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, SO2, NO2, O3, and PM10 was identified. Data on Covid-19 cases was extracted from Saudi Ministry of Health official website (https://covid19.moh.gov.sa). 194255 COVID-19 confirmed cases have been identified in the 13 regions of Saudi Arabia as of June 30, 2020. Our studied regions covered 70% of confirmed 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, NO2, CO, SO2 and O3 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 coefficients between mean values of PM 10, NO2, CO, SO2 and O3. The statistical tests were two-sided, and P values of less than 0.05 was considered statistically significant.
The statistical analysis of the 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.
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, NO2, CO,SO2 and O3). 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 efficacy 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, SO2, NO2, O3, and PM10 so that the aim of the study is fulfilled. Saudi Ministry of Health official 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, NO2, CO, SO2 and O3 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 finding 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.
Table 1 Distribution of Covid-19 cases on June 30 , 2020 (total number of cases, Deaths, critical cases) as per each Saudi Arabia region and the mean value of PM 10, NO2, CO,SO2 and O3 registered in each region during May 2020.
Saudi Arabia Regions
|
Total number of cases
(n)
|
Deaths
(n)
|
Critical cases
(n)
|
Mean PM10 in May, 2020
(µg/m3)
|
Mean NO2 in May, 2020
(ppb)
|
Mean CO in May, 2020
(ppm)
|
Mean SO2 in May, 2020
(ppb)
|
Mean O3 in May, 2020
(ppb)
|
Makkah Al Mukarramah
|
57548
|
954
|
482
|
101.00
|
12.76
|
0.74
|
6.24
|
28.97
|
Ar Riyad
|
52932
|
383
|
512
|
97.48
|
13.07
|
1.18
|
2.63
|
17.85
|
Eastern Region
|
48274
|
157
|
815
|
33.93
|
10.99
|
1.67
|
4.02
|
19.55
|
Al Madinah
|
15106
|
98
|
82
|
97.09
|
11.15
|
0.75
|
3.35
|
20.87
|
Aseer
|
7936
|
15
|
194
|
56.00
|
3.24
|
0.54
|
2.86
|
26.96
|
Al Qaseem
|
3812
|
20
|
82
|
107.55
|
2.77
|
0.73
|
2.16
|
31.25
|
Jazan
|
2448
|
30
|
23
|
21.40
|
5.60
|
1.01
|
4.92
|
8.19
|
Hail
|
1619
|
3
|
37
|
107.62
|
4.62
|
0.55
|
2.52
|
41.42
|
Tabuk
|
1555
|
17
|
5
|
79.38
|
5.02
|
0.68
|
3.38
|
39.46
|
Al Jouf
|
248
|
2
|
2
|
27.64
|
1.99
|
0.68
|
7.61
|
37.75
|
Al Baha
|
684
|
6
|
7
|
NA
|
NA
|
NA
|
NA
|
NA
|
Najran
|
1662
|
1
|
33
|
NA
|
NA
|
NA
|
NA
|
NA
|
Northern Region
|
431
|
15
|
2
|
NA
|
NA
|
NA
|
NA
|
NA
|
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, NO2, CO, SO2 and O3 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.
Table 2 Spearman Correlations coefficients between mean PM 10 ,NO2,CO,SO2 and O3 registered in May 2020 and COVID-19 cases in terms of total number, Deaths and critical cases per cumulative days (data updated to 30 Jun 2020).
Correlations
|
Pearson’s coefficient
(r-value)
|
Significance
(p-value)
|
Mean PM 10 – Total number cases
|
0.178
|
0.623
|
Mean PM 10 – Deaths
|
0.334
|
0.345
|
Mean PM 10 Vs. Critical cases per cumulative days
|
- 0.046
|
0.8995
|
|
|
|
Mean NO2 – Total number cases
|
0.885
|
0.001
|
Mean NO2 – Deaths
|
0.713
|
0.021
|
Mean NO2 Vs. Critical cases per cumulative days
|
0.722
|
0.0184
|
|
|
|
Mean CO – Total number cases
|
0.607
|
0.063
|
Mean CO – Deaths
|
0.136
|
0.709
|
Mean CO Vs. Critical cases per cumulative days
|
0.7387
|
0.0073
|
|
|
|
Mean SO2 – Total number cases
|
0.098
|
0.290
|
Mean SO2 – Deaths
|
0.327
|
0.357
|
Mean SO2 Vs. Critical cases per cumulative days
|
0.0017
|
0.996
|
|
|
|
Mean O3 – Total number cases
|
-0.372
|
0.290
|
Mean O3 – Deaths
|
-0.138
|
0.705
|
Mean O3 Vs. Critical cases per cumulative days
|
-0.3798
|
0.279
|
The above tables represented the relationship between air pollutant concentration (PM 10, NO2, CO, SO2 and O3 ) and COVID-19 wide outbreak concerning the transmission, number of patients, critical cases and number of deaths. The study correlation was conducted to show the link between air pollution in various Saudi Arabian regions and COVID-19 cases, mortality rate and critical cases.
Positive correlations were obtained among the total number of cases and Mean PM 10, NO2, CO, SO2 and O3 (showing r-value=0.178, 0.885,0.607 and 0.098) . But, the correlation was only significant with NO2 (showing p-value as 0.001). However, appreciable correlation was obtained between mean CO and total number cases of COVID-19 in Saudi Arabia. Positive correlations was obtained between total number of deaths and mean PM10, NO2, CO and SO2 (showing r-value as 0.334, 0.713,0.136 and 0.327), but the correlation was only found significant with NO2 (showing p-value to be 0.021). Positive correlations were obtained between total critical cases per cumulative days and Mean NO2,CO and SO2 (showing r-value as 0.722, 0.739 and 0.0017) . The correlation was observed to show significance with NO2 and CO with p-value as 0.0184 and 0.0073. Negative correlations were obtained between Mean O3 and total number of cases, total deaths and critical cases per cumulative days with r-value as - 0.372, - 0.138 and – 0.379. The correlation did not show any significance with all these relations with p-value greater than 0.1.
The correlation of the mean concentration of CO during May 2020 with the number of critical cases for COVID-19 infection per cumulative days (patient data updated at 30 June 2020) was represented by scatter plotting in Fig. 2.
Fig.2 shows the relation between CO and number of critical cases of COVID-19. Most of the critical cases of COVID-19 have been found in the Eastern Region of Saudi Arabia. Hail and Aseer have determined to have the least number of critical cases of COVID-19 among all the 13 regions selected for the study in Saudi Arabia. Ryadh has been determined to have more critical cases when compared with Makkah. Al Qaseem, Jazan, Hail, Tabuk, Al Jouf, Al Baha, Najran have been also determined to have less number of critical cases when compared to other regions selected in this study.
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 finding of this study showed a positive correlation between mean PM 10, NO2, CO and SO2 pollutants. The results indicated a 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 indicated significant correlation between mean NO2 and CO and total number of critical cases.