Air quality meets WHO standards in only three European countries

On March 24 this year, the eighth annual IQAir report assessing air quality in 143 countries worldwide was published. The results are not optimistic – only 14 percent of cities globally met the World Health Organization (WHO) annual guidelines for PM2.5 concentrations. This is 3 percent less than last year.

Where is the best air to breathe in the world?

IQAir analysts assessed air quality based on data from monitoring stations in 9,446 cities worldwide. Compared to last year, the ranking included 12 new countries. The main indicator used was the average annual concentration of PM2.5 particulate matter, which according to WHO standards should not exceed 5 µg/m3.

The IQAir Report for 2025 shows that this standard was met in only 13 of the countries studied – in the remaining 130 (81 percent) it was exceeded to a lesser or greater extent. In Europe, only Andorra, Estonia and Iceland can boast year-round clean air, while globally this distinction also applies to Australia and island states such as Barbados, French Polynesia and Reunion. Oceania was considered the cleanest region in the world last year, and the cleanest city was Nieuwoudtville in South Africa (1.0 µg/m3).

Elevated PM2.5 concentrations in the air pose a serious threat to public health. According to WHO data, they increase the risk of conditions such as ischemic heart disease, stroke, chronic obstructive pulmonary disease, asthma and cancer.

Air quality is a fragile asset that must be actively managed to protect public health – emphasizes Frank Hammes, CEO of IQAir Global.

Catastrophic air quality in Asia and Africa

In the most polluted countries in the world, average annual PM2.5 concentrations exceeded WHO standards by more than ten times. The worst offenders were Pakistan (67.3 µg/m3), Bangladesh (66.1 µg/m3), Tajikistan (57.3 µg/m3), Chad (53.6 µg/m3) and the Democratic Republic of the Congo (50.2 µg/m3).

Even more dramatic results were recorded in individual cities. The worst air quality was found in Loni, India, where the average annual PM2.5 concentration reached as much as 112.5 µg/m3. What is most concerning is the upward trend in pollution – an increase of 23 percent compared to 2024.

A more in-depth analysis indicates that India is home to three of the four most polluted cities in the world, while exceptionally high PM2.5 concentrations are also observed in major cities in Pakistan and China.

Problematic wildfires and dust storms

According to IQAir experts, air quality in 2025 was significantly affected by intense wildfires closely linked to climate change, specifically heatwaves and prolonged periods of drought. In the United States, the average annual PM2.5 level rose to 7.3 µg/m3, with particularly high pollution levels recorded in summer in the Great Lakes region and in autumn in the Pacific states.

Smoke from extensive wildfires in North America also affected air quality across the ocean – in Switzerland and Greece it was one of the key factors behind a 30 percent increase in average annual PM2.5 concentrations. Dust transport from the Sahara also played an important role in this case.

The largest dust storms in nearly a century hit the US state of Texas last year – in El Paso, the average annual PM2.5 concentration increased by 46 percent, reaching 11.4 µg/m3. Unfortunately, as the report’s authors point out, data collection in America will become more difficult, as the Trump administration has suspended the global air quality monitoring program, depriving millions of citizens of access to information crucial for health.