We study the impact of short-term exposure to ambient air pollution on the spread and severity of COVID-19 in Germany. We combine data at the county-by-day level on confirmed cases and deaths with information on local air quality and weather conditions. Following Deryugina et al. (2019), we instrument short-term variation in local concentrations of particulate matter (PM10) by region-specific daily variation in wind directions. We find significant positive effects of PM10 concentration on death numbers from four days before to ten days after the onset of symptoms. Specifically, for elderly patients (80+ years) an increase in ambient PM10 concentration by one standard deviation between two and four days after developing symptoms increases the number of deaths by 19 percent of a standard deviation. In addition, higher levels air pollution raise the number of confirmed cases of COVID-19 for all age groups. The timing of effects surrounding the onset of illness suggests that air pollution affects the severity of already-realized infections. We discuss the implications of our results for immediate policy levers to reduce the exposure and level of ambient air pollution, as well as for cost-benefit considerations of policies aiming at sustainable longer-term reductions of pollution levels.

我们研究了短期暴露于环境空气污染对德国 COVID-19 传播和严重程度的影响。我们将逐日的县级确诊病例和死亡数据与当地空气质量和天气状况信息相结合。在 Deryugina 等人之后。(2019)，我们通过区域特定的每日风向变化来测量局部颗粒物 (PM10) 浓度的短期变化。我们发现从症状出现前 4 天到出现症状后 10 天，PM10 浓度对死亡人数有显着的积极影响。具体而言，对于老年患者（80 岁以上），在出现症状后两到四天内环境 PM10 浓度增加一个标准差会使死亡人数增加 19% 的标准差。此外，更高水平的空气污染会增加所有年龄组的 COVID-19 确诊病例数。疾病发作的影响时间表明，空气污染会影响已经发生的感染的严重程度。我们讨论了我们的结果对直接政策杠杆的影响，以减少环境空气污染的暴露和水平，以及对旨在可持续地长期降低污染水平的政策的成本效益考虑。