Assessment of Air Quality Impact Due to Covid-19: A Global Scenario

Abstract

The global COVID-19 pandemic has put much of the world into lockdown which led to the unintended and positive changes in the environment surrounding us. It has benefited human race as it has led to improve air quality post-pandemic. Several studies state that the concentration of the various pollutants has decreased, where NO2 air quality index value falls more precipitously (23–37%) relative to the pre-lockdown period, followed by PM10 (14–20%), SO2 (2–20%), PM2.5 (7–16%), and CO (7–11%), but the O3 increases 10–27%. Due to this Covid-19 pandemic, D.C. has witnessed the cleanest spring since the last few decades, and L.A., one of the highly polluted city of the USA, has experienced improvement in the air quality. Air quality has always been an important issue where several big countries like China the COVID-19 outbreak has improved the air quality and lowered the pollution levels. According to several data analysis in the Chinese Ministry of Ecology and Environment, PM concentration levels decreased by more than 20% during January and April in more than 300 cities when compared to the previous month’s pollution levels. There were many cities in which the air pollution level fell drastically during lockdown, 16% in Hong Kong, and 13% in Sydney and in 14% in Singapore. Few researchers studied that when restrictions were eased the PM 2.5 level increased for cities like Beijing, Los Angeles, Melbourne, Madrid, Cape Town and New York. There were cities like New York the pollution level took a dip during the peak lockdown by 59%. Also when talking about the Indian context, the air quality improved for several cities and states including Maharashtra being worst hit state. The air pollution level resulted in ‘satisfactory’ level (AQI) due to this lockdown. After this dip, there was again a peak at 33% increase in the air pollution when the city slowly started and reached to the pre-lockdown levels. This air quality has direct impact on the health of the people. Several air pollutants like NOx have resulted on harmful effects such as increasing heart and lung disease. When examining the Indian population, around 7% of total population is above the age of 65 and 27% in the age 0–14 who are more prone to the air pollution leading diseases like asthma, bronchitis, emphysema, and possibly cancer. This onset of pandemic has cleared the thought of people where immediate changes in air quality within dense population/industry can be improved based on pollution mitigation. This chapter focuses on the worldwide air pollution studies and the findings can be implemented to maintain clean air. In addition, attempt has been made to assess the temporal behavior of daily Tropospheric Columnar NO2 Flux and Ground-level NO2 concentration for three days, one each in pre-lockdown, during lockdown and post-lockdown for three major cities of world, viz. New York, Mumbai and Wuhan. Also, NO2 pollution assessment is done by mapping the remotely sensed columnar tropospheric NO2 fluxes. Moreover, accelerated information approximately the hyperlink among air pollutants and COVID-19 can be useful worldwide with the aid of using informing public regarding fitness measures and sickness control techniques in scientific practice. The findings will be utilized by policymakers to set new benchmarks for air pollutants that could enhance the high-satisfactory lifestyles for principal sectors of the World’s populace and additionally to cut down the air pollutants in destiny with the aid of enforcing the strategic lockdowns on the pollutant hotspots with minimum financial drop.