Is PM similar to PM? A new insight into the association of PM and PM with children's lung function.

Experimental data suggests that PM is more toxic than PM although the epidemiologic evidence suggests that the health associations are similar. However, few objective exposure data are available to compare the associations of PM and PM with children lung function. Our objectives are a) to evaluate associations between long-term exposure to PM, PM and children's lung function, and b) to compare the associations between PM and PM.