The WHO announced coronavirus disease a Public Health Emergency on 30 January 2020, and it spreads across the whole planet. Aftermath of outbreak of this disease at the global level is more frightening and panicking than anyone’s worst nightmare. With more than 23 mln positive coronavirus cases and more than 800,000 causalities all over the world, the potential of this virus cannot be undermined. This pandemic has victimized all human beings residing on 209 countries and territories of the world. It emerged as an unbeatable global challenge that the world has never witnessed before. Consequently, the affected countries have sealed their borders and made populations reside in their homes until the pandemic is over. Thus, the victims of coronavirus are not only the ones who are exposed to it but also the ones who are affected by the lockdown imposed by the governments. The paper aims to evaluate the effect of COVID-19 on air pollution of various countries. Papers indicating the relationship between air pollution levels and lockdown measures are analyzed. The dramatic U-turn from environmental degradation is definitely a silver lining in these black clouds. This paper reviews the repercussions of the pandemic in some nations, while war-like preparations continue to fight it. COVID-19 has dramatically improved the quality of air. Also, it has greatly affected the economy of various countries due to lockdown.

中文翻译：

---

COVID-19 爆发对城市健康和环境的影响

世界卫生组织于 2020 年 1 月 30 日宣布冠状病毒病为突发公共卫生事件，并在全球蔓延。这种疾病在全球范围内爆发的后果比任何人最可怕的噩梦都更加可怕和恐慌。全世界有超过 2300 万例冠状病毒阳性病例和超过 800,000 人死亡，这种病毒的潜力不容忽视。这场流行病使居住在世界 209 个国家和地区的所有人成为受害者。它成为世界前所未有的无与伦比的全球挑战。因此，受影响的国家封锁了边境，让人们住在自己的家中，直到大流行结束。因此，冠状病毒的受害者不仅是暴露于它的人，而且是受到政府实施封锁影响的人。本文旨在评估 COVID-19 对各国空气污染的影响。分析了表明空气污染水平与封锁措施之间关系的论文。环境恶化导致的戏剧性掉头绝对是这些乌云中的一线希望。本文回顾了大流行对一些国家的影响，而战争般的准备工作仍在继续与之抗争。COVID-19 极大地改善了空气质量。此外，由于封锁，它极大地影响了各国的经济。分析了表明空气污染水平与封锁措施之间关系的论文。环境恶化导致的戏剧性掉头绝对是这些乌云中的一线希望。本文回顾了大流行对一些国家的影响，而战争般的准备工作仍在继续与之抗争。COVID-19 极大地改善了空气质量。此外，由于封锁，它极大地影响了各国的经济。分析了表明空气污染水平与封锁措施之间关系的论文。环境恶化导致的戏剧性掉头绝对是这些乌云中的一线希望。本文回顾了大流行对一些国家的影响，而战争般的准备工作仍在继续与之抗争。COVID-19 极大地改善了空气质量。此外，由于封锁，它极大地影响了各国的经济。