McElroy Sara, Vaidyanathan Ambarish
Oak Ridge Institute for Science and Education, Oak Ridge, TN USA and Climate and Health Program, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
Climate and Health Program, DEHSP, NCEH, CDC, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
Aerosol Air Qual Res. 2022 Nov;22(11). doi: 10.4209/aaqr.220047.
Traffic-related emissions continue to be a significant source of air pollution in the United States (US) and around the globe. Evidence has shown that previous policies implemented to restrict-traffic flows have affected air pollution levels. Thus, mitigation strategies associated with the COVID-19 pandemic that modified population-level mobility patterns provide a unique opportunity to study air pollution change across the US. For instance, to slow the spread of the pandemic, state and local governments started implementing various mitigation actions, including stay-at-home directives, social distancing measures, school closures, and travel restrictions. This scoping review aimed to summarize the existing evidence about how air quality changed through mitigation practices throughout the pandemic in the US. We found 66 articles that fit our inclusion criteria. Generally, the consolidated results revealed that nitrogen dioxide (NO) and carbon monoxide (CO) decreased across the country. Studies observed mixed directions and magnitudes of change for fine and coarse particulate matter (PM, PM), ozone (O), and sulfur dioxide (SO). Few articles tried to explain this notable heterogeneity in air quality changes by associating contextual factors, such as mobility, traffic flow, and demographic factors. However, all studies agreed that the change in air pollution was nonuniform across the US and even varied within a city.
在美国及全球范围内，与交通相关的排放仍然是空气污染的一个重要来源。有证据表明，先前实施的限制交通流量的政策已经影响了空气污染水平。因此，与新冠疫情相关的缓解策略改变了人口层面的流动模式，为研究美国各地的空气污染变化提供了一个独特的机会。例如，为了减缓疫情的传播，州和地方政府开始实施各种缓解措施，包括居家指令、社交距离措施、学校关闭和旅行限制。本综述旨在总结关于美国在整个疫情期间通过缓解措施空气质量如何变化的现有证据。我们找到了66篇符合我们纳入标准的文章。总体而言，综合结果显示，全国范围内二氧化氮（NO）和一氧化碳（CO）有所下降。对于细颗粒物和粗颗粒物（PM、PM）、臭氧（O）和二氧化硫（SO），研究观察到变化的方向和幅度各不相同。很少有文章试图通过关联诸如流动性、交通流量和人口因素等背景因素来解释空气质量变化中这种显著的异质性。然而，所有研究都一致认为，美国各地空气污染的变化并不均匀，甚至在一个城市内也有所不同。
