Phase Wise Variation of Criteria Pollutants across India during COVID-19 Lockdown

Abstract : The COVID-19 epidemic forced many countries around the world to lockdown completely. This occlusion influenced the atmospheric composition positively due to reduced anthropogenic activities. Recently, many studies across India have shown how the COVID-19 lockdown has affected air quality in different cities. However, these studies did not examine the phased percentage variation in air pollutant concentrations across different states of India. In this study, percentage variation in the concentration of five criteria pollutant, PM10, PM2.5, NO2, CO and Ozone were studied for 13 states across India during four phases of COVID-19 lockdown. A significant decrease in air pollutant levels was observed in all four phases, with phase 1 and phase 2 reporting a maximum decrease. PM10 and PM2.5, CO and NO2 showed a decrease in concentration in all states. Ozone showed a mixed response, with both increase and decrease recorded across states. During the COVID-19 lockdown period in India, AOD levels were reduced by 10.25%. This study will certainly help regulators set the guidelines and mitigation measures for appropriate control of air pollutants in different states in future