Variation of tropospheric NO2 over Indo-Gangetic plain during COVID-19 outbreak in India

Abstract

Nitrogen dioxide (NO 2 ) is a gaseous air pollutant which primarily gets in the air when fossil fuels such as coal, oil, gas or diesel are burned at high temperatures through industries, power plant, automobiles and locomotive. Continuous exposure to elevated concentration of NO 2 may impose development of asthma and potentially increase in susceptibility to respiratory infections in humans. The present study examined impact of lockdown due to COVID-19 in terms of spatial and temporal variation of tropospheric NO 2 in Indo-Gangetic plain. The results showed steep reduction in tropospheric NO 2 as a result of ceased industrial and economic activities. Analysis of Sentinel-5P satellite data was carried out for specific period during 2019–2020 at a regional scale and for major industrial cities. Tremendous positive impact of lockdown in atmospheric condition is observed, wherein NO 2 concentration has gone down by 20–40% in all major cities except few exceptions were noticed. The concomitant impact of Covid-19 has ensued pragmatic constructive impact on environment and climate, due to drop in NO 2 emissions.

State of air pollutants and related health risk over Haryana India as viewed from satellite platform in COVID-19 lockdown scenario

“…This indicates the potential of satellite-based products for regular air quality monitoring and ER% assessment. Our findings regarding the reduction in air pollution concentration due to COVID-19 driven lockdown were consistent with Ranja et al [ 4 ], Sharma et al [ 5 ], Siddiqui et al [ 6 ], Sur et al [ 12 ], and Singh and Nanda [ 27 ], among others. Objective-wise descriptions of results are described in forthcoming sections.…”

“…NO 2 also showed a decrease in concentration and results were following other studies from across the world such as Siddiqui et al and Sur et al [6,12] in India, Dantas et al [13] in Brazil, Brimblecombe and Lai [21] in China, and Jephcote et al [22] in United Kingdom (UK). Though the decrease in NO 2 concentration was significant (p = 0.05), it decreased less as compared to other pollutants (except CO and CH 4 ).…”

“…However, COVID-19 driven lockdown has shown glimpses of reduced air pollution in 2020 worldwide, including India [ 4 , 6 , 11 – 15 , 25 , 26 ]. Though, the assessment of effect of COVID-19 driven lockdown on air quality both at global [ 11 ] and regional [ 4 , 6 , 11 – 15 , 25 , 26 ] scale taking ground [ 5 , 15 ] and satellite-based [ 4 , 6 , 12 ] observations are available, no study reported the satellite-based AQI and ER% assessment over any region of the globe and over the Indian region (Haryana) in particular. Furthermore, there is no reported study for the validations of Sentinel-5P satellite-based pollutant products concerning ground observations which gives novelty to the current work.…”

Geospatial View of Air Pollution and Health Risk Over North Indian Region in COVID-19 Scenario

“…were allowed during lockdown (Sharma, 2020 ). The lockdown has significantly reduced the transportation, mobility, and industrial operations which resulted in to the reduced level of air pollutants and improvement in the air quality (Sharma et al, 2020 ; Siddiqui et al, 2020 ; Singh & Nanda et al, 2021c ; Srivastava et al, 2020 ; Sur et al, 2021 ).…”

“…The changes in the pattern and magnitude of anthropogenic activities amid COVID-19 lockdown have clear impact on air quality and recent pandemic, i.e. COVID-19 has shown the glimpses for the same (Bao & Zhang, 2020 ; Bhawre, 2020 ; Dantas et al, 2020 ; Filonchyk et al, 2020 ; Kant et al, 2020 ; Lal et al, 2020 ; Nakada & Urban, 2020 ; Otmani et al, 2020 ; Pathakoti et al, 2020 ; Ranjan et al, 2020 ; Sharma et al, 2020 ; Siddiqui et al, 2020 ; Singh & Nanda et al, 2021c ; Srivastava et al, 2020 ; Sur et al, 2021 ).…”