The high daily correlation, based on three months of
daily data collected at two sites, between PM10 and PM2.5,
indicates that the daily variation of PM in Bangkok is likely
driven by changes in combustion particles and perhaps
re-entrained road dust, both associated with motor vehicle
use. Taken together, the results provide strong evidence
that an association exists between daily mortality
and PM air pollution in an area where daily fluctuations
in PM10 are dominated by fine particles.