In Search of Fresh Air: Characterizing the Sources and Impacts of Air Pollution in Urban Areas

Cities with growing populations have turned to urban planning strategies like mixed-use development. In this type of development Individuals who live, work, and seek entertainment in these urban areas can be exposed to air pollution that is regionally transported and from locally emitted sources.

Urban air pollution measurements typically rely on a few, widely separated monitoring sites to assess population-scale exposure. Existing monitoring techniques may not be able to capture the spatial variability of the air pollutant. Dr. Naomi Zimmerman, a Postdoctoral Research Associate at Carnegie Mellon University’s Department of Mechanical Engineering, spoke about her research to characterize urban spatial and temporal pollutant gradients across Pittsburgh at the SOCAAR Seminar on May 29.

In this study, twelve air quality monitoring stations were deployed for one year at sites around Pittsburgh’s downtown urban locations consisting of traffic, restaurants and tall buildings. Mobile sampling data, collected using the Carnegie Mellon van, was used to increase spatial resolution of air pollutant data collected. Zimmerman reported that the three types of sites showed very different concentrations of ultrafine particulates, NO2, CO and PM2.5. A different air pollutant mix was also observed during different times at these sites.

In Pittsburgh’s downtown areas, organic aerosols associated with restaurants were found to be a more significant source of air pollution than traffic. Zimmerman reports that cooking plumes are currently driving the personal exposure to pollution in urban areas. In the next phase of their research, they will be expanding the monitoring site network across Pittsburgh to around 50 sites by July 1.