AIR-POLLUTION AND MORTALITY IN MADRID, SPAIN - A TIME-SERIES ANALYSIS

Objective: To assess the relationship, if any, between air pollutant ( sulfur dioxide and total suspended particulate) levels and mortality i n the city of Madrid during the period 1986-1992, controlling for weat her, season, and in influenza epidemics. Methods: Daily death counts w ere obtained from the Regional Mortality Registry. Pollution data were supplied by the Municipal Monitoring Network. Time-series analysis me thodology was used to assess the link between nonaccidental as well as circulatory- and respiratory-disease mortality, on the one hand, and mean daily concentrations of SO2 and total suspended particulate (TSP) , on the other. Multivariate autoregressive integrated moving-average (ARIMA) models were used to adjust for season, temperature, relative h umidity, and influenza. A sensitivity analysis was run to assess the r obustness of the estimators. Results: Graphical analysis revealed a li near relationship between mortality and TSP. The relationship was loga rithmic in the case of SO2. TSP lagged 1 day and SO2 lagged 3 days wit h an independent effect on mortality. This relationship was produced w ithout the detection of a minimal threshold in emission values. Conclu sions: These results support the hypothesis of an association between pollution levels and mortality between 1986-1992 in Madrid. Additional measures designed to reduce pollution levels without compromising the rmal comfort should be implemented.