Abstract：
Study of Air Quality Objectives (AQOs) and long-term changes of air pollution plays a decisive role in formulating and refining pollution control strategies. In this study, 10-year variations of six major air pollutants were analyzed at seven monitoring sites in Hong Kong. The continuous decrease of annual averaged concentrations of NO2, SO2, CO, PM2.5 and PM10 and numbers of days with severe pollution conditions validated the efficiency of the series of air pollution control schemes implemented by the Hong Kong government. However, there is still a big gap to meet the ultimate targets described by the World Health Organization. Besides, the concentration of O3 at roadside and urban stations increased by 135% ± 25% and 37% ± 18% from 2011 to 2020, respectively, meanwhile the highest 8 hr averaged O3 concentration was observed as 294 µg/m3 at background station in 2020, which pointed out the increasing ozone pollution in Hong Kong. There was a great decrease in the annual times of air quality health index (AQHI) laying in \"high\", \"very high\" and \"serious\" categories from 2011 to 2020 with the decrease rate of 89.70%, 91.30% and 89.74% at roadside stations, and 79.03%, 95.98% and 72.73% at urban stations, respectively. Nevertheless, the number of days categorized as \"high\" or above at roadside station was twice more than that in the urban station during the past ten years. Thus, more policies and attentions should be given to the roadside air quality and its adverse health effect to pedestrians on street.
摘要：
研究空气质量目标（AQO）和空气污染的长期变化在制定和完善污染控制策略中起着决定性作用。在这项研究中,在香港的七个监测站，分析了六种主要空气污染物的十年变化。NO2、SO2、CO、PM2.5和PM10以及严重污染状况的天数验证了香港政府实施的一系列空气污染控制计划的效率。然而,实现世界卫生组织描述的最终目标还有很大差距。此外,从2011年到2020年，路边和城市站的O3浓度分别增加了135%±25%和37%±18%，同时，在2020年的背景站观察到最高的8小时平均O3浓度为294µg/m3，这表明香港的臭氧污染日益增加。空气质量健康指数（AQHI）的年度下降幅度很大，处于“高”状态，从2011年到2020年，“非常高”和“严重”类别的下降率为89.70%，路边站91.30%和89.74%,和79.03%，城市车站95.98%和72.73%，分别。然而，在过去的十年中，路边车站被归类为“高”或以上的天数是城市车站的两倍多。因此，应该对路边空气质量及其对街道上行人的不利健康影响给予更多的政策和关注。
