The more than 50 percent soot reduction in Berlin stems from the city's systematic introduction of car emission zones, the environmental group BUND said on Wednesday. Berlin's comprehensive strategy addressing high pollution emitters and aimed at significantly decreasing car use has also played a role in improving its overall air quality.
The German capital also has a solid public transportation system, combined with a decade-long trend towards cycling in the city and constantly improving bicycle infrastructure.
According to the city's environmental officials, the traffic-related exposure to diesel exhaust particulate matter in 2010 has declined by 33 percent compared to 2009, and 52 percent compared to 2007.
"In Berlin the share of car traffic on the road has decreased by six percent. In addition, use of bicycles has doubled to 13 percent," said Werner Reh, a transportation expert for BUND. "The top spot in the fight against harmful exhaust emissions can be pegged on the consistent implementation of the environmental zone in Berlin.”
However, Copenhagen and Stockholm, which split the second place ranking, boast much higher percentages of bicycles users, 40 and 50 percent respectively, showing Berlin can still improve, Reh said.
Zurich and Vienna were ranked third in the study. Two other German cities examined – Düsseldorf and Stuttgart – ended up on the bottom of the lists, both with unsatisfactory scores.
The environmental spokesman for the centre-left Social Democrats, Daniel Buchholz, said on Wednesday that the green zones, with their proven positive effect on the air of Berlin, were a "success story."