Air Quality Assessment in the Foothills of Garhwal Himalayan Environment during the COVID-19 Pandemic Outbreak.

Strict lockdown procedures were implemented across the country, including major urban areas, to put a check on the COVID-19 outbreak. Due to the limited extent of commercial activities, these restrictions have significantly impacted improving ecological well-being. The lockdown was imposed at Haridwar, a famous Hindu pilgrimage site with heavy daily foot traffic, industrial activities, and a populated urban area The different air quality parameters (nitrogen dioxide, sulfur dioxide, particulate matter [PM]2.5, and PM10) were analyzed throughout the COVID-19 outbreak lockdown period as compared to a pre-lockdown period in both pandemic waves, 2020 and 2021. Significant variations were observed while assessing air quality during stages of lockdown at different sites during the first and second waves. Pre-lockdown air quality index (AQI) in the first wave varied from 91.12 to 55.47, with SIDCUL having the highest value and Jagjeetpur having the lowest. The AQI improved throughout the lockdown, rising from 41.04 to 54.59, with SIDCUL having the lowest score and Ranipur having the highest. Pre-lockdown AQI ranged from 54.930 to 88.0534 in the second wave, with SIDCUL once again having the highest and Jagjeetpur having the lowest. The lockdown AQI increased from 51.062 to 79.382, with Jagjeetpur continuously having the lowest values and SIDCUL continually having the highest. During the lockdown, the AQI was significantly improved in Haridwar, showing clear improvement throughout the successive phases of limitation. [ABSTRACT FROM AUTHOR]