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.

Although the deleterious effects of air pollution from fossil fuel combustion have been demonstrated in many Western nations, fewer studies have been conducted in Asia. The Public Health and Air Pollution in Asia (PAPA) project assessed the effects of shortterm exposure to air pollution on daily mortality in Bangkok, Thailand, and in three cities in China: Hong Kong, Shanghai, and Wuhan.