Centre for Environmental Health and Sustainability, University of Leicester, United Kingdom.
Centre for Environmental Health and Sustainability, University of Leicester, United Kingdom; NIHR HPRU Centre for Environmental Exposures and Health, University of Leicester, United Kingdom.
Environ Pollut. 2021 Mar 1;272:116011. doi: 10.1016/j.envpol.2020.116011. Epub 2020 Nov 20.
The UK implemented a lockdown in Spring (2020) to curtail the person-to-person transmission of the SARS-CoV-2 virus. Measures restricted movements to one outing per day for exercise and shopping, otherwise most people were restricted to their dwelling except for key workers (e.g. medical, supermarkets, and transport). In this study, we quantified changes to air quality across the United Kingdom from 30/03/2020 to 03/05/2020 (weeks 14-18), the period of most stringent travel restrictions. Daily pollutant measurements of NO, O and PM from the national network of monitoring sites during this period were compared with measurements over the same period during 2017-19. Comparisons were also made with predicted concentrations for the 2020 period from business-as-usual (BAU) modelling, where the contributions of normal anthropogenic activities were estimated under the observed meteorological conditions. During the lockdown study period there was a 69% reduction in traffic overall (74% reduction in light and 35% in heavy vehicles). Measurements from 129 monitoring stations, identified mean reductions in NO of 38.3% (-8.8 μg/m) and PM of 16.5% (-2.2 μg/m). Improvements in NO and PM were largest at urban traffic sites and more modest at background locations where a large proportion of the population live. In contrast, O concentrations on average increased by 7.6% (+4.8 μg/m) with the largest increases at roadside sites due to reductions in local emissions of NO. A lack of VOC monitoring limited our capacity to interpret changes in O at urban background locations. BAU models predicted comparable NO reductions and O gains, although PM episodes would have been more prominent without lockdown. Results demonstrate the relatively modest contribution of traffic to air quality, suggesting that sustained improvements in air quality require actions across various sectors, including working with international and European initiatives on long-range transport air pollutants, especially PM and O.
英国在春季（2020 年）实施封锁以限制 SARS-CoV-2 病毒的人际传播。这些措施限制了人们每天只能外出一次进行锻炼和购物，否则大多数人除了关键工人（例如医疗、超市和交通）外，都必须待在住所内。在这项研究中，我们量化了 2020 年 3 月 30 日至 5 月 3 日（第 14-18 周）期间英国各地的空气质量变化，这是旅行限制最严格的时期。在此期间，从国家监测站点网络获得的每日污染物测量值（NO、O 和 PM）与 2017-19 年同期的测量值进行了比较。还与业务照常（BAU）模型预测的 2020 年浓度进行了比较，该模型在观测到的气象条件下估算了正常人为活动的贡献。在封锁研究期间，交通总体减少了 69%（轻型车减少了 74%，重型车减少了 35%）。来自 129 个监测站的测量值显示，NO 平均减少了 38.3%（-8.8μg/m），PM 减少了 16.5%（-2.2μg/m）。在城市交通站点，NO 和 PM 的改善最大，而在人口居住比例较大的背景位置，改善则较为温和。相比之下，由于 NO 局部排放减少，O 浓度平均增加了 7.6%（+4.8μg/m），路边站点的增幅最大。由于缺乏 VOC 监测，我们对城市背景位置 O 变化的解释能力有限。BAU 模型预测了可比的 NO 减少和 O 增加，尽管如果没有封锁，PM 事件将更为突出。结果表明，交通对空气质量的贡献相对较小，这表明需要在各个领域采取行动来持续改善空气质量，包括与国际和欧洲长距离传输空气污染物倡议合作，特别是 PM 和 O。
