Increasing External Effects Negate Local Efforts to Control Ozone Air Pollution: A Case Study of Hong Kong and Implications for Other Chinese Cities

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• 作者：Likun Xue ; Tao Wang ; Peter K. K. Louie ; Connie W. Y. Luk ; Donald R. Blake ; Zheng Xu
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：September 16, 2014
• 年：2014
• 卷：48
• 期：18
• 页码：10769-10775
• 全文大小：290K
• ISSN：1520-5851

文摘

It is challenging to reduce ground-level ozone (O₃) pollution at a given locale, due in part to the contributions of both local and distant sources. We present direct evidence that the increasing regional effects have negated local control efforts for O₃ pollution in Hong Kong over the past decade, by analyzing the daily maximum 8 h average O₃ and O_x (=O₃+NO₂) concentrations observed during the high O₃ season (September鈥揘ovember) at Air Quality Monitoring Stations. The locally produced O_x showed a statistically significant decreasing trend over 2002鈥?013 in Hong Kong. Analysis by an observation-based model confirms this decline in in situ O_x production, which is attributable to a reduction in aromatic hydrocarbons. However, the regional background O_x transported into Hong Kong has increased more significantly during the same period, reflecting contributions from southern/eastern China. The combined result is a rise in O₃ and a nondecrease in O_x. This study highlights the urgent need for close cross-boundary cooperation to mitigate the O₃ problem in Hong Kong. China鈥檚 air pollution control policy applies primarily to its large cities, with little attention to developing areas elsewhere. The experience of Hong Kong suggests that this control policy does not effectively address secondary pollution, and that a coordinated multiregional program is required.