Daily mortality changes in Taiwan in the 1970s: An examination of the relationship between temperature and mortality

Growing evidence indicates that world temperatures have increased in recent history, and that this trend is likely to continue in the future. The rise in global temperatures has been accompanied by an increase in extreme weather events, which often have devastating environmental, economic, demographic, and social effects. As concern about the impact of climate change has grown in recent years, there has been a considerable increase in the number of studies published on the effects of extreme temperatures. However, detailed, systematic, and historical investigations into the relationship between temperature and mortality relationship are still difficult to find. This study fills some of these gaps. By examining the impact of extreme temperatures on mortality in Taiwan in the 1970s, our aim is to answer the following questions: (1) Is a lower or a higher temperature recorded in winter or summer related to higher daily mortality? (2) Is mortality higher in particular years with extreme temperatures than it is in the corresponding periods of other years with normal temperatures? (3) Finally, if more extreme temperatures are indeed associated with higher mortality, what kinds of people tend to face higher mortality risks? This study shows that variations in daily mortality were related to changes in temperature in Taiwan over the study period. Cold temperatures in the winter, hot temperatures in the summer, and unusually cold or hot temperatures were all associated with higher mortality. In comparison with other times of the year, the proportions of people who died at old or very young ages were relatively high during cold periods. The proportions of deaths caused by cardiovascular diseases were also relatively high, and these deaths contributed to the high mortality levels in winter time. Meanwhile, during the hot periods relatively high proportions of children and young people died of injuries or poisoning, and relatively high proportions of people died of respiratory diseases; both of these causes of death were closely related to mortality increases in the summer. In comparison with recent decades, however, these patterns were more observable in the 1970s, when the public health and the socioeconomic development levels in Taiwan were not as advanced as they are today.