Ozone and Daily Mortality Rate in 21 Cities of East Asia: How Does Season Modify the Association?

Renjie Chen, Jing Cai, Xia Meng, Ho Kim, Yasushi Honda, Yue Leon Guo, Evangelia Samoli, Xin Yang, Haidong Kan
2014 American Journal of Epidemiology  
Previous studies in East Asia have revealed that the short-term associations between tropospheric ozone and daily mortality rate were strongest in winter, which is opposite to the findings in North America and Western Europe. Therefore, we investigated the season-varying association between ozone and daily mortality rate in 21 cities of East Asia from 1979 to 2010. Time-series Poisson regression models were used to analyze the association between ozone and daily nonaccidental mortality rate in
more » ... ach city, testing for different temperature lags. The best-fitting model was obtained after adjustment for temperature in the previous 2 weeks. Bayesian hierarchical models were applied to pool the city-specific estimates. An interquartile-range increase of the moving average concentrations of same-day and previous-day ozone was associated with an increase of 1.44% (95% posterior interval (PI): 1.08%, 1.80%) in daily total mortality rate after adjustment for temperature in the previous 2 weeks. The corresponding increases were 0.62% (95% PI: 0.08%, 1.16%) in winter, 1.46% (95% PI: 0.89%, 2.03%) in spring, 1.60% (95% PI: 1.03%, 2.17%) in summer, and 1.12% (95% PI: 0.73%, 1.51%) in fall. We found significant associations between short-term exposure to ozone and higher mortality rate in East Asia that varied considerably from season to season with a significant trough in winter. air pollution; East Asia; mortality rate; ozone; season; temperature Abbreviations: IQR, interquartile range; NMMAPS, National Morbidity, Mortality, and Air Pollution Study; PI, posterior interval; PM 10 , particulate matter with aerodynamic diameter of 10 μm or less.
doi:10.1093/aje/kwu183 pmid:25139207 fatcat:6tszxtkq55ed7arm26medholni