Comparative Study of Atmospheric Particulate Matter Size Distribution in East and West Tehran, Iran
Year: 2026
Type: article
Abstract: In order to investigate the particle size distribution pattern of atmospheric suspended particles in Tehran, simultaneous sampling was conducted at six stations located in the western (ST1 to ST3) and eastern (ST4 to ST6) halves of the city. Mass concentrations were measured across nine size fractions ranging from particles larger than 11 µm to those smaller than 0.4 µm. The results indicated that at the western stations, the highest mass concentrations were mainly observed in the coarser particle fractions (11-7 µm and ≥11 µm), with maximum values of 19.6 and 16.3 µg.m-3 recorded at ST2 and ST1, respectively. This pattern suggests the dominance of mechanical sources and road dust resuspension in the western part of the city. In contrast, the eastern half of Tehran exhibited an increasing trend in concentration within the finer fractions (less than 2.1 µm), with the highest value measured at ST6 in the <0.4 µm fraction (18.7 µg.m-3). Additionally, in the 0.7-0.4 µm and 2.1-1.1 µm ranges, eastern stations showed higher concentrations compared to the western stations. This shift in size distribution pattern-from coarse-particle dominance in the west to fine-particle dominance in the east-may be attributed to differences in land use, traffic density, combustion-related sources, as well as topographic conditions and prevailing wind patterns across Tehran. Overall, the findings indicate a greater contribution of combustion-related and secondary fine particles in the eastern half, whereas the western half appears to be more influenced by primary sources and coarse particle resuspension. These results highlight the importance of region-specific management strategies for effective control of particulate matter pollution in the megacity of Tehran.
Source: Geofísica Internacional
Author: Balal Oroji
Institution: Kharazmi University
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7166458984