Analysing the Severity of Coronavirus Infection in Air Pollution: Evidence-Based Study From Saudi Arabia

COVID-19 has been considered as one of the major global pandemic which has caused different health problems by affecting the majority of the population throughout the world. Several studies have evolved the concerns of air pollution being considered as a major risk factor causing respiratory infection that are carried out by microorganisms which further affects the immunity system of the body. The present study involves the relationship between the air pollutants and COVID-19 total infection along with estimation of death rates in the several regions of Saudi Arabia. The major goal of this study comprises the analysis of the relationship between air pollutants concentration such as (PM10, NO2, CO, SO2 and O3) and COVID-19 wide outbreak, concerning the transmission, number of patients, critical cases and death rates . The results show that the estimation of COVID-19 cases were highest in number recorded in the most polluted regions, the mortality rate and critical cases were also more distinct in these regions more than other regions in Saudi Arabia. The finding of this study shows a positive correlation between mean PM 10, NO2, CO and SO2 pollutants. The results represent the significant relationship between air pollution resulting from high concentration of NO2 and COVID-19 infection and deaths. Null hypothesis of the relation between other pollutants and COVID-19 infection couldn’t be rejected. The study also indicates significant correlation between mean NO2 and CO and total number of critical cases, and negative correlations were obtained between Mean O3 and total number of cases, total deaths and critical case per cumulative days.


Introduction
Recently, a highly infectious virus named as SARS CoV-2 virus coronavirus has arised causing breakdown of COVID-19 pandemic causing health problems among the individuals across the globe. The COVID-19 on going pandemic has propagated rapidly and has sparked a universal health crisis This outbreak of COVID-19 has originated and transmitted rapidly leading towards the impact of universal health crisis (Adly et al. 2020). The transmission of COVID-19 has evolved through the infections from droplets by human breathing and through the direct contact with the affected individuals that has been already studied during July, 2020. The pandemic of COVID-19 has resulted in the occurrence of almost 14,747,822 cases across the world that further involves 610,791 death rates and 8,803,885 recovery rates (WHO 2020). It has been found that the current estimation of infected cases involves estimation of 5,333,146 cases among which 5,273,445 cases have been found to have mild conditions with 99% rates and the remaining 59,701 cases have been found to have critical conditions with 1% rate estimation (WHO 2020). Concerning the cases in Saudi Arabia, 250,920 con rmed cases of COVID-19 have been recorded until October, 2020 (Adly et al. 2020). Total number of con rmed cases has been obtained to be 338,539 and the total number of deaths have been determined as 4996 along with a fatality rate of 1.5%. Saudi Arabia has been ranked at second position in the affected regions of COVID-19 cases concerning the Eastern Mediterranean region majorly involving the two most sacred religious places for Muslims i.e., Mecca and Medina. Hence, it is necessary to know regarding the scenario in case numbers within the next 4-6 months, mainly during the Hajj pilgrimage season.
Novel coronavirus is considered as an explosive outbreak resulting in human mortality rate at rapid scale (Mizumoto et al. 2020). COVID-19 has symptoms of respiratory infections resulting in severe disease among certain groups of people, mainly involving the older population having some health related problems like diabetes, cardiovascular disease, etc. (Adler. 2020). The research is still ongoing concerning its epidemiology. This disease has found to be exponentially increasing at a higher rate. The emergence of coronavirus was found in 2019 in the city of Wuhan who experienced the rst outbreak in China affecting almost seventy thousand individuals and death of more than eighteen hundred people within the prior 50 days of the pandemic. The novel coronavirus was found to affect 120,000 people resulting in mortality of 2.9% population among 109 countries and the gures are still counting. Hence, this has revealed that the transmission rate of SARS-CoV-2 is much higher due to the occurrence of genetic combination that results in enhancing its transmission ability.
The virus has been proved to be the novel coronavirus by the sequence based analysis done by isolating the sequences from the infected patients. Some of the research studies revealed that some population has adhered to this infection with intake of seafood while those individuals are also present who are infected without the consumption of any seafood. These observations proved the spreading capability of the virus among human beings which almost affected the whole world at a very high rate. Hence, the severity of the disease has been considered to be high. The virus has been transmitted at a higher rate because of the close contact of one person with another infected person that may be exposed widely due to sneezing, coughing, respiratory droplets and aerosols. These aerosols have the capability of penetrating into the human body, mainly affecting the lungs by inhaling through nose and mouth (Phan et  The impact of air pollutants among the individuals have resulted in the cause of respiratory diseases and cardiovascular diseases leading to mortality among the population. The study analysis by WHO has revealed that the healthy life of individuals are deteriorated by exposure towards particulate matter for longer duration (Ezzati et al. 2002). The major air pollutants being responsible affecting human health include NO 2 ,CO and O 3 .
The impact of NO 2 consists of a complex mixture of different pollutants that are prevalent in the air concerned with the outdoor environment.
The exposure towards NO 2 is also found indoor occurring due to the unvented combustion appliances. Most of the urban population are affected by the exposure of NO 2 which is prevalent in the atmosphere through motor vehicles which has been known as strong indicators for the emission of vehicles. It has been considered as one of the precursors for many harmful secondary air pollutants involving nitric acid, nitrate part of secondary inorganic aerosols and photo oxidants involving ozone. It causes occurrence of photochemical reactions in the environment and further leads to generation of secondary air pollutants affecting the population. The exposure of NO 2 affects the lungs along with mild airway in ammation occurrence in humans. Bronchial reactivity has been found to increase rapidly due to the exposure towards NO 2 . The hospital admissions showed cases of respiratory diseases due to increasing levels of NO 2 in the environment. Also, cardiovascular disease occurrences have been observed among most of the population.
Carbon monoxide (CO) are another major air pollutant that are generated by motor vehicles and industries in the form of outdoor pollution and are emitted from un ued gas heaters, wood-burning heaters, and contained in cigarette smoke in the form of indoor pollution. It has major effects on the health of humans as it decreases the oxygen level reaching out the body organs such as the heart and brain. An extreme increase in the CO level tends to cause death among the individuals. Symptoms like headaches, dizziness, disorientation, nausea and fatigue are the major symptoms among people who are affected from this air pollutant. It causes coronary heart diseases with chest pain among the affected population. If the concentration of CO increases in the environment, impaired vision along with symptoms of dizziness and confusion tends to occur. Adverse health impact among unborn babies when exposed towards high concentration of CO has been observed among the population.
Dust is the major source of air pollutant in Saudi Arabia that tends to cause air pollution. The human induced air pollution is prevalent in Saudi Arabia and therefore to combat this issue, lead free gasolines are coveted and sulfur level is tended to decrease by 95% in Saudi Arabian regions. The level of air pollutants are increasing from the fuel combustion by emissions from different sectors involving transportation, power generation, desalination of seawater and industrial factories. These are responsible for emitting pollutant concentrations and emissions at higher levels in the environment.
Many studies have shown that the major air pollutants causing adverse health effects in Saudi Arabia include particulate matter (PMs), carbon monoxide (CO), carbon dioxide (CO 2 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ) and heavy metals ( On analysing the health variabilities, it has been found that most of the individuals suffering from COVID-19 infection were already prone to air pollution as the regions of Saudi Arabia are prone to high pollution rates. The air pollutants emerging from the vehicles and industries in Saudi Arabia has been the major source of pollution. Covid-19 affects the respiratory system of the human body and individuals who are already prone to some respiratory disease tend to get affected from the pandemic.
Several Italian studies revealed air pollution being a risk factor during COVID-19. A correlation with higher level of PM has major impact on the The present study aimed for analyzing the relationship between ambient air pollutants and COVID-19 total infection and death rate in Saudi Arabia regions. The collected data and its analysis evolved the clarity on the fact showing correlation of air pollution in various Saudi Arabian regions with COVID-19 cases involving mortality rate and critical cases. The analysis of impact of COVID-19 wide outbreak concerning transmission, number of patients, critical cases and number of deaths was signi cantly proved. The impact of past exposure towards the air pollutants has affected the COVID-19 cases and it has been determined with facts and gures in the present study. Hence, the present study has been considered as an helpful approach for understanding the importance of reduction of the air pollutant concentration in the atmosphere for leading a healthier life.

Study area and data
This study included 10 regions out of 13 regions (Makkah Al Mukarramah, Ar Riyad, Eastern Region, Al Madinah Al Munawwarah, Aseer, Al Qaseem, Jazan, Hail, Tabuk, Al Jouf, Al Baha, Najran, Northern Region) in the geographic regions of Saudi Arabia with 45.0792° east longitude and 23.885° north latitude. Fig. 1 shows a map of Saudi Arabia outlining its 13 administrative regions. According to the database collected from the website of the General authority of Meteorology and Environment Protection (GAMEP) (https://ncm.gov.sa/Ar/Environment/AirQuality/Pages/AQ-Reports.aspx?folderID=351e1157-509d-46d1-8118-bd78d008e33d) , air pollutant data including CO, SO 2 , NO 2 , O 3 , and PM10 was identi ed. Data on Covid-19 cases was extracted from Saudi Ministry of Health o cial website (https://covid19.moh.gov.sa). 194255 COVID-19 con rmed cases have been identi ed in the 13 regions of Saudi Arabia as of June 30, 2020. Our studied regions covered 70% of con rmed cases. We focused our analysis on these 10 regions of Saudi Arabia because of the limitation of the meteorological data and the air pollution data we have obtained. Air pollutant data were only available for 10 regions out of 13 regions of Saudi Arabia, but data on Covid-19 cases were available for all regions at the time of writing.

Statistical analysis
Statistical analysis was done using SPSS version 23. A descriptive analysis was executed for all the data. The extracted data was analysed using Spearman Correlations depicting correlation between mean PM 10, NO 2 , CO, SO 2 and O 3 registered in May 2020 and COVID-19 cases in terms of total number, Deaths and critical cases per cumulative days. All analyses in this study were conducted using the Spearman Correlations coe cients between mean values of PM 10, NO 2 , CO, SO2 and O3. The statistical tests were two-sided, and P values of less than 0.05 was considered statistically signi cant.
The statistical analysis of the study shows a positive correlation between mean PM 10, NO 2 , CO and SO 2 pollutants. The results represent the signi cant relationship between air pollution resulting from high concentration of NO 2 and COVID-19 infection and deaths. Null hypothesis of the relation between other pollutants and COVID-19 infection couldn't be rejected. The study also indicates signi cant correlation between mean NO 2 and CO and total number of critical cases.

Findings and Discussion
The present study aims towards analyzing the impact of COVID-19 wide outbreak concerning transmission, number of patients, critical cases and number of deaths along with analyzing the relationship between air pollutants concentration (PM 10, NO 2 , CO,SO 2 and O 3 ). Also, the link between air pollution in various Saudi Arabian regions and COVID-19 cases, mortality rate and critical cases has been represented in the given study for showing the e cacy of study that helps in representing correlation between air pollution and cases of COVID-19. A dataset concerning the air quality was obtained from the database of the General authority of Meteorology and Environment Protection (GAMEP) including CO, SO 2 , NO 2 , O 3 , and PM10 so that the aim of the study is ful lled. Saudi Ministry of Health o cial site about COVID-19 was used for date extraction. The data involves the 13 regions of Saudi Arabia and consist of COVID-19 cases Dated June, 30, 2020. The data involved the measurement of total number of cases of COVID-19 in particular regions of Saudi Arabia along with evaluation of mean value of air pollutants such as PM10, NO 2 , CO, SO 2 and O 3 registered in particular region of Saudi Arabia during May, 2020 one month before the start of the wider transmission of the COVID-19 epidemic in the Kingdom and the highest death rate in the country. Hence, the air pollution data of Saudi Arabia during COVID-19 helps in nding out the link between air pollution in various Saudi Arabian regions and COVID-19 cases, mortality rate and critical cases. Some of the data has been found missing in the dataset. The below Table 1 is the analysis data of air pollution of Saudi Arabian regions with air pollutant concentration and COVID-19 cases. . Air pollution data for Al Baha, Najran and Northern Region were unavailable at the time of writing. Statistical analysis was done using SPSS version 23. A descriptive analysis was executed for all the data. The extracted data was analyzed using Spearman Correlations depicting correlation between mean PM 10, NO 2 , CO, SO 2 and O 3 registered in May 2020 and COVID-19 cases in terms of total number, Deaths and critical cases per cumulative days. The below Table 2 represents the analysis of the data. Hence, the above results showed that the estimation of the highest number of COVID-19 cases were recorded among the polluted regions, the mortality rate and critical cases were also more distinct in these regions more than other regions in Saudi Arabia. The nding of this study showed a positive correlation between mean PM 10, NO 2 , CO and SO 2 pollutants. The results indicated a signi cant relationship between air pollution resulting from high concentration of NO 2 and COVID-19 infection and deaths. Null hypothesis of the relation between other pollutants and COVID-19 infection couldn't be rejected. The study also indicated signi cant correlation between mean NO 2 and CO and total number of critical cases.

Conclusion
The present study involves the facts and gures concerning the impact of COVID-19 resulting in health related problems across the globe. The correlation of air pollution with the COVID-19 pandemic has been presented as the major respiratory diseases have been considered as the major outcome of the COVID-19. Covid-19 tends to affect the respiratory system in humans and the individuals who have experienced past exposure towards air pollutants are more prone to get affected from the COVID-19 infection. Hence, to show the relevancy, the present study evolves the relationship between ambient air pollutants and COVID-19 total infection and death rate in Saudi Arabian regions. The relationship between air pollutant concentration (PM 10 ,NO 2 ,CO,SO 2 and O 3 ) and COVID-19 wide outbreak concerning the transmission, number of patients, critical cases and number of deaths has been analyzed in this study. The highest number of COVID-19 cases has been recorded in the most polluted regions and the mortality rate and critical cases has been found to be more distinct in these regions more than other regions in Saudi Arabia.
Hence, a positive correlation between mean PM 10, NO2, CO and SO2 pollutants is obtained showing a signi cant relationship between air pollution resulting from high concentration of NO2 and COVID-19 infection and deaths. Figure 1 Map of Saudi Arabia regions showing its 13 administrative regions Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.

Supplementary Files
This is a list of supplementary les associated with this preprint. Click to download.