On Clean Air Day 2021, cleantech business Airly has revealed its monthly insights into air pollution across Europe. This ranks cities* based on their air pollution levels as measured by levels of PM10 (Particulate Matter) and NO2 (Nitrogen Dioxide). Using sensors, Airly provides accurate, ultra-local, predictive data for governments, media and businesses to tackle the issue of air pollution head-on. Airly’s platform acts as a warning system for pollution at street level and in real time with greater accuracy and at lower cost for cities & enterprises.

PM10 analysis

PM10 is particulate matter (also called particle pollution), represents a mixture of solid particles and liquid droplets found in the air. Drops in concentrations are clearly visible when compared to April 2021, when some cities recorded much higher results, e.g. Milan (42.8), Łódź (29.1).

Although the concentrations of PM10 decreased relatively, an Italian city (Naples) was in the lead again (23,91 mean CAQI), and a very high concentration of Spanish cities (Gijon, Sevilla, Oviedo) can also be noticed. PM10 concentrations in Polish cities dropped significantly – the highest was Tychy with a recorded average CAQI of (16,82).

The ranking of the most polluted large cities in Europe (PM10) for May 2021 is below: