CARDIOVASCULAR-DISEASE HOSPITALIZATION AND AMBIENT LEVELS OF CARBON-MONOXIDE

Recent research suggests that some cases of cardiovascular mortality m ay be related to carbon monoxide (CO) air pollution. Clinically based studies indicate the adverse effects of CO on the cardiopulmonary syst em. However, little attention has been paid to the question of hospita l admissions for cardiovascular illness caused by ambient CO levels. T he present study assesses the association between hospital admissions for cardiovascular system illnesses and the ambient levels of CO iii t he Reno-Sparks, NV, area over a 6-yr period (1989-1994). Daily admissi ons to all three hospitals in the region and daily ambient concentrati ons of CO, monitored at five sites, were included. There were 32,705 t otal cardiovascular (CV) admissions, including 13,108 with the diagnos is of ischemic heart disease (IHD) during the study period. The averag e daily I-h maximum level of CO was 3.09 ppm. After adjusting for day- of-the-week and seasonal effects and controlling for the effects of au tocorrelation errors, both weighted least squares (WLS) and autoregres sive integrated moving average (ARIMA) methods showed consistently pos itive relationships between the ambient CO level and different groups of cardiovascular admissions, although the male gender and age older t han 60 groups tended to be most affected. Data suggest a positive corr elation between ambient CO levels and hospital admissions for CV disea ses.