Monitoring Pollution and the Trend of Air Quality in Brick Factories in the Nahrawan Region and its Impact on Baghdad, Using Remote Sensing Data

One of the most significant environmental issues facing the planet today is air pollution. Due to developments in industry and population density, air pollution has lately gotten worse. Like many developing nations, Iraq suffers from air pollution, particularly in urban areas with heavy industry. Our research was carried out in Baghdad's Al-Nahrawan neighbourhood. Recently, ground surveys and remote sensing were used to study the monitoring of air pollution. In order to extract different gaseous and particle data, the Earth Data Source, Google Earth Engine (GEE), and Geographic Information Systems (GIS) software were all employed. The findings demonstrated that there is a significant positive connection between data collected by ground-based devices and remote sensing platforms. The brick manufacturers' operations in the region's northwest and west directions from Baghdad were plainly having an impact on the region of Al-Air Nahrawan's quality. As a result, residents in the area are more likely to contract illnesses caused by pollution.


Introduction
One of the biggest environmental issues, which mostly affects cities, is air pollution.According to the WHO, air pollution is the contamination of an indoor or outdoor environment by chemical, physical, or biological factors that results in changes to the ambient air's normal characteristics and is detrimental to human health as well as the health of other living things [1].With the advancement of industrialization and urbanization, air pollution in Asian cities has increased [2].
Mobility practices, waste management, the burning of fossil fuels such as coal, natural gas, and oil, industrial development (the brick and cement industries), the production and use of energy (for processing, heating, and cooking), the combustion of plastic and organic compounds, the incomplete combustion of synthetic materials, motor vehicles, and activities that produce dust and suspended particles are all examples of anthropogenic sources of air pollution in urban areas.Urban air pollution has a negative impact on public health that is seen globally [3].
Nitrogen oxides (NOx), carbon dioxides (COx), Sulphur dioxide (SO2), and particulate matter (PM), which is ambient solid particles, including several heavy metal ions such as vanadium and lead from gasoline additives, are among the harmful chemical compounds released to the atmosphere [4].
Ground surveys or in-situ measurements are commonly used to monitor air quality and identify atmospheric pollution.However [5], remote sensing has been widely employed in environmental applications, such as studies of air and water quality and geographic information systems (GIS), where the area and level impacted by air pollution may be shown more accurately and objectively.[6] [7].
By employing sensors mounted on a platform far from the earth's surface, remote sensing is a method for gathering data about the planet without physically touching or sampling it [7].It offers frequently updated information on land-cover and land-use so users may monitor the density of water bodies, vegetation, towns, roads, open space, demographic information, and other elements [8] [9].GIS technology allows locating the pollutants source and monitor the areas for change to conserve the quality of air, providing boundary condition to the air quality models [10] [11] [12].In general, GIS models trends and spatial variations using remote sensing data as a database and various analyses, mapping, modelling, and visualization techniques [13] [14; 15].The foci of this research are to identify air pollutants, gaseous components, and atmospheric particles (PM2.5, CO2, CO, NO2, SO2, CH4, and O3) along Al-Nahrawan region in Baghdad and examine their relationship with meteorological parameters such as temperature, relative humidity, and precipitation to determine their impact in 2022 using satellite data.The study also examines the influence of the nearby brick manufacturers on the region's biodiversity and how air pollution is distributed in the area [1].

2.1.Description of Region of Study
The study area is Al-Nahrawan city located in the southeast direction of Baghdad.Baghdad is the capital city of Iraq, lying between longitude 33.35° N and latitude 44.45° E. Figure 1 depicts a map of the research region.There are more than 266 brick industries there; the largest brick factory complex in Baghdad is a leather tanning complex, and 66 laboratories are really operated by the more than 266 brick manufacturers because of the poor working conditions and expensive worker pay.

2.2.1.Ground Base measurements
The sampling was carried out during July 2022, with 10 sampling points distributed in the Al-Nahrawan region, as shown in Table 1.

2.2.2.Satellite Measurements
In the current investigation, ground measurements of pollutant concentrations were taken using a Gas Met device at ten distinct sites in Al-Nahrawan suburban.These data were used to determine the accuracy of the satellite observations.The Google Earth Engine (GEE) platform was used to extract the meteorological parameters (Temperature, Specific humidity, Precipitation) as well as the gaseous concentrations (Particulate Matters PM 2.5, Carbon Monoxide, Nitrogen Dioxide, Ozone, Sulphur Dioxide, and Methane).Carbon Dioxide concentration was obtained from Earth Data.After obtaining the spatial data of the average seasonal air pollution chemicals from GEE, the ARCGIS application was used to create the maps showing the distribution of air pollutants [15].Satellite images from passive sensors were analysed for this study.In order to monitor land cover, meteorological, and air pollutant parameters, a variety of spatial and temporal data types and sources are gathered using the instruments listed in Table 1.

3.1.In situ Ground Base Measurements
The air pollutant sampling was carried out for a day in July 2022 according to the 10 ground points by ground device measurement as shown in Table 3.

3.2.Satellite Measurement results
The air pollutant data shown in Table 4 was extracted from GEE for the same day in July 2022 from the same 10 points distributed in the Al-Nahrawan region (see Table 1).The wind is blowing in a southwest direction..

3.3.Comparison of satellite data and analysis of ground samples
The satellite-based data products derived using Google Earth Engine GEE must be statistically correlated with the majority of the independent ground-based datasets in order to ensure the validity of the satellite findings [16].
A study conducted in the Al-Nahrawan region found that the brick and tanning companies that make up the industrial process are the primary causes of the region's high pollution levels.In July 2022, the relationship between the satellite and ground device measurements from ten sites was similar for the pollutants CO, CO2, NO2, SO2, CH4 in July 2022.However, the R 2 of the relation between the measurements of the satellite and ground device of CO pollutant was 0.46 (Figure 2-A  Table 5 shows the Pearson correlation between both variables of satellite-based and groundbased observations.The highest correlation was for SO2 at 0.86 (p-value < 0.05), followed by CO2, CH4 and NO2 at 0.85 (p-value < 0.05), 0.84 (p-value < 0.05), and 0.72 (p-value < 0.05), respectively.The least one was for CO of 0.68 (p-value < 0.05).All correlations were greater than 0.5.This means that there is a strong positive correlation between ground and satellite readings.Thus, the extracted data are verified [17].

3.4.Relation between Air Pollutants Components.
It is possible to determine whether or not temperature, precipitation, and relative humidity have an impact on the quantity of air pollutants in the Al-Nahrawan region by analysing these variables.The primary sources of pollution in Al-Nahrawan are brick manufacturers and the western side of Baghdad.In Iraq's brick industry, for instance, there are still antiquated combustion methods in use, and no treatment facilities are present.The toxic substances that seep from these brick kilns adversely affect the soil, nearby plants, nearby people, and nearby animals, with brick workers, women, and children suffering the worst effects [18].As demonstrated in Figure 4-A, sulfur dioxide SO2 and temperature exhibit a strong linear association with a value of R2=0.5 and a strong negative significant Pearson correlation (r=-0.71,p-value= 0.01).As shown in Figure 4-D, carbon dioxide CO2 and precipitation were linearly correlated in a normal relationship with a value of R 2 =0.25, and they had a significant negative Pearson correlation (r=-0.5, p-value=0.09).The intensive fuel burning required for the production of bricks is the cause of the high increase in CO2 concentration.Additionally, the lack of vegetation in the Al-Nahrawan study area contributes to the rising CO2 levels.

As indicated in
According to Figure 4-E, precipitation and sulfur dioxide SO2 have a high positive significant Pearson correlation (r= 0.66, p-value= 0.02) and a linearly high correlation with a value of R2=0.43.
According to Figure 4-F, relative humidity and sulfur dioxide SO2 have a high positive significant Pearson correlation (r= 0.82, p-value= 0.01) and a linearly correlated relationship with a value of R 2 =0.67.The brick factories' industrial activity, which uses a lot of fuel oil to finish the brick-making process, is what causes the CO.The incomplete combustion of fuel produces CO, which causes an increase in its concentration in the Al-Nahrawan study area.According to the results of the NO2, SO2, CH4, and CO pollution distribution, brick firms produce a substantial amount of pollutants in the Al-Nahrawan region.Furthermore, as settlements are to blame for indoor pollution, it is assumed that pollution is worse in densely inhabited locations.It is likely that their shared source is to blame when pollutants are proven to positively correlate with one another across various regions.To evaluate if and how strongly two variables are associated, one might use a statistical technique called correlation [19].

As shown in
The displayed normalized difference vegetation index (NDVI) represents the vegetation cover in the Al-Nahrawan region.The maximum, however, was (0.3) in February and March, when precipitation was at its highest and temperatures were at their lowest.With an R 2 value of 0.48 and a strong positive and significant Pearson correlation (r= 0.7, p-value= 0.05), NDVI and precipitation have a linearly connected relationship.While the NDVI and temperature have a strong linear link with an R 2 of 0.6, they also have a strong negative significant Pearson correlation (r = -0.8,p-value = 0.05).Additionally, the NDVI and temperature show a strong linear link with an R 2 of 0.38 and a high positive and significant Pearson correlation (r=0.62,p-value=0.05)Figure 5.
The NDVI was correlated with CO2 and CH4, NDVI and CH4 exhibit a strong linear association with an R 2 of 0.6 and a strong negative significant Pearson correlation (r= -0.77, pvalue 0.05), respectively.This suggests that the presence of vegetation may contribute to a reduction in the amount of methane present in the region [20; 16].With a value of R2=0.4,NDVI and CO2 have a strong linear relationship with one another.Additionally, they have a strong negative and significant Pearson correlation (r=-0.63,p-value = 0.05) Figure 5.

4.Conclusion
The Al-Nahrawan Region is highly impacted by the pollutants released from brick factories in the region's northeast, and it was also discovered that Baghdad's emissions in the region's west also have a significant impact on the region.Limited data from the ground-based device can be analysed to enhance data collection methods, look into software capabilities, and validate data from the satellite.
In the fields of urban management and environmental studies, GIS and remote sensing have proven to be useful, intelligent, and productive technologies.By employing satellites, remote

Figure 1 .
Figure 1.Map showing the study area of Al-Nahrawan region (area) and the brick factories inside it.

Figure 2 .
Figure 2. Data relation between satellite-based tropospheric column number density and ground-based measurements of different gases.

Figure 3 -
Figure3-A shows that the relationship between relative humidity and temperature is linear and normal, with an R2 value of 0.84 and a significant negative Pearson correlation of 0.91 and a p-value of 0.05.

Figure 4 -
B, methane CH4 and precipitation were linearly interrelated in a normal relationship with a value of R2=0.42 and a strong negative significant Pearson correlation (r=-0.65,p-value=0.02).As demonstrated in Figure4-C, methane CH4 and temperature are linearly associated in a normal relationship with a value of R2=0.25 and a strong positive Pearson correlation (r= 0.5, p-value= 0.09).

Figure 4 .
Figure 4.The Linear relationship between air substances.

Figure 4 -
G, CO and CO2 have a linear correlation in a normal relationship with each other with a value of R 2 =0.28.They also have a significant negative Pearson correlation (r=-0.54,p-value=0.073).As shown inFigure 4-H, PM2.5 and Methane CH4 have a linear correlation in a normal relationship with a value of R 2 =0.3 and a significant negative Pearson correlation (r=-0.55,p-value=0.06).

Figure 5 .
Figure 5. Linear relationship between NDVI and air substances.

Table 1 .
The X Y coordination.

Table 2 .
Description of imagery datasets.

Table 3 .
Concentrations of air polluting gases and particles and statistic result from ground device during July 2022.

Table 4 .
Concentrations of air polluting gases and statistic result from Satellite during July 2022.

Table 5 .
Person correlation statistics results for different locations in the Al-Nahrawan region at July 2022 between both variables of satellite-based and ground-based observations.

Table 6 .
Pearson correlation between the atmospheric substances over Al-Nahrawan region.

Table 7 .
P-value for Pearson correlation between the atmospheric substances over Al-Nahrawan region.