[The effect of short-term changes in levels of air pollution on mortality from cardiovascular diseases among inhabitants of Krakow].

The analysis of short term relation between daily ambient air pollution and daily number of deaths in Kraków, Poland, during the period 1993-1996 was the purpose of the study. The exposure time series data dealt with sulphur dioxide (SO2) and particles with aero-diameter smaller than 10 microns (PM10). Daily mortality due to all causes and cardiovascular diseases were considered separately for two age groups. The statistical procedures included modelling of potential confounding factors (seasonal patterns, meteorological factors) and in the final analysis the Poisson regression model was applied. Effects were expressed as relative risks per 100 micrograms/m3 increase of the corresponding pollutant levels. It was found that sulphur dioxide was significantly related to mortality from all causes and cardiovascular conditions in the age group 65 years and over whereas the effect of suspended particles was at the borderline significance level. The relative risk of cardiovascular death associated with 100 micrograms/m3 increment of mean daily SO2 was 1.17 (1.10-1.25) in the total sample under study, higher for men (RR = 1.27, CI: 1.12-1.45) than for women (RR = 1.12, CI: 1.01-1.23). The corresponding RRs for PM10 and cardiovascular deaths were 1.06 (0.98-1.16) for men and 1.07 (0.99-1.13) for women. These results strengthen the evidence of casual relationship between ambient air pollution level and daily mortality and pinpoints important health hazards issues for the Kraków inhabitants.