Europe's Most Polluted Cities: Where They Are and Why

Finnish cities boast some of the cleanest air in Europe, but the country still fails to meet WHO guidelines for PM2.5. Only three European countries-Estonia, Iceland, and Andorra-met these guidelines in 2025, according to IQAir’s World Air Quality Report.

Eight countries-Bosnia and Herzegovina, North Macedonia, Serbia, Turkey, Moldova, Romania, Montenegro, and Poland-reported PM2.5 levels above 15 µg/m³, far exceeding the WHO’s 5 µg/m³ limit. Türkiye is particularly affected, with Iğdir topping the list of most polluted cities, followed by Buca, Gödekli, Konya, and Duzce.

Common pollution sources include coal-fired power plants, inefficient household heating, and heavy traffic. Meteorological conditions often trap pollutants, exacerbating the issue.

On the other end, Finland’s cities lead in clean air, with Utö, Muonio, Kittilä, Ranua, and Nivala among the least polluted. Finland’s success is attributed to strict emissions controls and high renewable energy usage.

To protect against PM2.5, monitor pollution levels, stay indoors during spikes, use air purifiers, and wear KN95 masks outdoors.