Neto Dora, Araújo Miguel Bastos
Rui Nabeiro Biodiversity Chair, MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, Universidade de Évora, Largo dos Colegiais, Évora, 7004-516, Portugal.
Biogeography and Global Change Department, National Museum of Natural Sciences, CSIC, C/ Jose Gutierrez Abascal, 2, Madrid, 28006, Spain.
BMC Public Health. 2024 Dec 20;24(1):3552. doi: 10.1186/s12889-024-21058-8.
The increased severity of extreme weather and anticipated climate change has intensified heat stress-related mortality worldwide. This study examines the historical short-term effects of heat on mortality in Alentejo, Portugal's warmest region, and projects it up to the end of the century.
Using data from 1980 to 2015 during warm seasons (May-September), the association between daily mortality by all-causes and mean temperature was examined following a case time series design, applied at both regional and subregional scales. Projections for daily temperatures were obtained from regional climate models and greenhouse gas emission scenarios (RCP4.5, RCP8.5). We also examined temporal shifts in mortality considering potential long-term and seasonal adaptative responses to heat. We then quantified the yearly effects of heat by calculating absolute and relative excess mortality from 1980 to 2015, specifically during the heatwave of 2003 (July 27 to August 15), and in future projections at 20-year intervals through 2100.
The analysis revealed a significant rise in mortality risk at temperatures exceeding a minimum mortality temperature (MMT) of 19.0 °C, with an exponential trend and delayed effects lasting up to 5 days. The risk increased by 413% at the maximum extreme temperature of 36.6 °C. From 1980 to 2015, 2.32% of total deaths, equating to over 5,296 deaths, were heat-associated. No significant shifts over time were noted in the population's response to heat. Future projections, without adaptation and demographic changes, show a potential increase in mortality by 15.88% under a "no mitigation policy" scenario by 2100, while mitigation measures could limit the rise to 6.61%.
Results underscore the urgent need for protective health policies to reduce regional population vulnerability and prevent premature heat-related deaths across the century.
极端天气的严重性增加以及预期的气候变化加剧了全球与热应激相关的死亡率。本研究考察了葡萄牙最温暖地区阿连特茹热对死亡率的历史短期影响，并预测至本世纪末。
利用1980年至2015年暖季（5月至9月）的数据，采用病例时间序列设计，在区域和次区域尺度上考察全因每日死亡率与平均温度之间的关联。每日温度预测来自区域气候模型和温室气体排放情景（RCP4.5、RCP8.5）。我们还考虑了对热的潜在长期和季节性适应性反应，研究了死亡率的时间变化。然后，我们通过计算1980年至2015年期间，特别是2003年热浪期间（7月27日至8月15日）以及到2100年每20年间隔的未来预测中的绝对和相对超额死亡率，来量化热的年度影响。
分析显示，当温度超过最低死亡率温度（MMT）19.0°C时，死亡风险显著上升，呈指数趋势且延迟效应可持续长达5天。在最高极端温度36.6°C时，风险增加了413%。1980年至2015年期间，总死亡人数的2.32%，即超过5296例死亡，与热有关。未观察到人群对热的反应随时间有显著变化。在不考虑适应和人口变化的情况下，未来预测显示，到2100年，在“无缓解政策”情景下，死亡率可能增加15.88%，而缓解措施可将上升幅度限制在6.61%。
研究结果强调迫切需要制定保护性健康政策，以降低区域人口脆弱性，并在本世纪预防与热相关的过早死亡。
