PM10s are 10 micrometres in size and considered to be the most damaging to health. These micro-dust particles can enter the lungs, and increase the risk of cancer, asthma, allergies and respiratory or cardiovascular disease.
When the concentration of these particles — due to industrial combustion, automobile engines and urban heating in particular — exceed 50 g / m³, the population must be notified so they might adapt their behaviour. Prolonged outdoor physical exercise, for instance, is not advisable. Limited car use or general energy consumption can also be beneficial to air quality.
Particle concentration is expected to remain high over the next few hours, according to IRCEL, but the warning threshold will not be reached. Both rain and wind should disperse the fine particles in the air.