How big a problem is air pollution globally?
Air pollution is the world’s leading environmental cause of illness and premature death. Fine air pollution particles or aerosols, also known as fine particulate matter or PM2.5, are responsible for 6.4 million deaths every year, caused by diseases such as ischemic heart disease, stroke, lung cancer, chronic obstructive pulmonary disease, pneumonia, type 2 diabetes, and neonatal disorders. About 95% of these deaths occur in developing countries, where billions of people are exposed to outdoor and indoor concentrations of PM2.5 that are multiple times higher than guidelines established by the World Health Organization. A World Bank report estimated that the cost of the health damage caused by air pollution amounts to $8.1 trillion a year, equivalent to 6.1% of global GDP.
Poor people, elderly people, and young children who come from poor families are the most affected and the least likely to be able to cope with the health impacts that come with air pollution. Global health crises such as the COVID-19 pandemic weaken the resilience of societies. Compounding this, exposure to air pollution is linked to increased incidence of COVID-19-related hospital admissions and mortality. In addition to health, air pollution is also linked to biodiversity and ecosystem loss, and has adverse impacts on human capital. Reducing air pollution, on the other hand, not only improves health but strengthens economies. A recent World Bank study found that a 20% decrease in PM2.5 concentration is associated with a 16% increase in employment growth rate and a 33% increase in labor productivity growth rate.
A World Bank report estimated that the cost of the health damage caused by air pollution amounts to $8.1 trillion a year, equivalent to 6.1% of global GDP.
How is air pollution related to climate change?
Air pollution and climate change are two sides of the same coin, but they are typically addressed separately. They should be tackled jointly, with a focus on protecting peoples’ health – particularly in low- and middle-income countries – to strengthen human capital and reduce poverty.
Air pollutants and greenhouse gases often come from the same sources, such as coal-fired power plants and diesel-fueled vehicles. Some air pollutants do not last long in the environment, notably black carbon – a part of fine particulate matter (PM2.5). Other short-lived climate pollutants (SLCPs) include methane, hydrofluorocarbons, and ground-level or tropospheric ozone. SLCPs are far more potent climate warmers than carbon dioxide. Methane is a precursor of ground-level ozone, which according to the Climate and Clean air Coalition and Stockholm Environment Institute, kills about a million people each year, and is 80 times more potent at warming the planet than carbon dioxide over a 20-year period. Their relatively short lifespans, coupled with their strong warming potential, means that interventions to reduce SLCP emissions can deliver climate benefits in a relatively short time. If we address short-lived climate pollutants, we gain dual benefits: better air quality and improved health where we live, and the global benefit of mitigating climate change.
A World Bank study found that PM2.5 from the burning of fossil fuels such as coal combustion or diesel-fueled vehicle emissions is among the most toxic types of PM2.5. Particles from these sources are more damaging to health than particles from most other air pollution sources. Addressing these sources of PM2.5 -- like coal combustion and traffic – would address the most toxic air pollution. Given that these sources are also key contributors to climate warming, tackling air pollution from these sources also mitigates climate change.
Air pollution and climate change are two sides of the same coin, but they are typically addressed separately. They should be tackled jointly, with a focus on protecting peoples’ health – particularly in low- and middle-income countries – to strengthen human capital and reduce poverty.
What are some requirements for effectively addressing air pollution?
Measure it and monitor it. Many developing countries do not have even rudimentary infrastructure for measuring air pollution. A World Bank study found that there was only one PM2.5 ground-level monitor per 65 million people in low-income countries, and one per 28 million people in Sub-Saharan Africa; in contrast, there is one monitor per 370,000 people in high-income countries. This is a serious issue, because you cannot properly manage what you do not measure. If you don't know how bad your problem is, you won’t know whether anything you do to fix it is effective. Countries need to establish ground-level monitoring networks and operate and maintain them properly so they yield reliable air quality data.
Know the main sources of air pollution and their contributions to poor air quality. For example, in City A, transport may be the biggest contributor, but in City B, it could be something completely different, such as emissions from dirty cooking fuels seeping from homes into the outside environment. With this information you can target interventions appropriately to abate air pollution. There are certainly intuitive, no-regret steps cities and countries can take to tackle air pollution, such as shifting to clean buses or renewable energy. But if you want to address air pollution comprehensively, you need to understand what your own sources are.
Disseminate air quality data to the public. People have a right to know the quality of the air they're breathing. Disseminating this information exerts pressure on those who can make the needed changes. Air quality data should be easily accessible in formats that are widely understood so people can reduce their exposure to air pollution and protect vulnerable groups such as young children, the elderly, and people with health conditions that can be exacerbated by poor air quality.
What are some interventions that countries can implement to reduce air pollution?
Reducing air pollution may require physical investments or it may require policy reforms or both. Not every intervention fits every context. Interventions whose benefits (notably improved health) outweigh the costs should be selected. Part of our work at the World Bank is to incorporate climate change considerations into analysis so that the climate benefits of improving air quality can be taken into account in the decision-making process. A few examples of interventions to improve air quality in different sectors:
- Energy: Change the energy mix to include cleaner, renewable energy sources and phase out subsidies that promote use of polluting fuels.
- Industry: Use renewable fuels, adopt cleaner production measures, and install scrubbers and electrostatic precipitators in industrial facilities to filter particulates from emissions before they are released into the air.
- Transport: Change from diesel to electric vehicles, install catalytic converters in vehicles to reduce toxicity of emissions, establish vehicle inspection and maintenance programs.
- Agriculture: Discourage use of nitrogen-based fertilizers; improve nitrogen-use efficiency of agricultural soils; and improve fertilizer and manure management. Nitrogen-based fertilizers release ammonia, a precursor of secondary PM2.5 formation. Nitrogen-based fertilizers can also be oxidized and emitted to the air as nitrous oxide, a long-lived greenhouse gas.
- Cooking and heating: Promote clean cooking and heating solutions including clean stoves and boilers.
Part of our work at the World Bank is to incorporate climate change considerations into analysis so that the climate benefits of improving air quality can be taken into account in the decision-making process.
What is the World Bank doing to help?
The World Bank has invested about $52 billion in addressing pollution in the past two decades. However, we need to scale this up. Some successful projects that address air pollution include:
In China, we supported a program in the Hebei region, the largest contributor to air pollution in the country. The overall result was a reduction in the concentration of PM2.5 in the atmosphere by almost 40% between 2013 and the end of 2017. The program linked loan disbursements to tangible results. Hebei issued the most stringent industrial emission standards in the country, replaced diesel buses with electric buses, coal stoves with gas stoves, and improved the efficiency of fertilizer use in agriculture. The program also supported effective use of a continuous emission monitoring system to track and enforce compliance by all major industrial enterprises in the province. The project delivered about 5 million tons of CO2 equivalent emissions reductions per year through interventions such as the installation of new stoves in municipalities, and addition of a new clean energy bus fleet. The emissions reductions generated from the installation of 1,221,500 new stoves alone were equivalent to taking more than 860,000 passenger cars off the road each year.
In Peru, the World Bank is supporting a project to develop environmental information systems that includes expanding the country's air quality monitoring network to six new cities. The project is also developing new systems to disseminate information on environmental quality to the public.
In Egypt, we assessed the health impacts from environmental pollution, including the effects of ambient air pollution in Greater Cairo. We found that 19,200 people died prematurely and over 3 billion days were lived with illness in Egypt in 2017 as a result of PM2.5 air pollution in Greater Cairo and inadequate water, sanitation, and hygiene in all of Egypt. This analytical work has led to a project to reduce vehicle emissions, improve the management of solid waste, and strengthen the air and climate decision-making system in Greater Cairo.
In Vietnam, we are working with the rapidly growing city of Hanoi to simultaneously combat the issues of climate change and air pollution. We are supporting the Ministry of Environment and Natural Resources to improve the Air Quality Monitoring Network and develop an understanding of emissions sources, as well as an Air Quality Management Plan for the city.
In Lao PDR, the World Bank program supported the government in establishing stringent ambient air quality standards, including a standard for annual average concentrations of PM2. in line with the World Health Organization’s air quality guideline value at the time. The program also supported the adoption of regulated procedures for sampling and analyzing PM2.5 and PM10 in air, and other pollutants in water.
We need to tackle air pollution and climate change challenges jointly rather than separately with a focus on protecting peoples’ health today, particularly in developing countries.
Can we expect better air quality in the future as countries decarbonize their economies?
First, we must continue to reduce poverty and meet the needs of poor people, whether through lower energy costs, ensuring cleaner air, or other means. With these goals in mind, we need to tackle air pollution and climate change challenges jointly rather than separately with a focus on protecting peoples’ health today, particularly in developing countries. The health benefits of reducing emissions from the burning of fossil fuels can occur in the near term. However, the reduction of carbon dioxide in the atmosphere would occur over a longer timeframe. If decarbonization efforts pay attention to non-CO2 pollutants as well, notably PM2.5, we cannot only expect better air quality, but also health benefits in the short term.
