Concentration of nitrogen dioxide (NO2) in ambient air

Nitrogen oxides (NOx) occur during combustion processes at high temperatures. Nitric oxide (NO) is converted into nitrogen dioxide (NO2) in the atmosphere. NO2 leads to respiratory irritation and asthma NOx contributes to the formation of secondary fine dust, plays a role in acidifying and fertilising deposition and photochemical smog formation the highest concentrations are linked to road traffic for the first time in 2020, an increase in the European annual limit value and WHO annual advisory value (2005) has not been measured, but still modelled. the WHO hourly advisory value (2005) was exceeded at 1 measuring site in 2020 the VMM measures a decreasing trend in NO2 concentrations