The association of the physical and social environment with mortality in urban areas: an ecological study on the city of Bologna, Italy

Aims: The urban environment influences health through many pathways. The aim of the present study was to map the distribution of mortality, environmental predictors (distribution of green areas and transport networks), and social predictors (income deprivation) in the mid-sized city of Bologna (Italy), and to analyse the relationship between these variables.

Methods: The study employed an ecological cross-sectional design using data from public sources. The units of analysis were the 18 city districts. The percentage of green areas, percentage of transport networks and age-standardised mortality rates were calculated for each district. These variables, and an indicator of income deprivation, were plotted on the city map to analyse their distribution. Simple and multiple linear regressions with mortality as the outcome and environmental and social data as predictors were run.

Results: The results showed an unequal distribution of the variables in the city, with the north-eastern districts presenting worse values. Green areas did not result significantly in being related to mortality. The income indicator and transport networks have an impact on mortality in the simple regression, but only transport networks were found to have a statistically significant relation with mortality in the multiple regression.

Conclusions: The results suggested that living close to major transport networks could affect mortality rates in the city, but further research is needed. Future studies are also needed to analyse the interaction between environmental exposures and socioeconomic factors in affecting health. These findings can be useful for urban planning and health promotion interventions.