This indicator is defined as the number of days where PM10 concentration in yg/m3 at ground level exceeds the norm values.
This indicator monitors global warming and climate change processes in urban environments. A reduction of greenhouse gas emission, ozone concentration and PM10 levels is of high political priority.
Air pollution by small particles is related to urbanization and industrialization. Areas where the PM10 concentration exceeds norm values most frequently in the BSR can be found in Germany, Poland, and the three Baltic states. Notably some large cities display zero days exceeding the norm, e.g. Tallinn, Stockholm, Gothenburg and Helsinki. A positive trend (in fewer days exceeding the norm value) can be observed in primarily Germany and in southern, as well as northern, Polish cities. However, in central and eastern Poland there has been deterioration with as much as 11-40 more days each year above the threshold.