PM10
Published 8 November 2026, 22:23
PM10 — partículas inaláveis (inhalable particles up to 10 micrometres)
Dust and other solid particles up to ten micrometres across: small enough to get past the nose and throat into the airways. In Portugal levels spike because of wildfires and dust blown in from the deserts of North Africa. When PM10 is high, the DGS declares poor air quality and advises children, older people, and people with asthma or heart conditions to stay indoors with the windows closed.
Where you come across it. Air quality reports, DGS notices and the QualAr app.
You will also come across PM2.5, even finer particles of up to 2.5 micrometres; they are more dangerous because they penetrate deeper. African dust mainly raises PM10; smoke from fires raises both.
Official website: qualar.apambiente.pt