Air pollution due to wildfire in the High Fens

Wednesday, 19 August 2026, 15:00

Following the wildfire in the High Fens, which started on Friday 14th August, high concentrations of particulate matter have been detected at the fixed monitoring stations in Wallonia.

The maximum values were measured on Sunday in Vielsalm, at 11am the PM_2.5 concentration almost reached 700 µg/m³. High concentrations were also recorded at other monitoring stations in the region, particularly in Sinsin (230 µg/m³ PM_2.5) and Dourbes (210 µg/m³ PM_2.5). In addition to these local, short-lived peaks, significantly elevated concentrations were observed throughout the day. The WHO air quality guidelines are 15 µg/m³ for PM_2.5 and 45 µg/m³ for PM₁₀, averaged over 24 hours.

On Monday and Tuesday no new peaks were observed, and concentrations returned to normal levels for this time of year.

Today, on Wednesday, the PM₁₀ concentrations in Vielsalm, Sinsin and Dourbes are well below 25 µg/m³. Changes in pollutant concentrations can be monitored here or via the BelAir app. Although normal levels are being recorded at our permanent monitoring stations, higher concentrations cannot be ruled out locally, in the vicinity of the fires.