The European information threshold for ozone pollution was exceeded at 15 monitoring stations across Belgium on Friday, with high levels expected to persist on Saturday before air quality improves on Sunday, the Interregional Environment Agency (IRCEL-CELINE) said.
The first breach of the European information threshold, set at 180mg/m2, was recorded on Thursday at a monitoring station in Damme, in West Flanders.
Conditions worsened on Friday amid hot, sunny weather, with the threshold exceeded at 15 stations, most of them in Flanders, as well as in Eupen, Herstal and Tournai.
The agency said ozone concentrations are likely to remain high on Saturday, particularly in the east and north of the country, due to a combination of air pollution and continued hot, sunny conditions.
It warned that the European information threshold could be exceeded again in areas where sunshine remains strong during the afternoon.
From Sunday, air quality is expected to improve, with ozone concentrations returning to levels considered normal for the time of year.
In areas affected by high ozone levels, sensitive groups, including children, older people and those with respiratory conditions, are advised to avoid unusual physical exertion and outdoor sport during the afternoon and evening.
Outdoor exercise such as jogging is also discouraged for the wider public during those periods.
