Global Centre for Mass Gatherings Medicine, Ministry of Health, Riyadh, Saudi Arabia.
Biostatistics, Epidemiology and Scientific Computing Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
Environ Health Perspect. 2023 Apr;131(4):47004. doi: 10.1289/EHP9838. Epub 2023 Apr 5.
Although the association between ambient temperature and mortality in local populations is evident, this relationship remains unclear in transient populations (e.g., due to immigration, mass gatherings, or displacement). The holy city of Mecca annually shelters two populations comprising its residents and the transitory Hajj pilgrims ( people from countries). Both live side by side in a hot desert climate, rendering the development of evidence-based heat-protective measures challenging.
We aimed to characterize the ambient temperature-mortality relationship and burden for the Mecca resident and Hajj transient populations, which have distinct levels of adaptation to ambient temperature.
We analyzed daily air temperature and mortality data for Mecca residents and pilgrims over nine Hajj seasons between 2006 and 2014, using a fitted standard time-series Poisson model. We characterized the temperature-mortality relationship with a distributed lag nonlinear model with 10 d of lag. We determined the minimum mortality temperature (MMT) and attributable deaths for heat and cold for the two populations.
The median average daily temperature during the Hajj seasons was 30°C (19°C-37°C). There were 8,543 and 10,457 nonaccidental deaths reported during the study period among Mecca residents and pilgrims, respectively. The MMT was 2.5°C lower for pilgrims in comparison with the MMT for Mecca residents (23.5°C vs. 26.0°C). The temperature-mortality relationship shape varied from inverted J to U shape for the Mecca and pilgrim populations, respectively. Neither hot nor cold temperatures had a statistically significant association with mortality in Mecca residents. In contrast, for pilgrims, elevated temperatures were associated with significantly high attributable mortality of 70.8% [95% confidence interval (CI): 62.8, 76.0]. The effect of heat on pilgrims was immediate and sustained.
Our findings indicate that pilgrims and Mecca residents exposed to the same hot environmental conditions exhibited distinct health outcomes. This conclusion suggests that a precision public health approach may be warranted to protect against high environmental temperature during mass gatherings of diverse populations. https://doi.org/10.1289/EHP9838.
尽管当地人群的环境温度与死亡率之间存在关联，但这种关联在流动人口中尚不清楚（例如，由于移民、大规模集会或流离失所）。圣城麦加每年收容两个群体，一个是居民，另一个是临时的朝觐朝圣者（来自 186 个国家的人）。这两个群体生活在炎热的沙漠气候中，这使得制定基于证据的防暑措施具有挑战性。
我们旨在描述麦加居民和朝觐临时人群的环境温度-死亡率关系和负担，这两个群体对环境温度的适应程度不同。
我们分析了 2006 年至 2014 年九个朝觐季节期间麦加居民和朝圣者的每日空气温度和死亡率数据，使用拟合的标准时间序列泊松模型。我们使用 10 天的滞后分布滞后非线性模型来描述温度-死亡率关系。我们确定了两个群体的最小死亡率温度（MMT）和热与冷的归因死亡人数。
朝觐季节的中位数平均日温度为 30°C（19°C-37°C）。在研究期间，麦加居民和朝圣者分别报告了 8543 例和 10457 例非意外死亡。与麦加居民的 MMT 相比，朝圣者的 MMT 低 2.5°C（23.5°C 与 26.0°C）。麦加和朝圣者人群的温度-死亡率关系形状分别呈倒 J 形和 U 形。无论是高温还是低温，在麦加居民中都与死亡率没有统计学上的显著关联。相比之下，对于朝圣者来说，高温与归因死亡率显著升高 70.8%（95%置信区间：62.8，76.0）有关。热对朝圣者的影响是即时的和持续的。
我们的研究结果表明，暴露在相同炎热环境条件下的朝圣者和麦加居民表现出不同的健康结果。这一结论表明，对于不同人群的大规模集会，可能需要采取精准的公共卫生方法来保护他们免受高温环境的影响。https://doi.org/10.1289/EHP9838.
