EFFECTS OF AIR POLLUTION ON ACUTE CARDIOVASCULAR VISITS IN AN AMBULATORY CARE SETTING: ISEE-336

Abstract

Several studies have found significant effects of particulate matter (PM) on cardio-respiratory outcomes, including emergency department visits, mortality, and individual symptoms and pulmonary function measurements. Few studies have investigated the effects of PM in an ambulatory care setting, and these studies have been limited in the scope of pollutants or population. Kaiser Permanente (KP), a not-for-profit health maintenance organization with over 270,000 members in the Georgia Region, is collaborating with the Electric Power Research Institute (EPRI) on the Atlanta ‘Superstation’ site of the Aerosol Research Inhalation Epidemiological Study (ARIES). ARIES provides detailed information on the physical, chemical, and geographical characteristics of particulate matter. The KP study involves a time-series investigation of the possible associations between daily levels of suspended particulate matter and ambulatory care acute visits for cardiovascular illnesses during the 25-month period from August 1, 1998 to August 31, 2000. Acute visits were identified as those visits with a same day appointment or urgent visit code. Acute visits to the nine Atlanta KP health facilities with a diagnosis code for cardiovascular disease (dysrhythmia, congestive heart failure, IHD, or peripheral and cerebrovascular disease) were identified through electronic visit data. Air quality variables investigated in this study were: 24 hour average measurements of PM2.5, coarse PM (2.5–10 μm), PM10, PM2.5 components (acidity, sulfates, OC, alkenes, aromatics and elemental carbon), 10–100 nm PM count and area (ultra-fines), pollen, mold, polar VOCs (OHC), ozone, NO2, CO, HNO3, and SO2. We also looked at daily 1-hour maximums for SO2, NO2, CO and ozone and 8-hour maximums for CO and ozone. Visit counts were modeled by selected air quality metrics using Poisson general linear modeling controlling for temporal trends and meteorologic variables. Moving averages of the 0 to 2 day, 3 to 5 day and 6 to 8 day lagged air quality variables were investigated. The mean number of daily acute visits in the total cardiovascular category was 9.70 (s.d. 7.17). The significant risk ratios (RRs) were 3 to 5 day lags for daily 1 hour maximum NO2 (RR = 1.13), CO (RR = 1.09) and ozone (RR = 1.11), and the daily 8 hour maximum for ozone (RR = 1.13). There was also a significant negative effect with the 0 to 2 day lagged PM10. Similarities and differences in the respiratory findings (asthma and upper and lower respiratory infections) for our study will be discussed. This study provides a unique assessment of the effects of PM, individual components of PM and gascous pollutants on acute cardiovascular and respiratory visits in an ambulatory care setting.