Researchers chose a 12-square-kilometer region in Louisville, KY, for long-term monitoring of major air pollutants and assessment of cardiovascular function and risk factors. A 2.3-square-kilometer contiguous region within the study domain serves as the intervention area where mature vegetation selected for ecological compatibility and pollutant removal characteristics is being installed for near-road and neighborhood-scale “greening”; the remaining area serves as the control. Data generated from the study, in conjunction with advanced GIS techniques such as hyperlocal land-use regression models, is used to estimate residential-level exposure to ambient air pollution before and after planting.