Characterization and source apportionment of water-soluble ion pollution in PM of typical cities in northern China.

Understanding the characteristics and sources of water-soluble ion pollution in particulate matter is crucial for preventing, controlling, and managing air pollution. In this study, we analyzed the pollution characteristics and sources of water-soluble ions in PM in three typical cities in northern China. Our results showed an increase in both PM and total water-soluble ions during the pollution period in all three cities. Wind speed was a key meteorological factor affecting the change in atmospheric aerosol concentration in Dunhuang and Zhongwei. Dunhuang, Zhongwei, and Dalian were affected by natural sources such as dust, but also by human sources such as coal combustion, industrial activities, transportation emissions, and biomass burning. This study is of great significance for understanding the sea-land air interactions and the transport, diffusion, and sources of water-soluble ions, and for the prevention, control, and management of air pollution in global desert regions and coastal areas.