Only seven of the 127 countries in the world analyzed by the Swiss IQAir company complied in 2023 with the new safety limits established by the World Health Organization (WHO) for suspended particles less than 2.5 microns in diameter ( known as PM₂,₅), a type of particles linked in part to fossil fuels and which are linked to around one million premature deaths each year in the world.

That only 5% of the states studied now comply with these guidelines – which the WHO tightened in 2021 after studying the scientific literature on the health effects of pollution – demonstrates the great challenge that nations have to face to ensure that its citizens are not exposed to unsafe air.

The seven countries that are already below the WHO maximum, set at an annual average of five micrograms per cubic meter (µg/m3), are Australia, Estonia, Finland, Grenada, Iceland, Mauritius and New Zealand.

At the opposite extreme, with the worst air quality due to the presence of these small particles in suspension, are Bangladesh, which exceeds that recommended by the WHO by more than 15 times, Pakistan (14 times more) and India (10 times more ).

They are followed by Tajikistan, Burkina Faso, Iraq and the United Arab Emirates, all of which exceed the maximum values ​​for this type of particles by between 8.5 and 10 times.

In addition to the 127 countries studied, the analysis of the IQAir platform, which has been producing this type of reports for six years, includes another seven regions and territories associated with other nations.

The global portrait does not change much when these regions are included, since the degree of compliance with the new WHO thresholds for fine particles - which are capable of entering the lungs and even reaching the bloodstream, causing cardiovascular and respiratory diseases - continues being very low.

The new guidelines adopted by experts three years ago meant halving the annual exposure considered safe, from 10 to five micrograms per cubic meter.

If the previous limits were still maintained, 40 countries and regions would be within the safety margins.

Among them, Spain, where this analysis sets an average value for 2023 of 9.9 micrograms per cubic meter.

This study also classifies capital cities based on poor air quality.

New Delhi, with an average annual concentration of 92.7 micrograms per cubic meter (more than 18 times above what is recommended), tops that list.

They are followed by the Bangladeshi capital, Dakha (80.2);

Ouagadougou, capital of Burkina Faso, with 46.6;

Dushanbe (46), capital Tajikistan;

and Iraq's Baghdad (45.8).

Beyond the capitals, the Central and South Asian region is home to the 10 most polluted cities in the world, this report highlights.

On the opposite side, the capitals of Puerto Rico (San Juan), New Zealand (Wellington), Australia (Canberra) and Iceland

(

Reykjavik) are the ones that enjoyed the best air in 2023 if only PM₂,₅ particles are analyzed.

Because, in addition, there are other types of air pollutants, such as particles smaller than 10 microns (PM₁₀), ozone (O₃) and nitrogen dioxide (NO₂) that are not examined in this study.

This sixth

annual IQAir Global Air Quality Report

is based on analysis of data from more than 30,000 air quality monitoring stations at 7,812 locations in 134 countries, territories and regions.

This uses low-cost air quality meters operated by research institutions, government agencies, universities and educational institutions, NGOs, private companies and citizen scientists, the study explains.

Countries without monitoring

The authors highlight that the number of countries and regions with monitoring has been increasing steadily over the last six years, but significant gaps remain.

For example, Africa remains the least represented continent: a third of the population still lacks access to air quality data.

“A clean, healthy and sustainable environment is a universal human right.

In many parts of the world, lack of data delays decisive action and perpetuates unnecessary human suffering.

“Air quality data saves lives,” says Frank Hammes, global CEO of IQAir, in a statement.

As the experts who have prepared these reports explain, PM₂,₅ originate from a wide variety of sources, and among the most common components are sulfates, black carbon, nitrates and ammonium.

Among the sources linked to humans, the most notable are combustion engines, industrial processes, energy generation, wood burning, agricultural activities and construction.

Natural sources include sandstorms, forest fires and dust intrusions.

The authors highlight the links between climate change and PM₂,₅ particle pollution.

“In many regions, intense pollution events coincide with extreme heat, exacerbated by air stagnation events in which weak winds hinder ventilation at ground level, allowing pollutants to accumulate,” they indicate.

“As climate change progresses, the frequency of these events is expected to increase.”

Additionally, “prolonged periods of hot, dry conditions have led to an increase in the frequency and severity of wildfires in many regions.”

Therefore, they highlight, “it is feasible to simultaneously address the objectives of air pollution and climate change,” the authors emphasize.

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