Ammonia control represents the key for PM2.5 elimination: insights for global air pollution control interconnected from PM2.5 events in China

Aerosol particulate represented by PM 2.5 is a globally environmental issue, which is associated with severe adverse impacts on human health and global climate. To address that problem, the urgent challenge is to find out the most important factor for PM 2.5 formation and therefore conduct more effective control. Herein, the characteristic and control strategy of PM 2.5 pollution in China is investigated, aiming to provide new insights for global air pollution control. Spatial and chemical characteristics of PM 2.5 in China are analyzed according to large amounts of air monitoring data. Charge analysis of PM 2.5 is conducted based on the concentration of water-soluble inorganic ion. Achievement and shortage of recent PM 2.5 control strategies are studied through policy analysis. PM 2.5 pollution is highly related to local population and economic development. NH 4 + represents the main cation in PM 2.5 and plays a key role in particulate generation. Ammonia is found to be concentrated in North China Plain of China, which is consistent with PM 2.5 spatial distribution. To further abate the PM 2.5 , ammonia emission from nitrogenous fertilization, livestock manures and industrial denitrification process should be controlled. Graphic abstract