Díaz-Collado Francisco, Chu Lingzhi, Carrión Daniel, Méndez-Lázaro Pablo A, Chen Kai
Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, United States of America.
Yale Center on Climate Change and Health, Yale School of Public Health, New Haven, CT, United States of America.
Environ Res Lett. 2025 Oct 1;20(10):104032. doi: 10.1088/1748-9326/ae013e. Epub 2025 Sep 9.
The effects of a changing climate are already evident in Caribbean small island developing states (SIDS) like Puerto Rico, where heat episodes have become more frequent. Despite reports of increasing heat-related death rates, robust epidemiological evidence on the health impacts of high temperatures, as well as the effects of low temperatures, remains scarce, particularly outside of urban settlements in Caribbean SIDS. In this study, we conducted a case time-series study on municipality-level mortality and temperature in Puerto Rico from 2015-2023. We modeled the relationship between daily mortality count and mean temperature using a conditional quasi-Poisson regression, combined with a distributed lag non-linear model (dlnm) with a 21 d lag, adjusting for relative humidity, seasonality, and day of the week. We estimated the minimum mortality temperature (MMT)-the optimal temperature associated with the lowest mortality risk-and calculated the relative risk associated with extreme low and high temperature, defined as the 2.5th and 97.5th percentiles of daily temperature. Additionally, we estimated the municipality- and island-level excess mortality fractions attributable to both low and high temperatures, relative to MMT. Our findings indicate that exposure to non-optimum temperatures (both low and high temperatures) is significantly associated with increased mortality risk. Specifically, extreme low temperature was associated with a 1.23 (95% CI: 1.07-1.40) times risk of all-cause mortality, while extreme high temperature was associated with a 1.16 (95% CI: 1.05-1.27) times risk. We estimated that temperature-related mortality accounted for 3.88% of the total 280 568 deaths (95% eCI: 3.39%-4.29%), with low temperatures contributing 2.02% (95% eCI: 1.69%-2.32%) and high temperatures contributing 1.86% (95% eCI: 1.35%-2.35%). Furthermore, we found substantial spatial variability in temperature-related mortality burdens across municipalities. Our study identifies the vulnerable municipalities to temperature-related deaths in Puerto Rico, providing evidence to inform municipality-specific climate adaptation and mitigation strategies.
气候变化的影响在波多黎各等加勒比小岛屿发展中国家（SIDS）已经很明显，那里的热浪事件变得更加频繁。尽管有报告称与高温相关的死亡率在上升，但关于高温以及低温对健康影响的有力流行病学证据仍然稀缺，尤其是在加勒比小岛屿发展中国家的城市住区之外。在本研究中，我们对2015 - 2023年波多黎各市级死亡率和温度进行了病例时间序列研究。我们使用条件准泊松回归模型，结合滞后21天的分布滞后非线性模型（dlnm），对每日死亡人数与平均温度之间的关系进行建模，并对相对湿度、季节性和星期几进行了调整。我们估计了最低死亡率温度（MMT）——与最低死亡风险相关的最佳温度——并计算了与极端低温和高温相关的相对风险，极端低温和高温定义为每日温度的第2.5和第97.5百分位数。此外，我们估计了相对于MMT，市级和岛屿级归因于低温和高温的超额死亡率分数。我们的研究结果表明，暴露于非最佳温度（低温和高温）与死亡风险增加显著相关。具体而言，极端低温与全因死亡率风险增加1.23倍（95% CI：1.07 - 1.40）相关，而极端高温与死亡风险增加1.16倍（95% CI：1.05 - 1.27）相关。我们估计，与温度相关的死亡占280568例总死亡人数的3.88%（95% eCI：3.39% - 4.29%），其中低温贡献2.02%（95% eCI：1.69% - 2.32%），高温贡献1.86%（95% eCI：1.35% - 2.35%）。此外，我们发现各城市之间与温度相关的死亡负担存在很大的空间差异。我们的研究确定了波多黎各易受温度相关死亡影响的城市，为制定针对具体城市的气候适应和缓解策略提供了证据。
