School greenness and individual-level academic performance in elementary-aged students: evidence from the Global South

Accumulating evidence of the beneficial effects of contact with nature on children’s mental and physical health suggests that exposure to green spaces can support learning and enhance academic performance in children. A limited number of studies exploring the relationship between vegetation in the school environment and academic outcomes has found positive associations. However, most studies use students’ contextual data and outcomes aggregated at the school level, and therefore are unable to adequately control for individual characteristics of students known to influence academic performance. Furthermore, these studies have been carried out in developed countries of North America and Europe, and therefore the extent to which their findings are generalizable to different socio-economic, cultural, and ecological contexts is not well understood. In this dissertation, we advance our understanding on the use of remote sensing data to assess greenness exposure, in order to evaluate the association between greenness in the school environment and student-level academic outcomes in a country of the Global South. We first estimated the influence of spatial resolution of normalized difference vegetation index (NDVI) on greenness exposure misclassification. We assessed residential greenness for a large cohort of children in Boston, Massachusetts using NDVI at different spatial resolutions and multiple buffer sizes, following methods commonly used in the environmental health literature. Using a reliability assessment framework, we compared continuous and categorical exposure estimates and found that exposure misclassification was higher with coarser spatial resolution, smaller buffers, and greater number of exposure quantiles. We conclude that greenness exposure assessment is sensitive to spatial resolution of NDVI, aggregation area, and number of exposure quantiles. Then, we linked satellite-derived greenness estimates for 2,931 schools in urban areas in Chile to administrative records of standardized test scores and contextual information at the individual and school level for 541,171 elementary-aged students. We evaluated the association between greenness in the school environment and individual-level academic performance in elementary-aged students in Santiago, Chile. Higher school greenness levels were associated with improved individual-level academic performance, with greater magnitude and strength of associations for students in public schools. Finally, we evaluated the individual-level association between greenness in the school environment and academic performance of students in schools in 16 cities across different climate zones in Chile. School greenness was positively associated with test scores and odds of attaining learning standards in mathematics and reading, although associations held only in public schools. The magnitude of associations varied widely across climate regions, decreasing from the desert region in the north to the more vegetated regions in the south. In light of the growing interest on health effects from urban green spaces, this dissertation provides insights on methodological decisions regarding greenness exposure assessment in environmental health research. Furthermore, it expands the evidence on a beneficial association between school-greenness and academic performance to different cultural, demographic, and climate settings. Our results highlight the nuanced nature of this association and the importance of considering students’ social and ecological contexts in urban greenspace management around schools to provide green spaces that effectively support learning.2024-12-05T00:00:00