Atmospheric aerosols analysis and identification of polluting sources in the industrial city of Arak, Iran

Total suspended particulates (TSP) were collected in the industrial city of Arak, Iran, during the windy and cold seasons of 2018-2019 to investigate the air pollution sources. The associated elements were analyzed by particle-induced X-ray emission technique. The major elements detected in the samples were Mg, Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Co, Cu, and Zn. In this investigation, the time trend, monthly and seasonal variations, the correlation between the elemental concentrations, and the sources of air pollution were evaluated. An increase in the concentrations of Zn, Ti, and Fe was seen in winter due to temperature inversions. The highest correlation coefficients were found between soil dust key elements, Fe-Si, Ca-S, Ca-Fe, Ca-Si, and Al-Si. From the aerosols time trend concentration and the wind map direction, it was identified that there are northwesterly winds bringing desert dusts to the sampling site. The statistical positive matrix factorization model in combination with correlation coefficient and enrichment factor values were used to identify the sources of air pollution. It was deduced that the soil dusts, machining and assembling activities, industrial salts, vehicle, aluminum metallurgy, and petrochemical productions were the main contribution to the detected TSP concentration.