The air quality evaluation report for 2024 by the Barcelona Public Health Agency (ASPB) notes that the annual levels of NO2 continue at their lowest ever levels since record began.

In addition, the figures for the evolution during the first semester of 2025 confirm the downward trend in this highly influential pollutant due to local traffic emissions, with reductions of between 2 and 14% in city monitoring stations compared to the first half of 2024.

PM10 and PM2.5 particle levels remain stable since 2013. Both of these pollutants are below the current legal limits established by the European Union.

Exposure to pollution

Besides specifying air pollution levels and estimating their impact on health, the report by the ASPB also calculates average levels of exposure among the population.

In 2024, the level of exposure to NO2 was 25 μg/m3, the lowest level recorded since 2018. The highest levels were generally in the city centre and the main access roads to the city.

As for PM2.5, the level of exposure was 14 μg/m3, a similar figure to the years from 2020-2023.

New European regulation

The new directive published in 2024 by the European Parliament significantly reduces the legal limits for the main atmospheric pollutants from 2030, bringing them closer to the protection guideline values by the World Health Organization (WHO).

Annual levels for NO2 and PM2.5 at all monitoring stations in Barcelona are below the current legal limits, but above the WHO guidelines and the European legal limit for 2030.

In an effort to speed up the measures and meet the new levels, the Pla Clima has been launched as the municipal roadmap, with 1,800 million euros to adapt the city and mitigate the effects of climate change. The plan should boost sustainable mobility, public transport, the metropolitan connection and the improvement and expansion of the bike lane network.

Impact on health

Air pollution is the main environmental risk to public health, particularly in large cities, mainly caused by motorised transport. Data on air quality for 2024 and the first half of 2025 confirm a reduction, with current levels some 32% lower that the estimated figure for 2018-2019.

Long-term exposure to pollution in the last four years is estimated to be responsible for around 8% of deaths by natural causes (13% in 2018-2019), 36% of new cases of asthma in children (51% in 2018-2019) and 12% of new lung cancer cases a year (17% in 208-2019).

Based on the main conclusions, the ASPB recommends an overall cut in traffic as the most effective measure, with the added health benefits this brings such as a reduction in noise, road traffic injuries and the freeing up of urban space for other healthier activities.