Size distributions of aerosol sulfates and nitrates in Beijing during the 2008 Olympic Games: Impacts of pollution control measures and regional transport

Xinfeng Wang, Tao Wang, Ravi Kant Pathak, Mattias Hallquist, Xiaomei Gao, Wei Nie, Likun Xue, Jian Gao, Rui Gao, Qingzhu Zhang, Wenxing Wang, Shulan Wang, Fahe Chai, Yizhen Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

20 Citations (Scopus)

Abstract

For the 2008 Olympic Games, drastic control measures were implemented on industrial and urban emissions of sulfur dioxide (SO2), nitrogen oxides (NOx) and other pollutants to address the issues of poor air quality in Beijing. To investigate the effects of SO2and NOxreductions on the particulate sulfate and nitrate concentrations as well as their size distributions, size-segregated aerosol samples were collected using micro-orifice uniform deposit impactors (MOUDIs) at urban and downwind rural sites in Beijing before and after full-scale controls. During the sampling period, the mass concentrations of fine particles (PM1. 8) at the urban and rural sites were 94. 0 and 85. 9 μg m-3, respectively. More than 90% of the sulfates and ~;60% of nitrates formed as fine particles. Benefiting from the advantageous meteorological conditions and the source controls, sulfates were observed in rather low concentrations and primarily in condensation mode during the Olympics. The effects of the control measures were separately analyzed for the northerly and the southerly air-mass-dominated days to account for any bias. After the control measures were implemented, PM, sulfates, and nitrates were significantly reduced when the northerly air masses prevailed, with a higher percentage of reduction in larger particles. The droplet mode particles, which dominated the sulfates and nitrates before the controls were implemented, were remarkably reduced in mass concentration after the control measures were implemented. Nevertheless, when the polluted southerly air masses prevailed, the local source control measures in Beijing did not effectively reduce the ambient sulfate concentration due to the enormous regional contribution from the North China Plain.
Original languageEnglish
Pages (from-to)341-353
Number of pages13
JournalAdvances in Atmospheric Sciences
Volume30
Issue number2
DOIs
Publication statusPublished - 18 Feb 2013

Keywords

  • aerosol
  • control
  • effect
  • nitrate
  • Olympic Games
  • size distribution
  • sulfate

ASJC Scopus subject areas

  • Atmospheric Science

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