Global studies of the health impacts of fine particulate matter (PM2.5) have been based on particle mass, but there is evolving evidence indicating that adverse health effects can vary depending on the source and composition of PM2.5.

Associations between long-term exposure to ambient fine particulate matter [with aerodynamic diameter ? 2.5

Air pollution data in Bangkok, Thailand, indicate that levels of particulate matter with aerodynamic diameter ? 10 ?m (PM10) are significantly higher than in most cities in North America and Western Europe, where the health effects of PM10 are well documented. However, the pollution mix, seasonality, and demographics are different from those in developed Western countries. It is important, therefore, to determine whether the large metropolitan area of Bangkok is subject to similar effects of PM10.