These are the conclusions of a paper published in Environment International with data from 37,000 children from Vancouver (Canada). The study was led by Matilda van den Bosch, researcher at the Barcelona Institute for Global Health (ISGlobal), a centre supported by the ”la Caixa” Foundation.
The aim of this scientific work was to investigate the possible associations between exposure to greenness, air pollution and noise in early life with later incidence of ADHD, one of the most prevalent neurodevelopmental disorders, which affects up to approximately 5-10% children and adolescents. One of the goals of the study was to evaluate possible joints effects of these exposures in relation to ADHD.
The study used administrative data of births in Metro Vancouver from 2000 to 2001 and retrieved data on ADHD cases from hospital records, physician visits and prescriptions. The percentage of green space in the participants’ neighbourhood was estimated with a novel and precise satellite metric, while the residential levels of two air pollutants —NO2 and PM2.5— as well as noise levels were estimated using available exposure models. Finally, the possible associations between the three environmental exposures and ADHD were assessed using a statistical model that allowed to determine hazard ratios.
The researchers were able to identify 1,217 cases of ADHD, equivalent to a 4.2% of the total study population. The green space analysis revealed that participants living in areas with a greater percentage of vegetation had a lower risk of ADHD. More specifically, the results show that a 12% increase in vegetation percentage was associated with a 10% reduction in the risk of ADHD .