Du Hang, Yan Meilin, Liu Xin, Zhong Yu, Ban Jie, Lu Kailai, Li Tiantian
China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health (NIEH), Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China.
Environ Health Perspect. 2024 Apr;132(4):47012. doi: 10.1289/EHP13790. Epub 2024 Apr 25.
Concurrent extreme events are projected to occur more frequently under a changing climate. Understanding the mortality risk and burden of the concurrent heatwaves and ozone () pollution may support the formulation of adaptation strategies and early warning systems for concurrent events in the context of climate change.
We aimed to estimate the mortality risk and excess deaths of concurrent heatwaves and pollution across 250 counties in China.
We collected daily mortality, meteorological, and air pollution data for the summer (1 June to 30 September) during 2013-2018. We defined heatwaves and high pollution days, then we divided the identified days into three categories: ) days with only heatwaves (heatwave-only event), ) days with only high pollution (high pollution-only event), and ) days with concurrent heatwaves and high pollution (concurrent event). A generalized linear model with a quasi-Poisson regression was used to estimate the risk of mortality associated with extreme events for each county. Then we conducted a random-effects meta-analysis to pool the county-specific estimates to derive the overall effect estimates. We used mixed-effects meta-regression to identify the drivers of the heterogeneity. Finally, we estimated the excess death attributable to extreme events (heatwave-only, high pollution-only, and concurrent events) from 2013 to 2020.
A higher all-cause mortality risk was associated with exposure to the concurrent heatwaves and high pollution than exposure to a heatwave-only or a high pollution-only event. The effects of a concurrent event on circulatory and respiratory mortality were higher than all-cause and nonaccidental mortality. Sex and age significantly impacted the association of concurrent events and heatwave-only events with all-cause mortality. We estimated that annual average excess deaths attributed to the concurrent events were 6,249 in China from 2017 to 2020, 5.7 times higher than the annual average excess deaths attributed to the concurrent events from 2013 to 2016. The annual average proportion of excess deaths attributed to the concurrent events in the total excess deaths caused by three types of events (heatwave-only events, high pollution-only events, and concurrent events) increased significantly in 2017-2020 (31.50%; 95% CI: 26.73%, 35.53%) compared with 2013-2016 (9.65%; 95% CI: 5.67%, 10.81%). Relative excess risk due to interaction revealed positive additive interaction considering the concurrent effect of heatwaves and high pollution.
Our findings may provide scientific basis for establishing a concurrent event early warning system to reduce the adverse health impact of the concurrent heatwaves and high pollution. https://doi.org/10.1289/EHP13790.
在气候变化的背景下，预计同时发生的极端事件将更频繁地出现。了解热浪和臭氧（）污染同时发生时的死亡风险和负担，可能有助于制定气候变化背景下同时发生事件的适应策略和预警系统。
我们旨在估算中国250个县同时发生热浪和污染时的死亡风险及超额死亡人数。
我们收集了2013 - 2018年夏季（6月1日至9月30日）的每日死亡率、气象和空气污染数据。我们定义了热浪和高污染日，然后将识别出的日子分为三类：）仅发生热浪的日子（仅热浪事件），）仅发生高污染的日子（仅高污染事件），以及）热浪和高污染同时发生的日子（同时发生事件）。使用具有拟泊松回归的广义线性模型来估算每个县与极端事件相关的死亡风险。然后我们进行随机效应荟萃分析，汇总各县的估计值以得出总体效应估计值。我们使用混合效应荟萃回归来识别异质性的驱动因素。最后，我们估算了2013年至2020年极端事件（仅热浪、仅高污染和同时发生事件）导致的超额死亡人数。
与仅暴露于热浪或仅暴露于高污染事件相比，同时暴露于热浪和高污染时全因死亡风险更高。同时发生事件对循环系统和呼吸系统死亡率的影响高于全因死亡率和非意外死亡率。性别和年龄显著影响同时发生事件和仅热浪事件与全因死亡率之间的关联。我们估计，2017年至2020年中国每年因同时发生事件导致的平均超额死亡人数为6249人，比2013年至2016年因同时发生事件导致的年平均超额死亡人数高5.7倍。2017 - 2020年，在三种类型事件（仅热浪事件、仅高污染事件和同时发生事件）导致的总超额死亡人数中，因同时发生事件导致的超额死亡人数的年平均比例与2013 - 2016年相比显著增加（31.50%；95%置信区间：26.73%，35.53%），而2013 - 2016年为9.65%；95%置信区间：5.67%；10.81%）。考虑热浪和高污染的同时效应，相互作用导致的相对超额风险显示出正相加相互作用。
我们的研究结果可能为建立同时发生事件预警系统提供科学依据，以减少热浪和高污染同时发生对健康的不利影响。https://doi.org/10.1289/EHP13790 。
