Improved distribution of green spaces in Barcelona can prevent 178 premature deaths each year, the study says

Greening every third street in Barcelona city can prevent the premature death of up to 178 people each year. Furthermore, in the months that heatwaves occur, urban trees and gardens can help prevent five more temperature-related deaths. These are the main conclusions of the Health Impact Survey conducted by the Barcelona Institute of Global Health (ISGlobal) and published in the Journal Environment International.

Green spaces are well known to be associated with many benefits for physical and mental health and well-being, including reduced preterm birth. Additionally, urban trees and vegetation provide shaded areas and help combat the effects of urban thermal islands.

Therefore, the Isglobal team set up the effect of comprehensive implementation of the Green Corridor Plan on mortality rates in Barcelona’s adult population for two variables. Ambient temperature. In its theoretical formulation, the Green Corridor Plan assumed that all streets in the city would be green corridors.

The team won 2019 as the reference year before the hypothetical implementation of the plan. They then obtained death data for that year and for the city of Barcelona from two sources: Catalonian Statistical Institute (IDESCAT) and National Statistical Institute (INE). The proportion of green spaces within the city was obtained from specific maps by the European Environment Agency (EEA).

According to the predictions listed in the Green Corridors Project itself, they estimated that the intervention would lead to a 7% or 15% increase in the green surface area of ​​each street or intersection, depending on the width.

Finally, to estimate the number of preventable deaths as a result of the planned increase in green spaces, they used previous scientific studies that quantified this relationship.

Green space increased by 3.64%

The results show that the creation of green corridors across the city means an increase of 3.64% in areas devoted to green space, from 7.3% in 2019 to 10.9%. This increase could prevent 178 premature deaths a year. Or the same thing. There are 13 deaths per 100,000 people.

“Barcelona is a challenging and compact city when it comes to green spaces. There are small areas allocated for this purpose, and some are less distributed, as they are primarily located in the suburbs,” Isglobal was a researcher and first author of the study.

“We estimate the increase in green spaces has not reached 4% and cities are still far from the recommended 25%, so it’s a modest degree, but health impacts are important. These spaces around town “Corridor Plans to provide an equitable distribution of the corridor,” she adds.

Five fever-related deaths are avoided

At the same time, the team conducted a second health impact survey related to fever-related mortality. With the help of various models, the expected increase in the area allocated to green spaces could result in a drop of 0.05ºC in average temperatures, and a drop of 0.42ºC in some cities. I did.

These figures are obtained and using the relationship between temperature exposure and mortality established in previous scientific studies, virtual Barcelona with green corridors, five people per month in high temperature situations such as recorded in summer It was estimated that deaths could be avoided. In the month of 2015, this was adopted as a reference. This amounts to one death every six days.

“The effect of green corridors on temperature cannot be ignored, but it is clear that complementary measures aim specifically to combat and adapt to heat, particularly in the context of climate change and aging populations. It’s related. It’s becoming more vulnerable to the effects of high temperatures,” warns Eunman.

Preventable deaths with the Metropolitan City Master Plan (PDUM)

Given the delay in the Green Corridor Plan, the team decided to analyze the alternative: the Metropolitan City Master Plan (PDUM) of the Barcelona Metropolitan Area (AMB) is a region assigned to green spaces each year. This is one of the purposes of increasing the number. 2030. Following the same methodology as the previous procedure, it was calculated that the expected increase in green space in this plan could prevent the premature death of 53 people per year. Barcelona city, that is, four deaths per 100,000 people.

In terms of temperature, PDUM achieves an average reduction of 0.03ºC, but in certain areas of the city, a maximum decrease of 0.77ºC. This temperature drop prevents deaths three times a month in temperature conditions such as those used as references.

“In our analysis, we observed that PDUM offers more health benefits than green corridors. This means that the interventions assumed in PDUM are more localized and equal across cities. This can be explained by the fact that it is not distributed in. Mark Niewenhuissen, director of Isglobal’s climate, air pollution, nature and urban health programs, said:

“It should be kept in mind that this study only took into account the direct relationship between green space and mortality. Urban planning interventions suggesting increased areas allocated to green space are considered to be diseased. Not only does it reduce the burden, but it also offers additional benefits related to reduced air and noise pollution and increased levels of physical activity, Nieuwenhuijsen adds.

Currently, the Isglobal science team is conducting research with the same methodology to assess the impact on mortality of the Green Roof Project, the current city council initiative that proposes roof greening.