New threshold for particulate matter in the three Regions

In addition to an alert threshold (70µg/m³) for particulate matter (PM10), the three Regions have decided to also set an information threshold (at 50 µg/m³). This information threshold (or threshold 0) is reached when following conditions are met:

- The measured concentrations of particulate matter (PM10), averaged for a 24 hour period and averaged for all stations in a Region, exceed 50 µg/m³.

- It becomes clear, from analysis of meterorological and air quality forecasts, there is a high probability that the PM10 concentrations will remain above 50 µg/m³ for at least 24 hours.

When the information threshold is exceeded IRCEL-CELINE will send a notice containing information on the actual and expected air quality.

The three Regions will each communicate and offer (sensitizing) advice to reduce particulate matter emisssions.

The conditions for a smog alert and accompagnying speed reduction on highways remains unchanged: the smog alert is activated when it is forecasted the alert threshold of 70 µg/m³ will be exceeded on at least 2 consecutive days. A speed limit is not imposed when the information threshold is exceeded.