Assessing the Immediate Impact of COVID-19 Lockdown on the Air Quality of Kolkata and Howrah, West Bengal, India

Abstract

<jats:title>Abstract</jats:title> <jats:p>The worldwide spread of COVID-19 caused a nationwide lockdown in India from 24<jats:sup>th </jats:sup>March 2020 and was further extended up to 3rd May 2020 to break off the transmission of novel Coronavirus. The study is designed to assess the changes in air quality from the pre lockdown period to the during lockdown period in Kolkata and Howrah municipal corporation, West Bengal, India. GIS-based techniques include the spatial and temporal distribution of pollutants using interpolation method, on the other hand, statistical methods like Analysis of Variance (ANOVA) was applied to determine the mean differences two phases and correlation matrix helps to understand the changing association of the pollutants in pre and during-lockdown phases. Significant correlations have been found among the pollutants, ANOVA (Two-Way) has shown the significant mean difference of NAQI between the two phases, F (1,611)=465.723, p&lt;0.0001; pairwise comparison for Ballygunj has shown the highest mean difference 108.194 at p&lt;0.0001 significant level between lockdown and pre lockdown phase. Significant positive correlation has been found between PM<jats:sub>2.5</jats:sub>, PM 10 (0.99*); PM<jats:sub>2.5,</jats:sub> NO<jats:sub>2</jats:sub> (0.81*); PM<jats:sub>10</jats:sub>,<jats:sub> </jats:sub>NO<jats:sub>2</jats:sub> (0.81*); CO, NO<jats:sub>2</jats:sub> (0.77*) and some negative correlations have also been found between O<jats:sub>3</jats:sub>, NO (-0.15); O<jats:sub>3</jats:sub> and NH<jats:sub>3</jats:sub> (-0.36) in the pre lockdown phase. The reduction amount of mean concentration from the pre lockdown phase to during lockdown of the main pollutants like PM <jats:sub>2.5</jats:sub>, PM<jats:sub>10</jats:sub> and NO<jats:sub>2</jats:sub> are ~58.71%, ~57.92% and ~55.23%. Near RBU constant emission of PM<jats:sub>2.5</jats:sub>, 10 and NO<jats:sub>2 </jats:sub>have been recorded due to the nearby Cossipore thermal power station.</jats:p>

Exploring short term spatio-temporal pattern of PM2.5 and PM10 and their relationship with meteorological parameters during COVID-19 in Delhi

“…After a quick review of the previously published studies on the assessment of air pollution level, few notable research gaps have been identified. First , the previous research studies on the assessment of air quality have focused on particular megacities such as Delhi ( Mahato et al, 2020 ; Khan, 2020 , Sikarwar et al, 2020 ) and Kolkata ( Sarkar et al, 2021 ), but very few studies were performed on the relationship between particulate matter concentration and meteorological parameters ( Dhaka et al, 2020 ). Second, although many recent studies have been performed to assess air pollution levels in India during lockdown phases ( Mahato and Ghosh, 2020 ; Sharma et al, 2020 ), very few studies have been carried out during the progression of the unlock phases of lockdown in India ( Ravindra et al, 2021 ).…”

Through Agnostic Eyes: Representations of Hinduism in the Cinema of Satyajit Ray

“…For the standard conceptualization of a nineteenth-century Bengal Renaissance characterized by a literary efflorescence, initiatives for social reform and the undermining of Hindu orthodoxy (all engendered by Western influence), see the pseudonymously published 1946 essay by the historian Susobhan Sarkar (Sen 1946) and the additional material in Sarkar (1979). Few historians today would agree unreservedly with Sarkar's interpretation, however; for a review of recent and ongoing debates on the topic, see Hatcher (2001).…”