Impact of the daily variations of the air pollution on the ambulatory emergency health services activity. Study in the urban area of Rouen (France)

Background: The aim of this study was to evaluate feasibility of using both the emergency phone rails (SAMU) and medical interventions (SMUR) related to ambulatory emergency services for local epidemiological surveillance of health impact of air pollution. Methods: A temporal ecological study was performed at Rouen area (France) ( 380 000 inhab) for 1990-1997 (SAMU) and 1990-1996 (SMUR). The pollutants te sted were: Sulphur dioxide (SO2). Particles (PM13), and Nitrogen dioxide (N O2), as collected routinely by a local automated network. For each phone ca ll (SAMU) or emergency interventions (SMUR), the date, medical reason for c alling (SAMU) or diagnosis after interventions (SMUR) (classified as respir atory, cardiovascular or other diseases) have been extracted from a specifi c information system. A statistical analysis based on rime series analysis associated to a Poisson regression was conducted taking into account tempor al trend, seasonal variations, influenza, days of the week, holiday and met eorological data. Results: An association was observed between ambulatory emergency services activity for cardiovascular diseases, and the daily variations of both SO2 (relative risk=1.008 [1.001-1.016]for SAMU with an increase of 10 mug/m(3)) and NO2 (relative risk=1.018 [1.008-1.030] for SAMU, relative risk=1.016 [ 1.001-1.032] for SMUR with an increase of 10 mug/m(3)). No association coul d be observed with the respiratory diseases for these pollutants. Conclusion: The ambulatory emergency services activity data could contribut e to an epidemiological surveillance of the health impact of the air pollut ion, but a better quality of data collected (concerning both procedures and codification) is requested The interest of an epidemiological surveillance , rather than usual pollutant monitoring, remains to evaluate.