Xu Zhiwei, Tong Shilu
School of Public Health and Social Work & Institute of Health and Biomedical Innovation, Queensland University of Technology, Australia.
School of Public Health and Social Work & Institute of Health and Biomedical Innovation, Queensland University of Technology, Australia.
Environ Res. 2017 Jul;156:770-774. doi: 10.1016/j.envres.2017.05.005. Epub 2017 May 8.
Heatwaves is the most hazardous natural disaster in Australia and its health impacts need to be well unveiled, but how to properly define a heatwave is still debatable. This study aimed to identify which type of heatwave is more detrimental to health and to elucidate which temperature indicator is more suitable for heatwave definition and early warning.
We categorized temperature into extremely-hot and not-extremely-hot, and extremely-hot temperature refers to temperature at least ≥96th percentile of the monthly temperature distribution, and accordingly, heatwaves were categorized into four types: 1) Type I: extremely-hot days followed by extremely-hot nights (HW); 2) Type II: extremely-hot days followed by not-extremely-hot nights (HW); 3) Type III: not-extremely-hot days followed by extremely-hot nights (HW); and 4) Type IV: not-extremely-hot days followed by not-extremely-hot nights (HW). A Poisson regression allowing for over-dispersion was used to examine the relationship between different types of heatwaves and mortality in Sydney, Melbourne and Brisbane using the data from 1988 to 2011.
Mortality in Brisbane increased significantly during HW and HW, and mortality in Melbourne increased significantly during HW and HW. For Sydney, HW, HW, and HW were all associated with mortality increase, although no appreciable difference in the magnitudes of mortality increase among these three heatwave types was observed. HW was not associated with any significant mortality increase in these cities. Mean temperature is the best temperature indicator for heatwaves in Brisbane and maximum temperature is the best temperature indicator for heatwaves in Melbourne.
Extremely-hot days rather than extremely-hot nights played a critical role in heatwave-related mortality. City-specific heatwave early warning may be optimal for Australia.
热浪是澳大利亚最具危害的自然灾害，其对健康的影响亟待深入揭示，但如何恰当地定义热浪仍存在争议。本研究旨在确定哪种类型的热浪对健康危害更大，并阐明哪种温度指标更适合用于热浪定义和预警。
我们将温度分为极热和非极热，极热温度是指至少处于月温度分布第96百分位数的温度，据此，热浪分为四种类型：1）I型：极热日随后是极热夜（HW）；2）II型：极热日随后是非极热夜（HW）；3）III型：非极热日随后是极热夜（HW）；4）IV型：非极热日随后是非极热夜（HW）。利用1988年至2011年的数据，采用允许过度离散的泊松回归分析来研究悉尼、墨尔本和布里斯班不同类型热浪与死亡率之间的关系。
在HW和HW期间，布里斯班的死亡率显著上升，在HW和HW期间，墨尔本的死亡率显著上升。对于悉尼，HW、HW和HW均与死亡率上升相关，尽管这三种热浪类型之间死亡率上升幅度没有明显差异。HW与这些城市的任何显著死亡率上升均无关。平均温度是布里斯班热浪的最佳温度指标，最高温度是墨尔本热浪的最佳温度指标。
极热日而非极热夜在与热浪相关的死亡率中起关键作用。针对澳大利亚特定城市的热浪预警可能是最佳选择。
