Application of positive matrix factorization and pollutants tracing for identification of dust sources: A case study in Khuzestan, Iran

In this study for identification of internal and external origins of dust events in the southwest of Iran, for the first time, a comprehensive dust sampling was performed in nine regions of Khuzestan over the four seasons. The dust samples were analyzed using INAA nuclear technique. Factors obtained from applying the PMF Modeling indicated five kinds of pollutant sources which include 1) Sedimentary surface soil/dried bed of wetlands, 2) steel and metalworking industries, 3) refineries, 4) waste, and 5) solid fuel as well as oil fuel power plants. These identified sources were used as the tracers to identify the internal dust sources. Investigation of NASA AOT images and the synoptic data at the event dates showed that in the period of mid-autumn up to the early winter, dust events had external origins, that are mainly situated in Iraq and Saudi Arabia, while in the period of mid-summer to early autumn and mid-winter up to the early spring, the internal sources such as mud-salt zones or areas with fine sediments with evaporitic deposits and puffy grounds in the regions between Omidieh - Mahshahr, south, and southeast of Ahvaz, “Dasht-E-Azadegan,” and dried bed of Hoor-Al-Azim are more dominant.