Abstract
OBJECTIVES: We evaluated the spatial and temporal patterns of traffic-related air pollutants in an urban neighborhood to determine factors contributing to elevated concentrations and to inform environmental justice concerns. METHODS: In the summer of 2007, we continuously monitored multiple air pollutants at a community site in the Mission Hill neighborhood of Boston, Massachusetts, and local high school students conducted mobile continuous monitoring throughout the neighborhood. We used regression models to explain variability in concentrations, considering various attributes of traffic, proximity to major roadways, and meteorology. RESULTS: Different attributes of traffic explained variability in fixed-site concentrations of ultrafine particles, fine particulate matter, and black carbon, with diurnal patterns and meteorological effects indicative of a greater local effect on ultrafine particles and black carbon. Mobile monitoring demonstrated that multiple traffic variables predict elevated levels of ultrafine particles, with concentrations of ultrafine particles decreasing by 50% within 400 meters of 2 major roadways. CONCLUSIONS: Unlike fine particulate matter, ultrafine particles demonstrate significant spatial and temporal variability within an urban neighborhood, contributing to environmental justice concerns, and patterns can be well characterized with a community-based participatory research design.