Every day, we breathe in air that contains polluting elements that reduce our quality of life. We are referring to high average annual levels of pollution both in terms of gases and suspended particles. In Barcelona, the daily levels set by the authorities are rarely exceeded, although the annual average level of air pollutants is still elevated as a group. This means that the presence of pollutants in the atmosphere is high throughout the year even though there are few days on which the limits determined by the declaration of a pollution episode are exceeded.
To combat the high annual levels of pollution in Barcelona city, different structural measures are being implemented to help to reduce the pollutants permanently over the whole year. These measures include actions relating to the urban model, mobility, infrastructure and other fields.
Atmospheric-pollution episodes are specific meteorological situations of high pollution in which the limits established by the competent authorities are exceeded and no improvement is forecast in the following days. This exceptional event necessitates the immediate application of specific measures to facilitate the dispersion and reduction of air pollutants to protect people’s health.
Certain meteorological circumstances, such as the absence of abundant rainfall or the presence of anticyclones, hinder the dispersion of polluting elements and facilitate their accumulation and concentration, which is why they often act as a trigger for atmospheric-pollution episodes in areas where high average levels are usually registered.
When high concentrations of polluting elements are registered in the atmosphere and they are not expected to disperse, the Government of Catalonia has the power to declare an atmospheric-pollution episode. This situation can occur in three different scenarios:
- Preventive warning: due to the concentration of NO2 gases or PM10 particles in the atmosphere.
- Declaration of a high atmospheric-pollution episode with traffic restrictions: due to the high concentration of NO2 gases in the atmosphere.
- Declaration of a high atmospheric-pollution episode without traffic restrictions: due to the high concentration of PM10 particles in the atmosphere.
To cope with atmospheric-pollution episodes, Barcelona City Council activates a pollution protocol with measures to reduce the principal emission factors, such as mobility or public works or actions in the street that generate dust.