ent in AQI causes acute and chronic mode health concern especially in the older age people and in children (Januszek et al. 2020; Pant et al. 2020). Due to the COVID-19 pandemic confinement, there is a significant reduction in the level of such toxic pollutants globally (Selvam et al. 2020; Singh and Chauhan 2020).
Fig. 1 Indian national air quality index—category and range
In the present study, concentrations of different pollutants i.e., PM2.5 (diameter < 2.5 μm), PM10 (diameter < 10 μm), NO2, NH3, SO2, C