Average PM2.5 levels in the most polluted capital cities in Europe 2020-2021

Sarajevo was the most polluted capital city in Europe in 2021, with an average PM2.5 concentration of 29.7 micrograms per cubic meter of air (μg/m³). This was despite average PM2.5 levels in Sarajevo falling by 13 μg/m³ from the previous year. The second most polluted capital city in Europe in 2021 was Skopje in North Macedonia, which had an average PM2.5 concentration of 27.7 μg/m³.

Air quality comparisons worldwide

The PM2.5 concentrations in the most polluted capital cities in Europe - which ranged from 20 to 30 μg/m³ - paled in comparison to other capital cities in 2021. For example, the world's most polluted capital city in 2021 was New Delhi, India, which had an average PM2.5 concentration of 85 μg/m³. Many cities around the world suffer poor from poor air quality, exposing millions of people to hazardous PM2.5 concentrations.

Sources of particulate matter emissions

There are several sources of PM2.5 emissions in the European Union, including transportation, energy supply, and agriculture, but the biggest contributor is the residential, commercial, and institutional sector. While PM2.5 emissions from other sectors have fallen notably since the turn of the century, residential, commercial, and institutional emissions have seen little change.