NO2 annual mean
All data below are the result of the RIO interpolation technique, in which the measurement observations are interpolated to a 4x4 km² grid resolution. Locally, concentrations can be higher or lower.
The European annual limit value for protection of human health is 40 μg/m³. This limit value applies as from 2010. Only the Port of Antwerp and Antwerp Agglomeration zones have been granted postponement until 2015 for compliance with this limit value. Until then, a limit value of 60 μg/m³, based on the limit value of 40 μg/m³ with a 50% margin of tolerance, applies in these two zones. The highest annual means are measured in the urban areas. This is not surprising due to the highly transport-related character of NO2. Annual mean concentrations above 40 μg/m³ were measured at sites in Antwerp and Brussels. The average across Belgium, taking account of the number of inhabitants per grid cell (population-weighted average) exceeds the non-population-weighted average across Belgium, which indicates that the grid cells with the highest population numbers are also those with higher NO2 annual mean concentrations, namely the urban areas.