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Liu A, Chen Y, Shao Y, Huo Y, Li J, Li Z, Ma L, Li Q. Condensable and filterable particulate matter emitted from typical diesel vehicles in steady and transient driving conditions. JOURNAL OF HAZARDOUS MATERIALS 2024; 479:135716. [PMID: 39236543 DOI: 10.1016/j.jhazmat.2024.135716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 08/29/2024] [Accepted: 08/30/2024] [Indexed: 09/07/2024]
Abstract
Condensable particulate matter (CPM) and filterable particulate matter (FPM) emitted from industrial sources have been well studied, but their emissions from vehicles have not yet been covered. This study explores the emission characteristics of CPM and FPM from typical diesel vehicles under various driving conditions. The emission factors (EFs) of CPMs under driving conditions were 5.4-10.4 times higher than those of FPMs, while CPMs EFs under transient driving conditions were about 2.5 times higher than those under steady driving conditions. CPM and FPM are mainly composed of organic matter accounting for 53.3 %-92.9 %, while the intermediate and semi-volatile organic compounds dominate the organic matter accounting for 86.3 %-98.6 %. Similar to industrial sources, alkanes are the predominant organic species emitted by diesel vehicles, comprising 42.0 %-64.0 % of the detected organic components. Inorganic CPM is primarily composed of NH4+ , representing 84.9 %-87.6 % of the total, in contrast to industrial sources where SO42- and Cl- dominate. Interestingly, the air pollution control devices installed on diesel vehicles under steady driving conditions perform better in removing organic CPM and producing higher inorganic CPM emissions than those under transient driving conditions. These findings will enhance the comprehensive understanding of particulate matter emitted from diesel vehicles and provide a scientific foundation for the development of related control technologies.
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Affiliation(s)
- Anlin Liu
- College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, Sichuan 610065, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Yuanzheng Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Shanghai Institute of Eco-Chongming (SIEC), No 3663 Northern Zhongshan Road, Shanghai 200062, China
| | - Yuankai Shao
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology & Research Center, Co, Ltd, Tianjin 300300, China
| | - Yaoqiang Huo
- Key Laboratory of Environmental Pollution Control and Remediation at Universities of Inner Mongolia Autonomous Region, College of Resources and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Jianping Li
- College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, Sichuan 610065, China
| | - Zhenguo Li
- National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology & Research Center, Co, Ltd, Tianjin 300300, China
| | - Liang Ma
- College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, Sichuan 610065, China.
| | - Qing Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Shanghai Institute of Eco-Chongming (SIEC), No 3663 Northern Zhongshan Road, Shanghai 200062, China.
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Zhang J, Peng J, Song A, Du Z, Guo J, Liu Y, Yang Y, Wu L, Wang T, Song K, Guo S, Collins D, Mao H. Secondary Organic Aerosol Formation Potential from Vehicular Non-tailpipe Emissions under Real-World Driving Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5419-5429. [PMID: 38390902 DOI: 10.1021/acs.est.3c06475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Traffic emissions are a dominant source of secondary organic aerosol (SOA) in urban environments. Though tailpipe exhaust has drawn extensive attention, the impact of non-tailpipe emissions on atmospheric SOA has not been well studied. Here, a closure study was performed combining urban tunnel experiments and dynamometer tests using an oxidation flow reactor in situ photo-oxidation. Results show a significant gap between field and laboratory research; the average SOA formation potential from real-world fleet is 639 ± 156 mg kg fuel-1, higher than the reconstructed result (188 mg kg fuel-1) based on dynamometer tests coupled with fleet composition inside the tunnel. Considering the minimal variation of SOA/CO in emission standards, we also reconstruct CO and find the critical role of high-emitting events in the real-world SOA burden. Different profiles of organic gases are detected inside the tunnel than tailpipe exhaust, such as more abundant C6-C9 aromatics, C11-C16 species, and benzothiazoles, denoting contributions from non-tailpipe emissions to SOA formation. Using these surrogate chemical compounds, we roughly estimate that high-emitting, evaporative emission, and asphalt-related and tire sublimation share 14, 20, and 10% of the SOA budget, respectively, partially explaining the gap between field and laboratory research. These experimental results highlight the importance of non-tailpipe emissions to atmospheric SOA.
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Affiliation(s)
- Jinsheng Zhang
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Jianfei Peng
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Ainan Song
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Zhuofei Du
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300382, China
| | - Jiliang Guo
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Yan Liu
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Yicheng Yang
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Lin Wu
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Ting Wang
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Kai Song
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Song Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Don Collins
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, 1084 Columbia Avenue, Riverside, California 92507, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, California 92521, United States
| | - Hongjun Mao
- Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
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Giammona A, Remedia S, Porro D, Lo Dico A, Bertoli G. The biological interplay between air pollutants and miRNAs regulation in cancer. Front Cell Dev Biol 2024; 12:1343385. [PMID: 38434617 PMCID: PMC10905188 DOI: 10.3389/fcell.2024.1343385] [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: 11/23/2023] [Accepted: 01/18/2024] [Indexed: 03/05/2024] Open
Abstract
Air pollution, especially fine particulate matter (PM2.5, with an aerodynamic diameter of less than 2.5 μm), represents a risk factor for human health. Many studies, regarding cancer onset and progression, correlated with the short and/or long exposition to PM2.5. This is mainly mediated by the ability of PM2.5 to reach the pulmonary alveoli by penetrating into the blood circulation. This review recapitulates the methodologies used to study PM2.5 in cellular models and the downstream effects on the main molecular pathways implicated in cancer. We report a set of data from the literature, that describe the involvement of miRNAs or long noncoding RNAs on the main biological processes involved in oxidative stress, inflammation, autophagy (PI3K), cell proliferation (NFkB, STAT3), and EMT (Notch, AKT, Wnt/β-catenin) pathways. microRNAs, as well as gene expression profile, responds to air pollution environment modulating some key genes involved in epigenetic modification or in key mediators of the biological processes described below. In this review, we provide some scientific evidences about the thigh correlation between miRNAs dysregulation, PM2.5 exposition, and gene pathways involved in cancer progression.
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Affiliation(s)
- Alessandro Giammona
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Segrate, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Sofia Remedia
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Segrate, Italy
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Segrate, Italy
| | - Danilo Porro
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Segrate, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Alessia Lo Dico
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Segrate, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Gloria Bertoli
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Segrate, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
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Ghadimi S, Zhu H, Durbin TD, Cocker DR, Karavalakis G. Exceedances of Secondary Aerosol Formation from In-Use Natural Gas Heavy-Duty Vehicles Compared to Diesel Heavy-Duty Vehicles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19979-19989. [PMID: 37988584 DOI: 10.1021/acs.est.3c04880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
This work, for the first time, assessed the secondary aerosol formation from both in-use diesel and natural gas heavy-duty vehicles of different vocations when they were operated on a chassis dynamometer while the vehicles were exercised on different driving cycles. Testing was performed on natural gas vehicles equipped with three-way catalysts (TWCs) and diesel trucks equipped with diesel oxidation catalysts, diesel particulate filters, and selective catalytic reduction systems. Secondary aerosol was measured after introducing dilute exhaust into a 30 m3 environmental chamber. Particulate matter ranged from 0.18 to 0.53 mg/mile for the diesel vehicles vs 1.4-85 mg/mile for the natural gas vehicles, total particle number ranged from 4.01 × 1012 to 3.61 × 1013 for the diesel vehicles vs 5.68 × 1012-2.75 × 1015 for the natural gas vehicles, and nonmethane organic gas emissions ranged from 0.032 to 0.05 mg/mile for the diesel vehicles vs 0.012-1.35 mg/mile for the natural gas vehicles. Ammonia formation was favored in the TWC and was found in higher concentrations for the natural gas vehicles (ranged from ∼0 to 1.75 g/mile) than diesel vehicles (ranged from ∼0 to 0.4 g/mile), leading to substantial secondary ammonium nitrate formation (ranging from 8.5 to 98.8 mg/mile for the natural gas vehicles). For the diesel vehicles, one had a secondary ammonium nitrate of 18.5 mg/mile, while the other showed essentially no secondary ammonium nitrate formation. The advanced aftertreatment controls in diesel vehicles resulted in almost negligible secondary organic aerosol (SOA) formation (ranging from 0.046 to 2.04 mg/mile), while the natural gas vehicles led to elevated SOA formation that was likely sourced from the engine lubricating oil (ranging from 3.11 to 39.7 mg/mile). For two natural gas vehicles, the contribution of lightly oxidized lubricating oil in the primary organic aerosol was dominant (as shown in the mass spectra analysis), leading to enhanced SOA mass. Heavily oxidized lubricating oil was also observed to contribute to the SOA formation for other natural gas vehicles.
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Affiliation(s)
- Sahar Ghadimi
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, 1084 Columbia Avenue, Riverside, California 92507, United States
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Hanwei Zhu
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, 1084 Columbia Avenue, Riverside, California 92507, United States
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Thomas D Durbin
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, 1084 Columbia Avenue, Riverside, California 92507, United States
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - David R Cocker
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, 1084 Columbia Avenue, Riverside, California 92507, United States
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Georgios Karavalakis
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, 1084 Columbia Avenue, Riverside, California 92507, United States
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
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Ho CS, Peng J, Lv Z, Sun B, Yang L, Zhang J, Guo J, Zhang Q, Du Z, Mao H. Tunnel measurements reveal significant reduction in traffic-related light-absorbing aerosol emissions in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159212. [PMID: 36206905 DOI: 10.1016/j.scitotenv.2022.159212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/23/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Light-absorbing aerosols (LAA), including black carbon (BC) and brown carbon (BrC), profoundly impact regional and global climate. Vehicle emission is an important source of LAA in urban areas, but real-world emission features of LAA from the urban vehicle fleet are not fully understood. This study evaluates traffic-related BC and BrC emission factors (EFs) and their vehicular emission inventories via road tunnel measurements in Tianjin, China, in 2017 and 2021. The distance-based and fuel-based EFs of BC for the mixed fleet were 1.05 ± 1.28 mg km-1 veh-1 and 0.057 ± 0.057 g (kg-fuel)-1, respectively, in 2021, with a dramatic decrease of 80.6 % compared to those in 2017. The BC EFs for gasoline vehicles (GVs, including traditional gasoline and hybrid vehicles) and diesel vehicles (DVs) were 0.55 ± 0.065 mg km-1 veh-1 and 10.5 ± 2.52 mg km-1 veh-1, respectively, in 2021. Compared to 2017, the BrC EFs also decreased significantly in 2021, by 10.8-53.6 %, with 0.32 ± 0.45 mg km-1 veh-1 and 0.018 ± 0.020 g (kg-fuel)-1 of distance-based and fuel-based EFs for mixed fleet. The BrC EFs for GVs and DVs were 0.091 ± 0.024 mg km-1 veh-1 and 3.06 ± 0.91 mg km-1 veh-1, respectively, in 2021. Based on the BC and BrC EFs for GVs and DVs and annual mileage for each vehicle category, the annual vehicular LAA emission inventories were estimated. From 2017 to 2021, the annual vehicular LAA emissions in Tianjin have been significantly reduced, by 69 % for BC and 10 % for BrC. DVs account for a small amount of the vehicle population (8.4 %), but contribute to most of the BC (83 %) and BrC (86 %). Our study demonstrates the significant reduction of vehicular light-absorbing aerosols emission due to vehicle pollution prevention and control in China.
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Affiliation(s)
- Chung Song Ho
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China; High-Tech Research and Development Center, Kim Il Sung University, Pyongyang 999093, Democratic People's Republic of Korea
| | - Jianfei Peng
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
| | - Zongyan Lv
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Bin Sun
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Lei Yang
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Jinsheng Zhang
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Jiliang Guo
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Qijun Zhang
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Zhuofei Du
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Hongjun Mao
- Tianjin Key Laboratory of Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
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Lau YS, Poon HY, Organ B, Chuang HC, Chan MN, Guo H, Ho SSH, Ho KF. Toxicological effects of fresh and aged gasoline exhaust particles in Hong Kong. JOURNAL OF HAZARDOUS MATERIALS 2023; 441:129846. [PMID: 36063712 DOI: 10.1016/j.jhazmat.2022.129846] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Exhaust emissions from gasoline vehicles are one of the major contributors to aerosol particles observed in urban areas. It is well-known that these tiny particles are associated with air pollution, climate forcing, and adverse health effects. However, their toxicity and bioreactivity after atmospheric ageing are less constrained. The aim of the present study was to investigate the chemical and toxicological properties of fresh and aged particulate matter samples derived from gasoline exhaust emissions. Chemical analyses showed that both fresh and aged PM samples were rich in organic carbon, and the dominating chemical species were n-alkane and polycyclic aromatic hydrocarbons. Comparisons between fresh and aged samples revealed that the latter contained larger amounts of oxygenated compounds. In most cases, the bioreactivity induced by the aged PM samples was significantly higher than that induced by the fresh samples. Moderate to weak correlations were identified between chemical species and the levels of biomarkers in the fresh and aged PM samples. The results of the stepwise regression analysis suggested that n-alkane and alkenoic acid were major contributors to the increase in lactate dehydrogenase (LDH) levels in the fresh samples, while polycyclic aromatic hydrocarbons (PAHs) and monocarboxylic acid were the main factors responsible for such increase in the aged samples.
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Affiliation(s)
- Yik-Sze Lau
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong; Now at: International Laboratory of Air Quality and Health (ILAQR), Queensland University of Technology, Australia
| | - Hon-Yin Poon
- Earth System Science Programme, The Chinese University of Hong Kong, Hong Kong
| | - Bruce Organ
- Jockey Club Heavy Vehicle Emissions Testing and Research Centre, Hong Kong, China
| | - Hsiao-Chi Chuang
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei 110, Taiwan, ROC
| | - Man-Nin Chan
- Earth System Science Programme, The Chinese University of Hong Kong, Hong Kong
| | - Hai Guo
- Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hong Kong
| | - Steven Sai Hang Ho
- Division of Atmosphere Sciences, Desert Research Institute, Reno, NV 89512, United States; Hong Kong Premium Services and Research Laboratory, Cheung Sha Wan, Kowloon, Hong Kong, China
| | - Kin-Fai Ho
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong.
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Sha Q, Liu X, Yuan Z, Zheng J, Lou S, Wang H, Li X, Yu F. Upgrading Emission Standards Inadvertently Increased OH Reactivity from Light-Duty Diesel Truck Exhaust in China: Evidence from Direct LP-LIF Measurement. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:9968-9977. [PMID: 35770386 DOI: 10.1021/acs.est.2c02944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Vehicular exhaust is an important source of reactive gases responsible for the formation of ozone and secondary organic aerosols (SOAs) in the atmosphere. Although significant efforts have been made to characterize the chemical compounds associated with vehicular exhaust, there is still a wealth of compounds that are unable to be detected, posing uncertainties in estimating their contribution to atmospheric reactivity. In this study, by improving laser-induced fluorescence techniques, we achieved the first-ever direct measurement of the total OH reactivity (TOR) from light-duty diesel truck (LDDT) exhaust with different emission standards. We found that the TOR from the LDDT exhaust was 80-130 times the TOR from the gasoline exhaust measured in Japan. Unexpectedly, we discovered increased TOR emissions along with upgrading emission standards, possibly as a collective result of high combustion temperature in the engine and the oxidation catalysts in the exhaust after-treatment that favor production of highly oxidized organics in the stricter emission standard. Most of these oxidized organics are unable to be speciated by routine measurements, resulting in the missing OH reactivity increasing rapidly from 1.91% for China III to 42.0% for China V LDDT. Upgrading the emission standard failed to reduce the TOR from LDDT exhaust, which may inadvertently promote the contribution of LDDT to the formation of ozone and SOA pollution in China.
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Affiliation(s)
- Qing'e Sha
- Institute of Environmental and Climate Research, Jinan University, Guangzhou 510632, China
| | - Xuehui Liu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Zibing Yuan
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Junyu Zheng
- Institute of Environmental and Climate Research, Jinan University, Guangzhou 510632, China
| | - Shengrong Lou
- State Environmental Protection Key Laboratory of the Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Hongli Wang
- State Environmental Protection Key Laboratory of the Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Xin Li
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China
| | - Fei Yu
- Institute of Environmental and Climate Research, Jinan University, Guangzhou 510632, China
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