Daily pollution levels in Barcelona consistently exceed those set out by the World Health Organization (WHO). This pollution mainly comes from traffic, which generates 60% of NO2 and 80% of ultrafine particles, which can cross the blood-brain barrier to reach the brain, or in the case of pregnant women, cross the placenta and reach the foetus.
Barcelona is the European city with the densest traffic, twice as much as Madrid and three times as dense as London: six thousand vehicles per square kilometre, generating consistently high levels of pollution. The city exceeds the 70% limit set by the WHO for suspended particles of less than 2.5 micrometres (PM2,5) and the air breathed in by half the population has excessive levels of nitrogen dioxide (NO2).
Where does Barcelona’s pollution come from?
Air pollution consists of various elements, with traffic playing a fundamental role in all of them. In the case of micro particles (PMx), vehicles are estimated to cause between 40% and 60% of them.
If we look at nitrogen dioxide, 60% comes from traffic, particularly diesel vehicles. Some 13% is generated outside the municipality, 8.3% by the industrial sector, 7.6% from emissions at the port and 11.1% from other sources such as heating systems and fires.
Why do traffic restrictions affect the oldest vehicles?
The environmental rating badges issued by the DGT classify vehicles according to their environmental impact. Those without a badge are the vehicles which pollute the most and will not be able to circulate in the low emissions zone (LEZ) delimited by Barcelona’s ring roads.
In general, the environmental impact coincides with the age of the vehicles: petrol-driven cars over 20 years old have been shown to emit 58 times more NO2 than new cars. At the same time, taking a diesel vehicle over 20 years old out of circulation is equivalent to taking out 35 modern vehicles of this type.
Permanent low emissions zone from 2020
The low emissions zone comes into force on 1 January 2020 and will apply on working days from 7 am to 8 pm. Vehicles which pollute the most (without the DGT badge) will not be allowed to circulate. Some vehicles are exempt and authorisations and a one-year moratorium for hauliers also exist. Full information can be found at zbe.barcelona.