RESUMEN
We investigated correlation between the normal level of air pollution, weather conditions and stroke occurrence in the region of Southeast Europe with a humid continental climate. This retrospective study included 1963 patients, 1712 (87.2%) with ischemic (IS) and 251 (12.8%) with hemorrhagic stroke (HS) admitted to emergency department. The number of patients, values of weather condition (meteorological parameters) [air temperature (°C), atmospheric pressure (kPa), relative humidity (%)] and concentrations of air pollutants [particulate matter (PM10), nitrogen dioxide (NO2), ozone (O3)], were recorded and evaluated for each season (spring, summer, autumn, winter) during 2 years (July 2008-June 2010). The highest rate of IS was observed during spring (28.9%) (p = 0.0002) and HS in winter (33.9%) (p = 0.0006). We have found negative Spearman's correlations (after Bonferroni adjustment for the multiple correlations) of the number of males with values of relative humidity (%) (day 0, rho = - 0.15), the total number of strokes (day 2, rho = - 0.12), females (day 2, rho = - 0.12) and IS (day 2, rho = - 0.13) with concentrations of PM10 (µg/m3), as well as negative correlations of the number of females (day 2, rho = - 0.12) and IS (day 2, rho = - 0.12) with concentrations of NO2 (µg/m3) (for all p < 0.002). In winter, the number of HS (day 0, rho = 0.25, p = 0.001) positively correlated with concentrations of O3 (µg/m3). The appearance of stroke has seasonal variations, with the highest rates during spring and winter. Positive correlation between the number of HS and values of O3 requires an additional reduction of the legally permitted pollutants concentrations.