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).
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