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Mejía C D, Faican G, Zalakeviciute R, Matovelle C, Bonilla S, Sobrino JA. Spatio-temporal evaluation of air pollution using ground-based and satellite data during COVID-19 in Ecuador. Heliyon 2024; 10:e28152. [PMID: 38560184 PMCID: PMC10979269 DOI: 10.1016/j.heliyon.2024.e28152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 02/27/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
The concentration of gases in the atmosphere is a topic of growing concern due to its effects on health, ecosystems etc. Its monitoring is commonly carried out through ground stations which offer high precision and temporal resolution. However, in countries with few stations, such as Ecuador, these data fail to adequately describe the spatial variability of pollutant concentrations. Remote sensing data have great potential to solve this complication. This study evaluates the spatiotemporal distribution of nitrogen dioxide (NO2) and ozone (O3) concentrations in Quito and Cuenca, using data obtained from ground-based and Sentinel-5 Precursor mission sources during the years 2019 and 2020. Moreover, a Linear Regression Model (LRM) was employed to analyze the correlation between ground-based and satellite datasets, revealing positive associations for O3 (R2 = 0.83, RMSE = 0.18) and NO2 (R2 = 0.83, RMSE = 0.25) in Quito; and O3 (R2 = 0.74, RMSE = 0.23) and NO2, (R2 = 0.73, RMSE = 0.23) for Cuenca. The agreement between ground-based and satellite datasets was analyzed by employing the intra-class correlation coefficient (ICC), reflecting good agreement between them (ICC ≥0.57); and using Bland and Altman coefficients, which showed low bias and that more than 95% of the differences are within the limits of agreement. Furthermore, the study investigated the impact of COVID-19 pandemic-related restrictions, such as social distancing and isolation, on atmospheric conditions. This was categorized into three periods for 2019 and 2020: before (from January 1st to March 15th), during (from March 16th to May 17th), and after (from March 18th to December 31st). A 51% decrease in NO2 concentrations was recorded for Cuenca, while Quito experienced a 14.7% decrease. The tropospheric column decreased by 27.3% in Cuenca and 15.1% in Quito. O3 showed an increasing trend, with tropospheric concentrations rising by 0.42% and 0.11% for Cuenca and Quito respectively, while the concentration in Cuenca decreased by 14.4%. Quito experienced an increase of 10.5%. Finally, the reduction of chemical species in the atmosphere as a consequence of mobility restrictions is highlighted. This study compared satellite and ground station data for NO2 and O3 concentrations. Despite differing units preventing data validation, it verified the Sentinel-5P satellite's effectiveness in anomaly detection. Our research's value lies in its applicability to developing countries, which may lack extensive monitoring networks, demonstrating the potential use of satellite technology in urban planning.
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Affiliation(s)
- Danilo Mejía C
- Grupo CATOx – CEA de la Universidad de Cuenca, Campus Balzay, 010207 Cuenca, Ecuador
- Carrera de Ingeniería Ambiental de la Universidad de Cuenca, Campus Balzay, 010207 Cuenca, Ecuador
| | - Gina Faican
- Grupo CATOx – CEA de la Universidad de Cuenca, Campus Balzay, 010207 Cuenca, Ecuador
| | - Rasa Zalakeviciute
- Grupo de Biodiversidad Medio Ambiente y Salud (BIOMAS), Universidad de Las Americas, Quito - EC 170125, Ecuador
| | - Carlos Matovelle
- Carrera de Ingeniería Ambienta de la Universidad Católica de Cuenca, Ecuador
| | - Santiago Bonilla
- Research Center for the Territory and Sustainable Habitat, Universidad Tecnológica Indoamérica, Machala y Sabanilla, 170301 Quito, Ecuador
| | - José A. Sobrino
- Gobal Change Unit (GCU), Image Processing Laboratory (IPL), University of Valencia, Spain
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Cazorla M, Giles DM, Herrera E, Suárez L, Estevan R, Andrade M, Bastidas Á. Latitudinal and temporal distribution of aerosols and precipitable water vapor in the tropical Andes from AERONET, sounding, and MERRA-2 data. Sci Rep 2024; 14:897. [PMID: 38195912 PMCID: PMC10776852 DOI: 10.1038/s41598-024-51247-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 01/02/2024] [Indexed: 01/11/2024] Open
Abstract
The aerosol and precipitable water vapor (PW) distribution over the tropical Andes region is characterized using Aerosol Robotic Network (AERONET) observations at stations in Medellin (Colombia), Quito (Ecuador), Huancayo (Peru), and La Paz (Bolivia). AERONET aerosol optical depth (AOD) is interpreted using PM2.5 data when available. Columnar water vapor derived from ozone soundings at Quito is used to compare against AERONET PW. MERRA-2 data are used to complement analyses. Urban pollution and biomass burning smoke (BBS) dominate the regional aerosol composition. AOD and PM2.5 yearly cycles for coincident measurements correlate linearly at Medellin and Quito. The Andes cordillera's orientation and elevation funnel or block BBS transport into valleys or highlands during the two fire seasons that systematically impact South America. The February-March season north of Colombia and the Colombian-Venezuelan border directly impacts Medellin. Possibly, the March aerosol signal over Quito has a long-range transport component. At Huancayo and La Paz, AOD increases in September due to the influence of BBS in the Amazon. AERONET PW and sounding data correlate linearly but a dry bias with respect to soundings was identified in AERONET. PW and rainfall progressively decrease from north to south due to increasing altitude. This regional diagnosis is an underlying basis to evaluate future changes in aerosol and PW given prevailing conditions of rapidly changing atmospheric composition.
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Affiliation(s)
- María Cazorla
- Universidad San Francisco de Quito USFQ, Instituto de Investigaciones Atmosféricas, Quito, Ecuador.
| | - David M Giles
- Science Systems and Applications, Inc. (SSAI), Lanham, MD, USA
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD, USA
| | - Edgar Herrera
- Universidad San Francisco de Quito USFQ, Instituto de Investigaciones Atmosféricas, Quito, Ecuador
| | - Luis Suárez
- Instituto Geofísico del Perú, Huancayo, Peru
| | | | - Marcos Andrade
- Laboratorio de Física de la Atmósfera, Universidad Mayor de San Andrés, La Paz, Bolivia
- Department of Atmospheric and Oceanic Sciences, University of Maryland, College Park, MD, USA
| | - Álvaro Bastidas
- Universidad Nacional de Colombia Sede Medellin, Medellin, Colombia
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Atiaga O, Guerrero F, Páez F, Castro R, Collahuazo E, Nunes LM, Grijalva M, Grijalva I, Otero XL. Assessment of variations in air quality in cities of Ecuador in relation to the lockdown due to the COVID-19 pandemic. Heliyon 2023; 9:e17033. [PMID: 37484275 PMCID: PMC10361106 DOI: 10.1016/j.heliyon.2023.e17033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 07/25/2023] Open
Abstract
This study analyzes the effect of lockdown due to COVID-19 on the spatiotemporal variability of ozone (O3), sulfur dioxide (SO2), and nitrogen dioxide (NO2) concentrations in different provinces of continental Ecuador using satellite information from Sentinel - 5P. The statistical analysis includes data from 2018 to March 2021 and was performed based on three periods defined a priori: before, during, and after lockdown due to COVID-19, focusing on the provinces with the highest concentrations of the studied gases (hotspots). The results showed a significant decrease in NO2 concentrations during the COVID-19 lockdown period in all the study areas: the Metropolitan District of Quito (DMQ) and the provinces of Guayas and Santo Domingo de los Tsáchilas. In the period after lockdown, NO2 concentrations increased by over 20% when compared to the pre-lockdown period, which may be attributable to a shift towards private transportation due to health concerns. On the other hand, SO2 concentrations during the lockdown period showed irregular, non-significant variations; however, increases were observed in the provinces of Chimborazo, Guayas, Santa Elena, and Morona Santiago, which could be partly attributed to the eruptive activity of the Sangay volcano during 2019-2020. Conversely, O3 concentrations increased by 2-3% in the study areas; this anomalous behavior could be attributed to decreased levels of NOx, which react with ozone, reducing its concentration. Finally, satellite data validation using the corresponding data from monitoring stations in the DMQ showed correlation values of 0.9 for O3 data and 0.7 for NO2 data, while no significant correlation was found for SO2.
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Affiliation(s)
- Oliva Atiaga
- Departamento de Ciencias de la Tierra y la Construcción, Universidad de las Fuerzas Armadas ESPE, Av. General Rumiñahui s/n, Sangolquí, P.O. Box 171-5-231B, Ecuador
- CRETUS. Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur, 15782 Santiago de Compostela, Spain
| | - Fernanda Guerrero
- Departamento de Ciencias de la Tierra y la Construcción, Universidad de las Fuerzas Armadas ESPE, Av. General Rumiñahui s/n, Sangolquí, P.O. Box 171-5-231B, Ecuador
| | - Fernando Páez
- Departamento de Ciencias de la Tierra y la Construcción, Universidad de las Fuerzas Armadas ESPE, Av. General Rumiñahui s/n, Sangolquí, P.O. Box 171-5-231B, Ecuador
| | - Rafael Castro
- Geospace Solutions, Av. Manuel Córdova Galarza km 4.5, P.O. Box 170177, Ecuador
| | - Edison Collahuazo
- Geospace Solutions, Av. Manuel Córdova Galarza km 4.5, P.O. Box 170177, Ecuador
| | - Luís Miguel Nunes
- Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
- CERIS, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001, Lisboa, Portugal
| | - Marcelo Grijalva
- Departamento de Ciencias de la Vida, Universidad de las Fuerzas Armadas ESPE, Av. General Rumiñahui s/n, Sangolquí, P.O. Box 171-5-231B, Ecuador
| | - Iván Grijalva
- Independent consultant. Avenida Amazonas N22-62 y Ramirez Dávalos, PO BOX 170526, Quito, Ecuador
| | - Xosé Luis Otero
- CRETUS. Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur, 15782 Santiago de Compostela, Spain
- REBUSC Network of Biological Field Stations of the University of Santiago de Compostela, Marine Biology Stations of A Graña and Ferrol, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
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Wong YJ, Shiu HY, Chang JHH, Ooi MCG, Li HH, Homma R, Shimizu Y, Chiueh PT, Maneechot L, Nik Sulaiman NM. Spatiotemporal impact of COVID-19 on Taiwan air quality in the absence of a lockdown: Influence of urban public transportation use and meteorological conditions. JOURNAL OF CLEANER PRODUCTION 2022; 365:132893. [PMID: 35781986 PMCID: PMC9234473 DOI: 10.1016/j.jclepro.2022.132893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 06/01/2022] [Accepted: 06/24/2022] [Indexed: 05/19/2023]
Abstract
The unprecedented outbreak of COVID-19 significantly improved the atmospheric environment for lockdown-imposed regions; however, scant evidence exists on its impacts on regions without lockdown. A novel research framework is proposed to evaluate the long-term monthly spatiotemporal impact of COVID-19 on Taiwan air quality through different statistical analyses, including geostatistical analysis, change detection analysis and identification of nonattainment pollutant occurrence between the average mean air pollutant concentrations from 2018-2019 and 2020, considering both meteorological and public transportation impacts. Contrary to lockdown-imposed regions, insignificant or worsened air quality conditions were observed at the beginning of COVID-19, but a delayed improvement occurred after April in Taiwan. The annual mean concentrations of PM10, PM2.5, SO2, NO2, CO and O3 in 2020 were reduced by 24%, 18%, 15%, 9.6%, 7.4% and 1.3%, respectively (relative to 2018-2019), and the overall occurrence frequency of nonattainment air pollutants declined by over 30%. Backward stepwise regression models for each air pollutant were successfully constructed utilizing 12 meteorological parameters (R2 > 0.8 except for SO2) to simulate the meteorological normalized business-as-usual concentration. The hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model simulated the fate of air pollutants (e.g., local emissions or transboundary pollution) for anomalous months. The changes in different public transportation usage volumes (e.g., roadway, railway, air, and waterway) moderately reduced air pollution, particularly CO and NO2. Reduced public transportation use had a more significant impact than meteorology on air quality improvement in Taiwan, highlighting the importance of proper public transportation management for air pollution control and paving a new path for sustainable air quality management even in the absence of a lockdown.
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Affiliation(s)
- Yong Jie Wong
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 520-0811, Japan
| | - Huan-Yu Shiu
- Graduate Institute of Environmental Engineering, National Taiwan University, 10617, Taiwan
| | - Jackson Hian-Hui Chang
- Department of Atmospheric Sciences, National Central University, 32001, Taiwan
- Preparatory Center for Science and Technology (PPST), Universiti Malaysia Sabah, 88400, Malaysia
| | - Maggie Chel Gee Ooi
- Institute of Climate Change, National University of Malaysia (UKM), Bangi, 43600, Malaysia
| | - Hsueh-Hsun Li
- Graduate Institute of Environmental Engineering, National Taiwan University, 10617, Taiwan
| | - Ryosuke Homma
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 520-0811, Japan
| | - Yoshihisa Shimizu
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 520-0811, Japan
| | - Pei-Te Chiueh
- Graduate Institute of Environmental Engineering, National Taiwan University, 10617, Taiwan
| | - Luksanaree Maneechot
- Environmental Engineering and Disaster Management Program, School of Interdisciplinary Studies, Mahidol University Kanchanaburi Campus (MUKA), Kanchanaburi, 71150, Thailand
| | - Nik Meriam Nik Sulaiman
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia
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Cao X, Liu X, Hadiatullah H, Xu Y, Zhang X, Cyrys J, Zimmermann R, Adam T. Investigation of COVID-19-related lockdowns on the air pollution changes in augsburg in 2020, Germany. ATMOSPHERIC POLLUTION RESEARCH 2022; 13:101536. [PMID: 36042786 PMCID: PMC9392961 DOI: 10.1016/j.apr.2022.101536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
The COVID-19 pandemic in Germany in 2020 brought many regulations to impede its transmission such as lockdown. Hence, in this study, we compared the annual air pollutants (CO, NO, NO2, O3, PM10, PM2.5, and BC) in Augsburg in 2020 to the record data in 2010-2019. The annual air pollutants in 2020 were significantly (p < 0.001) lower than that in 2010-2019 except O3, which was significantly (p = 0.02) higher than that in 2010-2019. In a depth perspective, we explored how lockdown impacted air pollutants in Augsburg. We simulated air pollutants based on the meteorological data, traffic density, and weekday and weekend/holiday by using four different models (i.e. Random Forest, K-nearest Neighbors, Linear Regression, and Lasso Regression). According to the best fitting effects, Random Forest was used to predict air pollutants during two lockdown periods (16/03/2020-19/04/2020, 1st lockdown and 02/11/2020-31/12/2020, 2nd lockdown) to explore how lockdown measures impacted air pollutants. Compared to the predicted values, the measured CO, NO2, and BC significantly reduced 18.21%, 21.75%, and 48.92% in the 1st lockdown as well as 7.67%, 32.28%, and 79.08% in the 2nd lockdown. It could be owing to the reduction of traffic and industrial activities. O3 significantly increased 15.62% in the 1st lockdown but decreased 40.39% in the 2nd lockdown, which may have relations with the fluctuations the NO titration effect and photochemistry effect. PM10 and PM2.5 were significantly increased 18.23% an 10.06% in the 1st lockdown but reduced 34.37% and 30.62% in the 2nd lockdown, which could be owing to their complex generation mechanisms.
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Affiliation(s)
- Xin Cao
- School of Sport Science, Beijing Sport University, Beijing, 100084, China
- Joint Mass Spectrometry Center, Cooperation Group Comprehensive Molecular Analytics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, Neuherberg, 85764, Germany
| | - Xiansheng Liu
- University of the Bundeswehr Munich, Faculty for Mechanical Engineering, Institute of Chemical and Environmental Engineering, 85577 Neubiberg, Germany
- Institute of Environmental Assessment and Water Research (IDAEA-CSIC), 08034, Barcelona, Spain
| | | | - Yanning Xu
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266525, China
| | - Xun Zhang
- Beijing Key Laboratory of Big Data Technology for Food Safety, School of Computer Science and Engineering, Beijing Technology and Business University, Beijing, 100048, China
| | - Josef Cyrys
- Research Unit Analytical BioGeoChemistry, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Ralf Zimmermann
- Joint Mass Spectrometry Center, Cooperation Group Comprehensive Molecular Analytics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, Neuherberg, 85764, Germany
- Joint Mass Spectrometry Center, Chair of Analytical Chemistry, University of Rostock, Rostock, 18059, Germany
| | - Thomas Adam
- Joint Mass Spectrometry Center, Cooperation Group Comprehensive Molecular Analytics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, Neuherberg, 85764, Germany
- University of the Bundeswehr Munich, Faculty for Mechanical Engineering, Institute of Chemical and Environmental Engineering, 85577 Neubiberg, Germany
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Sbai SE, Bentayeb F, Yin H. Atmospheric pollutants response to the emission reduction and meteorology during the COVID-19 lockdown in the north of Africa (Morocco). STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT : RESEARCH JOURNAL 2022; 36:3769-3784. [PMID: 35498271 PMCID: PMC9033931 DOI: 10.1007/s00477-022-02224-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
UNLABELLED Climate and air quality change due to COVID-19 lockdown (LCD) are extremely concerned subjects of several research recently. The contribution of meteorological factors and emission reduction to air pollution change over the north of Morocco has been investigated in this study using the framework generalized additive models, that have been proved to be a robust technique for the environmental data sets, focusing on main atmospheric pollutants in the region including ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter (PM2.5 and PM10), secondary inorganic aerosols (SIA), nom-methane volatile organic compounds and carbon monoxide (CO) from the regional air pollution dataset of the Copernicus Atmosphere Monitoring Service. Our results, indicate that secondary air pollutants (PM2.5, PM10 and O3) are more influenced by metrological factors and the other air pollutants reported by this study (NO2 and SO2). We show a negative effect for PBHL, total precipitation and NW10M on PM (PM2.5 and PM10 ), this meteorological parameters contribute to decrease in PM2.5 by 9, 2 and 9% respectively, before LCD and 8, 1 and 5% respectively during LCD. However, a positive marginal effect was found for SAT, Irradiance and RH that contribute to increase PM2.5 by 9, 12 and 18% respectively, before LCD and 17, 54 and 34% respectively during LCD. We found also that meteorological factors contribute to O3, PM2.5, PM10 and SIA average mass concentration by 22, 5, 3 and 34% before LCD and by 28, 19, 5 and 42% during LCD respectively. The increase in meteorological factors marginal effect during LCD shows the contribution of photochemical oxidation to air pollution due to increase in atmospheric oxidant (O3 and OH radical) during LCD, which can explain the response of PM to emission reduction. This study indicates that PM (PM2.5, PM10) has more controlled by SO2 due to the formation of sulfate particles especially under high oxidants level. The positive correlation between westward wind at 10 m (WW10M), Northward Wind at 10 m (NW10M) and PM indicates the implication of sea salt particles transported from Mediterranean Sea and Atlantic Ocean. The Ozone mass concentration shows a positive trend with Irradiance, Total and SAT during LCD; because temperature and irradiance enhance tropospheric ozone formation via photochemical reaction.This study shows the contribution of atmospheric oxidation capacity to air pollution change. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00477-022-02224-z.
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Affiliation(s)
- Salah Eddine Sbai
- Department of Physics, Laboratoires de Physique des Hauts Energies Modélisation et Simulation, Mohammed V University in Rabat, Rabat, Morocco
| | - Farida Bentayeb
- Department of Physics, Laboratoires de Physique des Hauts Energies Modélisation et Simulation, Mohammed V University in Rabat, Rabat, Morocco
| | - Hao Yin
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031 China
- University of Science and Technology of China, Hefei, 230026 China
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Chau PN, Zalakeviciute R, Thomas I, Rybarczyk Y. Deep Learning Approach for Assessing Air Quality During COVID-19 Lockdown in Quito. Front Big Data 2022; 5:842455. [PMID: 35445191 PMCID: PMC9014303 DOI: 10.3389/fdata.2022.842455] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/14/2022] [Indexed: 01/19/2023] Open
Abstract
Weather Normalized Models (WNMs) are modeling methods used for assessing air contaminants under a business-as-usual (BAU) assumption. Therefore, WNMs are used to assess the impact of many events on urban pollution. Recently, different approaches have been implemented to develop WNMs and quantify the lockdown effects of COVID-19 on air quality, including Machine Learning (ML). However, more advanced methods, such as Deep Learning (DL), have never been applied for developing WNMs. In this study, we proposed WNMs based on DL algorithms, aiming to test five DL architectures and compare their performances to a recent ML approach, namely Gradient Boosting Machine (GBM). The concentrations of five air pollutants (CO, NO2, PM2.5, SO2, and O3) are studied in the city of Quito, Ecuador. The results show that Long-Short Term Memory (LSTM) and Bidirectional Recurrent Neural Network (BiRNN) outperform the other algorithms and, consequently, are recommended as appropriate WNMs to quantify the effects of the lockdowns on air pollution. Furthermore, examining the variable importance in the LSTM and BiRNN models, we identify that the most relevant temporal and meteorological features for predicting air quality are Hours (time of day), Index (1 is the first collected data and increases by one after each instance), Julian Day (day of the year), Relative Humidity, Wind Speed, and Solar Radiation. During the full lockdown, the concentration of most pollutants has decreased drastically: −48.75%, for CO, −45.76%, for SO2, −42.17%, for PM2.5, and −63.98%, for NO2. The reduction of this latter gas has induced an increase of O3 by +26.54%.
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Affiliation(s)
- Phuong N. Chau
- School of Information and Engineering, Dalarna University, Falun, Sweden
- *Correspondence: Phuong N. Chau
| | - Rasa Zalakeviciute
- Grupo de Biodiversidad Medio Ambiente y Salud, Universidad de Las Américas, Quito, Ecuador
| | - Ilias Thomas
- School of Information and Engineering, Dalarna University, Falun, Sweden
| | - Yves Rybarczyk
- School of Information and Engineering, Dalarna University, Falun, Sweden
- Yves Rybarczyk
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Gu Y, Liu B, Dai Q, Zhang Y, Zhou M, Feng Y, Hopke PK. Multiply improved positive matrix factorization for source apportionment of volatile organic compounds during the COVID-19 shutdown in Tianjin, China. ENVIRONMENT INTERNATIONAL 2022; 158:106979. [PMID: 34991244 DOI: 10.1016/j.envint.2021.106979] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/13/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
Ambient concentrations of volatile organic compounds (VOCs) vary with emission rates, meteorology, and chemistry. Conventional positive matrix factorization (PMF) loses information because of dilution variations and chemical losses. Multiply improved PMF incorporates the ventilation coefficient, and total solar radiation or oxidants to reduce the effects of dispersion and chemical loss. These methods were applied to hourly speciated VOC data from November 2019 to March 2020 including during the COVID-19 shutdown. Various comparisons were made to assess the influences of these fluctuation drivers by time of day. Dispersion normalized PMF (DN-PMF) reduced the dispersion variations. Dispersion-radiation normalized PMF (DRN-PMF) reduced the impact of chemical loss, especially at night, which was better than Dispersion-Ox normalized PMF (DON-PMF). The conditional bivariate probability function (CBPF) plots of DRN-PMF results were consist with actual source locations. The DN-PMF, DRN-PMF, and DON-PMF results were consistent between 10:00 and 15:00, suggesting dispersion was significantly more influential than photochemical reactions during these times. The DRN-PMF results indicated that the highest VOC contributors during the COVID-19 shutdown were liquefied petroleum gas (LPG) (28.8%), natural gas (25.2%), and pulverized coal boilers emissions (19.6%). Except for petrochemical-related enterprises and LPG, the contribution concentrations of all other sources decreased substantially during the COVID-19 shutdown, by 94.7%, 90.6%, and 86.8% for vehicle emissions, gasoline evaporation, and the mixed source of diesel evaporation and solvent use, respectively. Controlling the use of motor vehicles and related volatilization of diesel fuel and gasoline can be effective in controlling VOCs in the future.
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Affiliation(s)
- Yao Gu
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300350, China
| | - Baoshuang Liu
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300350, China.
| | - Qili Dai
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300350, China
| | - Yufen Zhang
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300350, China
| | - Ming Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yinchang Feng
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300350, China
| | - Philip K Hopke
- Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA; Institute for a Sustainable Environment, Clarkson University, Potsdam, NY 13699, USA
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García-Dalmau M, Udina M, Bech J, Sola Y, Montolio J, Jaén C. Pollutant Concentration Changes During the COVID-19 Lockdown in Barcelona and Surrounding Regions: Modification of Diurnal Cycles and Limited Role of Meteorological Conditions. BOUNDARY-LAYER METEOROLOGY 2021; 183:273-294. [PMID: 34975160 PMCID: PMC8711231 DOI: 10.1007/s10546-021-00679-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/11/2021] [Indexed: 06/01/2023]
Abstract
One of the consequences of the COVID-19 lockdowns has been the modification of the air quality in many cities around the world. This study focuses on the variations in pollutant concentrations and how important meteorological conditions were for those variations in Barcelona and the surrounding area during the 2020 lockdown. Boundary-layer height, wind speed, and precipitation were compared between mid-March and April 2016-2019 (pre-lockdown) and the same period in 2020 (during lockdown). The results show the limited influence of meteorological factors on horizontal and vertical dispersion conditions. Compared with the pre-lockdown period, during lockdown the boundary-layer height slightly increased by between 5% and 9%, mean wind speed was very similar, and the fraction of days with rainfall increased only marginally, from 0.33 to 0.34, even though April 2020 was extremely wet in the study area. Variations in nitrogen dioxide ( NO 2 ), particulate matter with a diameter less than 10 μ m (PM10), and ozone ( O 3 ) concentrations over a 10-year period showed a 66% reduction in NO 2 , 37% reduction in PM10, and 27% increase in O 3 at a traffic station in Barcelona. The differences in the daily concentration cycle between weekends and weekdays were heavily smoothed for all pollutants considered. The afternoon NO 2 peak at the traffic station was suppressed compared with the average daily cycle. The analysis of ozone was extended to the regional scale, revealing lower concentrations at rural sites and higher ones in urban zones, especially in Barcelona and the surrounding area. The results presented not only complement previous air quality COVID-19 lockdown studies but also provide insights into the effects of road-traffic reduction.
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Affiliation(s)
- Miguel García-Dalmau
- Departament de Física Aplicada–Meteorologia, Universitat de Barcelona, Barcelona, Spain
| | - Mireia Udina
- Departament de Física Aplicada–Meteorologia, Universitat de Barcelona, Barcelona, Spain
| | - Joan Bech
- Departament de Física Aplicada–Meteorologia, Universitat de Barcelona, Barcelona, Spain
| | - Yolanda Sola
- Departament de Física Aplicada–Meteorologia, Universitat de Barcelona, Barcelona, Spain
| | - Joan Montolio
- Departament de Física Aplicada–Meteorologia, Universitat de Barcelona, Barcelona, Spain
- DT Catalonia, AEMET, Barcelona, Spain
| | - Clara Jaén
- Departament de Física Aplicada–Meteorologia, Universitat de Barcelona, Barcelona, Spain
- Institute of Environmental Assessment and Water Research (IDAEACSIC), Barcelona, Spain
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10
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Liu C, Shi K. A review on methodology in O 3-NOx-VOC sensitivity study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 291:118249. [PMID: 34600066 DOI: 10.1016/j.envpol.2021.118249] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/26/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Gaining insight into the response of surface ozone (O3) formation to its precursors plays an important role in the policy-making of O3 pollution control. However, the real atmosphere is an open and dissipative system, and its complexity poses a great challenge to the study of nonlinear relations between O3 and its precursors. At present, model-based methods based on reductionism try to restore the real atmospheric photochemical system, by coupling meteorological model and chemical transport model in temporal and spatial resolution completely. Nevertheless, large inconsistencies between predictions and true values still exist, due to the great uncertainty originated from emission inventory, photochemical reaction mechanism and meteorological factors. Recently, based on field observations, some nonlinear methods have successfully revealed the complex emergent properties (long-term persistence, multi-fractal, etc) in coupling correlation between O3 and its precursors at different time scales. The emergent properties are closely associated with the intrinsic dynamics of atmospheric photochemical system. Taking them into account when building O3 prediction model, is helpful to reduce the uncertainty in the results. Nonlinear methods (fractal, chaos, etc) based on holism can give new insights into the nonlinear relations between O3 and its precursors. Changes of thinking models in methodology are expected to improve the precision of forecasting O3 concentration. This paper has reviewed the advances of different methods for studying the sensitivity of O3 formation to its precursors during the past few decades. This review highlights that it is necessary to incorporate the emergent properties obtained by nonlinear methods into the modern models, for assessing O3 formation under combined air pollution environment more accurately. Moreover, the scaling property of coupling correlation detected in the real observations of O3 and its precursors could be used to test and improve the simulation performance of modern models.
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Affiliation(s)
- Chunqiong Liu
- College of Environmental Sciences and Engineering, China West Normal University, Nanchong, Sichuan, China; College of Biology and Environmental Sciences, Jishou University, Jishou, Hunan, China
| | - Kai Shi
- College of Environmental Sciences and Engineering, China West Normal University, Nanchong, Sichuan, China; College of Biology and Environmental Sciences, Jishou University, Jishou, Hunan, China.
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11
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El-Sayed MMH, Elshorbany YF, Koehler K. On the impact of the COVID-19 pandemic on air quality in Florida. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 285:117451. [PMID: 34082371 PMCID: PMC8802355 DOI: 10.1016/j.envpol.2021.117451] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/14/2021] [Accepted: 05/21/2021] [Indexed: 05/21/2023]
Abstract
Since early 2020, the world has faced an unprecedented pandemic caused by the novel COVID-19 virus. In this study, we characterize the impact of the lockdown associated with the pandemic on air quality in six major cities across the state of Florida, namely: Jacksonville, Tallahassee, Gainesville, Orlando, Tampa, and Miami. Hourly measurements of PM2.5, ozone, NO2, SO2, and CO were provided by the US EPA at thirty sites operated by the Florida Department of Environmental Protection during mid-February to mid-April from 2015 through 2020. To analyze the effect of the pandemic, atmospheric pollutant concentrations in 2020 were compared to historic data at these cities during the same period from 2015 to 2019. Reductions in NO2 and CO levels were observed across the state in most cities and were attributed to restrictions in mobility and the decrease in vehicle usage amid the lockdown. Likewise, decreases in O3 concentrations were observed and were related to the prevailing NOx-limited regime during this time period. Changes in concentrations of SO2 exhibited spatial variations, concentrations decreased in northern cities, however an increase was observed in central and southern cities, likely due to increased power generation at facilities primarily in the central and southern regions of the state. PM2.5 levels varied temporally during the study and were positively correlated with SO2 concentrations during the lockdown. In March, reductions in PM2.5 levels were observed, however elevations in PM2.5 concentrations in April were attributed to long-range transport of pollutants rather than local emissions. This study provides further insight into the impacts of the COVID-19 pandemic on anthropogenic sources from vehicular emissions and power generation in Florida. This work has implications for policies and regulations of vehicular emissions as well as consequences on the use of sustainable energy sources in the state.
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Affiliation(s)
- Marwa M H El-Sayed
- Department of Civil Engineering, Embry-Riddle Aeronautical University, Daytona Beach, 32114, USA.
| | - Yasin F Elshorbany
- College of Arts & Sciences, University of South Florida, St. Petersburg, FL, 33701, USA
| | - Kirsten Koehler
- Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
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12
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Abstract
The outbreak of the COVID-19 pandemic has emerged as a serious public health threat and has had a tremendous impact on all spheres of the environment. The air quality across the world improved because of COVID-19 lockdowns. Since the outbreak of COVID-19, large numbers of studies have been carried out on the impact of lockdowns on air quality around the world, but no studies have been carried out on the systematic review on the impact of lockdowns on air quality. This study aims to systematically assess the bibliographic review on the impact of lockdowns on air quality around the globe. A total of 237 studies were identified after rigorous review, and 144 studies met the criteria for the review. The literature was surveyed from Scopus, Google Scholar, PubMed, Web of Science, and the Google search engine. The results reveal that (i) most of the studies were carried out on Asia (about 65%), followed by Europe (18%), North America (6%), South America (5%), and Africa (3%); (ii) in the case of countries, the highest number of studies was performed on India (29%), followed by China (23%), the U.S. (5%), the UK (4%), and Italy; (iii) more than 60% of the studies included NO2 for study, followed by PM2.5 (about 50%), PM10, SO2, and CO; (iv) most of the studies were published by Science of the Total Environment (29%), followed by Aerosol and Air Quality Research (23%), Air Quality, Atmosphere & Health (9%), and Environmental Pollution (5%); (v) the studies reveal that there were significant improvements in air quality during lockdowns in comparison with previous time periods. Thus, this diversified study conducted on the impact of lockdowns on air quality will surely assist in identifying any gaps, as it outlines the insights of the current scientific research.
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13
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Pakkattil A, Muhsin M, Varma MKR. COVID-19 lockdown: Effects on selected volatile organic compound (VOC) emissions over the major Indian metro cities. URBAN CLIMATE 2021; 37:100838. [PMID: 33850699 PMCID: PMC8030744 DOI: 10.1016/j.uclim.2021.100838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/12/2021] [Accepted: 04/05/2021] [Indexed: 05/04/2023]
Abstract
Due to the COVID-19 pandemic, many countries across the world, including India, have imposed nationwide lockdowns to contain the spread of the virus. Many studies reported that the air quality had improved much due to the lockdown. This study examines the variation of Volatile Organic Compounds (VOCs) over the Indian metropolitan cities during the lockdown period by using ground-based and satellite observations. Ground-based BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) measurements from various metropolitan cities have shown a drastic drop of about 82% in the first phase of lockdown when compared with the pre-lockdown period. Whereas the spatial distribution of formaldehyde (HCHO), obtained from the TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinal-5P satellite, did not show any significant variation due to COVID-19 lockdown, indicating the major source of HCHO is biogenic or pyrogenic. The BTEX ratios were evaluated for a better understanding of the source and photochemical age of the air samples. The ozone forming potential of BTEX in all locations was found reduced; however, the corresponding decrease in ozone concentrations was not observed. The increase in ozone concentrations during the same period indicates alternative sources contributing to ozone formation.
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Affiliation(s)
- Anoop Pakkattil
- Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
| | - M Muhsin
- Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
| | - M K Ravi Varma
- Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
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14
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Kolluru SSR, Patra AK, Nazneen, Shiva Nagendra SM. Association of air pollution and meteorological variables with COVID-19 incidence: Evidence from five megacities in India. ENVIRONMENTAL RESEARCH 2021; 195:110854. [PMID: 33561448 PMCID: PMC7866844 DOI: 10.1016/j.envres.2021.110854] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/27/2021] [Accepted: 02/03/2021] [Indexed: 08/15/2023]
Abstract
Although lockdown of the industrial and transport sector and stay at home advisories to counter the COVID-19 pandemic have shown that the air quality has improved during this time, very little is known about the role of ambient air pollutants and meteorology in facilitating its transmission. This paper presents the findings from a study that was conducted to evaluate whether air quality index (AQI), three primary pollutants (PM2.5, PM10 and CO), Ground level ozone (O3) and three meteorological variables (temperature, relative humidity, wind speed) have promoted the COVID-19 transmission in five megacities of India. The results show significant correlation of PM2.5, PM10, CO, O3 concentrations, AQI and meteorological parameters with the confirmed cases and deaths during the lockdown period. Among the meteorological variables considered, temperature strongly correlated with the COVID-19 cases and deaths during the lockdown (r=0.54;0.25) and unlock period (r=0.66;0.25). Among the pollutants, ozone, and among the meteorological variables, temperature, explained the highest variability, up to 34% and 30% respectively, for COVID-19 confirmed cases and deaths. AQI was not a significant parameter for explaining the variations in confirmed and death cases. WS and RH could explain 10-11% and 4-6% variations of COVID-19 cases. A GLM model could explain 74% and 35% variability for confirmed cases and deaths during the lockdown and 66% and 19% variability during the unlock period. The results suggest that meteorological parameters may have promoted the COVID-19 incidences, especially the confirmed cases. Our findings may encourage future studies to explore more about the role of ambient air pollutants and meteorology on transmission of COVID-19 and similar infectious diseases.
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Affiliation(s)
- Soma Sekhara Rao Kolluru
- School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, India
| | - Aditya Kumar Patra
- Department of Mining Engineering, Indian Institute of Technology Kharagpur, India.
| | - Nazneen
- School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, India
| | - S M Shiva Nagendra
- Department of Civil Engineering, Indian Institute of Technology Madras, India
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15
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Gaubert B, Bouarar I, Doumbia T, Liu Y, Stavrakou T, Deroubaix A, Darras S, Elguindi N, Granier C, Lacey F, Müller J, Shi X, Tilmes S, Wang T, Brasseur GP. Global Changes in Secondary Atmospheric Pollutants During the 2020 COVID-19 Pandemic. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2021; 126:e2020JD034213. [PMID: 34230871 PMCID: PMC8250227 DOI: 10.1029/2020jd034213] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/15/2021] [Accepted: 03/21/2021] [Indexed: 05/08/2023]
Abstract
We use the global Community Earth System Model to investigate the response of secondary pollutants (ozone O3, secondary organic aerosols SOA) in different parts of the world in response to modified emissions of primary pollutants during the COVID-19 pandemic. We quantify the respective effects of the reductions in NOx and in volatile organic carbon (VOC) emissions, which, in most cases, affect oxidants in opposite ways. Using model simulations, we show that the level of NOx has been reduced by typically 40% in China during February 2020 and by similar amounts in many areas of Europe and North America in mid-March to mid-April 2020, in good agreement with space and surface observations. We show that, relative to a situation in which the emission reductions are ignored and despite the calculated increase in hydroxyl and peroxy radicals, the ozone concentration increased only in a few NOx-saturated regions (northern China, northern Europe, and the US) during the winter months of the pandemic when the titration of this molecule by NOx was reduced. In other regions, where ozone is NOx-controlled, the concentration of ozone decreased. SOA concentrations decrease in response to the concurrent reduction in the NOx and VOC emissions. The model also shows that atmospheric meteorological anomalies produced substantial variations in the concentrations of chemical species during the pandemic. In Europe, for example, a large fraction of the ozone increase in February 2020 was associated with meteorological anomalies, while in the North China Plain, enhanced ozone concentrations resulted primarily from reduced emissions of primary pollutants.
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Affiliation(s)
- Benjamin Gaubert
- National Center for Atmospheric ResearchAtmospheric Chemistry Observations and Modeling LaboratoryBoulderCOUSA
| | - Idir Bouarar
- Environmental Modeling GroupMax Planck Institute for MeteorologyHamburgGermany
| | | | - Yiming Liu
- Department of Civil and Environmental EngineeringThe Hong Kong Polytechnic UniversityHong KongChina
| | | | - Adrien Deroubaix
- Environmental Modeling GroupMax Planck Institute for MeteorologyHamburgGermany
| | | | | | - Claire Granier
- Laboratoire d’AérologieUniversité de ToulouseCNRSUPSFrance
- NOAA Chemical Sciences Laboratory/CIRESUniversity of ColoradoBoulderCOUSA
| | - Forrest Lacey
- National Center for Atmospheric ResearchAtmospheric Chemistry Observations and Modeling LaboratoryBoulderCOUSA
| | | | - Xiaoqin Shi
- Environmental Modeling GroupMax Planck Institute for MeteorologyHamburgGermany
| | - Simone Tilmes
- National Center for Atmospheric ResearchAtmospheric Chemistry Observations and Modeling LaboratoryBoulderCOUSA
| | - Tao Wang
- Department of Civil and Environmental EngineeringThe Hong Kong Polytechnic UniversityHong KongChina
| | - Guy P. Brasseur
- National Center for Atmospheric ResearchAtmospheric Chemistry Observations and Modeling LaboratoryBoulderCOUSA
- Environmental Modeling GroupMax Planck Institute for MeteorologyHamburgGermany
- Department of Civil and Environmental EngineeringThe Hong Kong Polytechnic UniversityHong KongChina
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16
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Latif MT, Dominick D, Hawari NSSL, Mohtar AAA, Othman M. The concentration of major air pollutants during the movement control order due to the COVID-19 pandemic in the Klang Valley, Malaysia. SUSTAINABLE CITIES AND SOCIETY 2021; 66:102660. [PMID: 33520606 PMCID: PMC7833430 DOI: 10.1016/j.scs.2020.102660] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/05/2020] [Accepted: 12/12/2020] [Indexed: 05/04/2023]
Abstract
The COVID-19 pandemic forced many governments across the world to implement some form of lockdown to minimalize the spread of the virus. On 18th March 2020, the Malaysian government put into action an enforced movement control order (MCO) to reduce the numbers of infections. This study aims to investigate the concentrations of air pollutants during the MCO in the Klang Valley. The concentrations of air pollutants were recorded by the continuous air quality monitoring system (CAQMS) operated by the Department of Environment. The results showed that there were significant reductions (p < 0.05) of PM10, PM2.5, NO2 and CO during the MCO compared with the same periods in 2019 and 2018. The highest percentage of reduction during the MCO was recorded by NO2 with a percentage reduction of between -55 % and -72 %. O3 concentrations at several stations showed an increase due to the reductions of its precursors such as NO. Further investigation using diurnal patterns of air pollutant concentrations both before and during the MCO showed that NO2 and CO were both reduced significantly during the rush hours, indicating the reduction in motor vehicles on the roads as a consequence of the MCO influenced the levels of these pollutants.
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Affiliation(s)
- Mohd Talib Latif
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
- Department of Environmental Health, Faculty of Public Health, Universitas Airlangga, 60115 Surabaya, Jawa Timur, Indonesia
| | - Doreena Dominick
- Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Nor Syamimi Sufiera Limi Hawari
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
| | - Anis Asma Ahmad Mohtar
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
| | - Murnira Othman
- Institute for Environment and Development (LESTARI), Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
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17
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The Status of Air Quality in the United States During the COVID-19 Pandemic: A Remote Sensing Perspective. REMOTE SENSING 2021. [DOI: 10.3390/rs13030369] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The recent COVID-19 pandemic has prompted global governments to take several measures to limit and contain the spread of the novel virus. In the United States (US), most states have imposed a partial to complete lockdown that has led to decreased traffic volumes and reduced vehicle emissions. In this study, we investigate the impacts of the pandemic-related lockdown on air quality in the US using remote sensing products for nitrogen dioxide tropospheric column (NO2), carbon monoxide atmospheric column (CO), tropospheric ozone column (O3), and aerosol optical depth (AOD). We focus on states with distinctive anomalies and high traffic volume, New York (NY), Illinois (IL), Florida (FL), Texas (TX), and California (CA). We evaluate the effectiveness of reduced traffic volume to improve air quality by comparing the significant reductions during the pandemic to the interannual variability (IAV) of a respective reference period for each pollutant. We also investigate and address the potential factors that might have contributed to changes in air quality during the pandemic. As a result of the lockdown and the significant reduction in traffic volume, there have been reductions in CO and NO2. These reductions were, in many instances, compensated by local emissions and, or affected by meteorological conditions. Ozone was reduced by varying magnitude in all cases related to the decrease or increase of NO2 concentrations, depending on ozone photochemical sensitivity. Regarding the policy impacts of this large-scale experiment, our results indicate that reduction of traffic volume during the pandemic was effective in improving air quality in regions where traffic is the main pollution source, such as in New York City and FL, while was not effective in reducing pollution events where other pollution sources dominate, such as in IL, TX and CA. Therefore, policies to reduce other emissions sources (e.g., industrial emissions) should also be considered, especially in places where the reduction in traffic volume was not effective in improving air quality (AQ).
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18
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Neale RE, Barnes PW, Robson TM, Neale PJ, Williamson CE, Zepp RG, Wilson SR, Madronich S, Andrady AL, Heikkilä AM, Bernhard GH, Bais AF, Aucamp PJ, Banaszak AT, Bornman JF, Bruckman LS, Byrne SN, Foereid B, Häder DP, Hollestein LM, Hou WC, Hylander S, Jansen MAK, Klekociuk AR, Liley JB, Longstreth J, Lucas RM, Martinez-Abaigar J, McNeill K, Olsen CM, Pandey KK, Rhodes LE, Robinson SA, Rose KC, Schikowski T, Solomon KR, Sulzberger B, Ukpebor JE, Wang QW, Wängberg SÅ, White CC, Yazar S, Young AR, Young PJ, Zhu L, Zhu M. Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020. Photochem Photobiol Sci 2021; 20:1-67. [PMID: 33721243 PMCID: PMC7816068 DOI: 10.1007/s43630-020-00001-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 11/10/2020] [Indexed: 01/31/2023]
Abstract
This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.
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Affiliation(s)
- R E Neale
- Population Health Department, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - P W Barnes
- Biological Sciences and Environmental Program, Loyola University New Orleans, New Orleans, LA, USA
| | - T M Robson
- Organismal and Evolutionary Biology (OEB), Viikki Plant Sciences Centre (ViPS), University of Helsinki, Helsinki, Finland
| | - P J Neale
- Smithsonian Environmental Research Center, Maryland, USA
| | - C E Williamson
- Department of Biology, Miami University, Oxford, OH, USA
| | - R G Zepp
- ORD/CEMM, US Environmental Protection Agency, Athens, GA, USA
| | - S R Wilson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, Australia
| | - S Madronich
- Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - A L Andrady
- Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - A M Heikkilä
- Finnish Meteorological Institute, Helsinki, Finland
| | - G H Bernhard
- Biospherical Instruments Inc, San Diego, CA, USA
| | - A F Bais
- Department of Physics, Laboratory of Atmospheric Physics, Aristotle University, Thessaloniki, Greece
| | - P J Aucamp
- Ptersa Environmental Consultants, Pretoria, South Africa
| | - A T Banaszak
- Unidad Académica de Sistemas Arrecifales, Universidad Nacional Autónoma de México, Puerto Morelos, México
| | - J F Bornman
- Food Futures Institute, Murdoch University, Perth, Australia.
| | - L S Bruckman
- Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - S N Byrne
- The University of Sydney, School of Medical Sciences, Discipline of Applied Medical Science, Sydney, Australia
| | - B Foereid
- Environment and Natural Resources, Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - D-P Häder
- Department of Biology, Friedrich-Alexander University, Möhrendorf, Germany
| | - L M Hollestein
- Department of Dermatology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - W-C Hou
- Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China
| | - S Hylander
- Centre for Ecology and Evolution in Microbial model Systems-EEMiS, Linnaeus University, Kalmar, Sweden.
| | - M A K Jansen
- School of BEES, Environmental Research Institute, University College Cork, Cork, Ireland
| | - A R Klekociuk
- Antarctic Climate Program, Australian Antarctic Division, Kingston, Australia
| | - J B Liley
- National Institute of Water and Atmospheric Research, Lauder, New Zealand
| | - J Longstreth
- The Institute for Global Risk Research, LLC, Bethesda, MD, USA
| | - R M Lucas
- National Centre of Epidemiology and Population Health, Australian National University, Canberra, Australia
| | - J Martinez-Abaigar
- Faculty of Science and Technology, University of La Rioja, Logroño, Spain
| | | | - C M Olsen
- Cancer Control Group, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - K K Pandey
- Department of Wood Properties and Uses, Institute of Wood Science and Technology, Bangalore, India
| | - L E Rhodes
- Photobiology Unit, Dermatology Research Centre, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - S A Robinson
- Securing Antarctica's Environmental Future, Global Challenges Program and School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, Australia
| | - K C Rose
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - T Schikowski
- IUF-Leibniz Institute of Environmental Medicine, Dusseldorf, Germany
| | - K R Solomon
- Centre for Toxicology, School of Environmental Sciences, University of Guelph, Guelph, Canada
| | - B Sulzberger
- Academic Guest Eawag: Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
| | - J E Ukpebor
- Chemistry Department, Faculty of Physical Sciences, University of Benin, Benin City, Nigeria
| | - Q-W Wang
- Institute of Applied Ecology, Chinese Academy of Sciences (CAS), Shenyang, China
| | - S-Å Wängberg
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - C C White
- Bee America, 5409 Mohican Rd, Bethesda, MD, USA
| | - S Yazar
- Garvan Institute of Medical Research, Sydney, Australia
| | - A R Young
- St John's Institute of Dermatology, King's College London, London, UK
| | - P J Young
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - L Zhu
- Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, China
| | - M Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, China
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