Health impact assessment of urban and transport developments in Barcelona: A case study

Background: Urban spaces need to be rethought to address growing health and environmental challenges. Urban density and transport systems contribute significantly to air pollution, negatively impacting public health. Barcelona has begun a transformation by introducing the Superblock model, an urban development with proven health benefits. However, there is a lack of understanding of the health impacts of various planned urban and transport interventions. This study aims to explore planned urban and transport developments in Barcelona (e.g. Superblocks, Low emission zone, tactical urban planning, port electrification) and estimates the health impacts of their related exposures.

Methods: We utilized modelled NO₂ reduction scenarios, which considered changes from implementing Barcelona's Urban Mobility Plan (UMP) of 2018-2024 and the Port electrification project. The UMP includes different interventions such as the low emission zones, tactical urban planning (reducing car traffic lanes), existing superblocks, and street greening. We established a baseline scenario for the year 2019, with no implementation of UMP or Port electrification. We devised three scenarios implementing the UMP: a) no change in private car use b) a 25% reduction in private car use, and c) a 25% reduction in private car use with port electrification. We estimated the effect on NO₂ levels and conducted a health impact assessment following a comparative risk assessment methodology to demonstrate the impacts of these scenarios on natural cause of adult mortality.

Results: The scenario with no change in private car use resulted in a 5.9 % reduction in NO₂, preventing 67 (34-133 95% CI) premature deaths annually. The scenario with a 25% reduction in private car use led to a 17.6% reduction in NO₂, preventing 199 (101-392 95% CI) premature deaths annually. Adding port electrification to the 25% reduction in private car use scenario resulted in a 19.4% reduction in NO₂, preventing 228 (115-447 95% CI) premature deaths annually.

Conclusion: Our findings suggest that implementing measures to reduce car use and electrifying the port in Barcelona can significantly reduce air pollution and prevent premature deaths in adults. This emphasizes the relevance of ambitious urban and transport policies in improving public health. Policymakers should consider assertive actions and broader implementation of such measures for greater health benefits. Further research is needed to explore additional measures and their potential impacts, facilitating the development of comprehensive urban and transport strategies.