Effects of temperature on mortality in Chiang Mai city, Thailand: A time series study

Yuming Guo, Kornwipa Punnasiri, Shilu Tong

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76 Citations (Scopus)

Abstract

Background: The association between temperature and mortality has been examined mainly in North America and Europe. However, less evidence is available in developing countries, especially in Thailand. In this study, we examined the relationship between temperature and mortality in Chiang Mai city, Thailand, during 1999-2008. Method. A time series model was used to examine the effects of temperature on cause-specific mortality (non-external, cardiopulmonary, cardiovascular, and respiratory) and age-specific non-external mortality (<=64, 65-74, 75-84, and>=85years), while controlling for relative humidity, air pollution, day of the week, season and long-term trend. We used a distributed lag non-linear model to examine the delayed effects of temperature on mortality up to 21days. Results: We found non-linear effects of temperature on all mortality types and age groups. Both hot and cold temperatures resulted in immediate increase in all mortality types and age groups. Generally, the hot effects on all mortality types and age groups were short-term, while the cold effects lasted longer. The relative risk of non-external mortality associated with cold temperature (19.35°C, 1st percentile of temperature) relative to 24.7°C (25th percentile of temperature) was 1.29 (95% confidence interval (CI): 1.16, 1.44) for lags 0-21. The relative risk of non-external mortality associated with high temperature (31.7°C, 99 th percentile of temperature) relative to 28°C (75th percentile of temperature) was 1.11 (95% CI: 1.00, 1.24) for lags 0-21. Conclusion: This study indicates that exposure to both hot and cold temperatures were related to increased mortality. Both cold and hot effects occurred immediately but cold effects lasted longer than hot effects. This study provides useful data for policy makers to better prepare local responses to manage the impact of hot and cold temperatures on population health.

Original languageEnglish
Article number36
JournalEnvironmental Health: A Global Access Science Source
Volume11
Issue number1
DOIs
Publication statusPublished - 2012
Externally publishedYes

Keywords

  • Cardiovascular
  • Mortality
  • Respiratory
  • Temperature
  • Time series analysis

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