Abstract
The health effects of ultrafine particles (UFP; particulate matter with a diameter of less than 0.1 m) released by motorized vehicles could be severe. Active motility, such as walking, is increasingly recommended to reduce traffic and improve physical activity levels. It has, however, sparked worries about increased exposure to UFP because of elevated breathing rates in traffic microenvironments immediately close to their source. This study used mobile measurements along the three walking routes, Rue Saint-Denis, Rue Rene-Levesque, and Saint Laurent Boulevard, to determine how exposed commuters were to ultrafine particles (UFP). The results show that the three pathways had significantly different UFP exposure levels, with mean particle number counts (PNC) of 24,804, 14,290, and 19,724 pt/cm3 correspondingly. Construction sites and heavy-duty vehicles (such as buses and trucks) were shown to be the primary contributors to peaks in UFP exposure. Compared to research undertaken in other cities, all routes in Montreal exhibited much lower PNC levels. The results of this study can guide the design of future road infrastructure, for instance, in the context of creating a low-emission zone for commuters, particularly walking individuals.