Two of the most harmful air pollution sources in the Asia Pacific region are particulate matter and ground-level ozone. Particulate matter is a collection of tiny particles smaller than 2.5 microns, just a fraction of the width of a human hair. These particles are mainly produced by the burning of fossil fuels and biomass such as wood. Particulate matter is particularly dangerous because its tiny size allows it to penetrate deep into the lungs and enter the bloodstream, potentially causing deadly diseases such as heart disease and lung cancer.
Ground-level ozone, a gas formed when fuel vapors, chemical solvents and other pollutants are heated by the sun, is a major component of smog and has been linked to a number of respiratory illnesses, including asthma, emphysema and chronic bronchitis. It can also slow down photosynthesis and stunt plant growth.
Nearly everyone living in East and Southeast Asia breathes polluted air, with nine countries in the region ranking among the 40 most polluted countries in the world in 2023, according to data from UNEP partner IQAir.
Live data from UNEP found that on a typical day in mid-August this year, more than 98% of people in China, Japan, Laos, South Korea and Vietnam breathed air with PM2.5 levels that exceeded World Health Organisation guidelines.
The boundaries and names shown on this map, and the designations used, do not imply official recognition or endorsement by the United Nations. Source: IQAir/UNEP
In the map above, the cities represented by the blue dots (concentrated in northern Japan and around the Gulf of Thailand) are the only ones that the WHO considers to have clean air.
Much of the air pollution comes from the burning of fossil fuels for electricity generation, industry and transport; the burning of biomass such as firewood for domestic cooking, heating and lighting; and the unregulated burning of garbage and agricultural residues.
The impact of this air pollution is devastating. By region, Southeast Asia, East Asia and Oceania had the second highest premature deaths due to PM2.5 in 2021, after the Middle East and North Africa. China (2.3 million deaths), Indonesia (221,600 deaths), Myanmar (101,600 deaths), Vietnam (99,700 deaths) and the Philippines (98,200 deaths) were particularly hard hit.
A series of recent UNEP-supported reports looked at air pollution trends in Cambodia, Indonesia and Thailand, where five common pollutants – carbon dioxide, nitrogen oxides, PM2.5, sulphur dioxide and ammonia – are all on the rise.
The report finds that by taking meaningful steps to reduce air pollution, the three countries could collectively save 230,000 lives, with the majority of those lives saved in Indonesia, where air pollution is expected to lead to more than 200,000 premature deaths per year by 2030.
A graph showing the increase in premature deaths due to PM2.5 in Cambodia, Indonesia and Thailand by 2030. Source: UNEP/International Institute for Applied Systems Analysis
By instituting policies to combat air pollution, the three countries could collectively save about $60 billion in health care costs by 2030, according to the report. Such measures could also significantly reduce hospitalizations for asthma and other respiratory illnesses.
A graph showing the annual cost of air pollution in US dollars for Cambodia, Indonesia and Thailand by 2030. Source: UNEP/International Institute for Applied Systems Analysis
Limiting air pollution not only saves lives and money, it also helps prevent climate change, because many of the substances that pollute our air, such as methane gas and black carbon, a type of PM2.5, trap heat from the sun and accelerate global warming.
Although these substances have relatively short lifetimes in the atmosphere, they cause much more warming per mass than the most common greenhouse gas, carbon dioxide.
For example, by investing in renewable energy, imposing stricter vehicle emission standards, and encouraging a shift to electric vehicles, Indonesia could improve air quality and reduce greenhouse gas emissions by 650 million tonnes – the equivalent of removing 130 million cars from the road.
Although the report looked at only three countries, its findings could apply to many in East and Southeast Asia, UNEP's Tshering said.
“Too many countries worry about how much it will cost to reduce air pollution,” she says, “but this UNEP data shows the enormous costs of doing nothing, both in lives and money.”
According to UNEP data, countries could save hundreds of thousands of lives and billions of dollars by reducing air pollution. Photo: AFP/STR
Experts say there are several things East and Southeast Asian countries can do to reduce air pollution, including:
Investing in renewable energy, adopting electric vehicles, improving waste management and eliminating open burning, eliminating open crop burning, and making available cleaner fuels such as natural gas for cooking.
Although these measures will cost money, they are negligible compared to the costs of health care and lost productivity, according to UNEP data. In Thailand, for example, implementing a clean air strategy will cost about $4 billion a year by 2030, compared with three times the cost of doing nothing.
Graph showing the cost of inaction (US$) in Cambodia, Indonesia and Thailand. Source: UNEP/International Institute for Applied Systems Analysis.
“Everything is due for countries to get serious about tackling air pollution,” UNEP's Tshering said. “Undoubtedly, some countries have made progress in recent years, but action needs to be dramatically scaled up to unlock the region's potential and help people live longer, healthier lives.”
UN Environment strengthens governments' capacity to work for clean air by improving understanding of air pollution and promoting transformative actions and policies. Through the Asia-Pacific Regional Health and Environment Forum, UNEP contributes to collaboration between the health and environment sectors in the region to address environmental and health challenges, such as air pollution. The Forum's joint secretariat is hosted by UNEP and the World Health Organization.
Held annually on 7 September, International Clean Air Day for Blue Skies is organised by the United Nations Environment Programme (UNEP) and aims to raise awareness of the importance of clean air to health, productivity, the economy and the environment. This year's theme, “Invest in #CleanAirNow”, highlights the economic, environmental and health benefits of investing in clean air.
