Indonesia has retained its position as the most polluted country in Southeast Asia in 2025, with fine particle pollution levels still far exceeding safe limits set by the World Health Organization (WHO), according to the latest World Air Quality Report by IQAir.
The Switzerland-based air quality monitoring firm reported that Indonesia’s annual average PM2.5 concentration dropped to 30 micrograms per cubic metre, down from 35.5 in 2024. Despite the improvement, the figure remains six times higher than the WHO guideline of 5 micrograms.
Coal-fired power plants, particularly those established before 2019 near Jakarta, continue to be among the main contributors to the country’s air pollution, the report noted.
PM2.5 refers to fine particulate matter measuring 2.5 micrometres or smaller, which can penetrate deep into the lungs and enter the bloodstream. Exposure to such particles has been linked to serious health risks, including heart disease, stroke, lung cancer and premature death.
Further findings from a 2024 study by the Centre for Research on Energy and Clean Air revealed that PM2.5 levels across the Greater Jakarta area, also known as Jabodetabek, ranged between 30 and 55 micrograms — up to 11 times above WHO recommendations.
Seasonal haze caused by forest and peatland burning in Sumatra and Kalimantan, along with heavy urban traffic and emissions from coal power plants, have long driven pollution levels in Indonesia.
Globally, only 13 countries and territories met WHO air quality standards in 2025, down from 17 the previous year, with none located in Asia.
Pakistan recorded the highest pollution levels at 67.3 micrograms per cubic metre, followed by Bangladesh (66.1), Tajikistan (57.3), Chad (53.6) and the Democratic Republic of Congo (50.2).
The eighth annual IQAir report compiled data from monitoring stations across 9,446 cities in 143 countries and regions worldwide.
