Air Pollution and Hospital Admissions for Cardiovascular Disease in Detroit, Michigan

In the December 1952 smog disaster in London, a substantial increase in mortality was closely associated with the increase in air pollution. Deaths from cardiovascular causes were elevated as well as respiratory deaths. The increase was greatest in the elderly. Hospital admissions were increased for both respiratory and cardiovascular diseases. Since then, many studies have reported associations between lower concentrations of air pollution and daily mortality. Little attention has been paid to the question of hospital admissions for cardiovascular illness, however. This study examined the association between air pollution and cardiovascular hospital admissions for persons aged 65 years and older in the Detroit, Michigan, metropolitan area during the years 1986-1989. After controlling for seasonal and other long-term temporal trends, temperature, and dew point temperature, the particulate matter with an aerodiameter of < or = 10 microns (PM10) was associated with daily admissions for ischemic heart disease (relative risk (RR) = 1.018, 95% confidence interval (CI) 1.005-1.032 for an interquartile range (32 micrograms/m3) increase in pollution). SO2, CO, and ozone made no independent contribution to ischemic heart disease admissions. Both PM10 (RR = 1.024, 95% CI 1.004-1.044) and CO (RR = 1.022, 95% CI 1.010-1.034 for an interquartile range (1.28 ppm) increase in pollution) showed independent associations with heart failure admissions. These results were robust to alternate methods of estimation and weather control.