| Title | Humidity plays an important role in the PM2.5 pollution in Beijing |
| Authors | Cheng, Yuan He, Ke-bin Du, Zhen-yu Zheng, Mei Duan, Feng-kui Ma, Yong-liang |
| Affiliation | Tsinghua Univ, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100084, Peoples R China. State Environm Protect Key Laboratoty Sources & C, Beijing, Peoples R China. Collaborat Innovat Ctr Reg Environm Qual, Beijing, Peoples R China. Peking Univ, Coll Environm Sci & Engn, Beijing 100871, Peoples R China. |
| Keywords | PM2.5 Chemical composition Meteorological parameter SOA Aqueous-phase reaction MASS SIZE DISTRIBUTIONS CHEMICAL CHARACTERISTICS SOURCE APPORTIONMENT AEROSOL CHINA WATER NITRATE PARTICLES MECHANISM EMISSIONS |
| Issue Date | 2015 |
| Publisher | environmental pollution |
| Citation | ENVIRONMENTAL POLLUTION.2015,197,68-75. |
| Abstract | Heavily-polluted PM2.5 (fine particulate matter) episodes frequently impacting Beijing, especially during winter, have become a substantial concern. We found that during winter, the daily variation of PM2.5 in Beijing tracked the pattern of relative humidity (RH). With the increase of PM2.5 (or RH), water-soluble components (especially inorganic ions) became more abundant, and the water-soluble organic carbon to organic carbon ratios increased. The nitrate to sulfate ratios also exhibited dependence on RH, and were higher than those measured about a decade ago, consistent with the increasing trend of nitrogen oxides emissions. Surprisingly, the ratios of water-insoluble organic carbon to elemental carbon showed significant increase at high RH levels, presumably indicating the formation of secondary organic aerosol that is not soluble in water. In addition, humid winters were occasionally identified during 1996-2013 which are expected to be favorable for the formation of air pollution episodes with high PM2.5 concentrations. (C) 2014 Elsevier Ltd. All rights reserved. |
| URI | http://hdl.handle.net/20.500.11897/188728 |
| ISSN | 0269-7491 |
| DOI | 10.1016/j.envpol.2014.11.028 |
| Indexed | SCI(E) EI PubMed |
| Appears in Collections: | 环境科学与工程学院 |
