Impact of COVID-19-Induced Lockdown on Air Quality of Major Cities of Uttar Pradesh, India

The effect of COVID-19-induced lockdown on ambient air quality was studied by comparing the change in the concentration of air quality parameters and Air Quality Index (AQI) value during the pre-lockdown and lockdown period in three major cities, namely Lucknow, Kanpur, and Varanasi in Uttar Pradesh, India. The concentration of PM2.5 and NO2 reduced by 55% and 71%, 65% and 59%, and 64% and 29% in Lucknow, Kanpur, and Varanasi, respectively, during the lockdown. Similarly, SO2 concentration reduced in Lucknow (29%) and Kanpur (34%) but increased in Varanasi (97%) and ozone concentration further increased by 8%, 42%, and 15%, respectively, during the lockdown period. The air pollutant concentration reduced substantially in the year 2020 as compared to the year 2019 indicating the impact of lockdown. The regression analysis results showed a negative correlation between AQI values and lockdown days indicating an overall improvement in air quality during the lockdown period.