High secondary aerosol contribution to particulate pollution during haze events in China
High secondary aerosol contribution to particulate pollution during haze events in China
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DOI：
10.1038/nature13774
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发表时间：
2014-10-09
期刊：
影响因子：
64.8
通讯作者：
Prevot, Andre S. H.
中科院分区：
文献类型：
--
作者：
Huang, Ru-Jin;Zhang, Yanlin;Prevot, Andre S. H.
发展中国家的快速工业化和城市化导致空气污染增加，沿着与发达国家以前经历的类似轨迹（1）。在中国，颗粒物污染是一个严重的环境问题，影响空气质量、区域和全球气候以及人类健康（2，3）。为应对2013年第一季度约8亿人经历的极其严重和持续的雾霾污染（参考文献4、5），中国国务院理事会宣布，其目标是到2017年将PM2.5（空气动力学直径小于2.5微米的颗粒物）浓度相对于2012年水平降低25%（参考文献6）。然而，这些努力需要阐明控制PM2.5丰度和组成的因素，这些因素在中国仍然缺乏约束（3，7，8）。在这里，我们联合收割机结合了一套全面的新的和最先进的离线分析方法和统计技术，以调查2013年1月在北京，上海，广州和西安的城市位置的颗粒物的化学性质和来源。我们发现，严重的雾霾污染事件在很大程度上是由二次气溶胶形成驱动的，二次气溶胶形成分别贡献了PM2.5和有机气溶胶的30%-77%和44%-71%（所有四个城市的平均值）。平均而言，二次有机气溶胶（SOA）和二次无机气溶胶（SIA）的贡献被认为是相似的重要性（SOA/SIA的比值范围从0.6到1.4）。我们的研究结果表明，除了减少一次颗粒物排放外，减少二次气溶胶前体物的排放，例如化石燃料燃烧和生物质燃烧，对于控制中国的PM2.5水平和减少颗粒物污染对环境，经济和健康的影响可能很重要。
Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations(1). In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health(2,3). In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China(3,7,8). Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.