“…Similarly, several studies had been conducted to find the association of air pollutants such as NO 2 , SO 2 and other particulate matters with the increased risk of respiratory infections and mortality rates (Ã et al, 2005;Ashikin et al, 2014;Galy-lacaux et al, 2016;Lau et al, 2020;Mason et al, 2019;Pan et al, 2010;Sahoo et al, 2017;Wang and Su, 2020;Jiandong Yang et al, 2020). It had been concluded from several researches that, exposure to critical air pollutants such as PM 2.5 , NO 2 and SO 2 were harmful to human health and led to persistent and increased risk of respiratory illness (Chen et al, 29 2019(Chen et al, 29 , 2020Dastoorpoor et al, 2019;Gao et al, 2019;Hu et al, 2020;Naclerio et al, 2020;Oh et al, 2020;Sangkharat et al, 2019;Thi et al, 2018;Yao et al, 2020).…”