The creation of parks and green areas in urban centres have positive effects on the health of residents. However, a new article published by the research group at the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) and the Municipal Institute for Medical Institute of the Hospital del Mar (IMIM) suggests that more socially disadvantaged neighbours could be pushed aside when it comes to the health effects of "ecologisation" and may not benefit equally from these positive effects on health.

The research is based on evidence that the "greenification" of cities, thanks to the creation of parks, green areas and ecological corridors, are beneficial to the physical and psychological health of people. This growing tendency to "ecologise" cities improves the quality of air, motivates people to exercise, and favours the creation of stronger social relations among residents, thereby lowering chronic stress levels and helping to improve people's health in general.

Nevertheless, researchers at the Barcelona Lab for Urban Environmental Justice and Sustainability (BCNUEJ) of the ICTA-UAB, co-led by sociologists and geographers Isabelle Anguelovski and James Connolly, established that the process of recovering natural spaces in cities tends to produce a phenomenon known as "green gentrification," in which the original population of a middle-low or low class district is pushed out by new inhabitants with higher economic status, drawn by the proximity of new parks, green areas and more attractive housing offers. In consequence, housing prices rise considerably and more vulnerable neighbours can no longer afford this growth in prices or the real estate pressure, causing them to seek housing in other less attractive areas with a lower quality of life.

Thus, the process of "green gentrification" contributes to perpetrating poverty by geographically concentrating the vulnerable population and may produce a rupture in the already existing social relations of a neighbourhood, as well as increase chronic stress and negatively affect the mental health of these residents. "Using what we known about green gentrification, we want to understand its impact on the health of residents living in neighbourhoods which have been gentrified by green areas. We believe green gentrification can modify the health effects of being exposed to green areas," says lead researcher Helen Cole, who affirms that greener cities are not equally fair and healthy for everyone.

"Public health professionals defend the greenification or ecologisation of cities and state their health benefits without taking into account these dynamics, and without thinking about what they imply for the relation of health equality in cities," Cole explains. For this reason, she considers that researchers in public health and epidemiology must take into account this situation and trust in a more dynamic community model to explain the possible unintentional social consequences of making cities greener and examine the impact of gentrification on the health of neighbourhoods, especially those which have become green neighbourhoods.

At the same time, Helen Cole and several other collaborators from the research group recently published a comment in the journal The Lancet -- Public Health which highlighted the danger of using transversal urban health initiatives to justify the construction of new luxurious housing promotions and gentrification.