Impact of the urban built environments on pedestrian exposure to ultrafine particles

The total pedestrian and resident exposure to air pollutants are highly related to the short periods of time spent on and near roadways because of the typically much higher pollutant concentrations in near-roadway micro-environments. In dense urban areas, near-roadway environments can include most street-level outdoor spaces. At the same time, traffic-related pollution levels in urban areas are highly variable. While our understanding of the built environment characteristics that influence street-level ultrafine particles (UFPs) concentrations is still developing, it is clear the design of the built environment plays a major role.

Here we consider the effect of different building configurations on the concentrations of traffic-related or other pollution, on pedestrian exposures. Using a numerical model capable of reproducing the very complex air flows at small scales in urban areas (the Quick Urban and Industrial complex model, QUIC) and validating its ability to accurately reproduce real-world data with an extensive field dataset collected in an earlier study. We also explore the value of open space interspersed with tall buildings, and of clustering buildings instead of spacing them evenly in dense urban areas.