Effects of air pollution on daily mortality in Zaragoza, Spain, 1991-1995.

Objective. To analyze the short-term impact of air pollution on daily morta lity in the City of Zaragoza (Spain). Material and methods. This ecologic s tudy was conducted in Zaragoza, Spain, from 1991 to 1993. Poisson autoregre ssive models were constructed to assess the association between air particu late matter and sulphur dioxide SO2 and daily deaths. Four outcome variable s were studied: overall mortality (excluding external deaths), mortality in subjects over 69 years of age, mortality due to respiratory disease, and m ortality due to cardiovascular disease. A sample size was not obtained. Dat a analysis was conducted using the statistical software EGRET and SPSS. Res ults. SO2 levels were significantly associated with cardiovascular deaths ( RR= 1.018 IC 95%:1.001-1.036) and particulate matter levels with respirator y deaths (RR= 1.028 IC 95%: 1.006-1.051). During the warm season,a signific ant relationship was found between particulate mater and cardiovascular dea ths (RR= 1.020 IC 95%:1.001-1.040). Conclusions. Low levels of air pollutio n were found in Zaragoza, with considerable variation in the concentration of air pollutant concentrations and daily respiratory and cardiovascular de aths, particularly during the warm season. The English version of this pape r is available at: http://www.insp.mx/salud/index.html.