[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 calls (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 inhabitants) for 1990-1997 (SAMU) and 1990-1996 (SMUR). The pollutants tested were: Sulphur dioxide (SO(2)), Particles (PM13), and Nitrogen dioxide (NO(2)), as collected routinely by a local automated network. For each phone call (SAMU) or emergency interventions (SMUR), the date, medical reason for calling (SAMU) or diagnosis after interventions (SMUR) (classified as respiratory, cardiovascular or other diseases) have been extracted from a specific information system. A statistical analysis based on time series analysis associated to a Poisson regression was conducted, taking into account temporal trend, seasonal variations, influenza, days of the week, holiday and meteorological data.

RESULTS

An association was observed between ambulatory emergency services activity for cardiovascular diseases, and the daily variations of both SO(2) (relative risk=1.008 [1.001-1.016] for SAMU with an increase of 10 microg/m(3)) and NO(2) (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 microg/m(3)). No association could be observed with the respiratory diseases for these pollutants.

CONCLUSION

The ambulatory emergency services activity data could contribute to an epidemiological surveillance of the health impact of the air pollution, 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.