7 COVID-19: Disaster or an Opportunity …
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individual. 98% of cities of low-income countries fail to meet air quality standards
set by WHO [47]. ‘Cleaner air is one of the goals of environment sustainability’.
The air quality is mainly deteriorated due to the presence of aerosols also known as
PM 2.5 which leads to cardiovascular and pulmonary diseases [11].
Impact and Reasons for Improvement in Quality of Air
The modifiable sources of air pollution can be modulated either by changing the
source intensity or activity levels such as electricity generation, traffic and cooking.
Regulations in respect of air pollution targets typically on factors that can reduce
emissions rather than on the activities that can be altered. The closures observed in
industries, factories, decrease in traffic on roads and other modifiable factors due
to COVID-19 provided a new opportunity to quantify and observe the impact in
real time situation [67]. In India, the lockdown was imposed from 24 March to
14 April 2020 due to which air pollution decreased significantly within few days
[40]. Industries like textile, pharmaceuticals, leather and electronics along with high
population index make Mumbai and Delhi as the cities which are most polluted
in the world. Almost all places of public gathering such as shopping complexes,
schools, cinemas, educational institutions, restaurants were closed, industrial and
manufacturing units shut, transportation and travelling services by air, road and rail
were stopped and people were asked to work from home during nationwide lockdown
affecting the economy negatively [35].
As industrial activities were closed, flights and other modes of transport restricted,
there was decrease in air pollution and emission of gases causing greenhouse effect.
There was decrease in carbon in atmosphere basically due to lessening in fossil
fuel burning emissions. Decrease in levels of nitrogen dioxide (NO 2 ) by 40% was
found in cities of Asia and Europe as compared to same period in 2019, 30% in
New York and 60% in UK. Delhi has witnessed a reduction of over 70% in PM 2.5
levels while US has witnessed a 33, 22 and 19% drop in PM 2.5 concentrations in
Los Angeles, New York and Seattle, respectively, during lockdown in the month
of March–April, 2020 [34]. The major source of nitrogen dioxide is road transport
and power plants which were almost shut due to coronavirus. Another reason for
improvement in air quality was the reduction in human activities [15]. There was also
reduction in particulate matter (PM) or aerosol levels after the COVID-19 lockdown.
Also reduction in waste and crop residue burning was found which improved the
air quality. Factories, markets, shops and places of worship closure, public transport
and construction work suspension have improved the air quality [53]. The air traffic
dropped by 60% globally which has lead to reduction in greenhouse gas emissions
which has a great impact on today’s climate change [27]. The improvement in air
quality index (AQI) across India is given in Table 7.1 [7].
Air pollution was reduced in Bangkok due to lockdown otherwise schools were
forced to close down few months back due to air pollution [45]. Some indirect benefits
were also seen due to improvement in the quality of air because of coronavirus and
lockdowns. Gradual repair of the ozone hole was also noticed because of reduction
in greenhouse gases and particulate matter in the upper atmosphere due to lessening
of air traffic. Upcoming monsoons were also impacted by lockdown [15]. It has
173
individual. 98% of cities of low-income countries fail to meet air quality standards
set by WHO [47]. ‘Cleaner air is one of the goals of environment sustainability’.
The air quality is mainly deteriorated due to the presence of aerosols also known as
PM 2.5 which leads to cardiovascular and pulmonary diseases [11].
Impact and Reasons for Improvement in Quality of Air
The modifiable sources of air pollution can be modulated either by changing the
source intensity or activity levels such as electricity generation, traffic and cooking.
Regulations in respect of air pollution targets typically on factors that can reduce
emissions rather than on the activities that can be altered. The closures observed in
industries, factories, decrease in traffic on roads and other modifiable factors due
to COVID-19 provided a new opportunity to quantify and observe the impact in
real time situation [67]. In India, the lockdown was imposed from 24 March to
14 April 2020 due to which air pollution decreased significantly within few days
[40]. Industries like textile, pharmaceuticals, leather and electronics along with high
population index make Mumbai and Delhi as the cities which are most polluted
in the world. Almost all places of public gathering such as shopping complexes,
schools, cinemas, educational institutions, restaurants were closed, industrial and
manufacturing units shut, transportation and travelling services by air, road and rail
were stopped and people were asked to work from home during nationwide lockdown
affecting the economy negatively [35].
As industrial activities were closed, flights and other modes of transport restricted,
there was decrease in air pollution and emission of gases causing greenhouse effect.
There was decrease in carbon in atmosphere basically due to lessening in fossil
fuel burning emissions. Decrease in levels of nitrogen dioxide (NO 2 ) by 40% was
found in cities of Asia and Europe as compared to same period in 2019, 30% in
New York and 60% in UK. Delhi has witnessed a reduction of over 70% in PM 2.5
levels while US has witnessed a 33, 22 and 19% drop in PM 2.5 concentrations in
Los Angeles, New York and Seattle, respectively, during lockdown in the month
of March–April, 2020 [34]. The major source of nitrogen dioxide is road transport
and power plants which were almost shut due to coronavirus. Another reason for
improvement in air quality was the reduction in human activities [15]. There was also
reduction in particulate matter (PM) or aerosol levels after the COVID-19 lockdown.
Also reduction in waste and crop residue burning was found which improved the
air quality. Factories, markets, shops and places of worship closure, public transport
and construction work suspension have improved the air quality [53]. The air traffic
dropped by 60% globally which has lead to reduction in greenhouse gas emissions
which has a great impact on today’s climate change [27]. The improvement in air
quality index (AQI) across India is given in Table 7.1 [7].
Air pollution was reduced in Bangkok due to lockdown otherwise schools were
forced to close down few months back due to air pollution [45]. Some indirect benefits
were also seen due to improvement in the quality of air because of coronavirus and
lockdowns. Gradual repair of the ozone hole was also noticed because of reduction
in greenhouse gases and particulate matter in the upper atmosphere due to lessening
of air traffic. Upcoming monsoons were also impacted by lockdown [15]. It has