Introduction

The World Health Organisation (WHO) states that air pollution has become a global environmental issue, causing seven million deaths each year, both indoors and outdoors. This is three times higher than the number of deaths caused by malaria, tuberculosis and AIDS combined (Khairina, 2019). These air polluting gases include Carbon Monoxide (CO), Nitrogen Oxides (NO), Sulphur Oxides (SO), Hydrocarbons (HC), particulate matter, and greenhouse gases.

Among these air polluting gases, CO is the largest contributor to air pollution (58%) (Anoka-Ramsey, 2024). CO gas belongs to the group of primart pollutants that have colourless and odourless physical properties, making it difficult to detect but harmful to human health. The main source of CO emissions is motorised vehicles. Research conducted by (Sasmita, Reza, Elystia, & Adriana, 2022) shows that the more vehicles, the greater the CO emissions. Bandung City is one of the cities with the largest number of vehicles. Based on data on registered motorised vehicles at the West Java Regional Revenue Agency, the number of vehicles in Bandung City is 1,568,795 units in 2021 and 1,551,769 units in 2023 (Open Data JABAR, 2024). This makes Bandung the city with the second highest number of motorised vehicles in West Java in 2021-2023.

The awareness of the public and especially the government as stakeholders of the dangers of air pollution for survival needs to be increased. A quick approach to this is to conduct air quality monitoring using remote sensing techniques. Indonesia has 49 Air Pollution Standard Index or ISPU monitoring stations

(Kementrian Lingkungan Hidup, 2024). Bandung City itself only has one station to monitor air quality. Based on this, the publication of this scientific work was carried out to provide a new view of air quality monitoring, especially the CO parameter using remote sensing techniques.

Study Area

Bandung City is located at 107°36' East and 6°55' LS, at an altitude of 700 metres above sea level, and covers an area of 16.729,65 hectares. Its geographical position is delineated by the following regions:

1. 1.
   North, bordered by Bandung Regency and West Bandung Regency;

1. 2.
   West, bordered by Cimahi City;

1. 3.
   East, bordered by Bandung Regency; and

1. 4.
   South, bordered by Bandung Regency

Bandung City is located in the centre of the 'Bandung Basin' with a dimension of 233,000 Ha. Climatic conditions in Bandung City are influenced by the climate of the surrounding mountains. The city is categorised as a region with high rainfall, and the average temperature is 25,86°C, with temperatures reaching as high as 33,00°C and as low as 15,90°C.

Data and Methods

The data used to monitor air quality for CO are Sentinel-5P satellite remote sensing data.

Sentinel-5 Precursor is the first Copernicus satellite with an atmospheric monitoring mission. Sentinel-5P is a collaborative project between ESA, the European Commission, the Dutch Space Agency, industry, data users and scientists. The main mission of the Sentinel 5P satellite is to measure gases in the troposphere with high spatio-temporal resolution to help monitor air quality, ozone and UV radiation, and climate change. The satellite carries the TROPOspheric Monitoring (TROPOMI) instrument. Sentinel-5P started its mission on 13 October 2017.

The methodology employed in this study involves the utilisation of Cloud Computing satellite data, facilitated by the Google Earth Engine platform. The selection of Google Earth Engine as a data processing instrument is predicated on its capacity to comprehend, manipulate, and present data from voluminous datasets, while obviating the necessity for either paid or open-source access.

Results and Discussion

The spatial distribution of the CO parameter air pollution measurements obtained from Sentinel-5P in Bandung City from 2021 to 2024 reveal a tendency for elevated CO concentrations in the southwestern region of the city (illustrated in dark red). In contrast, the northern region of Bandung City exhibits comparatively lower CO concentrations, as depicted in the map rendered in pink.

As illustrated in graph below, the concentrations of carbon monoxide (CO) have exhibited significant annual fluctuations from 2021 to 2024, while concurrently demonstrating an upward trendline. Notably, the CO concentration reached its nadir of 684,32 µg/m³ in early 2023, while the peak concentration of CO was recorded in October 2023, at 1.132,20 µg/m³.

A further analysis of the distribution pattern of CO concentration in Bandung City reveals the CO concentration in each sub-district.Statistical zonal results indicate that, from 2021 to 2024, two sub-districts stand out as having particularly high or low CO concentrations. The Bandung Kulon sub-district has been documented as the area with the highest CO concentration, recorded at 849,22 µg/m³, while the Cidadap sub-district has been identified as the area with the lowest CO concentration, recorded at 799,72 µg/m³.

Conclusions

The limited number of Ambient Air Quality Monitoring Stations (SPKUA) in Indonesia poses a considerable challenge in maintaining adequate air quality; however, this should not result in the community or stakeholders ignoring the importance of maintaining air quality.

Collaboration between the community and stakeholders will be very helpful in efforts to protect the environment. The involvement of academics, leveraging their intellectual capabilities, is crucial in this regard. Remote sensing-based approaches, utilising the Sentinel-5P satellite, as outlined in this scientific study, offer novel insights into the public's capacity to monitor air quality in a timely, widespread, and freely accessible.

References

Anoka-Ramsey. (2024). Introduction To Chemistry. California: Anoka-Ramsey Community College.

Kementrian Lingkungan Hidup. (2024, December 12). Lokasi Stasiun Pemantauan Indeks Standar Pencemar Udara. Accessed December 12, 2024, from ispu.menlhk.go.id: https://ispu.menlhk.go.id/webv4/#/stasiun

Khairina, M. (2019). The Description of CO Levels, COHb Levels, and Blood Pressure of Basement Workers X Shopping Centre, Malang. Journal of Enviromental Health.

Open Data JABAR. (2024, May 1). Jumlah Kendaraan Bermotor berdasarkan Kabupaten/Kota di Provinsi Jawa Barat. Retrieved from opendata.jabarprov.go.id: https://opendata.jabarprov.go.id/id/dataset/jumlah-kendaraan-bermotor-berdasarkan-kabupatenkota-di-provinsi-jawa-barat

Sasmita, A., Reza, M., Elystia, S., & Adriana, S. (2022). ANALISIS PENGARUH KECEPATAN DAN VOLUME KENDARAAN TERHADAP EMISI DAN KONSENTRASI KARBON MONOKSIDA DI JALAN JENDERAL SUDIRMAN, KOTA PEKANBARU. Jurnal Teknik Sipil, 16(269-270), 1-11.