areas and found the absolute PM exposures were underestimated
by the ambient monitoring data. Because there
is increasing concern about the adverse health effects of
air pollution in Bangkok, our research team conducted
environmental and epidemiologic surveys to monitor the
level of fine PM and its relationship with lung diseases.
The prevalence of chronic respiratory symptoms and respiratory
function was investigated in a group of traffic
police, a selected population considered to be at high risk
because of the roadside air pollution exposure during their
work. A significant association was found between particulate
levels and respiratory impairment.25
In the present study, PM levels reported by the PCD
were assessed because of their continuity and wide coverage
of the area monitored. In Bangkok and vicinity, 24-hr
average ambient air quality data of PM10, NO2, SO2
, and
O3
were used in the selection of appropriate sampling sites.
For the present study of particulate monitoring, PM10 and
PM2.5 were collected simultaneously at various locations
in urban and rural areas of Bangkok. The ratio of PM2.5
and PM10 and the relationship between personal exposure
and PCD data were investigated to validate and interpret
actual human exposure concentrations.
Although there have been several studies on personal
exposure of gaseous pollutants, few have been reported
on PM.24-26 PM exposure measurement requires active sampling
with a pump; therefore, it is not convenient to use
in practice. For a more comprehensive evaluation of the
health effects of PM, measuring PM10 was considered to
be insufficient, and thus, in the present study, personal
samplers for the simultaneous measurement of PM2.5 and
PM10 also have been used.