Background: The objective of this investigation is to determine the influence of air pollution (SO2 and particulate matter) on the existence of days of unusual attendance at emergency services for asthma and chronic obstructive pulmonary lung disease (COPD). A registry of attendances for these diseases and the daily mean concentrations of SO2 and particles were used (1989-1991).
Results: Unusual attendance days are establish by the fortnightly movable mean of the period that has that day as central one, under the hypothesis of a Poisson distribution with equal mean as the calculated one. In the logistic regression model, Odds Ratio (OR) between an excess of attendance of cases for asthma and SO2 levels greater than 80.60 m/m3 was 3.6 (CI95%: 1.1-11.7). For COPD, SO levels ten days before were introduced, and OR for SO2 levels more than 56.5m/m was 4.7 (CI95%: 1.5-15.1).
Conclusions: High SO2 levels are related with the appearances of days with an excessive use of emergencies for Asma and EPOC.