title: A review on recent progress in observations, sources, classification and regulations of PM2.5in Asian environments.
abstract: Natural and human activities generate a significant amount of PM2.5(particles ≤2.5 μm in aerodynamic diameter) into the surrounding atmospheric environments. Because of their small size, they can remain suspended for a relatively longer time in the air than coarse particles and thus can travel long distances in the atmosphere. PM2.5is one of the key indicators of pollution and known to cause numerous types of respiratory and lung-related diseases. Due to poor implementation of regulations and a time lag in introducing the vehicle technology, levels of PM2.5in most Asian cities are much worse than those in European environments. Dedicated reviews on understanding the characteristics of PM2.5in Asian urban environments are currently missing but much needed. In order to fill the existing gaps in the literature, the aim of this review article is to describe dominating sources and their classification, followed by current status and health impact of PM2.5, in Asian countries. Further objectives include a critical synthesis of the topics such as secondary and tertiary aerosol formation, chemical composition, monitoring and modelling methods, source apportionment, emissions and exposure impacts. The review concludes with the synthesis of regulatory guidelines and future perspectives for PM2.5in Asian countries. A critical synthesis of literature suggests a lack of exposure and monitoring studies to inform personal exposure in the household and rural areas of Asian environments.
authors: Institute of Environmental Engineering, National Chiao Tung University, No. 1001, University Road, Hsinchu, 30010, Taiwan.
authors: Sneha
authors: S
authors: Gautam
authors: The INCLEN Trust International, Okhla Industrial Area, Phase-I, New Delhi, 110020, India.
authors: Ankit
authors: A
authors: Yadav
authors: Institute of Environmental Engineering, National Chiao Tung University, No. 1001, University Road, Hsinchu, 30010, Taiwan. cjtsai@mail.nctu.edu.tw.
authors: Chuen-Jinn
authors: CJ
authors: Tsai
authors: Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK.|Environmental Flow (EnFlo) Research Centre, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
authors: Prashant
authors: P
authors: Kumar
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000032:analysis; D001208:Asia; D002947:Cities; D006801:Humans; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter
keywords: Air pollution exposure; Asian environment; Human health impact; PM2.5