Concentrations of fine particulate matter have dropped below critical levels throughout Belgium on Friday, the Interregional Cell for the Environment (Ircel) reports.
On Wednesday, Ircel announced that the fine particulate matter concentrations had exceeded the threshold of 50 microgrammes per cubic metre for PM10, fine dust with a diameter of 10 micrometres, and 35 microgrammes per cubic metre for PM2.5.
The higher levels occurred due to reactions between nitrogen oxides and ammonia, from traffic and agriculture, having ideal weather conditions with little wind, cool nights and sunshine.
The levels are not expected to cross the threshold again in the coming days.
The Brussels Times