Research on the Components of Dust Fall in Hohhot in Comparison with Surface Soil Components in Different Lands of Inner Mongolia Plateau

The dust fall in a region is closely related to upwind sources. Dust fall from sandstorms has a strong influence on industry, agriculture, and daily life. Hohhot, the capital of Inner Mongolia Autonomous Region, is downwind of the Inner Mongolia Plateau and experiences frequent sandstorms during the spring monsoon season. This study investigated the relationship between dust fall in the Hohhot area and surface soils on the Inner Mongolia Plateau. Samples of dust fall from Hohhot and surface soils from the plateau were analyzed for major and trace elements. The SiO₂ content of dust fall from sandstorms differs from that of the plateau soils by only 2.77%, indicating that the main dust fall source for Hohhot is surface soils from the plateau. Dust samples from coal smoke, roads, and buildings were used for comparison. The As content in dust fall from sandstorms is greater than that found in the plateau soils and in dust from non-sandstorm days. This indicates that As is added to the sand during transport from the plateau by coal factories near Hohhot. The second most important dust source is traffic, as evidenced by Pb contents. Preventing erosion of sand upwind of Hohhot during the spring monsoon is key to improving and managing air quality in the Hohhot region. This can be accomplished through management of the farm grassland areas.