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Deng L, Liu X. Features of extreme PM 2.5 pollution and its influencing factors: evidence from China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:892. [PMID: 39230774 DOI: 10.1007/s10661-024-12990-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 08/08/2024] [Indexed: 09/05/2024]
Abstract
Extreme PM 2.5 pollution has become a significant environmental problem in China in recent years, which is hazardous to human health and daily life. Noticing the importance of investigating the causes of extreme PM 2.5 pollution, this paper classifies cities across China into eight categories (four groups plus two scenarios) based on the generalized extreme value (GEV) distribution using hourly station-level PM 2.5 concentration data, and a series of multi-choice models are employed to assess the probabilities that cities fall into different categories. Various factors such as precursor pollutants and socio-economic factors are considered after controlling for meteorological conditions in each model. It turns out that SO 2 concentration, NO 2 concentration, and population density are the top three factors contributing most to the log ratios. Moreover, in both left- and right-skewed cases, the influence of a one-unit increase of SO 2 concentration on the relative probability of cities falling into different groups shows an increasing trend, while those of NO 2 concentration show a decreasing trend. At the same time, the higher the extreme pollution level, the bigger the effect of SO 2 and NO 2 concentrations on the probability of cities falling into normalized scenarios. The multivariate logit model is used for prediction and policy simulations. In summary, by analyzing the influences of various factors and the heterogeneity of their influence patterns, this paper provides valuable insights in formulating effective emission reduction policies.
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Affiliation(s)
- Lu Deng
- School of Statistics and Mathematics, Central University of Finance and Economics, Beijing, 100081, China
| | - Xinzhu Liu
- School of Statistics and Mathematics, Central University of Finance and Economics, Beijing, 100081, China.
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Fu X, Wang X, Liu T, He Q, Zhang Z, Zhang Y, Song W, Dai Q, Chen S, Dong F. Secondary inorganic aerosols and aerosol acidity at different PM 2.5 pollution levels during winter haze episodes in the Sichuan Basin, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170512. [PMID: 38286278 DOI: 10.1016/j.scitotenv.2024.170512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 01/31/2024]
Abstract
Wintertime fine particle (PM2.5) pollution remains to be perplexing air quality problems in many parts of China. In this study, PM2.5 compositions and aerosol acidity at different pollution levels at an urban cite in the southwest China's Sichuan Basin were investigated during a sustained winter haze episode. Organic matter was the most abundant component of PM2.5, followed by nitrate, sulfate and ammonium. Shares of organic aerosol in PM2.5 mass decreased with the elevated PM2.5 levels, while the enhancements of sulfate and secondary organic aerosol were much less than that of nitrate and ammonium during heavy pollution with increased ratios of nitrate to sulfate, implying a significant role of nitrate in the haze formation. Results also suggest the nighttime chemistry might contribute substantially to the formation of nitrate under severe pollutions. The daily average aerosol pH showed a decreasing trend with the elevated levels of PM2.5, and this increased aerosl acidity was mainly due to the fast rising secondary inorganic aerosol (SIA) concentration, with the increase in hydronium ion concentration in air (Hair+) surpassing the dilution effect of elevated aerosol liquid water content (LWC). Thermodynamic model calculations revealed that the air environment was NH3-rich with total NHx (NH3 + NH4+) greater than required NHx, and the aerosol pH exponentially declined with the decreasing excess NHx (p < 0.01). This study demonstrated that under air stagnation and NH3-rich environment during winter, the raised relative humidity (RH) would lead to an increase in LWC and thereby facilitate the aqueous chemistry processes with the neutralization capacity of NH3 to form sulfate and nitrate, which would further increase the LWC and lower the pH. This self-amplifying SIA formation might be crucial to the severe PM2.5 pollution and haze events during winter, and therefore cutting both NOx and NH3 emissions would benefit stopping the self-amplification.
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Affiliation(s)
- Xiaoxin Fu
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
| | - Tengyu Liu
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Quanfu He
- Institute for Energy and Climate Research, IEK-8, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Zhou Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Yanli Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Wei Song
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Qunwei Dai
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
| | - Shu Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
| | - Faqin Dong
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
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Feng X, Chen Y, Chen S, Peng Y, Liu Z, Jiang M, Feng Y, Wang L, Li L, Chen J. Dominant Contribution of NO 3 Radical to NO 3- Formation during Heavy Haze Episodes: Insights from High-Time Resolution of Dual Isotopes Δ 17O and δ 18O. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20726-20735. [PMID: 38035574 DOI: 10.1021/acs.est.3c07590] [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: 12/02/2023]
Abstract
δ18O is widely used to track nitrate (NO3-) formation but overlooks NO3 radical reactions with hydrocarbons (HCs), particularly in heavily emitting hazes. This study introduces high-time resolution Δ17O-NO3- as a powerful tool to quantify NO3- formation during five hazes in three cities. Results show significant differences between Δ17O-NO3- and δ18O-NO3- in identifying NO3- formation. δ18O-NO3- results suggested N2O5 hydrolysis (62.0-88.4%) as the major pathway of NO3- formation, while Δ17O-NO3- shows the NO3- formation contributions of NO2 + OH (17.7-66.3%), NO3 + HC (10.8-49.6%), and N2O5 hydrolysis (22.9-33.3%), revealing significant NO3 + HC contribution (41.7-56%) under severe pollution. Furthermore, NO3- formation varies with temperatures, NOx oxidation rate (NOR), and pollution levels. Higher NO2 + OH contribution and lower NO3 + HC contribution were observed at higher temperatures, except for low NOR haze where higher NO2 + OH contributions were observed at low temperatures (T ← 10 °C). This emphasizes the significance of NO2 + OH in emission-dominated haze. Contributions of NO2 + OH and NO3 + HC relate to NOR as positive (fP1 = 3.0*NOR2 - 2.4*NOR + 0.8) and negative (fP2 = -2.3*NOR2 + 1.8*NOR) quadratic functions, respectively, with min/max values at NOR = 0.4. At mild pollution, NO2 + OH (58.1 ± 22.2%) dominated NO3- formation, shifting to NO3 + HC (35.5 ± 16.3%) during severe pollution. Additionally, high-time resolution Δ17O-NO3- reveals that morning-evening rush hours and high temperatures at noon promote the contributions of NO3 + HC and NO2 + OH, respectively. Our results suggested that the differences in the NO3- pathway are attributed to temperatures, NOR, and pollution levels. Furthermore, high-time resolution Δ17O-NO3- is vital for quantifying NO3 + HC contribution during severe hazes.
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Affiliation(s)
- Xinxin Feng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
| | - Yingjun Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Shaofeng Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
| | - Yu Peng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
| | - Zeyu Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
| | - Minjun Jiang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yanli Feng
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Lina Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
| | - Li Li
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China
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Liu Z, Zhu W, Yan G, Bai L, Han J, Li J, Sun Y, Wang Y, Hu B. Exploring the formation mechanism of fine particles in an ex-heavily polluted Northwestern city, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161333. [PMID: 36623666 DOI: 10.1016/j.scitotenv.2022.161333] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/14/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Fine particle pollution is still a severe issue in the northwestern region of China where the formation mechanism of which remains ambiguous due to the limited studies there. In this study, a comprehensive study on the chemical composition and sources of PM2.5 at an ex-heavily polluted northwestern city was conducted, based on filter sampling data obtained from three consecutive winter campaigns during 2020-2022. The average PM2.5 during the three winter campaigns were 170.9 ± 66.4, 249.0 ± 75.7, and 200.9 ± 47.6 μg/m3, respectively, with the daily maximum value of PM2.5 exceeds 400 μg/m3 under stagnant meteorological conditions charactered by high relative humidity (>60 %) and low wind speed (<1 m/s). The major chemical components in PM2.5 were found to be inorganic aerosol (55.2 %) that mainly constituted by sulfate (24.2 %), and mineral dust (14.9 %); while the carbonous species contributed a minor fraction (∼13 %). In addition, (NH4)2SO4 and NH4NO3 were the dominate contributors to appearance of low visibility (<3 km) which together accounting for over 85 % of light extinction coefficient (bext) during heavy polluted period. Source appointment of fine particles was then conducted by applying the positive matrix factorization method, and the primary sources were resolved to be coal combustion (27.7 %) and biomass burning (18.6 %), followed by industrial dust (16.2 %), residential combustion (15.3 %), traffic emissions (11.9 %) and dust aerosol (10.4 %). To explore the potential formation mechanism of fine particle pollution, the chemical evolution pattern combined with gaseous pollutants and meteorological parameters were further analyzed, which refine the important role of primary emissions in the forming of high sulfate aerosol loading, while secondary formation was largely suppressed during the winter period that totally different from those reported in the developed regions of China, thus indicating more effort should be paid on the reduction of primary particles emissions in the northwestern cities than on its gaseous percussors.
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Affiliation(s)
- Zirui Liu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
| | - Weibin Zhu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangxuan Yan
- Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Henan Key Laboratory for Environmental Pollution Control, School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Lingyan Bai
- International Research Center of Big Data for Sustainable Development Goals, Beijing 100094, China; Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China.
| | - Jiaxing Han
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Li
- The Sixth Monitoring Station of Ecology and Environment Bureau, Xinjiang Production and Construction Corps, Urumqi 836099, China
| | - Yuyin Sun
- The First Monitoring Station of Ecology and Environment Bureau, Xinjiang Production and Construction Corps, Urumqi 830011, China
| | - Yuesi Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Bo Hu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
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Ren Y, Zhang H, Wu B, Zhang L, Liang J, Zhang X. Energy transition in the enhancement and break of turbulence barrier during heavy haze pollution. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 317:120770. [PMID: 36455770 DOI: 10.1016/j.envpol.2022.120770] [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: 07/12/2022] [Revised: 11/17/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Variation of the turbulence barrier effect caused by the turbulence intermittency have a strong impact on the vertical distribution and variation of pollutants, which limits the accuracy of pollution process simulation. Turbulence observation data from the five layers of the 255 m meteorological tower in Tianjin during two severe haze pollution periods were used to discuss energy changes during the enhancement and break of the turbulence barrier. Results showed that a sharp decrease in turbulence kinetic energy contributed to barrier enhancement and the kinetic energy transfer from sub-mesoscale motion to turbulence triggered the barrier break. The barrier break point tends to occur after Δ KE < 0 (the kinetic energy difference between turbulence and sub-mesoscale motion), subsequently followed by a significant increase in Δ KE. Due to the significant reduction in wind speed during severe haze pollution, type-B intermittency events occurred more frequently and existed at five heights. Type-A intermittency events were more likely to occur at the heights of 40 and 80 m, and type-C intermittency events were more likely to occur at heights above 80 m. Wind speed thresholds at different heights (2.5 m s-1 for 40 m, 4 m s-1 for 80 m, 4 m s-1 for 120 m, 4 m s-1 for 160 m, 4.5 m s-1 for 200 m) can be used to determine whether turbulent barrier effects occurred. This study provides an important research basis for solving the theoretical problem of the stable boundary layer that currently limits the accurate prediction of severe haze pollution processes.
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Affiliation(s)
- Yan Ren
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou, 730000, PR China; Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, 100081, PR China.
| | - Hongsheng Zhang
- Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, 100081, PR China
| | - Bingui Wu
- Tianjin Municipal Meteorological Bureau, Tianjin, 300074, PR China
| | - Lei Zhang
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou, 730000, PR China; Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Jiening Liang
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Xiaoye Zhang
- State Key Laboratory of Severe Weather and Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, China Meteorological Administration (CMA), Beijing, 100081, PR China
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Li R, Zhang M, Du Y, Wang G, Shang C, Liu Y, Zhang M, Meng Q, Cui M, Yan C. Impacts of dust events on chemical characterization and associated source contributions of atmospheric particulate matter in northern China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120597. [PMID: 36343856 DOI: 10.1016/j.envpol.2022.120597] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
Sand and dust have significant impacts on air quality, climate, and human health. To investigate the influences of dust storms on chemical characterization and source contributions of fine particulate matter (PM2.5) in areas with different distances from dust source regions, PM2.5 and associated chemical composition were measured in two industrial cities with one near sand sources (i.e., Wuhai) and the other far from sand sources (i.e., Jinan) in northern China in March 2021. Results showed that PM mass concentrations significantly increased and exceeded the Chinese National Ambient Air Quality standard during the dust events, with absolute concentrations and fractional contributions of PM2.5-bound crustal and trace elements increased while secondary inorganic ions decreased at both sites. Crustal materials dominated the increased PM2.5 mass from non-dust period to dust period in both cities. These were further evidenced by PM2.5 source apportionment results from positive matrix factorization model. During the dust events, dust sources contributed up to 88% of PM2.5 mass in Wuhai and ∼38% of PM2.5 mass in Jinan, a city about thousands of kilometers away from the sand source. Besides, the measurement data indicated that dust from northwest China may also bring along with high abundance of organic matter and vanadium. Secondary and traffic sources were two of the most important source contributors to PM2.5 in both cities during the non-dust periods. However, the near sand source city was more susceptible to the aggravating effects of dust and minerals, with much higher contributions by crustal materials (∼47%, from the aspect of chemical components) and dust-related sources (∼26%, from the aspect of sources) to PM2.5 mass even during non-dust periods. This study highlighted the urgent need for more action and effective control of sand sources to reduce the impact on air quality in downstream regions.
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Affiliation(s)
- Ruiyu Li
- Environment Research Institute, Shandong University, Qingdao 266237, China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Miao Zhang
- Shandong Provincial Eco-Environment Monitoring Center, Jinan, 250101, China
| | - Yuming Du
- Inner Mongolia Autonomous Region Environmental Monitoring Center, Wuhai Branch, Wuhai, 016000, China
| | - Guixia Wang
- Shandong Provincial Eco-Environment Monitoring Center, Jinan, 250101, China
| | - Chunlin Shang
- Inner Mongolia Autonomous Region Environmental Monitoring Center, Wuhai Branch, Wuhai, 016000, China
| | - Yao Liu
- Inner Mongolia Autonomous Region Environmental Monitoring Center, Wuhai Branch, Wuhai, 016000, China
| | - Min Zhang
- Inner Mongolia Autonomous Region Environmental Monitoring Center, Wuhai Branch, Wuhai, 016000, China
| | - Qingpeng Meng
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Min Cui
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225009, China
| | - Caiqing Yan
- Environment Research Institute, Shandong University, Qingdao 266237, China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
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Wang X, Chen L, Guo K, Liu B. Spatio-temporal trajectory evolution and cause analysis of air pollution in Chengdu, China. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2022; 72:876-894. [PMID: 35358021 DOI: 10.1080/10962247.2022.2058642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 02/22/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
This study comprehensively analyzed air pollution in Chengdu (CD), a megacity in southwest China, evaluated the Variation Characteristics of air quality during 2015-2018, and conducted Random Forest classification of air pollution data of 2017. The classification results showed three pollution periods: severe (December, January and February), ozone (May‒August), and slight (March and November). These features were combined with potential source contribution function (PSCF), concentration weighted trajectory (CWT) and backward trajectory model (HYSPLIT) for simulating spatio-temporal trajectory of air polluted during each pollution periods. The results show that PM2.5 mainly comes from CD and surrounding cities, and some may be from India, Myanmar and Chongqing; PM10 mainly comes from CD and surrounding cities and some may be from India and Myanmar; NO2 mainly comes from CD and surrounding cities and cities and Some of the pollution may come from the input of India, Myanmar, Chongqing and Inner Mongolia; O3 mainly comes from the urban agglomeration of Sichuan Basin and some areas from Chongqing, Sichuan Liangshan and Yunnan Guizhou. Combined with the meteorological data of temperature, relative humidity and wind speed, aerosol optical depth, planetary boundary layer height and thermal anomaly data, the Monthly, daily and hourly spatio-temporal characteristics and the possible occurred cause of the main air pollution during each pollution period in CD were revealed detail. The research in this paper is critical for pollution control and prevention and provides a scientific basis for studying the spatio-temporal characteristics and sources of pollution in megacities in terrain such as basins and mountains.Implications: Air pollution has a significant impact on human and ecological health. In 2013, Chengdu was one of the five cities with the most serious PM2.5 pollution in the world. In the previous study of air pollution in Chengdu, it was only for a short period of pollution. It is impossible to fully understand the spatio-temporal trajectory and cause of air pollution. Chengdu is surrounded by mountains, and the meteorological conditions have been stagnant for a long time. The research on the spatio-temporal evolution of the main air pollution trajectories in each pollution period in Chengdu is particularly important. Quantifying the pollution trajectory and air pollution concentration is helpful to fully understand the air quality in Chengdu. The comprehensive analysis of multi-source data such as air pollution and meteorology has focused on strengthening the in-depth research on the transmission law of air pollution, the spatio-temporal change trend of air pollution, the sources of air pollution and the causes of air pollution, so as to help people fully understand the sources and causes of pollution in Chengdu. Aiming at the trajectory law, causes and occurrence time of air pollution, it is conducive for the government to formulate corresponding policies, carry out regional emission reduction and joint prevention and control, improve air quality and minimize the harm of air pollution to the public.
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Affiliation(s)
- Xingjie Wang
- College of Geophysics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- College of Engineering and Technology, Chengdu University of Technology, Leshan, Sichuan, People's Republic of China
- Geomathematics Key Laboratory of Sichuan Province, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
| | - Ling Chen
- College of Geophysics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- Geomathematics Key Laboratory of Sichuan Province, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- College of Mathematics and Physics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
| | - Ke Guo
- College of Geophysics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- Geomathematics Key Laboratory of Sichuan Province, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- College of Mathematics and Physics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
| | - Bingli Liu
- College of Geophysics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- Geomathematics Key Laboratory of Sichuan Province, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
- College of Mathematics and Physics, Chengdu University of Technology, Chengdu, Sichuan, People's Republic of China
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Zhang Z, Su Y, Jing R, Qi J, Qi X, Xie Z, Cui B. Acute and lag effects of ambient fine particulate matter on the incidence of dyslipidemia in Chengdu, China: A time-series study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:37919-37929. [PMID: 35072876 DOI: 10.1007/s11356-021-18400-7] [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: 10/13/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
High levels of ambient fine particulate matter (PM2.5) might increase the risk of death due to cardiovascular diseases (CVDs). As a critical risk factor for CVDs, dyslipidemia can cause CVDs or exacerbate pre-existing ones. This study aimed to investigate whether a short-time exposure to PM2.5 leads to dyslipidemia (HyperTC, HyperLDL-C, HyperTG and HypoHDL-C) in adults. The serum lipid data were provided by the Sichuan Provincial People's Hospital Medical Examination Center. We included 309,654 subjects aged 18-79 between May 10, 2015, and May 10, 2017. An advanced distributed lag nonlinear model (DLNM) was applied to investigate the acute and lag effects of ambient PM2.5 on the risk of dyslipidemia. This study was also stratified by sex, age, BMI and season to examine potential effect modification. We observed that the associations between an interquartile increase in PM2.5 (43 μg/m3) and dyslipidemia were [relative risk (RR); 95% confidence interval (CI)]: 1.042 (1.013, 1.071) for HyperLDL-C and 1.027 (1.006, 1.049) for HyperTC at lag0 day. The lag effects were found at lag6 day for HyperLDL-C, in lag4-6 days for HyperTC and lag4-7 days for HyperTG. Short-term exposure to ambient PM2.5 was related to dyslipidemia and the effect modification was observed in the subgroup analysis. The female and normal-weight populations were more susceptible to the risks of PM2.5 on HyperLDL-C and HyperTC.
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Affiliation(s)
- Zizheng Zhang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yang Su
- Clinical Laboratory, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Renjie Jing
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiying Qi
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaohui Qi
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen Xie
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
- Department of Dermatology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Bin Cui
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Zhao X, Wang J, Xu B, Zhao R, Zhao G, Wang J, Ma Y, Liang H, Li X, Yang W. Causes of PM 2.5 pollution in an air pollution transport channel city of northern China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:23994-24009. [PMID: 34820758 DOI: 10.1007/s11356-021-17431-4] [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: 07/21/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
To develop effective mitigation policies, a comprehensive understanding of the evolution of the chemical composition, formation mechanisms, and the contribution of sources at different pollution levels is required. PM2.5 samples were collected for 1 year from August 2016 to August 2017 at an urban site in Zibo, then chemical compositions were analyzed. Secondary inorganic aerosols (SNA), anthropogenic minerals (MIN), and organic matter (OM) were the most abundant components of PM2.5, but only the mass fraction of SNA increased as the pollution evolved, implying that PM2.5 pollution was caused by the formation of secondary aerosols, especially nitrate. A more intense secondary transformation was found in the heating season (from November 15, 2016, to March 14, 2017), and a faster secondary conversion of nitrate than sulfate was discovered as the pollution level increased. The formation of sulfate was dominated by heterogeneous reactions. High relative humidity (RH) in polluted periods accelerated the formation of sulfate, and high temperature in the non-heating season also promoted the formation of sulfate. Zibo city was under ammonium-rich conditions during polluted periods in both seasons; therefore, nitrate was mainly formed through homogeneous reactions. The liquid water content increased significantly as the pollution levels increased when the RH was above 80%, indicating that the hygroscopic growth of aerosol aggravated the PM2.5 pollution. Source apportionment showed that PM2.5 was mainly from secondary aerosol formation, road dust, coal combustion, and vehicle emissions, contributing 36.6%, 16.5%, 14.7%, and 13.1% of PM2.5 mass, respectively. The contribution of secondary aerosol formation increased remarkably with the deterioration of air quality, especially in the heating season.
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Affiliation(s)
- Xueyan Zhao
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jing Wang
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Bo Xu
- Zibo Eco-Environmental Monitoring Center of Shandong Province, Zibo, 255000, China
| | - Ruojie Zhao
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Guangjie Zhao
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Jian Wang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yinhong Ma
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Handong Liang
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Xianqing Li
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
| | - Wen Yang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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10
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Li F, Tong S, Jia C, Zhang X, Lin D, Zhang W, Li W, Wang L, Ge M, Xia L. Sources of ambient non-methane hydrocarbon compounds and their impacts on O 3 formation during autumn, Beijing. J Environ Sci (China) 2022; 114:85-97. [PMID: 35459517 DOI: 10.1016/j.jes.2021.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/31/2021] [Accepted: 08/01/2021] [Indexed: 11/19/2022]
Abstract
The field observation of 54 non-methane hydrocarbon compounds (NMHCs) was conducted from September 1 to October 20 in 2020 during autumn in Haidian District, Beijing. The mean concentration of total NMHCs was 29.81 ± 11.39 ppbv during this period, and alkanes were the major components. There were typical festival effects of NMHCs with lower concentration during the National Day. Alkenes and aromatics were the dominant groups in ozone formation potential (OFP) and OH radical loss rate (LOH). The positive matrix factorization (PMF) running results revealed that vehicular exhaust became the biggest source in urban areas, followed by liquefied petroleum gas (LPG) usage, solvent usage, and fuel evaporation. The box model coupled with master chemical mechanism (MCM) was applied to study the impacts of different NMHCs sources on ozone (O3) formation in an O3 episode. The simulation results indicated that reducing NMHCs concentration could effectively suppress O3 formation. Moreover, reducing traffic-related emissions of NMHCs was an effective way to control O3 pollution at an urban site in Beijing.
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Affiliation(s)
- Fangjie Li
- College of Chemistry, Liaoning University, Shenyang 110036, China; State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Shengrui Tong
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Chenhui Jia
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xinran Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Deng Lin
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; Key Laboratory of Oasis Ecology, College of Resource and Environment Sciences, Xinjiang University, Urumqi 830046, China
| | - Wenqian Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Weiran Li
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lili Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing 100029, China
| | - Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lixin Xia
- College of Chemistry, Liaoning University, Shenyang 110036, China; Department of Chemical and Environmental Engineering, Yingkou Institute of Technology, Yingkou 115014, China.
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11
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Poor Visibility in Winter Due to Synergistic Effect Related to Fine Particulate Matter and Relative Humidity in the Taipei Metropolis, Taiwan. ATMOSPHERE 2022. [DOI: 10.3390/atmos13020270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Visibility is important because it influences transportation safety. This study examined the relationships among sea–land breezes, relative humidity (RH), and the urban heat island (UHI) effect. The study also sought to understand how the synergistic effects of fine particulate matter (PM2.5) and RH influence visibility. Hourly meteorological, PM2.5 concentration, and visibility data from 2016 to 2019 were obtained from government-owned stations. This study used quadratic equations, exponential functions, and multi-regression models, along with a comparison test, to analyse the relationships between these variables. While sea breezes alone cannot explain the presence of PM2.5, UHI circulation coupled with sea breezes during winter can promote the accumulation of PM2.5. The synergistic effects of RH, PM2,5, and aerosol hygroscopicity exist in synoptic patterns type I and type III. PM2.5 was negatively correlated with visibility in the winter, when the RH was 67–95% and the continental cold high-pressure (CCHP) system was over the Asian continent (type I), or when the RH was 49–89% and the CCHP had moved eastward, with its centre located beyond 125°E (type III). The synergistic predictor variable PM2.5×RH was more important than PM2.5 and RH individually in explaining the variation in visibility.
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Rilstone V, Vignale L, Craddock J, Cushing A, Filion Y, Champagne P. The role of antibiotics and heavy metals on the development, promotion, and dissemination of antimicrobial resistance in drinking water biofilms. CHEMOSPHERE 2021; 282:131048. [PMID: 34470147 DOI: 10.1016/j.chemosphere.2021.131048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/23/2021] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
Antimicrobial resistance (AMR), as well as the development of biofilms in drinking water distribution systems (DWDSs), have become an increasing concern for public health and management. As bulk water travels from source to tap, it may accumulate contaminants of emerging concern (CECs) such as antibiotics and heavy metals. When these CECs and other selective pressures, such as disinfection, pipe material, temperature, pH, and nutrient availability interact with planktonic cells and, consequently, DWDS biofilms, AMR is promoted. The purpose of this review is to highlight the mechanisms by which AMR develops and is disseminated within DWDS biofilms. First, this review will lay a foundation by describing how DWDS biofilms form, as well as their basic intrinsic and acquired resistance mechanisms. Next, the selective pressures that further induce AMR in DWDS biofilms will be elaborated. Then, the pressures by which antibiotic and heavy metal CECs accumulate in DWDS biofilms, their individual resistance mechanisms, and co-selection are described and discussed. Finally, the known human health risks and current management strategies to mitigate AMR in DWDSs will be presented. Overall, this review provides critical connections between several biotic and abiotic factors that influence and induce AMR in DWDS biofilms. Implications are made regarding the importance of monitoring and managing the development, promotion, and dissemination of AMR in DWDS biofilms.
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Affiliation(s)
- Victoria Rilstone
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Leah Vignale
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Justine Craddock
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Alexandria Cushing
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Yves Filion
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada.
| | - Pascale Champagne
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada; Institut National de la Recherche Scientifique (INRS), 490 rue de la Couronne, Québec City, Québec, G1K 9A9, Canada
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13
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Characteristics of Particulate Matter at Different Pollution Levels in Chengdu, Southwest of China. ATMOSPHERE 2021. [DOI: 10.3390/atmos12080990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Air pollution is becoming increasingly serious along with social and economic development in the southwest of China. The distribution characteristics of particle matter (PM) were studied in Chengdu from 2016 to 2017, and the changes of PM bearing water-soluble ions and heavy metals and the distribution of secondary ions were analyzed during the haze episode. The results showed that at different pollution levels, heavy metals were more likely to be enriched in fine particles and may be used as a tracer of primary pollution sources. The water-soluble ions in PM2.5 were mainly Sulfate-Nitrate-Ammonium (SNA) accounting for 43.02%, 24.23%, 23.50%, respectively. SO42−, NO3−, NH4+ in PM10 accounted for 34.56%, 27.43%, 19.18%, respectively. It was mainly SO42− in PM at Clean levels (PM2.5 = 0~75 μg/m3, PM10 = 0~150 μg/m3), and mainly NH4+ and NO3− at Light-Medium levels (PM2.5 = 75~150 μg/m3, PM10 = 150~350 μg/m3). At Heavy levels (PM2.5 = 150~250 μg/m3, PM10 = 350~420 μg/m3), it is mainly SO42− in PM2.5, and mainly NH4+ and NO3− in PM10. The contribution of mobile sources to the formation of haze in the study area was significant. SNA had significant contributions to the PM during the haze episode, and more attention should be paid to them in order to improve air quality.
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14
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Xiong Y, Zhou J, Xing Z, Du K. Cancer risk assessment for exposure to hazardous volatile organic compounds in Calgary, Canada. CHEMOSPHERE 2021; 272:129650. [PMID: 33486452 DOI: 10.1016/j.chemosphere.2021.129650] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
Oil and natural gas (O&G) extraction operations emit hazardous volatile organic compounds (VOCs) in quantities that have adverse effects on human health. Our current understanding of the exposure risks associated with upstream O&G exploitations remains limited, and very few quantitative on-site remediation strategies have been proposed. To this end, we assessed the health risks associated with the emission of hazardous VOCs and presented a set of remediation goals for the city of Calgary, which is a major center of the Canadian oil industry. Results from probabilistic risk assessment (PRA) suggested that although VOCs had a negligible impact on chronic non-cancer-associated risk, inhalation-associated cancer risk remained a significant concern. Carbon tetrachloride, benzene, and 1,3-butadiene were the dominant VOCs, representing 88% of the integrated inhalation cancer risk (= 7.8 × 10-5); background, solid fuel combustion, and O&G extraction were among the primary sources that posed the greatest threat to human health. Results of a Monte Carlo simulation revealed that the probability of developing cancer due to inhalation of hazardous VOCs was ∼13.1% on clean air days and 45.9% on days with significant levels of air pollution. Preliminary remediation goals (PRGs) included reductions of 24.2-65.1% and 11.4-50.9% targeting priority VOCs and their sources, respectively. Taken together, our findings suggest that stringent control of the sources of VOCs, particularly fossil fuel combustion, is an urgent priority. PRA coupled with PRGs provides informative risk assessments and suggests quantitative remediation strategies that can be applied toward improved management of hazardous pollutants.
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Affiliation(s)
- Ying Xiong
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
| | - Jiabin Zhou
- School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China.
| | - Zhenyu Xing
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
| | - Ke Du
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
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Li X, Hussain SA, Sobri S, Md Said MS. Overviewing the air quality models on air pollution in Sichuan Basin, China. CHEMOSPHERE 2021; 271:129502. [PMID: 33465622 DOI: 10.1016/j.chemosphere.2020.129502] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/27/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Most developing countries in the world face the common challenges of reducing air pollution and advancing the process of sustainable development, especially in China. Air pollution research is a complex system and one of the main methods is through numerical simulation. The air quality model is an important technical method, it allows researchers to better analyze air pollutants in different regions. In addition, the SCB is a high-humidity and foggy area, and the concentration of atmospheric pollutants is always high. However, research on this region, one of the four most polluted regions in China, is still lacking. Reviewing the application of air quality models in the SCB air pollution has not been reported thoroughly. To fill these gaps, this review provides a comprehensive narration about i) The status of air pollution in SCB; ii) The application of air quality models in SCB; iii) The problems and application prospects of air quality models in the research of air pollution. This paper may provide a theoretical reference for the prevention and control of air pollution in the SCB and other heavily polluted areas in China and give some1inspirations for air pollution forecast in other countries with complex terrain.
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Affiliation(s)
- Xiaoju Li
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia
| | - Siti Aslina Hussain
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
| | - Shafreeza Sobri
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia
| | - Mohamad Syazarudin Md Said
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia
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Evolution of Urban Haze in Greater Bangkok and Association with Local Meteorological and Synoptic Characteristics during Two Recent Haze Episodes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17249499. [PMID: 33352994 PMCID: PMC7766008 DOI: 10.3390/ijerph17249499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/10/2020] [Accepted: 12/15/2020] [Indexed: 11/17/2022]
Abstract
This present work investigates several local and synoptic meteorological aspects associated with two wintertime haze episodes in Greater Bangkok using observational data, covering synoptic patterns evolution, day-to-day and diurnal variation, dynamic stability, temperature inversion, and back-trajectories. The episodes include an elevated haze event of 16 days (14–29 January 2015) for the first episode and 8 days (19–26 December 2017) for the second episode, together with some days before and after the haze event. Daily PM2.5 was found to be 50 µg m−3 or higher over most of the days during both haze events. These haze events commonly have cold surges as the background synoptic feature to initiate or trigger haze evolution. A cold surge reached the study area before the start of each haze event, causing temperature and relative humidity to drop abruptly initially but then gradually increased as the cold surge weakened or dissipated. Wind speed was relatively high when the cold surge was active. Global radiation was generally modulated by cloud cover, which turns relatively high during each haze event because cold surge induces less cloud. Daytime dynamic stability was generally unstable along the course of each haze event, except being stable at the ending of the second haze event due to a tropical depression. In each haze event, low-level temperature inversion existed, with multiple layers seen in the beginning, effectively suppressing atmospheric dilution. Large-scale subsidence inversion aloft was also persistently present. In both episodes, PM2.5 showed stronger diurnality during the time of elevated haze, as compared to the pre- and post-haze periods. During the first episode, an apparent contrast of PM2.5 diurnality was seen between the first and second parts of the haze event with relatively low afternoon PM2.5 over its first part, but relatively high afternoon PM2.5 over its second part, possibly due to the role of secondary aerosols. PM2.5/PM10 ratio was relatively lower in the first episode because of more impact of biomass burning, which was in general agreement with back-trajectories and active fire hotspots. The second haze event, with little biomass burning in the region, was likely to be caused mainly by local anthropogenic emissions. These findings suggest a need for haze-related policymaking with an integrated approach that accounts for all important emission sectors for both particulate and gaseous precursors of secondary aerosols. Given that cold surges induce an abrupt change in local meteorology, the time window to apply control measures for haze is limited, emphasizing the need for readiness in mitigation responses and early public warning.
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17
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Observation-Based Summer O3 Control Effect Evaluation: A Case Study in Chengdu, a Megacity in Sichuan Basin, China. ATMOSPHERE 2020. [DOI: 10.3390/atmos11121278] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ground-level ozone (O3), which is mainly from the photochemical reactions of NOx and volatile organic compounds (VOCs), has become a crucial pollutant obstructing air quality improvement in China. Understanding the composition, temporal variability and source apportionment of VOCs is necessary for determining effective control measures to minimize VOCs and their related photochemical pollution. To provide a comprehensive analysis of VOC sources and their contributions to ozone formation in the city of Chengdu—a megacity with the highest rates of industrial and economic development in southwest China—we conducted a one-month monitoring project at three urban sites (Shuangliu, Xindu, Junpingjie; SL, XD and JPJ, respectively) along the main north–south meteorological transport channel before and during the implemented control measures. Alkanes were the dominant group at each site, contributing to around 50% of the observed total VOCs, followed by oxygen-containing VOCs (OVOCs), aromatics, halohydrocarbons and alkenes. During the control period, the mixing ratios of most measured VOC species decreased, and O3 concentrations were down by at least 20%. VOC species experiencing the most effect from control were aromatics and OVOCs, which had higher O3 formation reactivity. This indicated that the control policies had significant influence on reductions of reactive VOC species. We also identified VOC sources at SL and XD using positive matrix factorization (PMF) and assessed their contributions to photochemical O3 formation by calculating the O3 formation potential (OFP) based on mass concentrations and maximum incremental reactivity of related VOCs. Five dominant VOC sources were identified, with the highest contributions from vehicular exhaust and fuel evaporation before control, followed by solvent utilization, biogenic background and secondary formation, and industrial emissions. Contribution from vehicular exhaust was reduced the most at SL, while at XD, secondary formation VOCs decreased significantly. VOCs from vehicular and industrial emissions and solvent utilization were found to be the dominant precursors for OFPs, particularly the species of xylenes, toluene and propene. Our results therefore suggest that priority should be given to the alleviation of photochemical pollutants for effective control of O3 formation in Chengdu. The findings from this work have important implications for formulating effective emission control policies in Chengdu.
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Tan Q, Liu H, Xie S, Zhou L, Song T, Shi G, Jiang W, Yang F, Wei F. Temporal and spatial distribution characteristics and source origins of volatile organic compounds in a megacity of Sichuan Basin, China. ENVIRONMENTAL RESEARCH 2020; 185:109478. [PMID: 32276165 DOI: 10.1016/j.envres.2020.109478] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
As important pollution gases and represented precursors of both ozone and second organic aerosol (SOA), the component characteristics, source origins, environmental health and emission control of volatile organic compounds (VOCs), are gaining more and more attention in Chinese megacities. In order to understand the concentration, composition and temporal and spatial distribution characteristics of VOCs in the atmosphere of Chengdu, a megacity located in Sichuan basin in southwest China, the offline sampling measurements of VOCs were carried out at 28 different field sites covering all the districts and counties of Chengdu during special periods from May 2016 to January 2017. Speciated VOCs measurement was performed by the GC-FID/MS, and 99 species were identified. The averaged total VOC mixing ratios of each sampling site were in the range from 35.03 to 180.57 ppbv. Based on these observational data, the distribution characteristics of VOCs in different months and different regions of Chengdu were clarified. The VOCs data were used to estimate the potential amount of ozone, secondary aerosol formation and health risk assessment in Chengdu. Furthermore, the positive matrix factorization (PMF) model was used to identify the dominant emission sources and evaluate their contribution to VOCs in the city. The two main sources of VOCs in Chengdu were motor vehicle exhaust and solvent utilization. These accounted for 43% of all emission sources. In the summertime, due to higher temperatures and stronger sunlight, the contribution of natural sources and secondary emissions were also relatively high, which were supported by the regional emission inventories. Finally, the controlling direction of VOCs and O3 pollution in Chengdu was discussed, and the VOCs pollution control strategy was proposed for the near future.
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Affiliation(s)
- Qinwen Tan
- College of Architecture and Environment, Sichuan University, Chengdu, China; Chengdu Academy of Environmental Sciences, Chengdu, China
| | - Hefan Liu
- Chengdu Academy of Environmental Sciences, Chengdu, China
| | - Shaodong Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, China
| | - Li Zhou
- College of Architecture and Environment, Sichuan University, Chengdu, China.
| | - Tianli Song
- College of Architecture and Environment, Sichuan University, Chengdu, China
| | - Guangming Shi
- College of Architecture and Environment, Sichuan University, Chengdu, China
| | - Wenju Jiang
- College of Architecture and Environment, Sichuan University, Chengdu, China
| | - Fumo Yang
- College of Architecture and Environment, Sichuan University, Chengdu, China.
| | - Fusheng Wei
- College of Architecture and Environment, Sichuan University, Chengdu, China
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Simayi M, Shi Y, Xi Z, Li J, Yu X, Liu H, Tan Q, Song D, Zeng L, Lu S, Xie S. Understanding the sources and spatiotemporal characteristics of VOCs in the Chengdu Plain, China, through measurement and emission inventory. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 714:136692. [PMID: 32018956 DOI: 10.1016/j.scitotenv.2020.136692] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 01/13/2020] [Accepted: 01/13/2020] [Indexed: 05/16/2023]
Abstract
In order to evaluate the volatile organic compounds (VOCs) pollution characteristics in Chengdu and to identify their sources, ambient air sample collection and measurement were conducted at 28 sampling sites covering all districts/counties of Chengdu from May 2016 to January 2017. Meanwhile, a county-level anthropogenic speciated VOCs emission inventory was established by "bottom-up" method for 2016. Then, a comparison was made between the VOCs emissions, spatial variations, and source structures derived from the measurement and emission inventory. Ambient measurements showed that the annual average mixing ratios of VOCs in Chengdu were 57.54 ppbv (12.36 to 456.04 ppbv), of which mainly dominated by alkanes (38.8%) and OVOCs (22.0%). The ambient VOCs in Chengdu have distinct spatiotemporal characteristics, with a high concentration in January at the middle-northern part of the city and a low concentration in September at the southwestern part. The spatial distribution of VOCs estimated by the emission inventory was in good agreement with ambient measurements. Comparison of individual VOCs emissions indicated that the emissions of non-methane hydrocarbon species agreed within ±100% between the two methods. Both positive matrix factorization (PMF) model results and emission inventory showed that vehicle emissions were the major contributor of anthropogenic VOCs in Chengdu (31% and 37%), followed by solvent utilization (26% and 27%) and industrial processes (23% and 30%). The large discrepancies were found between the relative contribution of combustion sources, and the PMF resolved more contributions (20%) than the emission inventory (6%). Overall, this study demonstrates that measurement results and emission inventory were in a good agreement. However, to improve the reliability of the emission inventory, we suggest significant revision on source profiles of oxygenated volatile organic compounds (OVOCs) and halocarbons, as well as more detailed investigation should be made in terms of energy consumption in household.
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Affiliation(s)
- Maimaiti Simayi
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Yuqi Shi
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Ziyan Xi
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Jing Li
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Xuena Yu
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Hefan Liu
- Chengdu Academy of Environmental Science, Chengdu 610015, PR China
| | - Qinwen Tan
- Chengdu Academy of Environmental Science, Chengdu 610015, PR China
| | - Danlin Song
- Chengdu Academy of Environmental Science, Chengdu 610015, PR China
| | - Limin Zeng
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Sihua Lu
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China
| | - Shaodong Xie
- College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, PR China.
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Meng X, Zhang K, Pang K, Xiang X. Characterization of spatio-temporal distribution of vehicle emissions using web-based real-time traffic data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 709:136227. [PMID: 31927432 DOI: 10.1016/j.scitotenv.2019.136227] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/05/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
Vehicle emissions have become an increasingly important source to air pollution in China, thus an accurate estimate of vehicle emissions is essential but challenging for policy-making toward air quality improvement. Since vehicle emissions are episodic, roadway-based micro/meso-scale emissions are getting more and more attention for roadway exposure assessment and accuracy improvement of emission inventory. Hence, it is necessary to characterize the temporal and spatial distribution of vehicle emissions. However, due to the large number of vehicle population and managerial difficulties, it might not be practical to develop vehicle emission inventory based on all individual vehicles at a city level. This study aimed to develop an approach to use web-based real-time traffic data to estimate meso-scale vehicle emissions at a city level. Taking Chengdu as an example, traffic characteristics include driving modes, traffic flows, and fleet compositions under different traffic conditions were quantified using real-world measurements. Web-based traffic data was shown to have adequate accuracy for traffic characterization and thus emission estimation. Real-time traffic conditions of the study area derived from web-based traffic data were then matched with corresponding traffic characteristics. Combining with vehicle modal emission rates, roadway-based vehicle emissions were quantified both spatially and temporally. As expected, estimated roadway-based emissions correlated well with traffic conditions both temporally and spatially. Heavier traffic is usually associated with higher emissions. This study demonstrated that the web-based traffic data can be used in transportation and environment related research. Findings from this work can be used for hotspot identification in traffic and emissions and the associated risk analysis, traffic management, and many other applications.
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Affiliation(s)
- Xiangrui Meng
- Sichuan University, No.24 South Section 1 Yihuan Road, Chengdu, China
| | - Kaishan Zhang
- Sichuan University, No.24 South Section 1 Yihuan Road, Chengdu, China.
| | - Kaili Pang
- Sichuan University, No.24 South Section 1 Yihuan Road, Chengdu, China
| | - Xinpeng Xiang
- Sichuan University, No.24 South Section 1 Yihuan Road, Chengdu, China
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O3 Sensitivity and Contributions of Different NMHC Sources in O3 Formation at Urban and Suburban Sites in Shanghai. ATMOSPHERE 2020. [DOI: 10.3390/atmos11030295] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ground-level ozone (O3) pollution is still one of the priorities and challenges for air pollution control in the Yangtze River Delta (YRD) region of China. Understanding the relationship of O3 with its precursors and contributions of different sources in O3 formation is essential for the development of an O3 control strategy. This study analyzed O3 sensitivity to its precursors using a box model based on online observations of O3, non-methane hydrocarbons (NMHCs), nitrogen oxides (NOx), and carbon monoxide (CO) at an urban site and a suburban site in Shanghai in July 2017. Anthropogenic sources of NMHCs were identified using the positive matrix factorization (PMF) receptor model, and then contributions of different sources in O3 formation were estimated by the observation-based model (OBM). The relative incremental reactivity (RIR) values calculated by the OBM suggest that O3 formation at the urban site was in the NMHC-limited regime, while O3 formation at the suburban site tended between the transition regime and the NMHC-limited regime. Vehicular emission and liquefied petrochemical gas (LPG) use or aged air mass were found to be the two largest contributors at the urban and suburban sites in July, followed by paint and solvent use, and the petrochemical industry. However, from the perspective of O3 formation, vehicular emission and paint and solvent use were the largest two contributors at two sites due to the higher RIR values for paint and solvent use. In addition, the influence of transport on O3 sensitivity was identified by comparing O3 sensitivity at the suburban site across two days with different air mass paths. The result revealed that O3 formation in Shanghai is not only related to local emissions but also influenced by emissions from neighboring provinces. These findings on O3–NMHC–NOX sensitivity, contributions of different sources in O3 formation, and influence of transport could be useful for O3 pollution control in the YRD region. Nevertheless, more quantitative analyses on transport and further evaluation of the uncertainty of the OBM are still needed in future.
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