Shearston Jenni A, Cerna-Turoff Ilan, Hilpert Markus, Kioumourtzoglou Marianthi-Anna
Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 722 W 168th St., 11th Floor, New York, NY, 10032, USA.
Hyg Environ Health Adv. 2022 Dec;4:100032. doi: 10.1016/j.heha.2022.100032. Epub 2022 Oct 19.
Policy responses to the COVID-19 pandemic, such as the NY on Pause stay-at-home order (March 22 - June 8, 2020), substantially reduced traffic and traffic-related air pollution (TRAP) in New York City (NYC). We evaluated the magnitude of TRAP decreases and examined the role of modifying factors such as weekend/weekday, road proximity, location, and time-of-day.
Hourly nitrogen dioxide (NO) concentrations from January 1, 2018 through June 8, 2020 were obtained from the Environmental Protection Agency's Air Quality System for all six hourly monitors in the NYC area. We used an interrupted time series design to determine the impact of NY on Pause on NO concentrations, using a mixed effects model with random intercepts for monitor location, adjusted for meteorology and long-term trends. We evaluated effect modification through stratification.
NO concentrations decreased during NY on Pause by 19% (-3.2 ppb, 95% confidence interval [CI]: -3.5, -3.0), on average, compared to pre-Pause time trends. We found no evidence for modification by weekend/weekday, but greater decreases in NO at non-roadside monitors and weak evidence for modification by location. For time-of-day, we found the largest decreases for 5 am (27%, -4.5 ppb, 95% CI: -5.7, -3.3) through 7 am (24%, -4.0 ppb, 95% CI: -5.2, -2.8), followed by 6 pm and 7 pm (22%, -3.7 ppb, 95% CI: -4.8, -2.6 and 22%, -4.8, -2.5, respectively), while the smallest decreases occurred at 11 pm and 1 am (both: 11%, -1.9 ppb, 95% CI: -3.1, -0.7).
NY on Pause's impact on TRAP varied greatly diurnally. Decreases during early morning and evening time periods are likely due to decreases in traffic. Our results may be useful for planning traffic policies that vary by time of day, such as congestion tolling policies.
对新冠疫情的政策响应，如纽约的“暂停”居家令（2020年3月22日至6月8日），大幅减少了纽约市的交通流量以及与交通相关的空气污染（TRAP）。我们评估了TRAP下降的幅度，并研究了诸如周末/工作日、道路 proximity、位置和一天中的时间等调节因素的作用。
获取了2018年1月1日至2020年6月8日期间纽约市地区所有六个每小时监测器的每小时二氧化氮（NO）浓度，数据来自美国环境保护局的空气质量系统。我们使用中断时间序列设计来确定“纽约暂停”对NO浓度的影响，采用具有监测器位置随机截距的混合效应模型，并对气象和长期趋势进行了调整。我们通过分层评估效应修正。
与“暂停”前的时间趋势相比，“纽约暂停”期间NO浓度平均下降了19%（-3.2 ppb，95%置信区间[CI]：-3.5，-3.0）。我们没有发现周末/工作日进行修正的证据，但非路边监测器处的NO下降幅度更大，且有较弱的位置修正证据。对于一天中的时间，我们发现凌晨5点（27%，-4.5 ppb，95% CI：-5.7，-3.3）至上午7点（24%，-4.0 ppb，95% CI：-5.2，-2.8）下降幅度最大，其次是下午6点和7点（分别为22%，-3.7 ppb，95% CI：-4.8，-2.6和22%，-4.8，-2.5），而晚上11点和凌晨1点下降幅度最小（均为11%，-1.9 ppb，95% CI：-3.1，-0.7）。
“纽约暂停”对TRAP的影响在一天中变化很大。清晨和傍晚时段的下降可能是由于交通流量减少。我们的结果可能有助于制定按一天中的时间变化的交通政策，如拥堵收费政策。
