School of Transportation Science and Engineering, Civil Aviation University of China, Tianjin, China; Research Centre for Environment and Sustainable Development of Civil Aviation Administration of China, Civil Aviation University of China, Tianjin, China.
Research Centre for Environment and Sustainable Development of Civil Aviation Administration of China, Civil Aviation University of China, Tianjin, China.
Environ Res. 2022 Nov;214(Pt 4):114117. doi: 10.1016/j.envres.2022.114117. Epub 2022 Aug 17.
Emissions from aviation and airport-related activities degrade surface air quality but received limited attention relative to regular transportation sectors like road traffic and waterborne vessels. Statistically, assessing the impact of airport-related emissions remains a challenge due to the fact that its signal in the air quality time series data is largely dwarfed by meteorology and other emissions. Flight-ban policy has been implemented in a number of cities in response to the COVID-19 spread since early 2020, which provides an unprecedented opportunity to examine the changes in air quality attributable to airport closure. It would also be interesting to know whether such an intervention produces extra marginal air quality benefits, in addition to road traffic. Here we investigated the impact of airport-related emissions from a civil airport on nearby NO air quality by applying machine learning predictive model to observational data collected from this unique quasi-natural experiment. The whole lockdown-attributable change in NO was 16.7 μg/m, equals to a drop of 73% in NO with respect to the business-as-usual level. Meanwhile, the airport flight-ban aviation-attributable NO was 3.1 μg/m, accounting for a marginal reduction of 18.6% of the overall NO change that driven by the whole lockdown effect. The airport-related emissions contributed up to 24% of the local ambient NO under normal conditions. Additionally, the average impact of airport-related emissions on the nearby air quality was ∼0.01 ± 0.001 μg/m NO per air-flight. Our results highlight that attention needs to be paid to such a considerable emission source in many places where regular air quality regulatory measures were insufficient to bring NO concentration into compliance with the health-based limit.
航空和机场相关活动的排放会降低地表空气质量，但相对于道路交通和水上船只等常规运输部门而言，它们受到的关注有限。从统计学上讲，由于机场相关排放物在空气质量时间序列数据中的信号在很大程度上被气象和其他排放物所掩盖，因此评估其影响仍然具有挑战性。自 2020 年初以来，许多城市都实施了航班禁令政策，以应对 COVID-19 的传播，这为研究由于机场关闭而导致的空气质量变化提供了前所未有的机会。此外，了解这种干预措施除了对道路交通之外，是否还会带来额外的边际空气质量效益，也很有趣。在这里，我们通过将机器学习预测模型应用于从该独特准自然实验中收集的观测数据，研究了民用机场的机场相关排放物对附近 NO 空气质量的影响。整个封锁期间归因于 NO 的变化量为 16.7μg/m，相当于相对于正常水平 NO 下降了 73%。同时，机场航班禁令归因于航空的 NO 排放量为 3.1μg/m，占由于整个封锁效应引起的整体 NO 变化的边际减少 18.6%。在正常情况下，机场相关排放物占当地环境 NO 的 24%。此外，机场相关排放物对附近空气质量的平均影响约为每架航班 0.01±0.001μg/m 的 NO。我们的研究结果强调，在许多常规空气质量监管措施不足以使 NO 浓度符合基于健康的限值的地方，需要注意这种相当大的排放源。
