Who is sensitive to the effects of particulate air pollution on mortality?
GROUND: Populations susceptible to the effects of particulate matter have begun to be characterized, but the independent contributions of specific factors have not been explored. METHODS: We used a case-crossover study to examine PM10-associated mortality risk during 1988-1991 among 65,180 elderly residents of Cook County, Illinois, who had a history of hospitalization for heart or lung disease. We assessed how the effect was independently modified by specific diagnoses and personal characteristics. RESULTS: We found a 1.14% (95% confidence interval [CI] = 0.44% to 1.85%) increased risk of death per 10 microg/m3 increase in ambient PM10 concentration. Persons with heart or lung disease-but no specific diagnosis of myocardial infarction, diabetes, congestive heart failure, chronic obstructive pulmonary disorder, or conduction disorders-were at 0.74% (-0.29% to 1.79%) increased risk. Persons with a history of myocardial infarction had a 2.7-fold higher risk (CI = -2.1 to 7.4). Those with
