Status and chemical characteristics of ambient PM2.5 pollutions in China: A review

The ambient fine particulate matter is a considerable hazard to human health and the surrounding environment of the majority of Chinese cities. This article reviews the status of air pollution, especially PM2.5, in 21 cities of China, on the basis of their status, chemical characteristics, and regulations data collected from published literature. The observed results show Zhengzhou, Yulin, Jinan, Qingdao and Changchun as significantly polluted cities where the annual mean concentration of PM2.5 was noted to be greater than 120 µg m-3. However, some cities such as Xiamen, Hong Kong, Shenzhen, and Jinchang reported average annual PM2.5 concentrations less than 40 µg m-3. In general, the results of spatial distribution reported that the cities of the east, north and northeast China are highly polluted. According to the average mass of PM2.5 in maximum cities of China, the sum of sulfate, nitrate and ammonium (SNA) and organic matter (OM) contributed over 40% and 35%, respectively. The higher amount of SNA and OM in PM2.5 result from heavy traffic or vehicle emission and burning solid fuel utilized in most part of China. A proposed systemic approach to address the PM2.5 in China can improve the quality of ambient atmosphere