A Comprehensive Review on Environmental Factors Influencing COVID-19 Spread and Its Effects: A Global Approach

Coronavirus-19 is in a similar family as other human COVIDs that have caused worldwide flare-ups, for example, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). COVID causes respiratory tract diseases, which can prompt pneumonia furthermore, in extreme cases, death. Known transmission routes for COVID incorporates supported human-to-human transmission by means of respiratory beads created when a contaminated individual hack or then again sniffles. Likewise, with all novel and developing irresistible operators, it is conceivable that the proceeded with spread of the COVID could bring about a pandemic. The total clinical picture as to Coronavirus isn't completely perceived. Reported illnesses have ranged from gentle indications to extreme disease bringing about death. Current understanding about how the infection that causes void-19 spreads is that it is fundamentally from individual to-individual, between people who are in close contact with each other (inside around 6 feet) and through respiratory dabs when a polluted individual hacks or wheezes. People may be prepared to contract COVID-19 by reaching a surface or thing that has the disease on it and reaching their own mouth, nose, or, possibly, eyes, yet this isn't accepted to be the standard way the contamination spreads [1].

The COVID-19 is a communicable disease for medical society, which is caused by coronavirus of a new kind [2]. On 31 December 2019 the Chinese government originally uncovered a scene of COVID disease (COVID-19) in Wuhan, the capital of Hubei Province in China. The occurrence quickly spread from Wuhan into all provinces of China and as a minimum of 213 countries. As of 27 September, 27, 2020 33,104,362 cases of COVID-19 were authoritatively established, including 999,434 deaths. On 12 March 2020, the World Health Organization (WHO) pronounced a pandemic of the extreme intense respiratory condition Coronavirus 2 (SARS‐CoV‐2) infection, the pathogen accountable for the clinical sickness known as COVID‐19 [3]. Governments worldwide have been in putting place measures to restrict the spread of the illness, however later recent publications [4, 5] proposed the pandemic could last as long as year and a half. In this type of viral transmission, looking at the spatial spread in the beginning phases is very critical to avoid additional transmission [6]. It is anticipated that the yearly worldwide total national output will decrease by 24%, implying that it is extended to decrease by 2% every month, the forecasts likewise gauge a 13% to 32% decrease in worldwide exchange [7]. Covid-19 has reached its present form through mutations and this mutated form of this virus is responsible for the unavailability of proper medicines of this virus. It has been found that patients are mostly dependent on their natural immunity to combat the severity of the viral infection [8]. This lack of availability of proper medicine or vaccine of this virus and subsequent lack of clinical expertise has caused us to consider the only preventive measure available which is social lock down.

The direction to restrict physical interaction on an inter-individual level in order to escape individual as well as external environment is termed as social lock down. Social lock down allows people to leave their house as rarely as possible. Such as, for the shopping of basic necessities like food, for the purpose of collecting treatment or to attention for a exposed person, also to transportable to and from workplace, but all these are allowed only in the case of absolute necessity that could not be managed from home [9]. However, the atypical outburst of COVID-19 all around the world attacking cities and villages, poor and rich alike in countries like China, USA, UK, Italy, Taiwan, Spain, France, Iran, Turkey, South Korea, Germany, India, Australia, Bangladesh and many more [10]. Because of which the countries around the world went under partial or total lock down for quite a long span of time which is extending from about a limited week to a limited month. So as to evade network transmission, practically all nearby and focal organizations have given a restriction on the free movement of their residents outside of their home. Different ventures and processing plants have quit working for the present, travel have been dropped [11].

In the meantime, these actions taken to restrict the distribution of the SARS-CoV-2, by restriction of mass progress have led to a marvelous effect on the environment. The Environment pollution is a major issue of the present era. In their course of developing the civilization human beings have acted on their desires and whims causing tremendous damage to the natural environment [12]. As a result of this, global warming also came into being by the increase of concentration of greenhouse fumes like, CO₂, CH₄, N₂O etc. in the troposphere. The non-working of the businesses has added to diminishing mechanical waste discharge to an enormous degree [13]. A just about zero emission pace of green-house gases alongside harmful suspended particles in the climate have been seen because of the inaccessibility of vehicles on street. The same aforementioned reasons have also caused a reduction in the utilization of petroleum products and other customary fuel sources to a considerable extent. These factors seemingly are causing a revival in the ecosystems around the world. There have been reports of individuals encountering a spotless clear sky for the absolute first time in their lives in large urban areas [14]. Places like, Sea beaches, forests, hilly areas which are commonly used tourist spots have also seen a reduction in pollution. There was also the revival of the ozone layer to some extent. It can be said that, there was a quite contrasting effect of this pandemic on the human civilization (basing on the destruction and deaths it has caused) and on the natural environment [15]. Basing on the patterns of previous outbreaks of viruses and this recent one, it may be safe to assume that SARS-CoV-2 may turn out to not be the past novel virus to appear that can pose serious threats on global public health.

It was seen through numerous studies and observations that the pandemic nature of this virus has close connections with the environment. They seem to highly affect each other [16]. As it was found on a study conducted in the early phase of the pandemic, the endemic caused by COVID-19 tended to spread rapidly in regions with ambient temperature and thus making people confined indoor more susceptible [17]. This correlation between natural environment and this pandemic is still under study for the revelation of the correct nature of the relationship. However, the social lock down imposed for the sake of restriction of the spread of virus has definitely impacted the nature in various ways [18]. Past examinations demonstrated that freezing and dehydrated climate is useful for the endurance and spread of bead intervened viral maladies like influenza [19]. The SARS pandemic was progressively blurred with the warming climate coming, and was fundamentally finished in July, 2003 [20]. The infection was profoundly steady for an all-encompassing period at 4℃ [21]. It has been following a 7-day brooding at 22℃ (Room temperature, RT) and no irresistible infection could be identified on Day 14. They additionally watched no irresistible infection could be identified following a 30-minute brooding at 56℃ or a 5-minute hatching at 70℃. Lock down, including limited social contact and keeping open as it were those organizations basic to the nation's flexibly chains have had a helpful impact in nations [22]. For SARS-CoV-2, 1h half-life may be sufficient long for a compelling transmission, where temperature or dampness just applies seven days impact to the viral ingenuity [23]. Coronavirus is an intense respiratory ailment and could stay plausible in pressurized canned products for quite a long time [24]. Air contamination is mindful for some passing and expanded frequencies of respiratory illness [25]. SARS infection and other respiratory illnesses, for example, COPD (ceaseless obstructive aspiratory illness) find rich "region" in air poison elements and, in a straight connection, they endure extensive and become further forceful in a resistant framework previously irritated by these unsafe substances [26]. An expansion in rainfall by 1% decreases recuperation events 0.07% and increments affirmed events and passing through 1% and 0.86%, separately. A rate increment in outward weight heightens affirmed incidents and passing by 62% and 48% while it decays recuperation events by 0.07% [27].

From one point of view, climate experts foresee that ozone draining substance (GHG) releases could drop to degrees at no other time saw since World War II [28]. This outcome is generally a result of the social isolating game plans got by the governing bodies following the presence of the pandemic [29]. Despite the positive indirect ramifications for nature, the new Covid has in like manner made negative meandering ones. For example, in the USA, a couple of metropolitan networks have suspended reusing programs since specialists have been stressed over the threat of spreading the disease in reusing centers [30]. Of course, in the European nations particularly affected, the sensible waste organization has been restricted. For model, Italy has limited polluted tenants from masterminding their waste. Then again, a couple of endeavors have exploited the godsend to revoke superfluous pack blacklists. Associations that once upheld clients to bring their packs have logically changed to single-use packaging. For example, a notable coffee association announced a short limitation on the use of reusable cups. Finally, online food mentioning has extended. These improvements are achieving the extension of local waste, both regular and inorganic [31].

In a study by exploring the matter by considering both edges of the scenario as, the effect put by COVID-19 (transmission, mortality and preventive measures) on the environmental factors and vice versa it was concluded that COVID-19 pandemic had led to an improvement in the environmental quality [32]. Many countries including USA, Italy China and Spain who had severe cases of COVID-19 transmission have noticed a large reduction in air pollution, carbon emissions, sound pollution and also pollution in beaches. This came about because of the actions taken by the governments of the countries around the world, majorly due to the standstill caused by social lock down. However, the persistence of these affects in the long run is still under observation and subject to study [33]. Considering the threats posed by the viruses in the past and focusing on the challenges that lie ahead it is imperative that environmental science researchers and the scientist community in general yield a long-term, broader and more quantifiable method in understanding the viruses that spread throughout the environment [34]. It is important for us to understand and communicate our knowledge on how environmental influences effect and form the possible viral spread routes in the air, on surfaces and in solutions. In that way, we will be able to provide a more informed description on the persistence and transmission of the virus and may be able to recommend on how to mitigate the spread of the virus [35]. Therefore, in this review paper we have aimed to conduct a comparative study on how Environmental Factors are influencing COVID-19 spread as well as the way the spread of COVID-19 is affecting the environment from a global point of view.

It is essential to understand the co-relation between COVID-19 and each element of environment. For better understanding we divided the results into seven individual clauses, where we’ll be discussing if they follow any patterns, numerical value which will provide exact information and so on. Table 1 (See Appendix) shows a comprehensive insight of all literature. Figure 2 shows the top 15 countries considering to take literatures in this study.

3.1 COVID-19 and air pollution

Air contamination is an overall issue and its paraphernalia can be seen even transversely developed nations for example, Europe where 193,000 individuals died because of air contamination in 2012 [36]. Well-being of environment is a significant factor to maintain human health also, and well-being will be maintaining properly if the surrounding atmosphere remain pollution-free [37]. Most of our surrounding environment is filled with air, which is easily polluted by the industrial activity [38]. However, because of lockdowns and modern terminations as an impact constrained by COVID-19, contamination in city air and water bodies is getting a depressed mode because of nonappearance of enormous utilization of petroleum derivatives and arrival of mechanical effluents. Among numerous other areas, transportation is the utmost hard-hit portion due to lockdown [39]. Highway and inflight transport reached halt as individuals are not allowed or falter to travel. Presenting to report, air travel fell by 96% because of COVID-19, least in 75 years. NASA (National Aeronautics and Space Administration) and ESA (European Space Agency) unconfined new suggestion which proposes that ecological eminence enhanced and the release of NO₂ decreased up to 30% [40].

Higher PM_2.5 levels are related with higher number of cases and passing of COVID-19. The case-casualty rate (Deaths/cases*100) didn't increment with the expansion in PM_2.5 levels [41]. In the paper [42], any proof for the impact of air contamination was not found. There was no proof of a relationship between long-term introduction to PM_2.5 and death rate at the region level in Colombia [43]. The high centralization of viral RNA has been seen when the submicron, as well as super submicron particles having topped in the vaporized size dissemination bend, the connection between COVID-19 morbidity and mortality cases and air quality file, was not linear [44]. The most probable clarification is that the degrees of PM₁₀ and PM_2.5 found in their investigation create a fiery reaction in the lungs. In any case, key atomic occasions in reaction to PM introduction are engaged with changing the homeostasis of cardiovascular physiology [45]. Coronavirus would appear to help a comparative instrument, initiating the fast beginning of a condition of aggravation, with a similarly fast increment in incendiary cytokines, equivalent to that brought about by momentary introduction to PM [46]. The outcomes demonstrated that 78% of the passing from COVID-19 were moved in five regions situated in northern Italy and central Spain. In these zones, there was an elevated level of nitrogen dioxide [47]. (Figure 3) Coronavirus actuated social lockdown versus contamination in a few countries. NO₂ level (red lines) and atmospherical particulate issue (PM_2.5, blue lines) in a) Italy, b) Spain, c) France, d) Los Angeles, USA, e) Wuhan city, f) China and g) India as an element of lockdowns [48].

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Figure 2. Top 15 countries we have considered while taking literatures to review

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Figure 3. Coronavirus actuated social lockdown versus contamination in a few countries. NO2 level (red lines) and atmospherical particulate issue (PM2.5, blue lines) in a) Italy, b) Spain, c) France, d) Los Angeles, USA, e) Wuhan city, f) China and g) India as an element of lockdowns [11]

3.2 COVID-19 and meteorological factors

As implicated by many studies, meteorological factors are found to show an independent part in the spread of COVID-19 [49]. The two most significant weather factors are temperature and humidity. Temperature and humidity influence the Earth's climate, human wellbeing and human prosperity [50]. Air temperature changes influence how much water fume the air can hold. Qualities, for example, relative humidity and dew point help portray these impacts on climate. So, these two factors should be highly valued in terms of meteorological parameters studies.

3.3 COVID-19 and temperature

One of the major meteorological parameters is temperature. Numerous studies have been conducted around the world to find out the correct nature of correlation between COVID-19 spread and temperature. A study conducted in China found that, a weather with mild diurnal temperature and low temperature range are most probable to help the transmission of COVID-19. An obvious tendency was found amid established case counts and ambient temperature. A temperature rises in the range of -20℃ to 20℃ seemed to cause a surge in the number of confirmed cases. It was likewise demonstrated that the confirmed cases check declined with the expansion of in the Diurnal Temperature range of about 5℃-15℃ by the regression model. However, ambient temperature and Diurnal Temperature range both were found to be not positively associated with the surge of transmission of COVID-19 [51].

Another study in China found a positive association between daily Temperature range and newly death counts of COVID-19. A stable measure of temperature is represented by DTR, which acts as an indicator variability of temperature so that the effects on humanoid health, with morbidity and mortality can be evaluated [52]. A negative connection was demonstrated among temperature and COVID-19 mortality. As per another review it was found that, that lower temperature may repress the function of immunity [53]. However, a study conducted in the US found temperature to be an underprivileged metric for the study of the climate-based expand in the US, as it was not possible to identify any restricted weak scope of temperature. They found among an amount of test cases in a particular time interval to fall in a wider range of 4℃-11℃ temperature. Which was found to be in league with other studies around the world, where the majority of spread was found in temperature range of 5℃ to 11℃ and 3℃ to 17℃ [54]. A study conducted in Mexico found that, locally confirmed positive cases of COVID-19 was associated negatively with Temperature. There was a crucial role played by the climate characteristics on the regional infection throughout the phase 1 of transmission. Where the tempered regions (19.65℃) were more vulnerable than that of the dry (20.57℃) or the tropical areas (mean temperature around 25.95℃. An investigation led in Mainland China believes that, Countries and locales with lower temperature should give more consideration as temperature demonstrated negative relationship with COVID-19 [55]. A temperature increments in the scope of -20℃ to 20℃ appeared to cause an expansion in the quantity of affirmed cases. It was likewise demonstrated that the affirmed cases tally declined with the expansion of in the Diurnal Temperature scope of around 5℃-15℃ by the relapse model. Be that as it may, encompassing temperature and Diurnal Temperature range both were discovered to be contrarily connected with the expansion of transmission of COVID-19 [56].

A Global report found that, there was a negative connection among temperature and COVID-19 mortality, since at lower temperatures, the exhibition of the safe framework, and the liver declines. Subsequently, the circumstance will be helpful for the movement of irresistible specialists and viral transmission. An investigation in China reasoned that, Temperature is functioning as an ecological driver of the COVID-19 episode in China. Likewise, that, with the expansion of temperature a decline in the frequency of COVID-19 happens. A biphasic relationship was likewise found between temperature (with a top at 10℃) and every day affirmed cases pace of COVID-19. It was likewise discovered that at values beneath or more these qualities the day by day occurrence of COVID-19 diminished [57].

Temperature and the short-wave radiation were discovered to be the most affected factors in a Chinese report, where, the affirmed cases were discovered to be the most affected instances of climate factors. Then another Chinese examination found that, to clarify why cases spread quicker on specific days than others temperature could be a critical informative variable. On an average 1.2 rate point decline in the rate increment in affirmed cases is corresponded with each extra centigrade over 5 degrees of temperature. An examination in Indonesia found that, temperature normal (℃) was altogether associated with Coronavirus among five climate factors that were considered [58]. Another investigation discovered Temperature to be around the world contrarily identified with the everyday new passing and day by day new instances of COVID-19. Aftereffects of an investigation in China propose that, there is a positive straight connection between mean temperature and the quantity of COVID-19 cases with a limit of 3℃. A 4.861% expansion in the everyday affirmed cases were related with 1°C ascend in the mean temperature of a week ago. A Global report found that, development rates crested in areas that had a mean temperature of ~5℃ all through the episode month, while diminishing both in colder and hotter atmospheres.

In Turkey temperature upon the arrival of the case were found to impact the affect COVID-19 cases. In any case, an alternate report in Turkey found that, Air temperature and the quantity of bright days didn't influence the quantity of cases. A worldwide report discovered, negative relationship between COVID-19 diseases and nation normal temperature while watching no relationship among deaths and nation temperature. In an examination the quantity of cases analyzed appeared to increment under a most extreme temperature of 10℃ and were found to straightly diminish a while later. The highest spread of COVID-19 appeared to happen in Bangladesh at a normal temperature of 26℃. It was likewise discovered that, under a straight linear regression framework, the transmission of COVID-19 was discovered to be altogether decreased by high temperature. An investigation in Spain found no proof of a connection among temperature and COVID-19 cases [59].

In Bangladesh COVID-19 confirmed illness and death cases were found to have a strong confirmed correlation with average temperature and minimum temperature. Though they mention that, the relationship between COVID-19 cases and climate variables is still not understood well. The results of a study in Russia show that transmission in the humid continental region highest contribution for COVID-19 is of temperature seasonality (29.2 ± 0.9%). While, in the sub-arctic region temperature seasonality (14.6 ± 0.8%) and the diurnal temperature range (26.8 ± 0.4%) had the maximum impacts.

In Singapore a study found that, temperature shows a positive significant association with SARS-CoV-2 transmission [60]. A study conducted in China and Italy showed that, relationship of spread of coronavirus disease with maximum temperature is ranging between negligible to moderate. Results of a Brazilian study showed that higher mean temperatures favored the COVID-19 transmission. An examination in New York, USA indicated that base temperature and normal temperature have huge connection with COVID-19 scourge. An examination in the quantity of affirmed COVID-19 cases in the Russian Federation with temperature-most extreme, least, and normal found a solid relationship between normal temperature (rs = 0.75***) and furthermore a noteworthy connection for different variations of temperature. Subsequently, validating the theory of climate initiated COVID-19 spread. Another examination proposed that ecological temperature influences transmission instead of the disease severity. This examination demonstrated that, lower temperature may cause an expansion of SARS-CoV-2 transmission (estimated as an expanded assault rate), however there was no proof that temperature influences the disease severity of the ailment (estimated as case casualty rate) [61].

3.4 COVID-19 and humidity

As drawn up by numerous investigations, meteorological variables are found to assume an autonomous function in the transmission of COVID-19. An indicator to describe the mass of water fume per volume of air is Absolute humidity. One of the most significant climate boundaries in anticipating heat-related mortality among a range of climate boundaries is Absolute Humidity. A major meteorological parameter to correctly indicate the condition of the environment is Humidity. Studies have been conducted around the world to find out the correct nature of correlation between COVID-19 transmission and Humidity. It was indicated by many studies that, a superior pointer of humidity in intense wellbeing impacts is Absolute Humidity [62].

In China, the coronavirus outbreak happened in the wintertime and initial spring season with lesser Absolute Humidity. As specified by the results in this study, there might cohabit an optimal low humidity for the spread of COVID. There might be a possibility that, low Absolute humidity may favor the transmission and stability of coronavirus like influenza. It was confirmed by the researchers that respiratory contamination was found to be boosted during uncommonly frozen and subtle humidity conditions. Which indicates that, slight humidity might be a significant risk factor for the lung diseases [63].

The results of an analysis in Wuhan, China also indicate that with the increase of absolute humidity, the consequence of dying from COVID-19 decreases. The susceptibility of the host towards to respiratory virus infection may increase due to reduction of mucociliary clearance or epithelial damage caused by breathing dry air. It was found from a global study that; elevated humidity may decrease COVID-19 passing and surge recuperation rates. As, relative humidity may render coronaviruses to be inactive particularly on inanimate objects. According to reports, a higher relative humidity was found to diminish the determination and practicality of the infections contrasted with that in lower relative humidity. Coronaviruses were found to survive in a low relative humidity environment and thus prolonging its stability and viability on contaminated surfaces. It was found that, in an environment with low relative humidity and low temperature coronavirus contamination can be retained for 14 days. An US based study that claimed to be consistent with worldwide observations, found that the spread of COVID-19 was significantly upheld by climate boundaries in the reaches 3 to 8 g/m³ of Absolute humidity. In another study greater part of the new cases far and wide were discovered to be in nations with 4 to 9 g/m³ of Absolute humidity [64].

A study on Hubei province and in some other provinces of China suggested that, relative humidity and daily temperature both influenced the occurrence of COVID-19. A study conducted in Bangladesh suggests that, relative humidity reduces the transmission of COVID-19. Higher humidity was found to help prevent infection by keeping the layers in the nose and throat damp, which would empower them to catch infections, microscopic organisms, and earth before they can arrive at the lungs.

In Dhaka city of Bangladesh, a solid straight relationship has been watched for the COVID-19 aggregate and passing cases with relative humidity. An examination in Russia found that, in the sub-cold locale, diurnal temperature range, humidity positively affects the COVID-19 spread. It was additionally settled by this examination that, on the power of the COVID-19 transmission the function of normal relative humidity was modestly related and reliable. According to the outcomes, 75-80% relative moistness in the sub-arctic locale and 60-65% in the humid mainland district is more appropriate for the infection and decently related [65]. The COVID-19 transmission in a mild zone was discovered to be commonly appropriate in the states of high relative moistness additionally in tropical territories, high relative humidity is connected with the transmission of COVID-19 cases however not as unequivocally related as a temperate area. These discoveries are in accordance with another investigation from China that expressed that normal relative humidity running between 50%-80% comprise a fitting condition for the network transmission of this infection [66].

An investigation in Singapore discovered relative humidity, absolute humidity, and water fume to show positive noteworthy connection with COVID-19 pandemic. A study in Iran found an opposite relationship of humidity within the disease outbreak speediness. In Brazil intermediate relative humidity was found to influence the COVID-19 transmission rate. Thus, it was shown that, average relative humidity preferred the COVID-19 transmission, which was different from reports from most arctic countries or ages of time below calm temperatures.

A study combining four of the most concerned places of China and five of the most concerned places of Italy, it was found that, the relationship with maximum relative humidity is mostly negligible. While a study in Jakarta, Indonesia found humidity to not be significantly correlated with COVID-19 [67].

3.5 COVID-19 and wind speed

Wind is an essential factor in the transmission of respiratory irresistible sicknesses and it might adjust the elements of different vectors and microbes [68]. Wind speed has a huge and converse relationship with the pace of COVID-19 contamination rate. In this way, in the lower speed of the breeze, the contamination rate is higher [69]. Both breeze speed and surface weight are found to increase attested occurrences of SARS-CoV-2 across countries. If the airborne factor of Covid holds, by then, both breeze speed and surface weight controls fast track the spread of the contamination, by enlivening the strategy for adventure out beginning with one territory then onto the following [70]. Wind speed clarified 9% difference of the coverage or the quantity of cases. This clarification demonstrates that wind is a reasonably significant factor. It is hard to control the spread of the infection in blustery climate. Contingent upon the power of the breeze and the bearing of stream, the COVID-19 infection can be moved. In Turkey, the ordinary breeze speed in 14 days has the most significant relationship with the number of cases [71]. The higher the breeze speed is, the more the number of cases is. The results moreover show that the most reasonable time span is 14 days, which implies that the breeze speed in 14 days of the case should be considered for choosing the right relationship. Wind is a significant factor in irresistible infections transmission and it can regulate the elements of different microorganisms and vectors. Wind speed indicated noteworthy of negative correlation relationship with coronavirus cases over Singapore. Like this examination, negative connection between Coronavirus and wind speed was likewise detailed over Iran. Wind speed was not negatively associated with COVID-19 case over Oslo, Norway [72]. Also, wind speed and precipitation likewise demonstrated a huge positive connection with COVID-19 cases in Dhaka, Bangladesh. In Italy inspects shows that metropolitan territories with low wind speed have more critical degree of tainted individuals than metropolitan networks having higher breeze speed [73].

3.6 COVID-19 and precipitation

In our course to discovery the correlations among climatic factors and COVID-19 spread we studied the relation between an important climatic factor, precipitation and spread of COVID-19 as presented by many studies around the world. A global study found that, there is a sturdy correlation and interconnection between confirmed cases and moisture-based weather factors, like precipitation. Rather it was found that precipitation and other moisture -based meteorological factors convert dehydrated environment to a humid and freezing condition by lessening temperatures to low levels establishing a climate positive for the endurance and transmission of the infection. A report demonstrated that, human COVID make due for a couple of hours in a dry climate yet in a sodden suspension can remain alive for a few days.

It was likewise discovered that, precipitation had caused an expansion in the pace of number of passing from COVID-19 and has additionally nullified the pace of recuperation [74]. Another worldwide examination found a positive connection between SARS-CoV-2 transmission and precipitation, with the end goal that, an expansion of 56.01 cases/day happened for every 1-in. increment in precipitation/day [75].

A study conducted in Dhaka, Bangladesh shows that, rainfall showed a substantively positive association with the number of COVID-19 cases [76]. However, a study in China has shown more varying results as rainfall having a negative movement with confirmed and recovered cases in Shanghai while showing a strong positive movement with Deaths cases in Fujian. Some studies also found precipitation to not be significantly correlated with COVID-19 [77]. While some studies claimed that they did not find precipitation to be related with COVID-19 [78]. In some studies precipitation was not evaluated as a sole parameter but in combination with temperature as a combined weather condition [79].

Such a study showed that, the regional climate of states in Mexico had statistically significant association with LCPC and LTR. Where dry and mild virus atmospheres with the most reduced temperatures and precipitations enrolled (19.65℃ and 8.48 mm individually) were the more appropriate natural conditions for transmission and watched the quickest local onsets. Notwithstanding, in locales with lower temperatures and higher precipitations (20.57℃ and 20.87 mm separately) beginning happened sooner than in different areas in dry atmosphere [80]. While the heat and humidity with mean temperature around 25.95℃ and mean precipitation around 8.74 mm encountered a deferral in the local beginning [81].

3.7 COVID-19 and other factors

Noise pollution affects around 100 million people all over Europe, as per the WHO. Much health degrading issues can arrive due to noise pollution including low to extreme level of stress, mental discomfort, rise of blood pressure as well as heart rates. Every single source of noise contamination at present are because of some type of humanoid actions, from traffic to residential or industrial and many more [82].

During this lockdown period, street and inflight traffic has fallen considerably in most counties. For example, in the Indian main cities of Mumbai, New Delhi, Chennai and Bengaluru the foot print (estimated as the everyday normal changeover of impressions (%) regarding walk-ins from home to food supplies, petroleum pumps, diagnostic hubs and bank) to corresponding sectors has noticeably decreased during lockdown [83]. With this decrease in human movement, the planet is said to have calmed down. Seismologists have been known to be reporting lower levels of vibration from “cultural noise” than they did prior to the pandemic [84].

As the COVID-19 induced lockdown has pushed about one third of the human population indoors, the wild animals seem to be taking advantage of this absence, they are found affecting across human inhabitation roads, cities etc. Overall population have come to watch some unconstrained changes happening in nature and in this manner seeing its self-restoration. Air Quality Index (AQI) is one of the strong measurements which appear to be changing for the nature and its solid environment [85].