Diurnal Apparent Temperature Range and Socioeconomic Vulnerability in Seoul, Korea

Abstract

ISEE-0104 Background and Objective: Rapid temperature changes within a single day may be critical for populations vulnerable to thermal stress who have difficulty adjusting themselves behaviorally and physiologically. We hypothesized that the diurnal apparent temperature range (DATR) within 1 day was associated with cause-specific mortality, and its association was modified by determinants of vulnerability and season. We examined the association between temperature and cause-specific mortality and effects of season and individual socioeconomic status (SES) on the DATR and mortality in Seoul, Korea, from 2000 to 2005. Methods: We applied generalized adaptive Poisson regression models adjusting for influenza epidemics, day of the week, seasonal trends, PM10 concentrations, and apparent temperature. A total of 204,126 non-accidental deaths were included. Results: The effects of DATR on cardiovascular mortality were greatest in the spring/fall, while the greatest effects on respiratory mortality were in the spring/fall and winter. One degree Celsius increase in the DATR in the spring/fall corresponded to a 1.19% increase in cardiovascular mortality [95% confidence interval (CI), 0.45%-1.93%] in a time series analysis in Seoul, Korea. Increases in respiratory in the spring/fall and the winter due to DATR were 2.53% (95% CI, 0.24-4.87) and 2.74% (95% CI, 0.21-5.34), respectively. Disadvantaged groups such as the elderly and the less educated were found to be the most vulnerable groups to DATR for both cardiovascular and respiratory mortality. Conclusion: Diurnal apparent temperature range was a strong predictor of mortality, independent of apparent temperature. Furthermore, DATR effects differed by season and individual SES.