10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Vertical Variations in Outdoor Particulate Matter along the Height of a Tall Building in an Urban Environment
PARHAM AZIMI, Haoran Zhao, Torkan Fazli, Dan Zhao, Afshin Faramarzi, Luke Leung, Brent Stephens, Illinois Institute of Technology
Abstract Number: 1114 Working Group: Aerosol Exposure
Abstract It is generally assumed that building height can affect indoor exposures to pollutants of outdoor origin in tall buildings, as some ground-level pollutants such as particulate matter may be diluted at higher elevations. However, we are aware of very few measurements of airborne particle concentrations that have been made along the height of tall buildings. Therefore, we conducted a pilot study to measure the vertical variation of environmental conditions, outdoor particulate matter, and several other outdoor pollutants along the height of a ~60-story (~300 m) building in downtown Chicago, IL during a one-week period in the summer of 2017. Simultaneous measurements of size-resolved particulate matter (0.3 to 10 µm, which were used to estimate PM1, PM2.5, and PM10 mass concentrations), were made using multiple sets of instrumentation installed in the outdoor air intakes of the mechanical systems on the 2nd, 16th, 29th, and 44th floors and in an open-air area on the 61st floor. The results demonstrate that PM1, PM2.5, and PM10 concentrations generally decreased approximately linearly with building height. The vast majority of measured differences were statistically significant. Most strikingly, the average PM1 and PM2.5 concentrations on the top two floors were more than 30% lower than on the 2nd floor. Moreover, we used a simple well-mixed mass balance model to demonstrate how the measured differences in particle concentrations along the height of the test building would likely manifest in differences in indoor concentrations of particles of outdoor origin in a typical office space.