Impact of the Levels of COVID-19 Pandemic Prevention and Control Measures on Air Quality: A Case Study of Jiangsu Province, China

Abstract

In order to control the spread of the COVID-19 pandemic, the prevention and control measures of public health emergencies were initiated in all provinces of China in early 2020, which had a certain impact on air quality. In this study, taking Jiangsu Province in China as an example, the air pollution levels in different regions under different levels of pandemic prevention and control (PPC) measures are evaluated. The implementation of the prevention and control policies of COVID-19 pandemic directly affected the concentration of air pollutants. No matter what level of PPC measures was implemented, the air quality index (AQI) and pollutant concentrations of NO2, CO, PM10 and PM2.5 were all reduced by varied degrees. The higher the level of PPC measures, the greater the reduction was in air pollutant concentrations. Specifically, NO2 was the most sensitive to PPC policies. The concentrations of CO and atmospheric particulate matter (PM10 and PM2.5) decreased most obviously under the first and second level of PPC. The response speed of air quality to different levels of PPC measures varied greatly among different cities. Southern Jiangsu, which has a higher level of economic development and is dominated by secondary and tertiary industries, had a faster response speed and a stronger responsiveness. The results of this study reflect the economic vitality of different cities in economically advanced regions (i.e., Jiangsu Province) in China. Furthermore, the results can provide references for the formulation of PPC policies and help the government make more scientific and reasonable strategies for air pollution prevention and control.

Comparing the Change in Air Quality during the COVID-19 Lockdown between Dry and Wet Seasons in Nepal

“…During the lockdown period, people's mobility and road transportation were restricted resulting into a massive drop in transport sector NO 2 emissions, which might have -6.87 -1.50 caused a higher drop in NO 2 concentration over the heavily urbanized areas, such as Kathmandu, compared to rural areas in the country. It suggests that the NO 2 would be more sensitive among the pollutants to the lockdown in urban areas, as a prior study conducted in Jiangsu Province, China, suggested (Ai et al, 2022). This result also agrees with a prior investigation conducted in the UK, which concluded that NO 2 reduction during lockdown was higher at urban traffic sites and lower at background sites (Jephcote et al, 2021).…”

“…A study showed a 4.1% to 10.0% decrease in average NO 2 over Bangladesh, Pakistan, and India, while a 12.6% increase over the south Asia region during the lockdown period compared to the long-term averages (Upadhyay et al, 2022). The decrease in NO 2 column number density over Nepal obtained in the present study was comparable to that over India reported by Upadhyay et al Moreover, a study conducted in Jiangsu Province, China, showed a 12.0% decrease in NO 2 during the implementation of the most restrictive control measure to contain the COVID-19 pandemic (Ai et al, 2022), which was comparable to the findings of the present study. However, a 12.6% increase in the region-average NO 2 column number density during the lockdown has been reported over south Asia (Upadhyay et al, 2022), which suggested that the regional analysis may not represent the sub-regional scenario of Nepal.…”

“…In Jiangsu Province, China, the PM 2.5 concentration b This is the mean ± SD of PM 2.5 concentration for "normal" years (2017-2019). decreased by 28.9% during the implementation of the most restrictive control measures related to the COVID-19 pandemic (Ai et al, 2022), which was similar to the change in PM 2.5 concentration in the Kathmandu Valley obtained during the LDD period in 2020. These ground-based monitoring data indicated that there was a remarkable drop in ambient PM 2.5 concentrations in the Kathmandu Valley during the LDD period in 2020.…”

“…Over the Indian sub-continent, such spatial heterogeneities have been explained as the combined effect of change in anthropogenic and natural emissions and meteorological dynamics during the lockdown (Madineni et al, 2021). Another study conducted in China showed substantial reductions in concentrations of many air pollutants, such as NO2 (-49.96%), CO (-24.99%), PM 10 (particulate matter with a diameter of 10 µm or less, -39.30%), and PM 2.5 (particulate matter with a diameter of 2.5 µm or less, -32.34%), in the atmosphere during the implementation of the most restrictive control measures compared to the respective air pollutant concentrations during the normal years (Ai et al, 2022).…”

Analysis of Factors Influencing Air Quality in Different Periods during COVID-19: A Case Study of Tangshan, China

“…Compared with 2019, the national average PM 2.5 , PM 10 , SO 2 , NO 2 , and CO concentrations decreased significantly during the period from 24 January to 30 April 2020, and the O 3 concentration did not change significantly or showed an upward trend in some areas [3][4][5]. With the resumption of work and production at the end of February, PM 2.5 and NO 2 concentrations in most cities began to increase gradually [6,7]. Compared with the previous Spring Festival holiday and the days before the Spring Festival, the anthropogenic emissions of PM 2.5 , SO 2 , and NO 2 during the Spring Festival in 2020 were significantly reduced, and the concentration of pollutants in most cities was significantly reduced [8,9].…”