Changes in Air Quality from the COVID to the Post-COVID Era in the Beijing-Tianjin-Tangshan Region in China

Qingchun Guo,Jingjing Meng,Zhaosheng Wang,Zhenfang He,Jiaoxue Yang,Xinzhou Li,Zhanfang Hou

doi:10.4209/aaqr.210270

Abstract

ABSTRACT This article discussed air quality changes in the Beijing-Tianjin-Tangshan (BTT) region. The air quality index (AQI) values, and the concentrations of PM2.5, PM10, SO2, CO, NO2, and O3 in the BTT region during the COVID-19 outbreak in 2020 were, respectively, 79.4, 47.2 µg m–3, 73.4 µg m–3, 10.3 µg m–3, 0.87 mg m–3, 33.6 µg m–3, and 90.7 µg m–3. However, they were, respectively, 102.7, 61.4 µg m–3, 121.0 µg m–3, 9.0 µg m–3, 0.88 mg m–3, 40.1 µg m–3, and 84.0 µg m–3 during the same period in 2021, which is an increase of 29.2%, 30.1%, 64.8%, –12.9%, 1.94 %, 19.5%, and –7.4% compared with the values in 2020. The combined proportions of grade I and grade II during the COVID-19 outbreak in 2020 were 16.7% higher than those in the same period in 2021, so the air quality has deteriorated rapidly from 2020 to the post-COVID era in 2021. The possible reasons for poorer air quality are that the frequency of dusty weather and air pollutant discharge has increased, and meteorological conditions have been relatively unfavorable. The average AQI values, and concentrations of PM2.5, PM10, SO2, CO, NO2, and O3 during the post-COVID period in 2021 respectively decreased by 14.8%, 29.0%, 14.6%, 22.5%, 37.4%, 14.8%, and 8.7%, compared with those in 2020. It is also worth noting that all the changes in air pollution during the post-COVID era have been consistent. The combined proportions of grade I and grade II during post-COVID period in 2021 were 18.4% higher than those during the same period of 2020, which indicates that the air quality during post-COVID 2021 has obviously improved compared with those in the same period of 2020. The possible reasons are a series of clean air policies and clean air actions, as well as favorable atmospheric diffusion conditions. These results indicate that clean air policies play a very important role in improving air quality.

Highlights

Up to November 14, 2021 globally, over 5, 092, 761 people have died, and 252, 826, 597 have been infected with COVID-19 (WHO)
The concentrations of PM10 and PM2.5 during the lockdown in Delhi decreased in comparison to the period prior to the lockdown, and the Carbon monoxide (CO) and NO2 levels dropped during the lockdown period (Mahato et al, 2020)
Air quality has markedly changed from the COVID to post-COVID era in the Beijing-TianjinTangshan region in China

Summary

Introduction

Up to November 14, 2021 globally, over 5, 092, 761 people have died, and 252, 826, 597 have been infected with COVID-19 (WHO). China closed business activities, restricted travel and required people to stay at home starting in late January of 2020 (Guo and He, 2021). In 2020, travel restrictions in many cities in China greatly reduced air pollution emissions. It was found that air pollution was significantly reduced because of the decrease in transportation and industrial emissions (Wang et al, 2020a). Restrictions on human activities during the lockdown have greatly reduced the concentrations of environmental pollutants in China and in the United States (Shakoor et al, 2020)

Methods

Results

Conclusion