonitoring, biomagnetism.
