The Impact of Particulate Matter on Daily Mortality in Bangkok, Thailand

Abstract

Several studies conducted in U.S. cities report an association between acute exposures to particulate matter (PM), usually measured as PM and mortality. Evidence of high concentrations of PM in Eastern Europe and in large metropolitan areas outside of the United States, such as Mexico City and Bangkok, underscores the need to determine whether these same associations occur outside of the United States. In addition, conducting studies of mortality and air pollution in regions that have distinctly different seasonal patterns than those of the United States provides an effective opportunity to assess the potentially confounding aspects of seasonality. Over the last few years, daily measures of ambient PM have been collected in Bangkok, a tropical city of over 6 million people. In this metropolitan area, PM consists largely of fine particles generated from diesel- and gasoline-powered automobiles, and from two-stroke motorcycle engines. Our analysis involved the examination of the relationship between PM and daily mortality for 1992 through 1995. In addition to counts of daily natural mortality (total mortality net of accidents, homicides, and suicides), the data were compiled to assess both cardiovascular and respiratory mortality, and natural mortality by age group. A multivariate Poisson regression model was used to explain daily mortality while controlling for several covariates including temperature, humidity, day of the week, season, and time. The analysis indicated a statistically significant association between PM10 and all of the alternative measures of mortality. The results suggest a 10-µg/m change in daily PM is associated with a 1-2% increase in natural mortality, a 1-2% increase in cardiovascular mortality, and a 3-6% increase in respiratory mortality. These relative risks are generally consistent with or greater than those reported in most studies undertaken in the United States.

Temperature variation in the 24 hours before the initial symptoms of stroke

“…However, the differences between environmental and room temperature exposition could be a bias for our study. On the other hand, the association among daily variation of temperature in the environment, pollution and cardiovascular mortality has been demonstrated in epidemiological studies [15][16][17][18] . An interesting study found out some factors that have increased the cardiovascular risk, such as the variation of environmental temperature, drier air, upper respiratory infections, grass pollen, SO2, and particulate air pollution 19 .…”

Roadside Particulate Air Pollution in Bangkok

“…They indicated a statistically significant association between daily PM 10 and daily mortality. 22 Nouchpramool et al 23 reported on the airborne particulate characterization by neutron activation analysis. This study was conducted from January 1997 to May 1998.…”

“…[18][19][20] In many of its congested streets, the levels of total suspended particulates (TSP) and PM 10 were higher than the NAAQS (24-hr average concentration of TSP = 330 µg/m 3 and PM 10 = 120 µg/m 3 ). 21 Ostro et al 22 studied the impact of PM on daily mortality in Bangkok from 1992 to 1995. They indicated a statistically significant association between daily PM 10 and daily mortality.…”

The temporal pattern of respiratory and heart disease mortality in response to air pollution.

“…Some studies found an association between airborne particles and mortality by age groups (Bremner et al 1999;Goldberg et al 2000;Ostro et al 1999a;Ponka et al 1998;Verhoeff et al 1996), but again, none analyzed the distribution of the effect over time since exposure and whether the mortality displacement is short term.…”