Particulate matter exposure along designated bicycle routes in Vancouver, British Columbia

An instrumented bicycle was used to elucidate particulate matter exposures along bicycle routes passing through a variety of land uses over 14 days during summer and fall in a midlatitude traffic dominated urban setting. Overall, exposures were low or comparable to those found in studies elsewhere (mean PM2.5 and PM10 concentrations over each daily bicycle traverse varied between 7–34 μg m−3 and 26–77 μg m−3 respectively). Meteorological factors were responsible for significant day-to-day variability with PM2.5 positively correlated with air temperature, PM10 negatively correlated with precipitation, and ultrafine particles negatively correlated with both air temperature and wind speed. On individual days, land use and proximity to traffic were factors significantly affecting exposure along designated bicycle routes. While concentrations of PM2.5 were found to be relatively spatially uniform over the length of the study route, PM10 showed a more heterogeneous spatial distribution. Specifically, construction sites and areas susceptible to the suspension of road dust have higher concentrations of coarse particles. Ultrafine particles were also heterogeneously distributed in space, with areas with heavy traffic volumes having the highest concentrations. Observations show qualitative agreement in terms of spatial patterns with a land-use regression (LUR) model for annual PM2.5 concentrations