The amount of suspended particles containing heavy metals in the air of the 21st district of Tehran, 2021 autumn

Suspended particles contain polluting heavy metals present in industrial areas adjacent to residential areas and negatively affect residents' health. The main goal of this research is to sample and determine the concentration of suspended particles and heavy metals in the autumn season of 2021 in the air of the 21st district of Tehran. The sampling method is according to ASTM and EPA standards, 20 active samples were taken from residential, semi-residential, industrial, semi-industrial and park uses by a high-volume pump in the autumn season. The findings show that the average concentration of TSP in the stations of region 21 in the cold season is an increasing trend in 5S (  = 99.71), 2S (  = 124), 1S ( = 144.21), 3S (  = 173.10) and 4S (  = 220/37). The average concentration of HM10 in the whole region 21 is in the order of increasing Al>Cr>Zn>Fe>Mg>Pb>Sr>W>Ti>Li. The findings show that among all the elements, aluminum has the highest concentration with 89.65 µg/m3 in industrial use, 78.72 µg/m3 in semi-industrial use, 68.98 µg/m3 in semi-residential use, 55.76 µg/m3 in residential use, 41.65 µg/m3 in garden use. Also, lithium element has the lowest concentration in all stations. Determining the concentration of suspended particles and heavy metals helps urban planning officials in prioritizing and controlling air pollutants.