Particulate matter is the pollutant generally viewed as most unsafe to human wellbeing. PM comprises a combination of liquid and solid particles suspended in the atmosphere. Its minuscule size permits the particles to enter the circulation system by means of respiration, causing asthma and heart disease. COVID-19 has been declared as a Public Health Emergency of International Concern by WHO on 30th January 2020. The objectives of the present study include air quality (with respect to PM2.5 and PM10) monitoring at pre-selected locations during and post COVID- 19 phase, comparative assessment of air quality parameters PM2.5 and PM10 concentrations in Delhi during and post COVID-19. To conduct this study the station for air quality monitoring selected is near Hauz Khas metro station, Delhi. Total 4 locations are selected around CPCB Air pollution monitoring station, Hauz Khas. PM sampling has been done for 12 continuous days. The dataset of the time frame (March and April of 2020) of the lockdown phase is collected from CPCB and compared with the dataset of the same time frame (March and April 2021) using excel software. The pollution level drastically increases after the lockdown phase according to present observation and improvement in air quality could not last long after the reopening of industries and vehicular activities according to this investigation.
