The logging interval for all measurements was set at 1 min. During
monitoring, measurements were taken every 15 min (short-term)
at each sampling site. Then, short-term PM (or CO2) levels were
obtained based on 15 min time-averaged. All measurements were
taken between 8:00 and 21:00 during day or night and on weekdays
or weekends from February to April 2010.
The outdoor hourly PM10 and PM2.5 levels measured by ambient
air-quality monitoring stations at Wanhua Station about 900 m
from the Taipei Bus Station are considered the corresponding PM
levels in the urban atmosphere in Taipei. These hourly PM10 and
PM2.5 concentrations were measured by automatic Met One BAM
1020 beta gauge monitors (Met One, Inc., Grants Pass, OR, USA)
deployed in Taiwan’s air-quality monitoring network. Hourly traffic
data of the bus terminal was obtained from the Bus Station
Administration.