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

Abstract

Aerosol particulate represented by PM2.5 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 PM2.5 formation and therefore conduct more effective control. Herein, the characteristic and control strategy of PM2.5 pollution in China is investigated, aiming to provide new insights for global air pollution control. Spatial and chemical characteristics of PM2.5 in China are analyzed according to large amounts of air monitoring data. Charge analysis of PM2.5 is conducted based on the concentration of water-soluble inorganic ion. Achievement and shortage of recent PM2.5 control strategies are studied through policy analysis. PM2.5 pollution is highly related to local population and economic development. NH4+ represents the main cation in PM2.5 and plays a key role in particulate generation. Ammonia is found to be concentrated in North China Plain of China, which is consistent with PM2.5 spatial distribution. To further abate the PM2.5, ammonia emission from nitrogenous fertilization, livestock manures and industrial denitrification process should be controlled.