ABSTRACT
Recent epidemiological studies show that exposures to particulate air pollution are associated with increased respiratory disease morbidity and mortality (1-8). Although mechanisms leading to these effects have not yet been delineated, these epidemiological studies offer important clues about potential mechanisms, such as that persons with chronic respiratory disease (asthma, chronic bronchitis) and cardiovascular disease are particularly susceptible (2,9-13). The theme of this chapter is that ambient air particles have intrinsic toxicity and are more harmful in the setting of preexisting pulmonary inflammation because they exacerbate both inflammatory and airway obstructive responses, as well as systemic effects manifested in the heart. Such processes can account for the increased morbidity and be related to the increased mortality seen in epidemiological studies, and they can specifically produce the cardiopulmonary events described in the epidemiological studies.
