Health Science Center, School of Public Health, Xi'an Jiaotong University, Xi'an 710061, China.
Int J Environ Res Public Health. 2021 Mar 19;18(6):3172. doi: 10.3390/ijerph18063172.
Over the past decades, urbanization and industrialization have led to a change in air quality, bringing researchers to a full realization of the damaging effects of human activities on the environment. This study focused on describing air quality during the initial phase of the Novel Coronavirus disease (COVID-19) pandemic (since there were fewer anthropogenic activities) in 10 Chinese mega-cities. Using the independent -test, the means of air quality index (AQI) scores and individual air pollutants concentration during the outbreak were compared with the means before the outbreak. Cohen's d was estimated to quantify how much difference was observed. Based on the AQI score, the air quality in these 10 cities ranged from excellent (Shenzhen) to light pollution (Xi'an) with 44.8 μg m and 119.7 μg m, respectively. In comparison to the 2019 air quality, Guangzhou and Wuhan noted major differences in air quality during the outbreak. Indicators of traffic pollution, particularly NO, were significantly lower during the outbreak in all cities. Particulate matter pollution varied, with some cities observing lower concentrations and other higher concentrations during the outbreak. There was a significant decrease in air pollution levels during the outbreak. More researchers should observe changes in air quality during peculiar or major events. Implementation of stringent regulation on vehicle use should be considered in mega-cities. Relevant findings should be employed in emphasizing the detrimental effects of anthropogenic activities and support the need for stringent emission control regulations.
在过去的几十年里，城市化和工业化导致了空气质量的变化，使研究人员充分认识到人类活动对环境的破坏影响。本研究集中描述了新型冠状病毒病（COVID-19）大流行初期（由于人为活动较少）在中国 10 个特大城市的空气质量。采用独立检验，比较了疫情期间空气质量指数（AQI）得分和个别空气污染物浓度的平均值与疫情前的平均值。用 Cohen's d 来量化观察到的差异程度。根据 AQI 得分，这 10 个城市的空气质量从优秀（深圳）到轻度污染（西安）不等，分别为 44.8μg/m 和 119.7μg/m。与 2019 年的空气质量相比，广州和武汉在疫情期间空气质量有明显差异。所有城市的交通污染指标，特别是氮氧化物（NO），在疫情期间明显降低。颗粒物污染情况不一，一些城市在疫情期间的浓度较低，而另一些城市则较高。疫情期间空气污染水平显著下降。应该有更多的研究人员观察特殊或重大事件期间空气质量的变化。应考虑在特大城市实施严格的车辆使用规定。相关研究结果应强调人为活动的有害影响，并支持实施严格的排放控制法规。
