Air pollution poses adverse consequences for human health and the environment in urban areas. Among all types of ecosystems, urban ecosystems manifest the greatest degree of heterogeneity in the spatio-temporal patterns of pollutant concentrations. We are conducing geospatial air quality research in several cities to generate knowledge for air pollution-health outcomes and to improve city-scale pollution prediction capacities through an integrated personal monitoring, regional-scale mapping, and multidisciplinary modeling framework.