Throughout Tuesday a strong north-east wind is expected to slowly improvement air quality from north to south, according to CELINE. Particle concentrations are expected to drop even further on Wednesday.
The particulate matter concentrations in Belgium have been high since this weekend. For the first time in four years, the air quality index is at level 10, which stands for ‘extremely bad’. This is true in Brussels, but also in Flanders and Wallonia.
The high concentrations are in part due to the formation of “inorganic secondary aerosols”. These are formed by reactions between NOx (nitrogen oxides emitted primarily by traffic) and NH3 (ammonia, mainly due to agriculture) under favourable spring weather conditions.
On Monday, high concentrations of fine particles were measured throughout the country.