TL;DR — The World Health Organization recently updated their air quality guidelines, which set recommended benchmark levels for a variety of pollutants like particulate matter and nitrogen dioxide, as well as intermittent benchmarks to help countries gradually reach lower levels of air pollution. The updated guidelines set forth more stringent recommendations that are in line with our current understanding of air pollutants and their drastic impacts on health and the environment. While making air quality guidelines more stringent is an important step to improving global air quality, it is also vital to keep in mind that research shows there is no safe level of air pollution — and the vast majority of countries still have a long way to go in developing the regulatory frameworks that will prompt the action required to reach clean, unpolluted air for all. We compare these WHO guidelines to different existing ambient air quality standards across the globe to take stock of where various countries and regions stand with respect to regulating air quality.

The recent update to the World Health Organization air quality guidelines

In September 2021, the World Health Organization (WHO) made adjustments to their recommended air quality guidelines for the first time since 2005. As of this change, their recommended benchmarks levels for particulate matter (PM), ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide have become more stringent in order to protect public and environmental health, which still suffer significantly due to air pollution.

The primary global guidance on air quality is scientific, as provided by the World Health Organization (WHO) air quality guideline values for ambient air quality. These guideline values are not intended to be binding upon States, but they reflect a high degree of scientific consensus, giving them global authority."

- UNEP, First Global Assessment of Air Pollution Legislation (GAAPL)
The World Health Organization (WHO) tightened their recommended maximum levels of air pollutants in 2021. The graphic above compares the 24-hour air pollutant levels recommended in 2005 compared to their corresponding guidelines in 2021. These new guidelines are intended to address the global issue of air quality and reduce its significant negative impacts on health and the environment worldwide. (Image source: WHO)

Despite the fact that these guidelines were recently tightened, many countries still have not met the levels that the WHO put forth in 2005. In fact, a vast number of individuals across the globe do not breathe clean air. According to the World Health Organization, 90% of the world population in 2019 was breathing air considered unhealthy by the 2005 guidelines — which again, were far less stringent than the most recent recommendations.

Creating more stringent air quality guidelines is an important step towards reducing the massive environmental, economic, and public health costs caused by air pollution today. According to a rapid scenario analysis performed by the WHO, reducing global air pollutant concentrations to those recommended by the new guidelines would help avoid nearly 80% of the premature deaths that occur due to fine particulate matter (PM2.5) exposure. 

These WHO guidelines not only set recommended maximum levels for key pollutants, but also highlight good practices for managing certain types of pollutants that compose particulate matter. We do not yet have sufficient quantitative evidence to set a corresponding threshold for black carbon and ultrafine particles, but they still present a threat to human and environmental health, and thus have not been ignored by these guidelines.

While these guidelines are a significant improvement and will help prompt bolder action to protect individuals across the world from the harmful effects of air pollution, even meeting these recommended levels would not make the threat disappear. In reality, there is no safe level of air pollution. Negative health and environmental effects have been observed even at low levels of air pollution that fall within existing regulatory standards.

Even at very low levels, research has shown ‘air pollution affects all parts of the body, from the brain to a growing baby in a mother's womb."

— WHO Director-General Tedros Adhanom Ghebreyesus

Air pollution exposure is responsible for harm to human health across the lifespan, but especially during pregnancy and childhood, as shown by evidence for the long-term effects that air pollution exposure has on growth and cognitive ability.

When looking at air quality management policies, it is vital to keep in mind that there is no safe level of air pollution. Though implemented policies can help to decrease air pollution, in most places around the world air quality has a long way to go before it can truly be at a safe level. Furthermore, as urbanization and population growth continue, air quality is likely to only worsen unless specific action is taken against it.

Air quality standards that exist around the world

Given the recent update to the WHO air quality guidelines, we decided to look at what countries around the world are doing to regulate air pollution and how those actions compare with the WHO’s recommendations. While these guidelines will help prompt bolder action to protect individuals across the world from air pollution, guidelines alone do not represent a solution — countries around the world need to implement scientifically sound policies that drive data-backed action on air quality. 

To effectively regulate air pollution you need to measure it — as of 2018, more than 4300 cities in 108 countries around the world contributed air quality monitoring data to the WHO’s ambient air quality database. This means that 87 countries — or a little less than 45% of countries in the world — have not reported air quality monitoring data. 

This is substantiated by OpenAQ’s 2020 finding that 51% of countries globally showed no evidence of any type of AQ data production. Unfortunately, there also seems to be a strong inverse correlation between air pollution levels and the number of monitoring stations in a country — meaning that the places that are the most polluted often have the least data to support their air quality efforts. 

The image above displays the relationship between the number of air quality monitoring stations and the average PM2.5 concentration, according to the data collected by OpenAQ. The graph shows that those places with high air pollution tend to have less available air quality data.(Source: OpenAQ, “Open Air Quality Data: The Global State of Play”)

With no air quality data being collected in roughly half of all countries, it is little surprise that according to a recent UNEP report, 1 in 3 countries worldwide lack any kind of legally mandated ambient air quality standards. In Africa, only seven of 54 countries on the continent have real-time, reliable air pollution monitors, according to a 2019 UNICEF report

The WHO identified that at least 31% of countries without existing ambient air quality standards have the power to introduce them. With the monumental impact that air quality has — having been identified by the WHO as the single largest environmental health risk, and with studies showing its correlations with COVID-19 health outcomes — it is vital that more countries adopt air quality regulations.

The image above displays the countries which have legal instruments used to measure ambient air quality standards in blue, and those which have no legal instruments to do so in white. Clear regional disparities are evident — while all of Europe and North America have legal devices to measure air quality standards, most countries in Africa, as well as multiple in South America and the Southern Pacific region, lack legal instruments to measure ambient air quality according to government-backed standards. (Data source: UNEP)

While there is still significant headway to be made in regulating air quality, positive progress has been made in recent years. In a UNEP report analyzing policy and program changes made since 2016, 21 more countries have adopted clean production policies, and 18 more countries have added new vehicle emission standards. However, 118 countries have no national ambient air quality monitoring network in place, and 34 of the countries with monitoring infrastructure lack continuous monitoring.

Source: UNEP

With the growing evidence of the harm of air pollution, there is a greater need than ever to mitigate air pollution. According to WHO data, air pollution is the cause of 7 million premature deaths per year globally. By other estimates, 10.2 million premature deaths occur due to air pollution exposure.

Even in countries with existing air quality regulations, their standards often misalign with the WHO recommendations. For example, air quality regulations in some regions of Asia, as well as many economically developing countries, allow higher levels of major air pollutants like particulate matter and nitrogen dioxide than the WHO recommends. Even in those countries with standards similar to the WHO, the vast number of people who still do not breathe clean air goes to show that these standards are not always effectively met to reduce air pollution.

Overall, the global picture of national air quality laws is one of heterogeneity. Different metrics, standards and obligations are adopted, and different governance actors are implicated within air quality regimes which can be explained by different systems of government and sociolegal cultures, different technical knowledge and approaches, and historical patterns of influence in relation to air quality law. Variation in AAQS themselves is particularly complex. Standards can be set at different levels of stringency in terms of allowed pollutant concentration levels; different exceedances or margins of tolerance may be allowed; they may be averaged over different time periods; and/ or they may only apply to or exclude certain pollutants. This heterogeneity makes comparison of standards across countries challenging.”

— UNEP, First Global Assessment of Air Pollution Legislation (GAAPL)

While the landscape of air quality regulations is broad and varied, we can look to several regions that have had success with regulating air quality — such as the European Union and the United States — for best practices. 

Air quality regulation in the European Union aligns with WHO guidelines

In the European Union, a variety of air pollutants are subject to regulatory standards, including particulate matter, ozone, and nitrogen dioxide. If the standards are exceeded, authorities are required to develop and implement air quality management plans to bring the values back under the maximum allowed levels. By having this legal aspect, the EU’s regulations are enforceable — meaning that polluters are held accountable in a way that will result in positive action. 

Some member states within the EU, such as Austria, have more stringent values for certain pollutants. These numbers are relatively comparable to the corresponding standards in the United States.

The European Union sets its own ambient air quality standards to regulate air quality within its member countries. These current standards are more relaxed than those set forth by the WHO. (Image source: European Environmental Agency)

The United States Clean Air Act: Setting a positive trajectory towards cleaner air

In the United States, air pollution regulation began in the 1970s with the Clean Air Act, which designated maximum allowed levels for six criteria pollutants — particulate matter, nitrogen dioxide, carbon monoxide, ground-level ozone, lead, and sulfur dioxide. This prompted the regional implementation of federal reference-grade monitoring across the country. 

In the 50 years since the Clean Air Act, the combined criteria pollutants and precursor pollutants have dropped by 77%. Like with the member states in the European Union, different states within the United States can choose to add additional, more stringent guidelines, such as with the California Ambient Air Quality Standards (CAAQS).

A cost-benefit analysis of the Clean Air Act performed by the USEPA provides a good example of why investing in air quality regulation and management brings net gains to a country. This analysis found that the reduction in air pollution from the 1990 Clean Air Act Amendments prevented approximately 230,000 premature deaths in 2020. Some of the other benefits brought by this air quality improvement are shown below.

The improvements in health and productivity outcomes as a result of the 1990 Clean Air Act Amendments — specifically those programs which reduce levels of fine particulate matter and ozone — are shown in the table above, according to the cost-benefit analysis performed by the USEPA. Significant reductions in negative health effects and lost school and work days were calculated, presenting a strong case for why the cost of air quality regulation is worth its benefits. (Image source: USEPA)

The USEPA reported that the approximate cost of air quality management under the 1990 Clean Air Act Amendments was $65 billion, while the benefits amounted to $2 trillion — meaning that benefits exceed the costs by 90 times. Even according to the most conservative calculations with low benefits, the costs are still exceeded by a factor of three. 

When looking at the benefits that come with air pollution reduction, air quality’s synergistic relationship with climate change cannot be ignored. Because many actions that reduce air pollution also work towards mitigating climate change, policies crafted to improve air quality come with even more benefits than initially meet the eye. 

The co-benefits that come with switching from fossil fuels to clean energy, for example, reduce both air pollution and the greenhouse gases that contribute to climate change. To learn more about these co-benefits and how they open up exciting possibilities for improved environmental policy with immediately measurable benefits, check out our blog on the relationship between climate change and air quality here.

A positive step for global air quality with the updated WHO guidelines

Though significant grounds still need to be made in ensuring that countries are working to reach the more stringent air quality guidelines set forth by the WHO, the guidelines are an important step forward in working towards cleaner air for everyone. You can view more information on the specific updates to these standards here.

Several themes emerge when looking at the places where air quality regulations have been successful in reducing air pollution, such as the United States and European Union. The regulations must be science-based — alignment with WHO guidelines is a good starting point — and they must be supported by adequate air monitoring infrastructure to set baselines, measure progress, and inform data-based air quality action. 

While regulations and monitoring infrastructure are key to enabling clean air action, we would like to invite you to consider a more fundamental question — is it time for a right to clean air?

As our collaborator Dr. Gary Fuller points out in a recent Pollutionwatch article for the Guardian, making clean air a legal right would go a long way toward promoting further air quality regulation, strengthening enforcement, and generally raising awareness of the importance of breathing clean air. Fortunately, recent action by the UN seems to be moving us in this direction: 

Is it time for a right to clean air? In March this year the UN called for the global recognition of the right to a healthy environment, which would include air quality. This right is already recognised by 80% of UN members, but the UK and US are not among them.”

— Dr. Gary Fuller for The Guardian

At Clarity we believe that everyone should have the right to breathe clean air — that’s why this Clean Air Day, we’re thrilled to support the Coalition for Clean Air’s efforts to make this right a reality for everyone. 

There is no need to wait for regulation to catch up with the science — you can take action to improve air quality today. Whether as an individual, organization, or community, everyone can take action to improve air quality. Individual actions that make an impact include changing home air filters, using electric rather than gas-powered tools, and switching to all-natural cleaning products. Businesses and organizations take encourage members to take the Clean Air Pledge and create incentives for employees to carpool, use public transportation, or walk to work. For more ideas on how to take steps towards clean air in your everyday actions, and to take the Clean Air Pledge, check out the California Clean Air Day website here.