A total of 19 cities around the world have managed to significantly reduce air pollution in recent years. An analysis of nearly 100 cities showed that since 2010, levels of the two most dangerous pollutants — fine particulate matter PM2.5 and nitrogen dioxide NO2 — have fallen by more than 20% in those cities. PM2.5 is especially dangerous because it can enter the bloodstream and damage internal organs, while nitrogen dioxide irritates the airways and contributes to the formation of acid rain.
The strongest results were achieved in Beijing and Warsaw, where PM2.5 levels fell by more than 45%. Amsterdam and Rotterdam lead in reducing NO2, with cuts of more than 40%. San Francisco became the only city in the United States to reduce both pollutants by more than 20% at the same time.
The study links this progress to specific measures: expanding cycling infrastructure, switching to electric vehicles, restrictions on high-emission vehicles, and moving away from coal and wood heating. China is focusing on electric transport, while European cities are expanding bike lanes and low-emission zones. Until recently, such results seemed almost unattainable, but now it is clear that pollution can be cut by 20–45% in just one decade if action is sustained.
