Understanding Jakarta's Air Quality
Introduction to the Clean Air Catalyst’s Data Insights Series
By: Hafidz Abdillah, Khalisha Qatrunnada, Paulista Surjadi, Tasya Ramadini, Beth Elliott
The Clean Air Catalyst (Catalyst) is a US Agency for International Development-funded global partnership led by WRI Indonesia. It is supporting the Jakarta government's efforts to improve air quality through multi-stakeholder cooperation and data-driven policies to identify solutions for Jakarta's most significant sources of pollution. The Catalyst also plans to conduct regular analysis of data from these monitors to understand urban air pollution patterns and determine appropriate measures to reduce pollution in various city areas. It will be published through a series of articles under #KenaliKualitasUdaraJakarta—or Understanding Jakarta’s Air Quality.
Before diving into the data, here is an overview of the Catalyst air quality monitoring project's goals and approach.
Why is the Catalyst focused on scaling up air quality monitoring in Jakarta?
The Catalyst is collecting air quality information to study and understand the city's ambient air – or the air breathed on the earth's surface that can affect human health. The goal is to identify trends and patterns in air pollution levels, determine which pollutants are most prevalent, assess the impact of human activities and natural phenomena such as temperature, relative humidity, wind direction and speed on air quality, and suggest possible solutions.
What pollutants are being monitored?
Air quality is determined based on the concentration of certain toxic emissions and pollutants, commonly referred to as "pollutant parameters", namely particulates (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), tropospheric or ground-level ozone (O3), and lead (Pb).
The Air Quality Life Index calculated that 10.7 million residents in the city and surrounding region are on track to lose 2.4 years of life expectancy due to this exposure to fine particulate matter. Moreover, illnesses such as cardiovascular disease, chronic respiratory infections, childhood stunting, and premature birth are all linked to air pollution (Global Burden of Disease 2021).
The Catalyst monitoring stations are focused on measuring PM2.5, the tiny particles or droplets in the air that are two and one-half microns or less in width, due to its adverse impacts on public health. PM2.5 pollution comes from many sources such as transportation, smokestacks, construction sites, dusty roads, open-burning, cooking, and agricultural activities. Data on PM2.5 concentrations and trends in Jakarta, combined with source apportionment and emission inventories, will offer a clearer understanding of the city's air pollution challenges, pinpoint the sources, and guide the development of effective solutions.
Several Catalyst sites are also measuring black carbon, a form of sooty particulate matter that is emitted from gas and diesel engines, coal-fired power plants, and other sources that burn fossil fuel or biomass. It is often highest in areas near high-traffic zones and is associated with increased respiratory issues. Black carbon is also linked to climate change due to its ability to absorb infrared wavelengths, making it a short-lived climate pollutant. One of the goals of the Catalyst is to reduce air pollution to lessen negative impacts on climate and investigating Black Carbon has become a crucial way for us to achieve that and to advance global climate change mitigation efforts.
In addition, the monitoring sites include meteorological instruments to measure weather parameters such as wind speed, wind direction, temperature, humidity, and barometric pressure. This data can be useful in determining the location of pollution sources.
What monitoring method is being used?
Two main methods are used to measure the composition and amount of pollutants:
The reference-grade method is a measurement with recognized accuracy. According to the U.S. EPA, it is considered the "gold standard" of air quality monitoring systems. Although reference-grade monitors are recognized for their accuracy, However, this equipment requires trained operators and is expensive to buy and maintain.
The indicative method is a more affordable and easy-to-use alternative that uses low-cost sensors. However, it is a less accurate technology and requires extensive calibration with reference-grade instruments to ensure accuracy.
A study by the Jakarta Provincial Environment Agency (DLH) determined that the Jakarta region needs at least 25 reference-grade monitoring stations to manage and regulate air quality, with complementary monitoring provided by low-cost sensor networks. In 2023, Catalyst installed new equipment throughout the city, bringing the total number of stations to 12—or about half the recommended coverage.
Where are the Catalyst monitors in place?
The Catalyst air quality monitoring instruments are located at seven sites throughout Jakarta, as seen in Figure 1.
The three new stations were constructed at these locations:
1. The South Kembangan Monitoring Location ('CAC1'), located on the rooftop of the West Jakarta Mayor's Office Building in a business and residential area.. The site was chosen because the surrounding area has reported a high number of respiratory diseases and to gain insight on transboundary pollutants coming from the West, by measuring levels of PM2.5 as well as meteorological parameters.
2. Pulo Gebang Monitoring Location (CAC2), located on the rooftop of the East Jakarta Mayor's Office Building. It is located in a suburban residential area close to the industrial area and bordered by the Eastern Part of Jakarta Bekasi area. The site was chosen to gain insights on transboundary pollution coming from the East by measuring Particulate Matter (PM2.5) and Black Carbon levels as well as meteorological parameters, particularly its cross-analysis with wind direction and wind speed. This “super-site” station also has an additional filter sampler that provides PM2.5 samples to a laboratory to further analyze their chemical composition to aid in determining the exact source of the pollution.
3. Marunda Monitoring Location (CAC3), located on the 5th floor of Rusunawa Marunda Cluster D, is in an industrial and coastal area previously lacking any monitoring coverage. Communities in this area are exposed to air pollutants coming from the nearby port on the north side of Jakarta, combined with sea salt aerosols that can worsen air pollution. PM2.5 and meteorology instruments are also installed in this location, similar to West and East Jakarta.
In addition, existing Jakarta Provincial Environment Agency (DKI) sites were upgraded with Black Carbon measurement instruments in Jakarta's four administrative areas, namely the Eastern, Western, Southern, and Northern regions.
How Is Pollution Determined In Indonesia?
The concentration of pollutants in the air is evaluated based on the Ambient Air Quality Standard (NAAQS), which is a limit that, if exceeded, can be considered air pollution. In 2021, the World Health Organization (WHO) made significant revisions to its air quality guidelines, marking the first substantial update in 15 years. These revised recommendations reflect a growing recognition that no level of air pollution is truly safe for human health. Consequently, Indonesia’s ambient air quality standards now align with WHO's interim target 3, which sets a limit of 15 μg/m³ for PM2.5. This is still a considerable distance from the recommended average annual concentration of 5 μg/m³.
To better communicate with the public, the Indonesian government translates concentration (the actual number of pollutants in the air) into Indonesia’s Air Pollutant Standard Index (ISPU).
Levels of pollutants such as PM2.5 and ground-level ozone (O3) far exceed ambient air quality standards (39.6 μg/m³ for PM2.5 and 93 μg/m³ for O3), averaging over double the recommended limits last year. Based on the ISPU, most days were classified as "Moderate" or "Unhealthy." During the 2023 dry season, due to a combination of weather and pollution conditions, Jakarta topped the list of cities with the worst air quality in the world.
Driving Clean Air Action with Air Quality Monitoring
The data collected by Catalyst’s air quality monitors provides critical insights into pollution patterns across Jakarta. By analyzing monthly and daily concentrations of pollutants such as PM2.5, the Catalyst helps identify trends and determine the most significant sources of pollution in various areas. This analysis enables local authorities and stakeholders to make informed decisions on where interventions are most needed to reduce pollution. Additionally, by regularly sharing these insights through the #KenaliKualitasUdaraJakarta series, the Catalyst is focused on raising public awareness about the health impacts of air pollution, and on empowering communities to support clean air initiatives. The data will also be instrumental in evaluating the success of interventions over time, helping refine strategies to ensure lasting improvements in Jakarta’s air quality.
