The role of roadside vegetation near school in mitigating air pollution: an exploratory case study in Zielonka

This study investigates the role of urban vegetation in mitigating particulate matter (PM₁, PM₂.₅, PM₁₀) pollution along school routes in Zielonka, a small town near Warsaw. Measurements were collected during leaf-off (March) and leaf-on (September) conditions using a Sniffer4D mobile air quality monitor carried along pupils’ commuting paths, alongside vegetation density estimates obtained with a SunScan Canopy Analysis System. Initial correlation analyses across the entire dataset revealed weak negative relationships between leaf area index (LAI) and particulate concentrations. To refine interpretation, the study introduced spatial stratification using built-up area percentages derived from the BDOT10k topographic database. While mean PM levels decreased with higher LAI, occasional local maxima were observed in dense canopy sections. The findings highlight that vegetation’s effectiveness in improving air quality is highly context-dependent, shaped by urban form and season. Although the explanatory power was modest, the results emphasize the importance of integrating vegetation and built-environment interactions in air quality assessments. Further studies with broader spatial and temporal coverage are recommended to better characterize these relationships and guide targeted greening strategies along school routes.