Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
Environ Res. 2023 Jan 1;216(Pt 1):114481. doi: 10.1016/j.envres.2022.114481. Epub 2022 Oct 4.
Several studies are pointing out that exposure to elevated air pollutants could contribute to increased COVID-19 mortality. However, literature on the associations between air pollution exposure and COVID-19 severe morbidity is rather sparse. In addition, the majority of the studies used an ecological study design and were applied in regions with rather high air pollution levels. Here, we study the differential effects of long-term exposure to air pollution on severe morbidity and mortality risks from COVID-19 in various population subgroups in Switzerland, a country known for clean air. We perform individual-level analyses using data covering the first two major waves of COVID-19 between February 2020 and May 2021. High-resolution maps of particulate matter (PM) and nitrogen dioxide (NO) concentrations were produced for the 6 years preceding the pandemic using Bayesian geostatistical models. Air pollution exposure for each patient was measured by the long-term average concentration across the municipality of residence. The models were adjusted for the effects of individual characteristics, socio-economic, health-system, and climatic factors. The variables with an important association to COVID-19 case-severity were identified using Bayesian spatial variable selection. The results have shown that the individual-level characteristics are important factors related to COVID-19 morbidity and mortality in all the models. Long-term exposure to air pollution appears to influence the severity of the disease only when analyzing data during the first wave; this effect is attenuated upon adjustment for health-system related factors during the entire study period. Our findings suggest that the burden of air pollution increased the risks of COVID-19 in Switzerland during the first wave of the pandemic, but not during the second wave, when the national health system was better prepared.
几项研究指出，暴露于升高的空气污染物可能导致 COVID-19 死亡率增加。然而，关于空气污染暴露与 COVID-19 严重发病之间的关联的文献相当稀少。此外，大多数研究使用了生态研究设计，并且应用于空气污染水平相当高的地区。在这里，我们研究了在瑞士这个以空气清新著称的国家，长期暴露于空气污染对 COVID-19 严重发病和死亡率的不同影响，研究涵盖了各个人群亚组。我们使用涵盖了 2020 年 2 月至 2021 年 5 月期间 COVID-19 前两个主要浪潮的数据进行了个体水平分析。使用贝叶斯地质统计学模型为大流行前的 6 年制作了颗粒物 (PM) 和二氧化氮 (NO) 浓度的高分辨率地图。每个患者的空气污染暴露量通过居住的市的长期平均浓度来衡量。模型调整了个体特征、社会经济、卫生系统和气候因素的影响。使用贝叶斯空间变量选择来识别与 COVID-19 病例严重程度相关的重要变量。结果表明，在所有模型中，个体水平特征是与 COVID-19 发病率和死亡率相关的重要因素。只有在分析第一波疫情期间的数据时，长期暴露于空气污染才会影响疾病的严重程度；在整个研究期间，当调整与卫生系统相关的因素时，这种影响会减弱。我们的研究结果表明，在大流行的第一波期间，空气污染的负担增加了瑞士 COVID-19 的风险，但在第二次波期间，由于国家卫生系统准备更好，风险没有增加。
