1. Status and characteristics of ambient PM2.5 pollution in global megacities.
- Author
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Cheng, Zhen, Luo, Lina, Wang, Shuxiao, Wang, Yungang, Sharma, Sumit, Shimadera, Hikari, Wang, Xiaoliang, Bressi, Michael, de Miranda, Regina Maura, Jiang, Jingkun, Zhou, Wei, Fajardo, Oscar, Yan, Naiqiang, and Hao, Jiming
- Subjects
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MEGALOPOLIS , *PUBLIC health , *GEOCHEMISTRY , *AIR pollution , *MASS concentrations (Astronomy) , *GREENHOUSE gas mitigation , *PARTICULATE matter - Abstract
Ambient PM 2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM 2.5 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 PM 2.5 greater than 89 μg/m 3 . The five cleanest megacities were Miami, Toronto, New York, Madrid and Philadelphia, the annual averages of which were less than 10 μg/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 PM 2.5 mass for all megacities. Notable seasonal variation of PM 2.5 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 PM 2.5 pollution between developing and developed megacities require more effort on local emissions reduction as well as global cooperation to address the PM 2.5 pollution of those megacities mainly in Asia. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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