Does air pollution upsurge in megacities after Covid-19 lockdown? A spatial approach

Shehzad, Khurram; Liu, Xiaoxing; Ahmad, Mahmood; Majeed, Abdul; Tariq, Farheen; Wahab, Salman

doi:10.1016/j.envres.2021.111052

Cited by 19 publications

(14 citation statements)

References 24 publications

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“…In comparison, PM 2.5 in pre-lockdown was 1.2 and 1.6 times those during lockdown and post-lockdown, respectively, according to the mass weighting (Figure 4), which may be due to the relatively high wind speed (4.5 ± 3.0 m s −1 ) and low relative humidity (50 ± 5%); after lockdown provided favorable meteorological conditions for the diffusion of air pollutants compared with before and during the lockdown. Similar continuous decrease in PM 2.5 concentration in the post-lockdown period were observed in Wuhan, China [67] and Mumbai, India [68]. It is inferred that the lockdown policies have a relatively long-term and lasting effect on reducing the concentration of air pollutants.…”

Section: Pm 25 From Offline Filter Samplessupporting

confidence: 63%

Quantifying Air Pollutant Variations during COVID-19 Lockdown in a Capital City in Northwest China

Feng

Wang

et al. 2021

Atmosphere

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In the context of the outbreak of coronavirus disease 2019 (COVID-19), strict lockdown policies were implemented to control nonessential human activities in Xi’an, northwest China, which greatly limited the spread of the pandemic and affected air quality. Compared with pre-lockdown, the air quality index and concentrations of PM2.5, PM10, SO2, and CO during the lockdown reduced, but the reductions were not very significant. NO2 levels exhibited the largest decrease (52%) during lockdown, owing to the remarkable decreased motor vehicle emissions. The highest K+ and lowest Ca2+ concentrations in PM2.5 samples could be attributed to the increase in household biomass fuel consumption in suburbs and rural areas around Xi’an and the decrease in human physical activities in Xi’an (e.g., human travel, vehicle emissions, construction activities), respectively, during the lockdown period. Secondary chemical reactions in the atmosphere increased in the lockdown period, as evidenced by the increased O3 level (increased by 160%) and OC/EC ratios in PM2.5 (increased by 26%), compared with pre-lockdown levels. The results, based on a natural experiment in this study, can be used as a reference for studying the formation and source of air pollution in Xi’an and provide evidence for establishing future long-term air pollution control policies.

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Section: Pm 25 From Offline Filter Samplessupporting

confidence: 63%

Quantifying Air Pollutant Variations during COVID-19 Lockdown in a Capital City in Northwest China

Feng

Wang

et al. 2021

Atmosphere

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“…Nevertheless, not all evidenced an increase of the pollutants after the lockdown, because of the slow economic recovery [ 48 , 61 , 70 ]. Similarly, studies that compared to the same period in previous years [ 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 ], and even more robustly with historical data of more than 5 years ( Table 1 ), reported a decrease of pollutants’ concentrations during the lockdown. As shown in Table 1 , decreases between 9–60%, 21.4–61.6%, and 30–66% were obtained for PM 2 .…”

Section: Discussionmentioning

confidence: 60%

Impact of COVID-19 Pandemic on Air Quality: A Systematic Review

Silva

Branco

Sousa

2022

IJERPH

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With the emergence of the COVID-19 pandemic, several governments imposed severe restrictions on socio-economic activities, putting most of the world population into a general lockdown in March 2020. Although scattered, studies on this topic worldwide have rapidly emerged in the literature. Hence, this systematic review aimed to identify and discuss the scientifically validated literature that evaluated the impact of the COVID-19 pandemic and associated restrictions on air quality. Thus, a total of 114 studies that quantified the impact of the COVID-19 pandemic on air quality through monitoring were selected from three databases. The most evaluated countries were India and China; all the studies intended to evaluate the impact of the pandemic on air quality, mainly concerning PM10, PM2.5, NO2, O3, CO, and SO2. Most of them focused on the 1st lockdown, comparing with the pre- and post-lockdown periods and usually in urban areas. Many studies conducted a descriptive analysis, while others complemented it with more advanced statistical analysis. Although using different methodologies, some studies reported a temporary air quality improvement during the lockdown. More studies are still needed, comparing different lockdown and lifting periods and, in other areas, for a definition of better-targeted policies to reduce air pollution.

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“…With the world still waiting for an effective mass vaccination using the developed anti-COVID-19 vaccines (Costanzo et al 2021 ; He et al 2021 ) and despite the efforts by pharmaceutical companies and the scientific community to develop effective therapies through drug repurposing (Borbone et al 2021 ; Costanzo et al 2020 ; Kumawat et al 2021 ; Khan et al 2021 ), herbal medicine (Vicidomini et al 2021b ) and other recently proposed approaches (Vicidomini et al 2021a ; Wang et al 2020b ), SARS-CoV-2 and its mutations remain a major global issue leaving our future unclear. COVID-19 has also had an environmental impact on the planet, and while initial data from ESA (European Space Agency) and NASA (U.S. National Aeronautics and Space Administration) seemed to suggest that pollution in the first epicenters of COVID-19 such as the Hubei region of China, Italy, Spain and the USA had reduced significantly (up to 30%) (Muhammad et al 2020 ), in the subsequent phases of the pandemic, an increasing pollution trend was recorded globally (Wang et al 2020a ; Zheng et al 2021 ; Shehzad et al 2021 ). Of equal importance, there has also been an increase in plastic pollution (Gorrasi et al 2020 ; Ufnalska and Lichtfouse 2021 ) due to face masks, gloves and other single-use COVID-19-related plastics that are posing a major risk for marine ecosystems and aquatic organisms (Aragaw 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Less COVID-19 deaths in southern and insular Italy explained by forest bathing, Mediterranean environment, and antiviral plant volatile organic compounds

Roviello

2021

Environ Chem Lett

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The coronavirus disease 2019 (COVID-19) is causing major sanitary and socioeconomic issues, yet some locations are less impacted than others. While densely populated areas are likely to favor viral transmission, we hypothesize that other environmental factors could explain lower cases in some areas. We studied COVID-19 impact and population statistics in highly forested Mediterranean Italian regions versus some northern regions where the amount of trees per capita is much lower. We also evaluated the affinity of Mediterranean plant-emitted volatile organic compounds (VOCs) isoprene, α-pinene, linalool and limonene for COVID-19 protein targets by molecular docking modeling. Results show that while mean death number increased about 4 times from 2020 to 2021, the percentage of deaths per population (0.06–0.10%) was lower in the greener Mediterranean regions such as Sardinia, Calabria and Basilica versus northern regions with low forest coverage, such as Lombardy (0.33%) and Emilia Romagna (0.29%). Data also show that the pandemic severity cannot be explained solely by population density. Modeling reveals that plant organic compounds could bind and interfere with the complex formed by the receptor binding domain of the coronavirus spike protein with the human cell receptor. Overall, our findings are likely explained by sea proximity and mild climate, Mediterranean diet and the abundance of non-deciduous Mediterranean plants which emit immunomodulatory and antiviral compounds. Potential implications include ‘forest bathing’ as a therapeutic practice, designing nasal sprays containing plant volatile organic compounds, and preserving and increasing forest coverage. Supplementary Information The online version contains supplementary material available at 10.1007/s10311-021-01309-5.

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Does air pollution upsurge in megacities after Covid-19 lockdown? A spatial approach

Cited by 19 publications

References 24 publications

Quantifying Air Pollutant Variations during COVID-19 Lockdown in a Capital City in Northwest China

Quantifying Air Pollutant Variations during COVID-19 Lockdown in a Capital City in Northwest China

Impact of COVID-19 Pandemic on Air Quality: A Systematic Review

Less COVID-19 deaths in southern and insular Italy explained by forest bathing, Mediterranean environment, and antiviral plant volatile organic compounds

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