[영문]BACKGROUND: The temporal pattern of effects of summertime ozone (O3) in total, cardiovascular and respiratory mortality were investigated in 21 European cities participating in the APHEA-2 (Air Pollution and Health: a European Approach) project, which is fundamental in determining the importance of the effect in terms of life loss. METHODS: Data from each city were analysed separately using distributed lag models with up to 21 lags. City-specific air pollution estimates were regressed on city-specific covariates to obtain overall estimates and to explore sources of possible heterogeneity. RESULTS: Stronger effects on respiratory mortality that extend to a period of 2 weeks were found. A 10 μg/m3increase in O3was associated with a 0.36% (95% CI ?0.21% to 0.94%) increase in respiratory deaths for lag 0 and with 3.35% (95% CI 1.90% to 4.83%) for lags 0?20. Significant adverse health effects were found of summer O3(June?August) on total and cardiovascular mortality that persist up to a week, but are counterbalanced by negative effects thereafter. CONCLUSIONS: The results indicate that studies on acute health effects of O3using single-day exposures may have overestimated the effects on total and cardiovascular mortality, but underestimated the effects on respiratory mortality.