Epidemiology of particulate air pollution: exploiting observable exposure variability

Epidemiological studies of PM pollution and health have attempted to exploit observable sources of exposure variability to evaluate potential health consequences. These studies have become increasingly ingenious and rigorous in their ability to use natural exposure variability. Although a large majority of studies have evaluated only changes in short-term exposures, long-term, chronic exposure may be more important in terms of overall public health. This paper outlines the various dimensions of natural PM exposure variability that have been exploited in the epidemiology of PM literature, discuss how this exposure variablilty has or has not been utilized in recent epidemiology studies of PM exposure and human health, outline the inferences being drawn from the studies, and present the major limitations of these studies.Copyright © 1999 John Wiley & Sons, Ltd.