Environmental Impact of Corona Virus (COVID-19) and Nationwide Lockdown in India: An Alarm to Future Lockdown Strategies

Global emerge of zoonotic novel coronavirus (COVID-19) became a pandemic and its effect to mankind is talk of the town now a days. This tiny, invisible enemy has affected every country in the world and almost every living directly or indirectly and nationwide complete lockdown has triggered a short-term environmental impact. Since 2003, coronavirus came into existence in the form of Severe Acute Respiratory Syndrome (SARS) and more evolved Middle East Respiratory Syndrome (MERS) in 2012. This time, at the end of December 2019, outbreak of novel coronavirus COVID-19 (also known as SARS-CoV2, nCoV-2019) draw attention as global health emergency. World Health Organization (WHO) report says that the outbreak of this virus is so immense, it has already affected 35,57,235 people and caused death to 2,45,150 people worldwide and 46,433 Indians got affected with 1568 death as on 5 May 2020 (2:00 am) and these numbers are increasing exponentially day by day. Virologist, micro-biologist and science community are hammering their head very hard to find out cure and vaccine against this powerful virus and to prevent mass demise of mankind. In order to curb the spread of COVID-19, Janta curfew on 22.03.2020 and nationwide complete lockdown was implemented in India for 21 days (phase-I, from 25.03.2020 to 14.04.2020) to stop community transmission of third stage, for 19 days (phase-II, 15.04.2020 to 03.05.2020) and 14 days (phase-III, 04.05.2020 to 17.05.2020) complete lockdown to minimize the community transmission effect. During complete lockdown and quarantine period a drastic change in Earth’s atmosphere, including reduction in emission of greenhouse gases, air pollution (~50% fall in air quality index), noise pollution, water pollution and solid waste pollution, have been recorded by government agencies as well as private agencies. In this paper we considered data of Janta curfew, phase-I and phase-II lockdown to link between geological and environmental aspect related to environmental impact due to emerge of COVID19 and massive reduction in pollution level during complete lockdown in India. We propose future lockdown strategies to minimise the emission of greenhouse gas by ~100 Mt to ~200Mt (3.33% to 6.66%) of GHGtotal per year by 2-4 days per month nationwide lockdown or ~70 Mt to ~140 Mt (2.33% to 4.66%) of GHGtotal per year by 2-4 days per month complete lockdown of energy sectors only.


Introduction
China, first ranked greenhouse gas emitting nation, became the epicentre for the global emerges of zoonotic novel coronavirus  as first case was reported by the end of December-2019, from Wuhan, a capital city of Hubei province in the People's Republic of China (Fan et, al. 2019). Outbreak of coronavirus have been reported by number of workers from past two decades. During 2003, coronavirus came into existence in the form of Severe Acute Respiratory Syndrome (SARS) and more evolved Middle East Respiratory Syndrome (MERS) in 2012 and SARS was also originated in China (Yi Fan et, al. 2019). Now, third one, a zoonotic novel coronavirus COVID-19 also known as SARS-CoV2, nCoV-2019, become global health emergency, has been reported first from China only (Peeri N C et, al. 2020). Past and present study on spread of coronavirus enhances the level of confidence between scientist and researchers that bats, a powerful reservoir hosts, is a connecting link between cross-species transmission of COVID-19 to human. The first case of COVID-19 was reported from Huanan sea food market of Wuhan where a variety of animals (terrestrial and sea animals) including bats were sold out as food in large quantity. World Health Organization (WHO, 2020) has announced a global health emergency citing its immense spread and uncontrollable community transmission of this zoonotic novel coronavirus . Virologist, micro-biologist and science community are exploring all the possible way, to find out cure and vaccine against this powerful virus and to save lives. This tiny, invisible enemy has affected every country worldwide and almost every living directly or indirectly. In order to curb spread of virus, a nationwide complete lockdown was implemented which has triggered a short-term environmental change.
India, the second most populous country in the world, has also got affected by the outbreak of COVID-19 and community transmission. WHO has reported 46433 COVID-19 confirmed cases with 1568 death in India as on 5 th May 2020, 2:00 am and these numbers are compounding each day (WHO, 2020). To minimize the spread and community transmission of third stage, Government of India has taken a very strict decision of nationwide complete lockdown which affected every citizen but not as much as COVID-19 could have. Prior to complete lockdown, one day 'Janta Curfew' was imposed on 22.03.2020 to analyse the seriousness of COVID-19. The complete lockdown was planned in three phases. Phase-I was implemented from 25.03.2020 to 14.04.2020 to identify the red-zone cities (cities with maximum COVID-19 cases) and to control third stage community transmission. Nationwide complete lockdown was further extended from 15.04.2020 to 03.05.2020 (phase-II) and from 04.05.2020 to 14.05.2020 (phase-III) to minimize the spread and to save maximum lives .
Due to combined effect of 'Janta Curfew' and phase-wise complete lockdown, India has witnessed an exponential fall in emission of greenhouse gases, air pollution (~50% fall in air quality index), noise pollution, water pollution and solid waste pollution which positively impacted the environment in such a short period. The complete lockdown and its enormous environmental impact, has open a new window to restructure the current environmental laws and act of Government of India to lower the pollution level for betterment of mankind. In this paper we have correlated air quality index (AQI) data of top three polluted cities of India during outbreak of COVID-19, during 'Janta Curfew' and during compete lockdown phase-I and phase-II. An attempt is also made to formulate future lockdown strategies to lower the pollution level.

Link between pollution and virus
Geologically, the pollution can be defined as the addition of any substance (solid, liquid, gas) or any form of energy (heat, sound, or radioactivity) to the Earth's atmosphere above permissible limit which directly affect environment, every living and human health. The major kinds of pollutions are air pollution (greenhouse gas emission), noise pollution, water pollution and solid waste pollution (NEERI, 2013). Troposphere, the lowest layer of Earth's atmosphere (0km to 12km), is the most affected layer by pollution as maximum number of living and most of the polluting agents have direct exposure to this layer. Ozone layer, part of upper troposphere and lower stratosphere ( 10km to 50km), filters out sunlight wavelengths by ultraviolet wave absorption through ordinary oxygen and nitrogen in air which is one of the most important factor to effective life sustainability . Low level ozone (O3), in troposphere, is the resultant of higher rate of air pollution which is increasing in general and causing relatively higher temperatures and raising heat-related mortality during heat waves (Diem et al, 2010(Diem et al, , 2017. On the other hand, virus, a submicroscopic infectious agent that replicates only inside the living cells of an organism, can infect all types of life forms viz. animals, plants and microorganisms (Koonin et, al. 20016). Researcher has already established a direct link between pollution and virus by lab experiment (Salk andGori, 1960, Mumford et, al 1987, Gerba et, al. 2017 and many more). Virus aggregation-disaggregation is a complex process and varies with environmental circumstances (Gerba and Betancourt, 2017). It has also been proved that pollution in any form is directly concerned to human health. More precisely, air pollution (higher AQI) has both acute and chronic effects on human health. It affects number of different systems and organs resulted in minor upper respiratory irritation to chronic respiratory and heart disease, lung cancer and acute respiratory infections (Kampa and Castanas, 2008). In nut cell, human coronaviruses, including present COVID-19, which causes lethal respiratory tract infection are also related to level of air pollution. Although, more research is needed in respect of COVID-19 aggregation-disaggregation in given set of environmental circumstances by actual experimental data.

Pollution in India
Pollution is the introduction of any harmful material into the environment which has negative impact on living organism. These harmful materials are called pollutants. The major pollutions are air pollution, noise pollution, water pollution and solid waste pollution in order of abundance. Pollutions are the largest environmental cause of disease and premature death in nation and worldwide now a days. Diseases caused by pollutions were responsible for an estimated 9 million premature deaths in 2015, nearly 16% of all deaths worldwide (Landrigan et al., 2017).
The Air (Prevention and Control of Pollution) Act, 1981 describe, air pollution is the presence of any solid, liquid, or gaseous substances in the atmosphere above permissible limit which is injurious to human health and other living creatures or plants or land or environment.
It is mainly due to population explosion, rapid industrialization, deforestation, unplanned urbanization and unbalanced scientific advancement. Air pollution kills an estimated seven million people worldwide every year (WHO, 2018). WHO emphasizes that 9 out of 10 people breathe air containing high levels of pollutants. The most commonly contributing sources for air pollution are vehicles, manufacturing and electricity generation industries, construction activities, road dust, waste burning, combustion of oil, coal, biomass in the households and marine/sea salt. India for years has been striving to improve its air quality in urban areas, which takes a massive toll on the health of millions of its residents. Air pollution was the second largest risk factor contributing to disease burden in India after malnutrition in 2016 (India State-Level Disease Burden Initiative Air Pollution Collaborators, 2019).

Air Quality Index (AQI)
Quality air is prime source for sustenance of life on Earth. Air quality is determined to understand the trend of pollution which mainly includes particulate matter (PM2.5 and PM10), SO2, NO2, CO, O3, NH3, and Pb. Air pollution has maximum impact on environment and public health and its quality can be represented by measuring concentration of pollutants with standard levels. Air pollution is root cause to premature mortality and disease burden globally (Cohen AJ et al., 2017). An estimated 4.2 million premature deaths globally are linked to ambient air pollution, mainly from heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections in children (WHO, 2018). PM is currently considered to be the best indicator for health effects of ambient air pollution (Burnett et al., 2014). PM is capable of penetrating deep into lung passageways and entering the bloodstream causing cardiovascular, cerebrovascular and respiratory impacts.

Noise pollution in India
Rapid and unplanned urbanization has amplified to many health challenges that includes environmental air and noise pollution. Noise, the unwanted sound, emitted from any source above permissible limit and harmful to health is defined as noise pollution. The environmental noise is accepted as a biggest threat to human kind as it is more intense and widespread than ever before because of its exponential growth in the urban areas. From road to air traffic, humans are that much dependent on machinery that there is no way to escape from noise pollution. Noise is regarded as a pollutant under the Prevention and Control of Pollution Act, 1981 of India (MoEF 1981 Act). The World Health Organization (WHO) estimates that 10% of the world population is exposed to sound pressure levels that could potentially causes noise induced hearing loss (N (Oishi and Schacht, 2011;Basner et al., 2014). Motor vehicles are the main sources of urban noise pollution contributing about 55% to the total noise (Banerjee et al., 2008;Pandya and Dharmadhikari, 2010;Sinha and Sridharan, 2003).

Future lockdown strategies
The environmental impact of nationwide complete lockdown during outbreak of COVID-19 has opened a wide window to reform present environmental safety rules in India.
Though, the nationwide lockdown will certainly affect economic growth, GDP and every individual directly but proper strategy can minimise the loss and maximize the environmental impact for betterment. Environmental safety is directly related to human health and sustainable  Data on AQI of most polluted cities in India indicates substantial decrease (~50%) in pollution level and GHG emission during Janta curfew, phase-I lockdown and phase-II lockdown in India.
The major sectors, producing extensive air pollution (GHG emission) are transport, industries, power plants, construction activities, biomass & refuse burning, road dust suspension, were completely locked down. This resulted in air quality improvement across the nation. We have calculated GHG emission per day (approx.) in India with the formula mentioned below (figure 5).

Lockdown Strategy Model (LSM-2)
This model is based on nationwide complete lockdown of energy sector only. As per WRI CAIT, 2017 data India in 2014, emitted a total of 3163.7 Mt (MtCO2e) of greenhouse gas (GHG) and energy sector contributed almost 70% of the total. We suggest nationwide complete lockdown of energy sector once in every 15 days will save about 70Mt (2.33%) GHGtotal emission per year and 2 days continuous lockdown in every 15 days or once in a week complete lockdown of energy sector will save about 140Mt (4.66%) GHGtotal emission per year (figure 6).
Although, additional and effective future strategies are expected with respect to minimising the economic loss and maximizing the environmental impact for betterment by more research.

Some other strategy
Trees are like mask to save humans from air pollution. Afforestation, the establishment of a forest or forestation in an area where no previous tree cover was recorded, is the need of the hour. Government and non-governmental organizations directly engage in programs of afforestation to create forests and increase carbon capture but a strict rule, similar to COVID-19, is needed to percolate at individual levels. In wake of COVID-19, it can be understood that awareness can be generated in mass regarding environmental as well as health issues. Similar to COVID-19 prevention and measures, India need to warn every individual regarding seriousness of this another unseen enemy called pollution. Mandatory plantation in housing and firm land with ensuring strict compliance by government will be helpful in achieving this goal This movement can be exploited for formulation and implementation of future policy.
Afforestation and forestation help in carbon fixation and GHG reduction which are directly related to public health. Similar strategy with strict rule is also required for minimizing pollution levels, GHG emission and maximizing environmental impact for betterment.

Assessments of lockdown effect on human
A zoonotic coronavirus COVID-19 has been a pandemic worldwide since December 2019.  (Gettleman and Schultz, 2020). This resulted in thousands of people emigrated out of major Indian cities, as they became jobless after the lockdown (Priyali and Ben, 2020).
At the same time the Indian economy is expected to lose over ₹32,000 crore per day during the lockdown (The Hindu Business Line, 2020). This has affected every individual directly or indirectly up to a great extent. GHGtotal per year by 2-4 days per month complete lockdown of energy sectors only.

Conclusions
• This is a quantitative approach to minimise greenhouse gas emission and other pollutions in country after outbreak of COVID-19.
• Public health is directly related to pollution level and minimizing pollution level in country is need of the hour. The environmental impact of nationwide complete lockdown during outbreak of COVID-19 was very significant for reducing pollution levels includes air pollution (GHG emission), noise pollution, water pollution and solid waste pollution.
Nationwide lockdown with proper planning is very effective process which can be implemented strictly for environmental seftey and lowering the pollution levels.
• We propose future lockdown strategy models for reducing greenhouse gas emission. The LSM-1 model suggests nationwide complete lockdown once in every 15 days which will save about 100Mt (3.33%) GHGtotal emission per year and 2 days continuous lockdown in every 15 days or once in a week complete lockdown will save about 200Mt (6.66%) GHGtotal emission per year • The LSM-2 model suggests nationwide complete lockdown of energy sector only, once in every 15 days will save about 70Mt (2.33%) GHGtotal emission per year and 2 days continuous lockdown in every 15 days or once in a week complete lockdown of energy sector will save about 140Mt (4.66%) GHGtotal emission per year.
• Afforestation and forestation help in carbon fixation and GHG reduction up to a great extent which are directly related to public health. Mandatory plantation in housing and firm land with ensuring strict compliance by government will be helpful in achieving this goal. This movement can be achieved by formulation, implementation and strict compliance of future strategy.  3.5+ May cause respiratory effects even on healthy people and serious health impacts on people with lung/heart diseases. The health impacts may be experienced even during light physical activity.