In the study, published in "Environmental International" magazine, researchers analysed the biological markers of 3,100 children, 7 years old, from the Metropolitan Area of Porto belonging to the Generation XXI (a longitudinal study by ISPUP that has accompanied, since 2005, 8,600 children).

"These children are all georeferenced, that is, we know in which pair of coordinates they live and in which schools they study. Based on this information, we cross-referenced the child's health data with the environmental information”.

The study included 226 public and open-air green spaces in the Metropolitan Area of Porto, which were later correlated with health data for each child, such as blood pressure, waist to hip ratio, glycated haemoglobin, cholesterol and C-reactive protein.

"We were able to measure geographic accessibility and, as a general rule, we saw that children who had green spaces around school and at home presented more favorable levels of biomarkers," she said.

"The children who had green spaces between 400-800 metres from their schools, i.e. respectively 20% and 40% of the children had better biomarker levels, especially in terms of markers related to cardiovascular health".

Taking into account the evidence observed with this study, Ana Isabel Ribeiro warned of the need "not to neglect" these areas, suggesting a "greater investment in the provision of these spaces near schools", where children spend most of their time.

"It is essential that local governments and planners ensure that the population has green areas within a reasonable distance of their places of residence and school parks," she concluded.

The study, developed by researchers from the Epidemiology Research Unit (EPIUnit) of ISPUP, is part of Exalar XXI, a project that studies the relationship between the urban environment and child health.