Exceeding the Limit Values

Especially diesel vehicles without a suitable exhaust gas purification system bear the responsibility for air pollution. As it has been known for several years, the nitrogen oxide pollution of German town centres does not correspond to legal requirements. The problem with nitrogen oxide (NO2) in Germany is preliminarily attributed to the traffic in town centres.
According to the Federal Environmental Agency (Umweltbundesamt, 01-2018), nitrogen dioxide values exceeded the allowed annual average limit value of 40 μg/m3 in 66 German cities in 2017.
All current values are available here.