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Yin H, Liu C, Hu Q, Liu T, Wang S, Gao M, Xu S, Zhang C, Su W. Opposite impact of emission reduction during the COVID-19 lockdown period on the surface concentrations of PM 2.5 and O 3 in Wuhan, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 289:117899. [PMID: 34358865 PMCID: PMC8326756 DOI: 10.1016/j.envpol.2021.117899] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/26/2021] [Accepted: 08/01/2021] [Indexed: 05/28/2023]
Abstract
To prevent the spread of the COVID-19 epidemic, the Chinese megacity Wuhan has taken emergent lockdown measures starting on January 23, 2020. This provided a natural experiment to investigate the response of air quality to such emission reductions. Here, we decoupled the influence of meteorological and non-meteorological factors on main air pollutants using generalized additive models (GAMs), driven by data from the China National Environmental Monitoring Center (CNEMC) network. During the lockdown period (Jan. 23 - Apr. 8, 2020), PM2.5, PM10, NO2, SO2, and CO concentrations decreased significantly by 45 %, 49 %, 56 %, 39 %, and 18 % compared with the corresponding period in 2015-2019, with contributions by S(meteos) of 15 %, 17 %, 13 %, 10 %, and 6 %. This indicates an emission reduction of NOx at least 43 %. However, O3 increased by 43 % with a contribution by S(meteos) of 6 %. In spite of the reduced volatile organic compound (VOC) emissions by 30 % during the strict lockdown period (Jan. 23 - Feb. 14, 2020), which likely reduced the production of O3, O3 concentrations increased due to a weakening of the titration effect of NO. Our results suggest that conventional emission reduction (NOx reduction only) measures may not be sufficient to reduce (or even lead to an increase of) surface O3 concentrations, even if reaching the limit, and VOC-specific measures should also be taken.
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Affiliation(s)
- Hao Yin
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Cheng Liu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei, 230026, China; Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, 230026, China.
| | - Qihou Hu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Ting Liu
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Shuntian Wang
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Meng Gao
- Department of Geography, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Shiqi Xu
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Chengxin Zhang
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Wenjing Su
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
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Cieslik S. Ozone fluxes over various plant ecosystems in Italy: a review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:1487-1496. [PMID: 19027210 DOI: 10.1016/j.envpol.2008.09.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 09/26/2008] [Accepted: 09/27/2008] [Indexed: 05/27/2023]
Abstract
Among air pollutants, ozone is the most important stressor to vegetation, which undergoes damage and biomass reduction after penetration of ozone molecules into the leaf tissues through the stomata. Stomatal ozone fluxes are considered the governing factor needed to assess risk to plant health due to ozone. Although this parameter may be calculated by modeling, direct measurements are scarce. Moreover, southern European situations, especially regarding Italy, require special attention due to the decoupling between ozone concentrations and fluxes. This work reviews ozone flux measurements made during the last 15 years through Italy.
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Affiliation(s)
- S Cieslik
- Joint Research Centre, I-21027 Ispra, Italy.
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Carnevale C, Decanini E, Volta M. Design and validation of a multiphase 3D model to simulate tropospheric pollution. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 390:166-176. [PMID: 17963821 DOI: 10.1016/j.scitotenv.2007.09.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 08/29/2007] [Accepted: 09/06/2007] [Indexed: 05/25/2023]
Abstract
This work presents the Transport and Chemical Aerosol Model (TCAM) formulation and its validation in the frame of CityDelta-CAFE project. TCAM is a 3D eulerian multiphase model simulating tropospheric secondary pollution at mesoscale. It is included in the GAMES (Gas Aerosol Modelling Evaluation System) modelling system, designed to support the analysis of secondary pollution dynamics and to assess the impact of emission control strategies. The presented validation assessment has been performed in the frame of the CityDelta II project over the Milan domain and concerns both gas and aerosol 1999 simulations. Ozone, nitrogen oxides and aerosol computed and observed patterns have been compared and analysed by means of statistical indicators showing high model performances for both winter and summer pollution regimes.
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Affiliation(s)
- Claudio Carnevale
- Department of Electronics for the Automation, University of Brescia, Via Branze 38, I-25123 Brescia, Italy.
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Liu L, Andreani-Aksoyoglu S, Keller J, Ordóñez C, Junkermann W, Hak C, Braathen GO, Reimann S, Astorga-Llorens C, Schultz M, Prévôt ASH, Isaksen ISA. A photochemical modeling study of ozone and formaldehyde generation and budget in the Po basin. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd008172] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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