Measuring health outcomes of OECD countries’ urban greenspace, with a special focus on Milan (Italy)

Background Urban world population has raised to 4.2 billion in 2018, with 2.5 billion more forecasted by 2050. Cities are places of opportunities but, at the same time, sites of environmental and social risk factors. Scientific evidence about urban green's environmental benefits is abundant, but Public Health outcomes are seldom carefully defined. The project aims at assessing the Public, Urban and Mental Health outcomes of urban green areas in Organisation for Economic Co-operation and Development (OECD) countries, and at exploring citizen urban greenspace perception in Milan, Italy. Methods A systematic review of literature was conducted according to the 2015 PRISMA statement. Two online databases (Medline and Embase), were consulted, and inclusion criteria were set, ruling in all OECD countries-based, English-written studies from 2000 to December 2019. Only objectively measurable health outcomes were deemed suitable for analysis. Based on the main review findings, a community-based survey was created, targeting residents of Milan and its suburban area to understand better how they benefit from the urban green areas in their city. The study is being carried out by an interdisciplinary team of medical doctors and architects. Results We grouped health outcomes into five separate domains, namely cardiovascular, obesity, respiratory, neoplasia and mental health. We found negative associations between disease prevalence and urban greenspace overall quantity. Size, perceived quality and accessibility were powerfully explanatory variables. Milan community-based survey drafting is underway. Results are still preliminary and will be presented by tables, graphs and plots. Conclusions Cities are increasingly becoming critical points for many emerging Public Health challenges. The results of our study may help urban planners, key stakeholders, policymakers and communities to preserve and increase existing green spaces, and to improve Urban Public Health.