Ozone is triggered by a combination of air pollution, very hot weather and intense sunshine. The poor air quality means that older people, children or those battling lung problems are advised to avoid physical efforts between roughly noon and 8PM. However, when ozone levels are really high like on Friday, even those who deem themselves to be in top shape are advised to avoid heavy physical exercise or sports.
Yesterday, ozone levels exceeded the alert level of 180 in 33 measuring stations. Sint-Pieters-Leeuw, near Brussels, had the highest 'score': 238. Neder-over-Heembeek and Haren, also close to the capital had 234 and 233. Twelve of the measuring stations showing soaring ozone levels were situated in Flanders, seven in Brussels.
The good news is that the situation is expected to ease in the weekend, experts of the environmental agency Ircel told the press. The top photo shows the situation at 2PM in Belgium. Flanders and north-west Belgium are okay, but the situation deteriorates when you move to the south-east. Click here to follow the situation online via Ircel, with hourly updates.