Résumé :
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[BDSP. Notice produite par INIST pR0x5G3q. Diffusion soumise à autorisation]. Population-based studies of hospital usage have been used to identify the ongoing adverse impacts of photochemical air pollutants on respiratory health. In this study we examined the relationship between the number of daily emergency room (ER) visits for respiratory illnesses (25 hospitals) and outdoor air pollution in Montreal, Quebec (June-August, 1989-1990). Air pollutants measured included 1-and 8-h maximum ozone (O3) and estimated particulate matter<2.5 mum in aerometric diameter (PM2.5). Seasonal and day-of-week trends, autocorrelation, temperature, and relative humidity were controlled for in-time series regressions. Although O3 levels never exceeded the U.S. National Ambient Air Quality Standard (NAAQS) of 120 ppb (maximum day, 106 ppb), statistically significant (P<0.01) relationships were found between respiratory ER visits for patients over the age of 64 and both 1-and 8-h maximum O3 measured 1 day prior to the ER visit day during the 1989 summer : ER visits were 18.7% higher than average (95% Cl, 6.5-30.9%) for a mean increase of 44 ppb O3 (1-h maximum), and 21.8% higher than average (95% Cl, 9.7-33.8%) for a mean increase of 38 ppb O3 (8-h maximum). There was an association between respiratory ER visits for the elderly and estimated PM2.5 lagged 1 day (0.1 visit/mug/m3 PM2.5, P<0.07), but this was confounded by both temperature and O3. (...)
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