Air pollution has improved significantly over the last 25 years. Sulphur dioxide and benzene currently play virtually no role in connection with the exposure of the population in Germany and the corresponding health effects. These components have therefore largely fallen out of the focus of monitoring in air quality networks and are only taken into account in special cases. Ozone does not play a major role in urban areas, as cities/conurbations serve as a source area for the so-called ozone precursors. High / higher ozone concentrations therefore generally occur in appropriate weather conditions (summer weather / high solar radiation) away from cities and conurbations, in the downwind area.