Ground-level ozone in the Pearl River Delta and the roles of VOC and NO.sub.x in its production

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2007.12.008 Byline: Min Shao (a), Yuanhang Zhang (a), Limin Zeng (a), Xiaoyan Tang (a), Jing Zhang (b), Liuju Zhong (c), Boguang Wang (d) Abstract: In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO.sub.2 increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO.sub.x) emission controls. Nonetheless, ambient NO.sub.2 levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290ppbC in summer and 190ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O.sub.3 production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO.sub.x . Author Affiliation: (a) State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China (b) Institute of Environmental Sciences, Beijing Normal University, Beijing 100875, China (c) Guangdong Provincial Environmental Monitoring Center, Guangdong 510045, China (d) Institute of Environmental Engineering, Jinan University, Guangdong 510632, China Article History: Received 24 November 2006; Revised 15 October 2007; Accepted 2 December 2007