Assessing the Impact of Urban Green Spaces on Local Air Quality Improvement

Thesis Abstract

Urban air pollution poses a significant health and environmental challenge in contemporary cities, necessitating sustainable interventions such as the strategic development and management of green spaces. This study investigates the extent to which urban green spaces influence local air quality, aiming to provide empirical evidence to inform urban environmental policies. The primary objectives are to quantify air pollutant levels across areas with varying green cover, assess residents' perceptions of air quality improvements attributable to green spaces, and identify the key factors mediating the relationship between green space attributes and air quality indicators. Employing a mixed-methods research design, the study integrates quantitative measurements of ambient air pollutants with qualitative insights from stakeholder interviews. The population encompasses residents living within 500 meters of selected urban green spaces in the city of Greenfield, totaling approximately 1,200 households. A stratified random sampling approach selected a sample of 300 households for household surveys, while air quality data were collected from five strategically placed monitoring stations within the studied zones over a 12-month period, capturing seasonal variations. Data collection instruments included calibrated portable air quality monitors measuring particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3), alongside structured questionnaires designed to capture residents’ perceptions of air quality and usage of green spaces. The reliability and validity of instruments were verified through pilot testing and Cronbach’s alpha analysis, achieving coefficients exceeding 0.8. Quantitative data were analyzed using descriptive statistics, Pearson correlation matrices, and multiple linear regression models to examine the relationships between green space characteristics (size, vegetation density, and spatial distribution) and pollutant concentrations. Spatial analysis utilizing Geographic Information Systems (GIS) mapped pollution dispersion patterns relative to green space distribution. Qualitative data from interviews underwent thematic content analysis to explore residents’ perceptions and behavioral adaptations related to green space use and air quality awareness. The study applies the Ecological Theory of Urban Resilience to interpret the dynamic interactions between green infrastructure and environmental health, and the Theory of Perceived Environmental Quality to contextualize residents’ subjective assessments. Expected findings indicate that areas with higher green space density exhibit statistically significant reductions in PM2.5, PM10, and NO2 levels, with regression analysis demonstrating green space size and vegetation density as key predictors of improved air quality (p < 0.05). Residents generally perceive greener neighborhoods as cleaner and healthier, correlating with measured pollutant reductions, although some knowledge gaps are likely to emerge. The study anticipates revealing how specific green space attributes influence pollutant dispersion and residents’ perceptions, thus bridging empirical measurements with socio-perceptual dimensions. This research significantly contributes to environmental management literature by providing comprehensive, location-specific evidence on the air quality benefits of urban green spaces, thus guiding urban planners and policymakers in optimizing green infrastructure deployment for pollution mitigation. It highlights critical factors such as vegetation type, spatial configuration, and community engagement that enhance green spaces’ efficacy in improving air quality. The study concludes with actionable recommendations for integrating green space planning within broader urban environmental strategies, emphasizing community participation, maintenance, and continuous monitoring. Overall, the findings underscore that well-designed urban green spaces serve as effective natural buffers against air pollution, with implications extending to public health improvement, climate resilience enhancement, and urban sustainability. Future research should explore longitudinal impacts and the integration of green spaces with other urban green infrastructure solutions to maximize air quality improvements across diverse city environments.