Air pollution causes millions of deaths each year, particularly in the world’s largest cities. What measures have megacities implemented to purify the air?
According to the World Health Organization (WHO), air pollution is a major global issue as it contributes to approximately 7 million deaths annually. Residents of the world’s largest cities, from New Delhi (India) to Istanbul (Turkey) and Los Angeles (USA), are among the most severely affected by air pollution. However, an analysis by DW (Germany) shows a positive trend: in many megacities, air quality is gradually improving. The analysis focused on the air pollution metric of fine particulate matter, PM2.5.
Ms. Sophie Gumy from the WHO’s Climate Change, Environment, and Health department explains: “The smaller the fine particles, the deeper they can penetrate into the body.” PM2.5 is small enough to enter the lungs and bloodstream, causing respiratory issues, heart disease, and lung cancer.
Particulate matter in cities primarily comes from vehicle emissions and other sources. Solid fuels such as coal, wood, or kerosene used for energy, heating, and cooking also contribute to pollution.
To assess pollution levels in recent years, DW analyzed data from IQAir, a Swiss company that operates the AirVisual air quality monitoring platform. The data included PM2.5 levels in cities with populations over 10 million. Twenty-one cities have improved their air pollution levels from 2017 to 2022.
Green Transportation
To combat air pollution, cities are implementing various strategies. In many locations, transportation plays a crucial role. Effective measures often prioritize more environmentally friendly vehicles or reduce their use, encouraging walking, cycling, and expanding public transportation. For instance, Bangkok (Thailand) is expanding its elevated rail and subway services, while New Delhi (India) aims for 80% of buses to run on electricity.
Mr. Zoe Chafe from the C40 network, which helps nearly 100 member cities become more environmentally friendly, told DW that many urban areas are also experimenting with low-emission zones. These are areas that restrict or completely ban cars, designing streets to create more space for pedestrians and cyclists. Mr. Chafe stated, “This is something that is resonating across all regions of the world, and it is really exciting.”
Industrial Sources
Dense fog in Amritsar, India on December 30, 2023. (Photo: AFP).
Industry is another critical aspect that needs addressing. For example, New Delhi’s action plan against air pollution also focuses on reducing dust from construction sites and transitioning to cleaner fuels and more efficient technologies.
New Delhi remains one of the most polluted places on the planet, especially during the winter months. In 2023, the smog was so severe that schools in New Delhi had to close. Nevertheless, New Delhi has reduced its pollution levels by 15% from 2017 to 2022. One major reason could be the shutdown of the Badarpur coal power plant in 2018, which is estimated to have been a “culprit” responsible for about 10% of particulate air pollution solely in New Delhi.
Waste Management
In areas where waste is not collected and managed properly, residents are forced to burn it outdoors, leading to toxic smoke and contributing to air pollution. Therefore, regulations and infrastructure for waste management must be an integral part of cities’ plans to combat air pollution.
Ms. Bhavreen Kandhari, founder of Warrior Moms advocating for cleaner air across India for over 20 years, told DW: “There are solid waste management regulations since 2016, but they have yet to be enforced.”
Clean Energy
When measures are implemented thoroughly, the impact can be significant. For example, cities across China have dramatically reduced pollution levels in recent years. This is the result of what the Chinese government calls the “war on air pollution”, which encompasses a range of measures targeting all major causes of the issue, including energy consumption for heating and electricity.
Beijing has imposed strict emission limits on boilers used for heating and hot water in households. The city also subsidizes households to switch from coal-fired boilers to natural gas or electric options.
A study concluded that upgrading these boilers contributed to a 20% reduction in air pollution levels in Beijing. Beyond China, many countries worldwide are investing in renewable energy, phasing out coal, and seeking alternatives to wood and coal-burning stoves. The capital Seoul (South Korea) transitioned to gas heaters in the early 1990s and is now considering more environmentally friendly alternatives like heat pumps.
Good Data
Fog covering a road in Lahore, Pakistan, on December 4, 2023. (Photo: AFP).
When cities want to improve air quality, the first step often involves enhancing data collection. For example, in Pakistan, there are still very few official government monitoring stations, making it challenging to assess air quality. However, individuals like Mr. Abid Omar, who founded the Pakistan Air Quality Initiative in 2016, are working to change this. He stated, “Individuals, corporations, and like-minded organizations have collaborated using low-cost monitoring equipment and are providing data publicly on the internet. That data is driving awareness.”
Mr. Zoe Chafe of C40 believes that financial resources are crucial for cities to implement changes.
He argues, “Beijing has invested heavily in air quality issues. And that is a critical question for many other cities today. Do they have the budget to make significant improvements in air quality?” China has invested over 20 billion yuan annually in air pollution control in recent years.
Collaboration
Air pollution can travel vast distances, crossing political boundaries. For instance, the burning of straw in rural northern India has caused severe smog in New Delhi and surrounding areas each year after the harvest season. Similar issues affect the Nile Delta around Cairo in Egypt or Indonesia, where smoke from agricultural fires even spreads to neighboring countries like Singapore and Malaysia. Therefore, Mr. Chafe emphasizes that cities, regions, and countries must coordinate to effect change. He concludes, “The core issue is the health of the people. Where the air pollution comes from is not important; what is crucial is that it is reduced.”
However, there is still a long way to go with much work to be done. Air pollution levels in most cities worldwide still exceed the WHO’s limit of 5 micrograms per cubic meter of air. Ms. Sophie Gumy of WHO notes that even in places where pollution remains high, any reduction will improve health. Efforts to curb air pollution will also help combat climate change.
