Table 5 Estimated reductions to mean waiting exposures with the simulation of station exposures being reduced to that of bus stops.

From: Personal exposures to traffic-related air pollution in three Canadian bus transit systems: the Urban Transportation Exposure Study

Pollutant City Mean daily concentration (SD) Mean % reduction of waiting exposures (SD)
Sampled data After the reduction of bus station exposures to that of bus stopsa
PM2.5 (µg/m3) Toronto 27.5 (14.2) 24.3 (13.6) 13 (7.5)
Ottawa 24.2 (14.4) 24.1 (14.3) 0.5 (0.8)
Vancouver 15.2 (5.6)
Ultrafine particles (103 pts/cm3) Toronto 23.5 (8.1)
Ottawa 26.8 (15.7) 23.6 (13.6) 11.4 (2.6)
Vancouver 18.5 (14.1)
BC (µg/m3) Toronto 4.5 (4.3) 4.1 (4.3) 15.8 (13.2)
Ottawa 2.9 (1.6) 2.5 (1.3) 14.1 (4.1)
Vancouver 1.9 (0.6)
  1. “–” denotes no evidence of higher stations exposures, relative to bus stops.
  2. aBased on the percent increases of exposure for at outdoor and enclosed bus stations, relative to bus stops (Table 3).