IQAir 2025 Report: Global Air Quality Continues to Deteriorate
The IQAir 2025 report has been released, analyzing 9,446 cities in 143 countries. The verdict is clear: the situation is worsening. Today, 86% of the world's cities have air deemed hazardous to health.
The Indicator: PM2.5
The indicator used is the PM2.5 rate - particles so fine they pass through the lungs and directly into the bloodstream. They cause respiratory, cardiovascular diseases, and cancers. The World Health Organization (WHO) sets the limit at 5 µg/m³ per year. Most countries are far from meeting this threshold.
Who Breathes Easy?
Only 13 countries pass the test. Most are islands, far from factories and large cities. These countries include:
- Iceland
- Estonia
- Andorra
- Australia
- Panama
- Barbados
- Grenada
- French Polynesia
- New Caledonia
- Réunion
- Bermuda
- Puerto Rico
- US Virgin Islands
In continental Europe, only Andorra and Estonia make the list. France, Germany, and the United Kingdom are not included.
The Most Polluted: South Asia Leads
The most polluted city in the world is Loni, India, with an average annual PM2.5 rate of 112.5 µg/m³ - 22 times the WHO limit. The situation has worsened by 23% in just one year.
The top 5 most polluted countries are:
- Pakistan
- Bangladesh
- Tajikistan
- Chad
- Democratic Republic of the Congo
Why is it Getting Worse?
Two main causes dominate in 2025:
- Forest Fires: 2025 was the most destructive year on record in Europe.
- Fossil Fuel Combustion: The continued burning of fossil fuels.
Additional factors contributing to the problem include:
- Saharan dust
- Agricultural emissions
A Measurement Problem
In March 2025, the United States eliminated its global air quality monitoring program. As a result, monitoring has been weakened in 44 countries, and six countries now have no reliable data.
