Due to the strikes taking place on public transport in Barcelona, the air quality in the city has fallen. This change has illustrated the essential role played by public transport services in improving air quality and reducing urban air pollution in Barcelona.
The Barcelona Institute for Global Health, or ISGlobal, has carried out research into the impact of public transport on air quality. The ISGlobal research centre is supported by la Caixa Banking Foundation and the Institute of Environmental Assessment and Water Research.
The change in the availability of public transport has led to an increase in the number of private vehicle trips taken around the city. This has had a significant impact of air quality as it leads to an increase in air pollution levels. The study that has been carried out by ISGlobal has been published in a scientific journal, the Science of Total Environment. The research that has been published covers an exploration of the changes in air pollution concentrations around Barcelona during the strikes in the public transport sector.
During the study, researchers measured the daily levels of a range of different pollutants including nitrogen monoxide, nitrogen dioxide, particulate matters, black carbon and carbon monoxide. The measurements were taken throughout the 208 days between 2005 and 2016 where stoppages were caused by strikes impacted on the underground, rail and bus systems in Barcelona. On the days a strike was in effect there was a mean daily increase in air pollution levels across the city. The air pollution levels rose by 4% for nitrogen dioxide, and 8% for nitrogen monoxide in comparison to days when the system was operational. During periods when the metro service was impacted by strike action there was a rise in the mean daily levels of pollutants between 10% and 48%. The increases were found in the pollutants that are associated with cars in comparison to other transport systems. This means that there was more of an increase in black carbon, nitrogen monoxide and carbon monoxide.