Discussion
Taking the results of the three panels
together, there is evidence of an association
between upper and lower respiratory symptoms
and PM10. Replicating previous studies
from the Western industrialized cities in a
city such as Bangkok, which has very different
meteorologic conditions, baseline health
status, and activity patterns, provides strong
evidence for causality.
The results of the daily symptom diaries
for adults in the Odean Circle area show
substantial and robust PM10 effects on the
incidence of upper and lower respiratory
symptoms. One of the selection criteria for
this subject group was that they worked in
shops not air conditioned in a high-traffic
commercial area. This group, therefore, is
expected to have fairly high exposures to
outdoor air pollution during the day.
Positive associations of smaller magnitude
were also found between PM10 and symptoms
for nurses working and living at
Chulalongkorn Hospital. The nurses were
expected to have lower exposures to outdoor
air pollution because they worked primarily