Green spaces in the city decrease premature deaths

Green spaces in cities are important and can prevent premature deaths for any cause according to a new study published in The Lancet Planetary Health. The analysis was based on new longitudinal studies concerning seven different countries for a total of 8 million inhabitants and, as specified in the press release, “provides strong evidence of the impact of the increase in green areas on mortality.”

Considering that almost half of the world’s population lives in urban contexts and considering that in many of these areas green spaces are lacking or not enough, this research reveals once again how much this is not just “urban decoration” but a method direct and effective to improve the health of citizens. In particular, green spaces, according to researchers, reduce stress, improving mental health, and are a weapon of contrast for cardiovascular diseases, metabolic syndrome and in general for premature deaths.

Similar studies have been carried out in the past but have focused on specific areas or have used different methods to measure citizens’ exposure to plants and general greenery. Precisely for this reason, researchers from the Barcelona Institute for Global Health (ISGlobal), who collaborated with the Colorado State University and the world health organization, decided to focus on longitudinal studies carried out in different areas.

The researchers used a particular methodology to measure exposure to green called the Normalized Difference Vegetation Index (NDVI) also based on satellite images. They then compared these data with those related to statistics for premature mortality for all causes. The study considered the inhabitants of areas of Canada, the United States, Italy, Spain, Australia, Switzerland and China.

The researchers discovered a link between the amount of greenery around homes with a significantly reduced amount of premature mortality. Deaths decreased by an average of 4% for each 0.1 increase in vegetation score when it was present within 500 meters of the houses.

As David Rojas, a researcher at ISGlobal and first author of the study, says, these results “support interventions and policies to increase green spaces as a strategy to improve public health.”