Wong Yong Jie, Shiu Huan-Yu, Chang Jackson Hian-Hui, Ooi Maggie Chel Gee, Li Hsueh-Hsun, Homma Ryosuke, Shimizu Yoshihisa, Chiueh Pei-Te, Maneechot Luksanaree, Nik Sulaiman Nik Meriam
Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 520-0811, Japan.
Graduate Institute of Environmental Engineering, National Taiwan University, 10617, Taiwan.
J Clean Prod. 2022 Sep 10;365:132893. doi: 10.1016/j.jclepro.2022.132893. Epub 2022 Jun 27.
The unprecedented outbreak of COVID-19 significantly improved the atmospheric environment for lockdown-imposed regions; however, scant evidence exists on its impacts on regions without lockdown. A novel research framework is proposed to evaluate the long-term monthly spatiotemporal impact of COVID-19 on Taiwan air quality through different statistical analyses, including geostatistical analysis, change detection analysis and identification of nonattainment pollutant occurrence between the average mean air pollutant concentrations from 2018-2019 and 2020, considering both meteorological and public transportation impacts. Contrary to lockdown-imposed regions, insignificant or worsened air quality conditions were observed at the beginning of COVID-19, but a delayed improvement occurred after April in Taiwan. The annual mean concentrations of PM, PM, SO, NO, CO and O in 2020 were reduced by 24%, 18%, 15%, 9.6%, 7.4% and 1.3%, respectively (relative to 2018-2019), and the overall occurrence frequency of nonattainment air pollutants declined by over 30%. Backward stepwise regression models for each air pollutant were successfully constructed utilizing 12 meteorological parameters (R > 0.8 except for SO) to simulate the meteorological normalized business-as-usual concentration. The hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model simulated the fate of air pollutants ( local emissions or transboundary pollution) for anomalous months. The changes in different public transportation usage volumes ( roadway, railway, air, and waterway) moderately reduced air pollution, particularly CO and NO. Reduced public transportation use had a more significant impact than meteorology on air quality improvement in Taiwan, highlighting the importance of proper public transportation management for air pollution control and paving a new path for sustainable air quality management even in the absence of a lockdown.
新型冠状病毒肺炎（COVID-19）的空前爆发显著改善了实施封锁地区的大气环境；然而，关于其对未实施封锁地区影响的证据却很少。本文提出了一个新颖的研究框架，通过不同的统计分析，包括地统计分析、变化检测分析以及识别2018 - 2019年和2020年平均空气污染物浓度之间未达标的污染物发生情况，来评估COVID-19对台湾空气质量的长期月度时空影响，同时考虑气象和公共交通的影响。与实施封锁的地区相反，在COVID-19初期，台湾观测到空气质量状况无显著变化或恶化，但在4月之后出现了延迟改善。2020年，PM、PM、SO、NO、CO和O的年均浓度分别下降了24%、18%、15%、9.6%、7.4%和1.3%（相对于2018 - 2019年），未达标的空气污染物总体出现频率下降了30%以上。利用12个气象参数成功构建了每种空气污染物的向后逐步回归模型（除SO外，R>0.8），以模拟气象归一化的照常营业浓度。混合单粒子拉格朗日积分轨迹（HYSPLIT）模型模拟了异常月份空气污染物（本地排放或跨界污染）的归宿。不同公共交通使用量（道路、铁路、航空和水路）的变化适度降低了空气污染，尤其是CO和NO。公共交通使用量的减少对台湾空气质量改善的影响比气象因素更为显著，凸显了合理的公共交通管理对空气污染控制的重要性，即使在没有封锁的情况下，也为可持续空气质量管理开辟了一条新路径。
