Tanzer-Gruener Rebecca, Li Jiayu, Eilenberg S Rose, Robinson Allen L, Presto Albert A
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
Environ Sci Technol Lett. 2020 Jun 23;7(8):554-559. doi: 10.1021/acs.estlett.0c00365. eCollection 2020 Jan 11.
COVID-19-related closures offered a novel opportunity to observe and quantify the impact of activity levels of modifiable factors on ambient air pollution in real time. We use data from a network of low-cost Real-time Affordable Multi-Pollutant (RAMP) sensor packages deployed throughout Pittsburgh, Pennsylvania, along with data from Environmental Protection Agency regulatory monitors. The RAMP locations were divided into four site groups based on land use. Concentrations of PM, CO, and NO following the COVID-related closures at each site group were compared to measurements from "business-as-usual" periods. Overall, PM concentrations decreased across the domain by ∼3 μg/m. The morning rush-hour-induced CO and NO concentrations at the high-traffic sites were both reduced by ∼50%, which is consistent with observed reductions in commuter traffic (∼50%). The morning rush-hour PM enhancement from traffic emissions was reduced nearly 100%, from 1.4 to ∼0 μg/m across all site groups. There was no significant change in the industry-related intraday variability of CO and PM at the industrial sites following the COVID-related closures. If PM National Ambient Air Quality Standards (NAAQS) are tightened, this natural experiment sheds light on the extent to which reductions in traffic-related emissions can aid in meeting more stringent regulations.
与新冠疫情相关的封闭措施提供了一个全新的机会，可实时观察和量化可改变因素的活动水平对环境空气污染的影响。我们使用了部署在宾夕法尼亚州匹兹堡市的低成本实时多污染物（RAMP）传感器网络的数据，以及美国环境保护局监管监测器的数据。RAMP监测点根据土地用途分为四个站点组。将每个站点组在与新冠疫情相关的封闭措施实施后的PM、CO和NO浓度与“正常营业”时期的测量值进行比较。总体而言，整个区域的PM浓度下降了约3μg/m³。交通繁忙站点早高峰时段的CO和NO浓度均降低了约50%，这与通勤交通量下降（约50%）的情况相符。所有站点组早高峰时段交通排放导致的PM增加量从1.4μg/m³降至约0μg/m³，几乎降低了100%。在与新冠疫情相关的封闭措施实施后，工业站点与工业相关的CO和PM日内变化没有显著变化。如果收紧PM国家环境空气质量标准（NAAQS），这个自然实验将揭示交通相关排放的减少在多大程度上有助于满足更严格的法规要求。
