Air pollution remains critical in Portuguese urban traffic zones

Environmental associations Zero and the Portuguese Council for Health and Environment (CPSA) have warned that nitrogen dioxide (NO2) remains a critical pollutant in Portuguese urban areas. According to 2024 data from the Portuguese Environment Agency’s QualAr information system, traffic continues to be a primary source of air pollution.

In 2024, the most severe concentrations were recorded at the Avenida da Liberdade station in Lisbon and the Frei Bartolomeu Mártires station in Braga, where annual average NO2 levels exceeded the current limit of 40 µg/m³. Provisional data for 2025 shows Avenida da Liberdade recorded 40.3 µg/m³, barely meeting the limit due to rounding.

The organizations attribute these figures to meteorological conditions and vehicle fleet renewal rather than specific public policy measures. Of the 16 traffic monitoring stations, 43.8% exceeded 20 µg/m³ and 93.8% exceeded 10 µg/m³ in 2024. These levels surpass both the 2030 EU Directive limit of 20 µg/m³ and the World Health Organization’s recommended annual reference value of 10 µg/m³.