Pedestrian Exposure to PM2.5 in Commercial Core, Seattle

Abstract

The thesis explores how environmental factors influence pedestrian exposure to PM2.5 by collecting and analyzing air quality data in Downtown Seattle, Washington. After reviewing related research, the influences from outdoor smoking, bus loading activities, and restaurants are chosen to be analyzed in this research. The study collected measurements along a fixed route surrounded by 1st Ave, 3rd Ave, Pike Street, and Yesler Way. After data cleaning, measurements of PM2.5 intensity, temperature, and other indicators a linear mixed-effects model. This model is applied because of clustered data by day. Data were collected for five workdays with a similar pattern, satisfying the assumptions of the linear mixed effect model. Analysis results indicate that outdoor smoking ranks top among all factors that have a significant influence on pedestrian exposure to PM2.5. In contrast, restaurants and bus loading are not considered as important. Therefore, this research motivates further policy on how to regulate outdoor smoking behavior through city regulations.