Institute of Epidemiology, Helmholtz Zentrum München, Neuherberg, Germany; Department of Environmental Health Sciences, Yale School of Public Health, New Haven, United States.
Institute of Epidemiology, Helmholtz Zentrum München, Neuherberg, Germany; Institute for Medical Information Processing, Biometry, and Epidemiology, LMU, Munich, Germany.
Environ Res. 2024 Dec 15;263(Pt 1):120023. doi: 10.1016/j.envres.2024.120023. Epub 2024 Sep 16.
Evidence suggests that air pollution modifies the association between heat and mortality. However, most studies have been conducted in cities without rural data. This time-series study examined potential effect modification of particulate matter (PM) and ozone (O) on heat-related mortality using small-area data from five European countries, and explored the influence of area characteristics.
We obtained daily non-accidental death counts from both urban and rural areas in Norway, England and Wales, Germany, Italy, and the Attica region of Greece during the warm season (2000-2018). Daily mean temperatures and air pollutant concentrations were estimated by spatial-temporal models. Heat effect modification by air pollution was assessed in each small area by over-dispersed Poisson regression models with a tensor smoother between temperature and air pollution. We extracted temperature-mortality relationships at the 5th (low), 50th (medium), and 95th (high) percentiles of pollutant distributions. At each air pollution level, we estimated heat-related mortality for a temperature increase from the 75th to the 99th percentile. We applied random-effects meta-analysis to derive the country-specific and overall associations, and mixed-effects meta-regression to examine the influence of urban-rural and coastal typologies and greenness on the heat effect modification by air pollution.
Heat-related mortality risks increased with higher PM levels, rising by 6.4% (95% CI: -2.0%-15.7%), 10.7% (2.6%-19.5%), and 14.1% (4.4%-24.6%) at low, medium, and high PM levels, respectively. This effect modification was consistent in urban and rural regions but more pronounced in non-coastal regions. In addition, heat-mortality associations were slightly stronger at high O levels, particularly in regions with low greenness.
Our analyses of both urban and rural data indicate that air pollution may intensify heat-related mortality, particularly in non-coastal and less green regions. The synergistic effect of heat and air pollution implies a potential pathway of reducing heat-related health impacts by improving air quality.
有证据表明，空气污染会改变热与死亡之间的关联。然而，大多数研究都是在没有农村数据的城市进行的。本时间序列研究使用来自五个欧洲国家的小区域数据，检验了颗粒物（PM）和臭氧（O）对与热相关的死亡率的潜在效应修饰，并探讨了区域特征的影响。
我们从挪威、英国和威尔士、德国、意大利以及希腊阿提卡地区的城市和农村地区获得了 2000 年至 2018 年温暖季节的非意外死亡人数逐日数据。通过时空模型估计每日平均温度和空气污染物浓度。通过温度和空气污染物之间的张量平滑过度分散泊松回归模型，在每个小区域评估空气污染对热效应的修饰作用。我们在污染物分布的第 5（低）、50（中）和 95（高）百分位数处提取了温度-死亡率关系。在每个空气污染水平下，我们估计了从第 75 百分位到第 99 百分位的温度升高引起的与热相关的死亡率。我们应用随机效应荟萃分析得出国家特定和总体关联，并应用混合效应荟萃回归检验城乡和沿海类型以及绿化对空气污染引起的热效应修饰的影响。
与热相关的死亡率风险随着 PM 水平的升高而增加，在低、中、高 PM 水平下分别增加了 6.4%（95%CI：-2.0%-15.7%）、10.7%（2.6%-19.5%）和 14.1%（4.4%-24.6%）。这种效应修饰在城市和农村地区是一致的，但在非沿海地区更为明显。此外，在高 O 水平下，热死亡率的相关性略强，尤其是在绿化程度较低的地区。
我们对城市和农村数据的分析表明，空气污染可能会加剧与热相关的死亡率，特别是在非沿海和绿化程度较低的地区。热和空气污染的协同效应意味着通过改善空气质量来降低与热相关的健康影响的潜在途径。
