EPIUnit, Institute of Public Health of the University of Porto, Porto, Portugal2
Basic and Clinical Immunology Service, Department of Pathology, Medical School, University of Porto, Porto, Portugal3
Department of Public Health and Forensic Sciences and Medical Education, Medical School, University of Porto, Porto, Portugal4
Nutrition and Food Sciences School, University of Porto, Porto, PortugalHistory
Published online: 29 July 2020
Accepted: 6 July 2020
Received: 4 May 2020
Greenspaces in school's neighbourhood represent an important environment to promote healthy development. The aim of this study was to assess the association between the density and type of trees around schools and exhaled nitric oxide (NO) levels in schoolchildren. Data on 845 children from 20 primary schools in Porto was analysed. Airway inflammation was assessed by measuring exhaled NO level. The density and type of trees were quantified within a 500 m buffer around schools. Associations were estimated using mixed-effect models. A significant association was observed between non-tree covered areas around schools and exhaled NO levels in schoolchildren (‚=-1.42, 95%CI -2.84, -0.001). Our results suggested that the presence of trees in school neighbourhoods may play a role in the biological mechanisms underlying the complex links between environment and airway inflammation.
Children; exhaled nitric oxide; greenness; school neighborhood; tree density.