Details

Autor(en) / Beteiligte

• Shi, Xiaoqin
• Brasseur, Guy P.

Titel

The Response in Air Quality to the Reduction of Chinese Economic Activities During the COVID‐19 Outbreak

Ist Teil von

• Geophysical research letters, 2020-06, Vol.47 (11), p.n/a

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Wiley Online Library

Beschreibungen/Notizen

• During the COVID‐19 outbreak that took place in early 2020, the economic activities in China were drastically reduced and accompanied by a strong reduction in the emission of primary air pollutants. On the basis of measurements made at the monitoring stations operated by the China National Environmental Monitoring Center, we quantify the reduction in surface PM2.5, NO2, CO, and SO2 concentrations in northern China during the lockdown, which started on 23 January 2020. We find that, on the average, the levels of surface PM2.5 and NO2 have decreased by approximately 35% and 60%, respectively, between the period 1 and 22 January 2020 and the period 23 January and 29 February 2020. At the same time, the mean ozone concentration has increased by a factor 1.5–2. In urban area of Wuhan, where drastic measures were adopted to limit the spread of the coronavirus, similar changes in the concentrations of PM2.5, NO2, and ozone are found. Plain Language Summary During the COVID‐19 outbreak that took place in China in early 2020, the surface emissions of air pollutants including nitrogen oxides (a product of combustion by traffic, industry, and residential activity) have been severely reduced following the lockdown of major cities. The level of aerosol pollution (particulate matter) has also been substantially reduced. These conditions have led to a substantial increase (a factor 1.5 to 2) in the concentration of surface ozone, a powerful oxidant that is responsible for severe health problems including pulmonary and cardiac diseases. The atmospheric concentration of tropospheric ozone results from complex photochemical processes that involve the presence of nitrogen oxides, hydrocarbons, and water vapor. Key Points Surface measurements made at more than 800 monitoring stations show that the mean levels of PM2.5 and NO2 in northern China have decreased by approximately 35% and 60%, respectively, after the lockdown following the COVID‐19 outbreak of early 2020 Simultaneously, the ozone concentration, a secondary pollutant responsible for severe health problems, has increased by a factor 1.5–2 The same type of behavior was observed specifically in the city of Wuhan, where COVID‐19 outbreak was first reported