title: Status and characteristics of ambient PM2.5 pollution in global megacities.
abstract: Ambient PM2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM2.5 pollution of 45 global megacities in 2013, based on mass concentration from official monitoring networks and composition data reported in the literature. The results showed that the five most polluted megacities were Delhi, Cairo, Xi'an, Tianjin and Chengdu, all of which had an annual average concentration of PM2.5 greater than 89μg/m(3). The five cleanest megacities were Miami, Toronto, New York, Madrid and Philadelphia, the annual averages of which were less than 10μg/m(3). Spatial distribution indicated that the highly polluted megacities are concentrated in east-central China and the Indo-Gangetic Plain. Organic matter and SNA (sum of sulfate, nitrate and ammonium) contributed 30% and 36%, respectively, of the average PM2.5 mass for all megacities. Notable seasonal variation of PM2.5 polluted days was observed, especially for the polluted megacities of China and India, resulting in frequent heavy pollution episodes occurring during more polluted seasons such as winter. Marked differences in PM2.5 pollution between developing and developed megacities require more effort on local emissions reduction as well as global cooperation to address the PM2.5 pollution of those megacities mainly in Asia.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Luo
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China. Electronic address: shxwang@tsinghua.edu.cn.
authors.forename: Shuxiao
authors.initials: S
authors.lastname: Wang
authors.affiliation: Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 9472 0, USA; GAGO Inc., San Jose, CA 95131, USA.
authors.forename: Yungang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Earth Science and Climate Change Division, The Energy and Resources Institute, IHC complex, Lodi Road, New Delhi-3, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Hikari
authors.initials: H
authors.lastname: Shimadera
authors.affiliation: Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Wang
authors.affiliation: European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra, VA, Italy.
authors.forename: Michael
authors.initials: M
authors.lastname: Bressi
authors.affiliation: School of Arts, Sciences, and Humanities, University of São Paulo, Rua Arlindo Béttio,1000, Ermelino Matarazzo, CEP 03828-000 São Paulo, Brazil.
authors.forename: Regina Maura
authors.initials: RM
authors.lastname: de Miranda
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Jingkun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Oscar
authors.initials: O
authors.lastname: Fajardo
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Naiqiang
authors.initials: N
authors.lastname: Yan
authors.affiliation: School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Jiming
authors.initials: J
authors.lastname: Hao
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D001208:Asia; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D005060:Europe; D009656:North America; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry; D012621:Seasons; D014507:Urbanization
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Air pollution; Chemical composition; Megacity; PM(2.5) (fine particulate matter)