Unravelling Bangalore's air quality during the second wave: Multifaceted analysis of COVID-19 lockdown impact

Abstract

This study assesses the impact of the second wave COVID-19 lockdown (March–June 2021) on air pollution levels in Bangalore, India, using real-time data from eight CPCB monitoring stations across the city. This research endeavours to dissect the multifaceted impact of the 2021 ​s wave COVID-19 lockdown on Bangalore's air quality. Leveraging real-time data sourced from eight CPCB monitoring stations across the city, the study meticulously delves into diverse analyses to grasp the nuanced implications of the lockdown measures. It scrutinizes changes in six major pollutants: PM_2.5, PM₁₀, CO, NO₂, SO₂, and O₃ during the 2021 lockdown compared to the same period in 2020. The comprehensive studies of different temporal scales were examined such as daily, weekly, and seasonal. The daily and weekly averages were computed to assess the percentage change in air pollutant concentrations during the March to June 2021 lockdown and pre-lockdown phases. The seasonal averages were derived to capture trends in seasonal variations. The examination of air pollution disparities across the city's eight monitoring stations (ST1 to ST8), unravelling localized variations and comprehending the spatial intricacies influencing air quality levels within Bangalore. The comparison of air pollution concentrations between the 2021 and 2020 lockdown periods, offering insights into relative changes in pollutant levels. The concentrations during the 2021 lockdown period (April 27 to June 14) significantly dropped compared to the pre-lockdown phase (March 9 to April 26) by considerable percentages across various pollutants: PM_2.5 (45 %), PM₁₀ (49 %), O₃ (37 %), NO₂ (41 %), SO₂ (5 %), and CO (30 %). The comparative evaluation between air pollutant intensity changes during the common lockdown periods of the first wave (2020) and the second wave (2021) of COVID-19. This contiguity illuminates the shifts in pollution levels and underscores the differing dynamics of air quality between these distinct phases. This research provides comprehensive insights into air quality over Bangalore city during the second wave lockdown. The multifaceted analyses offer a detailed understanding of temporal, spatial, and comparative facets of air pollution dynamics, shedding light on the significant impact of COVID-19 restrictions on urban air quality.