Chemical Composition of Asian Dust in Daejeon, Korea, during the Spring Season

Asian dust, which originates from the arid and loess regions of Central Asia, affects biological systems in remarkable ways in Northeast Asian countries. It contains a high amount of mineral dust composed of major metallic oxides, SiO2, Al2O3, CaO, and Fe2O3, which can cause adverse health effects upon high-level exposure. In the present study, Asian dust samples of spring seasons were collected for three consecutive years (2017-2019) and their elemental compositions were analyzed. A total of 42 major, minor, and trace elements were determined using two complementary analysis methods, wavelength-dispersive X-ray fluorescence spectrometry and k(0)-based instrumental neutron activation analysis. Sources of elements/dust and their contamination levels were evaluated using the data analysis tools including the HYSPLIT back-trajectory analysis, Pearson's correlation, enrichment factor, and geoaccumulation index. Although the concentrations of Earth's major crustal elements of the dust samples in spring seasons decreased appreciably for sampling events spanning 3 years, their major sources turned out to be the same, the Central Asia desert region, with negligible contaminations from the other sources. It was further supported by the back-trajectory analysis and the characteristic calcite compositions of different desert soils. This study successfully demonstrated the performances of combined data analysis tools for source identification, providing results with excellent consistency.