Ozone concentrations in Belgium could exceed the information threshold on Saturday, according to the inter-regional environment cell, CELINE.
However, the amount of ozone in the air was not expected to be extraordinarily high on Thursday and Friday, CELINE said in its air-quality bulletin, published on Thursday.
High ozone levels were registered in all three of Belgium’s regions on Wednesday, and the European information threshold was exceeded for one hour in one measuring station: Sinsin, in Namur Province. The maximum hourly concentration at Sinsin was 183 microgrammes per cubic metre (µg/m3) between 7.00 p.m. and 8.00 p.m. on Wednesday. This was slightly above the threshold of 180 µg/m3 beyond which European Union member States are required to inform their populations.
In Flanders, the maximum hourly concentrations on Wednesday reached a high of 172 µg/m3 in Sint-Pieters-Leeuw. In Brussels, Berchem-Sainte-Agathe registered the highest concentration, with 175 µg/m3.
The forecast for Thursday and Friday is for normal ozone concentrations for this time of the year in most of the country, with no highs exceeding the information level.
On Saturday, however, the warm sunny weather will once again favour ozone build-ups and the threshold could be exceeded in some areas.
Ozone, which is produced when the weather is very hot, is due to the action of ultraviolet rays present in the atmosphere, most of it given off by vehicular traffic.
The EU’s long-term goal is a daily threshold of 120 µg/m3.