COVID-19 pandemic in Wuhan: Ambient air quality and the relationships between criteria air pollutants and meteorological variables before, during, and after lockdown

Air pollution impacts from COVID-19 pandemic control strategies in Malaysia

“…This was likely to be due to the location of Delhi as it is inland and would generally experience low SO 2 concentrations. Compared to other studies, higher reduction of SO 2 than this study was observed ( Nakada and Urban, 2020 ; Sulaymon et al., 2021 ; Tobías et al., 2020 ; Yuan et al., 2021 ) which suggested that the different levels of SO 2 during the regular day without lockdown could be unlikely due to different intensity and source of SO 2 concentration, which in turns provide different percentages of reduction. Furthermore, the effect of strengthened air pollution regulation during the APEC Meeting and the Victory-day Parade in Beijing; and World Internet Conference in Jiaxing which had reported reduction of 56.5% and 7.1% which suggested effectiveness of stringent regulation to reduced air pollution ( Li et al., 2017 ; Shen et al., 2017 ).…”

“…Decreases in the calculated average monthly concentrations of NO 2 were observed in Alor Star, Ipoh, Johor Bahru, Kuala Lumpur and Seremban. Higher NO 2 concentration during lockdown were observed by Bao and Zhang (2020) , Nakada and Urban (2020) , Sulaymon et al. (2021) and Tobías et al.…”

“…Previous studies (as shown in Table S1 ) critically investigated lockdown effects toward concentrations of air pollutants ( Abdullah et al., 2020 ; Nakada and Urban, 2020 ; Tanzer-Gruener et al., 2020 ; Tobías et al., 2020 ; Venter et al., 2021 ; Yuan et al., 2021 ); air pollution relationship with COVID-19 cases ( Accarino et al., 2021 ; Tello-Leal and Macías-Hernández, 2020 ); meteorology and air pollutants changes ( Hossain et al., 2021 ; Sulaymon et al., 2021 ); traffic and mobility changes ( Aloi et al., 2020 ); and the application of statistical and modelling ( Bao and Zhang, 2020 ; He et al., 2020 ; Liu et al., 2020b ) while this study focuses mainly on air pollutants effects in cities with the analysis related to population exposure to non-carcinogenic risks. The COVID-19 pandemic affected human activities, primarily when the MCO was implemented to reduce the chain of infection among the population in Malaysia.…”

Multiple relationships between aerosol and COVID-19: A framework for global studies

“…As shown in Fig. 2 , compared with the preceding period of COVID-19 lockdown, the average concentration of PM2.5 has decreased by 38% in California ( Liu et al, 2020b ), 21.8% in Hat Yai, Thailand ( Stratoulias and Nuthammachot, 2020 ), 52% in Pearl River Delta ( Wang et al, 2021 ) and 41.2% in Wuhan ( Sulaymon et al, 2021 ) during COVID-19 lockdown, and the average concentration of PM 10 has decreased by 31% in Barcelona, Spain ( Tobias et al, 2020 ), 22.9% in Hat Yai, Thailand ( Stratoulias and Nuthammachot, 2020 ) and 33.1% in Wuhan ( Sulaymon et al, 2021 ). Compared with the preceding years, PM 2.5 and PM 10 mass concentrations of 22 cities in India decreased by about 43% and 31% during the lockdown ( Sharma et al, 2020 ).…”

COVID-19 and Air Pollution: Measuring Pandemic Impact to Air Quality in Five European Countries

“…Recent satellite data analysis-based reports by the Copernicus Atmosphere Monitoring Service confirm a reduction of air pollutants in the main European cities during the lockdown. Most studies that analyzed air pollution by including meteorological variables, such as temperature, wind speed, wind direction, and humidity concluded that meteorological variables had no significant effect on air pollutant concentration during the pandemic [28][29][30].…”