Table 6.

Revisiting contemporary research related to air pollution amid COVID-19.

Study region	Issues addressed/major outcomes	References
Cities across the globe	World's leading cities have experienced noticeable reduction of air pollution after lockdown	Saadat et al. (2020); Muhammad et al. (2020); Anjum (2020); Shrestha et al. (2020)
Eastern China	Reduction of primary emissions (like NOx) compensates enhanced secondary pollution (like O3) during lockdown.	- Huang et al. (2020)
	Emissions reductions were overwhelmed by adverse meteorology.	- Wang et al. (2020)
China	Regions with poor air quality are associated with higher mortality rate.	- Isaifan (2020)
	Lockdown in some cities led to upgrading in air quality and lessened premature deaths.	- Wang and Su (2020), He et al. (2020)
	There is a considerable relationship between air pollution and COVID-19infection	- Zhu et al. (2020)
Major cities of India	Restricted human activities have lead up gradation of air quality and lessened allied excessive risk	Sharma et al. (2020)
New York, USA	Avg. temperature, minimum temperature and air quality were significantly associated with the COVID-19pandemic.	Bashir et al. (2020)
Barcelona, Spain	A significant reduction of most pollutants and increase in O3 concentrations during lockdown	Tobías et al. (2020)
Italian province capitals	Accelerated transmissions of COVID-19are principally by means of “air pollution-to-human transmission” rather than “human-to-human transmission”.	Coccia (2020)