ABSTRACT
High-PM Exposure ................................................................................................................76
4.4 Experimental Studies on PM and Airway Wall Remodeling ...............................................78
4.5 Interactions of PM and Ozone...............................................................................................81
4.6 Functional Consequences and Perspective ............................................................................84
Acknowledgment ............................................................................................................................85
References .......................................................................................................................................85
Small airway remodeling is an important cause of chronic obstructive pulmonary disease (COPD)
in cigarette smokers. The incidence of COPD in subjects exposed to chronically high levels of
particulate air pollutants (i.e., particulate matter) appears to be increased, and morphologic studies
have shown that particulate matter (PM) produces small airway remodeling that is structurally
similar to that seen in cigarette smokers. Experimental studies show that PM enters airway walls
and suggest that the most important component of airway remodeling, increased airway wall fibrous
tissue, is driven by oxidants and iron released from PM particles. Release of the fibrogenic cytokine,
TGFb
