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Souza EJDS, Fomba KW, van Pinxteren M, Deabji N, Herrmann H. Strong synergistic and antagonistic effects of quinones and metal ions in oxidative potential (OP) determination by ascorbic acid (AA) assays. JOURNAL OF HAZARDOUS MATERIALS 2024; 478:135599. [PMID: 39180997 DOI: 10.1016/j.jhazmat.2024.135599] [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: 06/04/2024] [Revised: 08/07/2024] [Accepted: 08/20/2024] [Indexed: 08/27/2024]
Abstract
A key challenge in oxidative potential (OP) assays is to accurately assess the cumulative impact of redox-active aerosol species rather than only their individual effects. This study investigates the OP of single and combined mixtures of 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ), 9,10-phenanthrenequinone (9,10-PQ), 1,4-benzoquinone (1,4-BQ), Cu, Fe, Mn, and Zn in standard ascorbic acid (OPAA) and the synthetic respiratory tract lining fluid (OPRTLF) assays. In both OPAA and OPRTLF, binary mixtures showed additive and synergistic effects in the presence of 1,2-NQ. The mixture of Cu and Zn showed substantial synergisms in both assays, while the mixtures in the absence of 1,2-NQ primarily induced antagonistic effects. For the first time, we propose linear equations to improve the prediction of OP values by considering the impacts of synergistic and antagonistic effects. Under this approach, we observed that the potential effects caused by binary mixtures in ambient particulate matter (PM) samples could account for up to 68 % of the PM-OP values in Fez, Morocco (OPmAA: 0.34 nmol min-1 µg-1 and OPmRTLF: 0.18 nmol min-1 µg-1). The present study improves the understanding of effects of chemical interaction of potentially toxic substances that are important in the understanding of PM-induced oxidative stress in the human body.
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Affiliation(s)
- Eduardo José Dos Santos Souza
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Khanneh Wadinga Fomba
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Manuela van Pinxteren
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Nabil Deabji
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Hartmut Herrmann
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany.
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2
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Novo-Quiza N, Sánchez-Piñero J, Moreda-Piñeiro J, Turnes-Carou I, Muniategui-Lorenzo S, López-Mahía P. Oxidative potential of the inhalation bioaccessible fraction of PM 10 and bioaccessible concentrations of polycyclic aromatic hydrocarbons and metal(oid)s in PM 10. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:31862-31877. [PMID: 38637483 PMCID: PMC11133103 DOI: 10.1007/s11356-024-33331-9] [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: 10/24/2023] [Accepted: 04/11/2024] [Indexed: 04/20/2024]
Abstract
Atmospheric particulate matter (PM) has been related to numerous adverse health effects in humans. Nowadays, it is believed that one of the possible mechanisms of toxicity could be the oxidative stress, which involves the development of reactive oxygen species (ROS). Different assays have been proposed to characterize oxidative stress, such as dithiothreitol (DTT) and ascorbic acid (AA) acellular assays (OPDTT and OPAA), as a metric more relevant than PM mass measurement for PM toxicity. This study evaluates the OP of the bioaccessible fraction of 65 PM10 samples collected at an Atlantic Coastal European urban site using DTT and AA assays. A physiologically based extraction (PBET) using Gamble's solution (GS) as a simulated lung fluid (SLF) was used for the assessment of the bioaccessible fraction of PM10. The use of the bioaccessible fraction, instead of the fraction assessed using conventional phosphate buffer and ultrasounds assisted extraction (UAE), was compared for OP assessment. Correlations between OPDTT and OPAA, as well as total and bioaccessible concentrations of polycyclic aromatic hydrocarbons (PAHs) and metal(oid)s, were investigated to explore the association between those compounds and OP. A correlation was found between both OP (OPDTT and OPAA) and total and bioaccessible concentrations of PAHs and several metal(oid)s such as As, Bi, Cd, Cu, Ni, and V. Additionally, OPDTT was found to be related to the level of K+.
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Affiliation(s)
- Natalia Novo-Quiza
- Department of Chemistry, Faculty of Sciences, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), University of A Coruña, Campus de A Coruña, S/N. 15071, A Coruña, Spain
| | - Joel Sánchez-Piñero
- Department of Chemistry, Faculty of Sciences, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), University of A Coruña, Campus de A Coruña, S/N. 15071, A Coruña, Spain
| | - Jorge Moreda-Piñeiro
- Department of Chemistry, Faculty of Sciences, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), University of A Coruña, Campus de A Coruña, S/N. 15071, A Coruña, Spain.
| | - Isabel Turnes-Carou
- Department of Chemistry, Faculty of Sciences, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), University of A Coruña, Campus de A Coruña, S/N. 15071, A Coruña, Spain
| | - Soledad Muniategui-Lorenzo
- Department of Chemistry, Faculty of Sciences, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), University of A Coruña, Campus de A Coruña, S/N. 15071, A Coruña, Spain
| | - Purificación López-Mahía
- Department of Chemistry, Faculty of Sciences, Grupo Química Analítica Aplicada (QANAP), University Institute of Research in Environmental Studies (IUMA), University of A Coruña, Campus de A Coruña, S/N. 15071, A Coruña, Spain
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3
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Li J, Hua C, Ma L, Chen K, Zheng F, Chen Q, Bao X, Sun J, Xie R, Bianchi F, Kerminen VM, Petäjä T, Kulmala M, Liu Y. Key drivers of the oxidative potential of PM 2.5 in Beijing in the context of air quality improvement from 2018 to 2022. ENVIRONMENT INTERNATIONAL 2024; 187:108724. [PMID: 38735076 DOI: 10.1016/j.envint.2024.108724] [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: 02/15/2024] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 05/14/2024]
Abstract
The mass concentration of atmospheric particulate matter (PM) has been continuously decreasing in the Beijing-Tianjin-Hebei region. However, health endpoints do not exhibit a linear correlation with PM mass concentrations. Thus, it is urgent to clarify the prior toxicological components of PM to further improve air quality. In this study, we analyzed the long-term oxidative potential (OP) of water-soluble PM2.5, which is generally considered more effective in assessing hazardous exposure to PM in Beijing from 2018 to 2022 based on the dithiothreitol assay and identified the crucial drivers of the OP of PM2.5 based on online monitoring of air pollutants, receptor model, and random forest (RF) model. Our results indicate that dust, traffic, and biomass combustion are the main sources of the OP of PM2.5 in Beijing. The complex interactions of dust particles, black carbon, and gaseous pollutants (nitrogen dioxide and sulfur dioxide) are the main factors driving the OP evolution, in particular, leading to the abnormal rise of OP in Beijing in 2022. Our data shows that a higher OP is observed in winter and spring compared to summer and autumn. The diurnal variation of the OP is characterized by a declining trend from 0:00 to 14:00 and an increasing trend from 14:00 to 23:00. The spatial variation in OP of PM2.5 was observed as the OP in Beijing is lower than that in Shijiazhuang, while it is higher than that in Zhenjiang and Haikou, which is primarily influenced by the distribution of black carbon. Our results are of significance in identifying the key drivers influencing the OP of PM2.5 and provide new insights for advancing air quality improvement efforts with a focus on safeguarding human health in Beijing.
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Affiliation(s)
- Jinwen Li
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Chenjie Hua
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Li Ma
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Kaiyun Chen
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Feixue Zheng
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Qingcai Chen
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Xiaolei Bao
- Hebei Chemical & Pharmaceutical College, Shijiazhuang 050026, China
| | - Juan Sun
- Jiangsu Nanjing Environmental Monitoring Center, Nanjing 210019, China
| | - Rongfu Xie
- College of Ecology and Environment, Hainan University, Haikou 570228, China
| | - Federico Bianchi
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki 00014, Finland
| | - Veli-Matti Kerminen
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki 00014, Finland
| | - Tuukka Petäjä
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki 00014, Finland
| | - Markku Kulmala
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki 00014, Finland
| | - Yongchun Liu
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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4
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Sun N, Wu L, Zheng F, Liang D, Qi F, Song S, Peng J, Zhang Y, Mao H. Atmospheric environment characteristic of severe dust storms and its impact on sulfate formation in downstream city. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171128. [PMID: 38395168 DOI: 10.1016/j.scitotenv.2024.171128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/09/2024] [Accepted: 02/18/2024] [Indexed: 02/25/2024]
Abstract
This study comprehensively investigated the impact of dust storms (DSs) on downstream cities, by selecting representative DS events. In this paper, we discussed the characteristics of meteorological conditions, air pollutants, PM2.5 components, and their influence on sulfate formation mechanisms. During DSs, strong winds, reaching speeds of up to 10 m/s, led to significant increases in PM10 and PM2.5, with maximum concentrations of 2684.5 and 429 μg/m3, respectively. Primary gaseous pollutants experienced substantial reductions, with decline rates of 48.1, 34.9, 36.8, and 9.0 % for SO2, NO2, NH3, and CO, respectively. Despite a notable increase in PM2.5 concentrations, only 7.6 % of the total mass of PM2.5 was attributed to ionic and carbonaceous components, a much lower value than observed before the DSs (77.3 %). Concentrations of Fe, Ti, and Mn exhibited increases by factors of 6.5-14.1, 10.4-17.0, and 1.6-4.7, respectively. In contrast to the significant decrease of >76.2 % in nitrogen oxidation ratio (NOR), sulfur oxidation ratio (SOR) remained at a relatively high level, displaying a strong positive correlation with high concentrations of Fe, Mn, and Ti. Quantitative analysis revealed an average increase of 0.187 and 0.045 μg/m3 in sulfate from natural sources and heterogeneous generation, respectively. The heterogeneous reaction on mineral dust was closely linked to atmospheric humidity, radiation intensity, the form of metal existence, and concentrations of it. High concentrations of titanium dioxide and iron‑manganese oxides in mineral dust promoted heterogeneous oxidation of SO2 through photocatalysis during the daytime and metal ion catalysis during the nighttime. This study establishes that the metal components in mineral dust promote heterogeneous sulfate formation, quantifies the yield of sulfate generated as a result, and provides possible mechanisms for heterogeneous sulfate formation.
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Affiliation(s)
- Naixiu 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
| | - Lin Wu
- 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.
| | - Fangyuan Zheng
- 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
| | - Danni Liang
- Tianjin Shuangyun Environmental Protection Technology Co., Ltd., Tianjin 300350, China
| | - FuYuan Qi
- 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
| | - Shaojie Song
- 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
| | - 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
| | - Yufen 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
| | - 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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Aldekheel M, Tohidi R, Al-Hemoud A, Alkudari F, Verma V, Subramanian PSG, Sioutas C. Identifying urban emission sources and their contribution to the oxidative potential of fine particulate matter (PM 2.5) in Kuwait. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 343:123165. [PMID: 38103716 PMCID: PMC10923010 DOI: 10.1016/j.envpol.2023.123165] [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: 11/05/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
In this study, we investigated the seasonal variations, chemical composition, sources, and oxidative potential of ambient PM2.5 (particles with a diameter of less than 2.5 μm) in Kuwait City. The sampling campaign was conducted within the premises of Kuwait Institute for Scientific Research from June 2022 to May 2023, covering different seasons throughout the year. The personal cascade impactor sampler (PCIS) operated at flow rate of 9 L/min was employed to collect weekly PM2.5 samples on PTFE and quarts filters. These collected samples were analyzed for carbonaceous species (i.e., elemental and organic carbon), metals and transition elements, inorganic ions, and DTT (dithiothreitol) redox activity. Furthermore, principal component analysis (PCA) and multi-linear regression (MLR) were used to identify the predominant emission sources and their percentage contribution to the redox activity of PM2.5 in Kuwait. The results of this study highlighted that the annual-averaged ambient PM2.5 mass concentrations in Kuwait (59.9 μg/m3) substantially exceeded the World Health Organization (WHO) guideline of 10 μg/m3. Additionally, the summer season displayed the highest PM2.5 mass concentration (75.2 μg/m3) compared to other seasons, primarily due to frequent dust events exacerbated by high-speed winds. The PCA identified four primary PM2.5 sources: mineral dust, fossil fuel combustion, road traffic, and secondary aerosols. The mineral dust was found to be the predominant source, contributing 36.1% to the PM2.5 mass, followed by fossil fuel combustion and traffic emissions with contributions of 23.7% and 20.3%, respectively. The findings of MLR revealed that road traffic was the most significant contributor to PM2.5 oxidative potential, accounting for 47% of the total DTT activity. In conclusion, this comprehensive investigation provides essential insights into the sources and health implications of PM2.5 in Kuwait, underscoring the critical need for effective air quality management strategies to mitigate the impacts of particulate pollution in the region.
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Affiliation(s)
- Mohammad Aldekheel
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA, 90089, USA; Department of Civil Engineering, Kuwait University, P.O Box 5969, Safat, 13060, Kuwait
| | - Ramin Tohidi
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Ali Al-Hemoud
- Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat, 13109, Kuwait
| | - Fahad Alkudari
- Public Administration of Experts, Ministry of Justice, P.O. Box 6, Safat, 12008, Kuwait
| | - Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA
| | - P S Ganesh Subramanian
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA, 90089, USA.
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Raparthi N, Yadav S, Khare A, Dubey S, Phuleria HC. Chemical and oxidative properties of fine particulate matter from near-road traffic sources. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 337:122514. [PMID: 37678733 DOI: 10.1016/j.envpol.2023.122514] [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: 07/06/2023] [Revised: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 09/09/2023]
Abstract
The toxicity associated with the fine particulate matter (PM2.5) has not been well studied, particularly in relation to the emissions from on-road vehicles and other sources in low- and middle-income countries such as India. Thus, a study was conducted to examine the oxidative potential (OP) of PM2.5 at a roadside (RS) site with heavy vehicular traffic and an urban background (BG) site in Mumbai using the dithiothreitol (DTT) assay. Simultaneous gravimetric PM2.5 was measured at both sites and characterized for carbonaceous constituents and water-soluble trace elements and metals. Results depicted higher PM2.5, elemental carbon (EC), and organic carbon (OC) concentrations on the RS than BG (by a factor of 1.7, 4.6, and 1.2, respectively), while BG had higher water-soluble organic carbon (WSOC) levels (by a factor of 1.4) and a higher WSOC to OC ratio (86%), likely due to the dominance of secondary aerosol formation. In contrast, the measured OPDTTv at RS (8.9 ± 5.5 nmol/min/m3) and BG (8.1 ± 6.4 nmol/min/m3) sites were similar. However, OPDTTv at BG was higher during the afternoon, suggesting the influence of photochemical transformation on measured OPDTTv at BG. At RS, OC and redox-active metals (Cu, Zn, Mn, and Fe) were significantly associated with measured OP (p < 0.05), while at BG, WSOC was most strongly associated (p < 0.05). The coefficient of divergence (COD) for PM2.5, its chemical species, and OPDTTv was >0.2, indicating spatial heterogeneity between the sites, and differences in emission sources and toxicity. The estimated hazard index (HI) was not associated with OPDTTv, indicating that current PM2.5 mass regulations may not adequately capture the health effects of PM2.5. The study highlights the need for further studies examining PM2.5 toxicity and developing toxicity-based air quality regulations.
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Affiliation(s)
- Nagendra Raparthi
- Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Mumbai, India; Air Quality Research Center, University of California Davis, Davis, CA, USA
| | - Suman Yadav
- Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Mumbai, India
| | - Ashi Khare
- Centre for Technology Alternatives for Rural Areas, Indian Institute of Technology Bombay, Mumbai, India
| | - Shreya Dubey
- Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Mumbai, India
| | - Harish C Phuleria
- Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Mumbai, India; IDP in Climate Studies, Indian Institute of Technology Bombay, Mumbai, India; Koita Centre for Digital Health, Indian Institute of Technology Bombay, Mumbai, India.
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7
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Bhardwaj A, Haswani D, Yadav K, Sunder Raman R. PM 2.5 carbonaceous components and mineral dust at a COALESCE network site - Bhopal, India: Estimating site-specific optical characteristics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163277. [PMID: 37028678 DOI: 10.1016/j.scitotenv.2023.163277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/14/2023] [Accepted: 03/31/2023] [Indexed: 05/27/2023]
Abstract
Atmospheric PM2.5 thermal elemental carbon (EC), optical black carbon (BC), brown carbon (BrC), and mineral dust (MD) were characterized during a field campaign at a regionally representative site (Bhopal, central India) all year-long during 2019. In this study, the optical characteristics of PM2.5 during 'EC-rich', 'OC-rich', and 'MD-rich' days were used in a three-component model to estimate site-specific Absorption Ångström exponent (AAE) and absorption coefficient (babs) of light-absorbing PM2.5 constituents. The AAE for 'EC-rich', 'OC-rich', and 'MD-rich' days were 1.1 ± 0.2, 2.7 ± 0.3, and 3.0 ± 0.9, respectively. The percentage contribution of calculated babs of EC, BrC, and MD to the total babs at 405 nm was dominated by EC during the entire study period (EC; 64 % ± 36 %, BrC: 30 % ± 5 %, MD: 10 % ± 1 %). Further, site-specific mass absorption cross-section (MAC) values were calculated to assess the impact of their use over the use of manufacturer-specified MAC values in estimating BC concentrations. The r2 between thermal EC and optical BC was higher (r2 = 0.67, slope = 1.1) when daily site-specific MAC values were used rather than using the default MAC value (16.6 m2 g-1; r2 = 0.54 and slope = 0.6). Overall, had the default MAC880 been used instead of the site-specific values, we would have underestimated the BC concentration by 39 % ± 18 % during the study period.
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Affiliation(s)
- Ankur Bhardwaj
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal by-pass road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Diksha Haswani
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal by-pass road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Kajal Yadav
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal by-pass road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Ramya Sunder Raman
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal by-pass road, Bhauri, Bhopal 462066, Madhya Pradesh, India.
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8
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Guascito MR, Lionetto MG, Mazzotta F, Conte M, Giordano ME, Caricato R, De Bartolomeo AR, Dinoi A, Cesari D, Merico E, Mazzotta L, Contini D. Characterisation of the correlations between oxidative potential and in vitro biological effects of PM 10 at three sites in the central Mediterranean. JOURNAL OF HAZARDOUS MATERIALS 2023; 448:130872. [PMID: 36716558 DOI: 10.1016/j.jhazmat.2023.130872] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/09/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Atmospheric particulate matter (PM) is one of the major risks for global health. The exact mechanisms of toxicity are still not completely understood leading to contrasting results when different toxicity metrics are compared. In this work, PM10 was collected at three sites for the determination of acellular oxidative potential (OP), intracellular oxidative stress (OSGC), cytotoxicity (MTT assay), and genotoxicity (Comet assay). The in vitro tests were done on the A549 cell line. The objective was to investigate the correlations among acellular and intracellular toxicity indicators, the variability among the sites, and how these correlations were influenced by the main sources by using PMF receptor model coupled with MLR. The OPDTTV, OSGCV, and cytotoxicity were strongly influenced by combustion sources. Advection of African dust led to lower-than-average intrinsic toxicity indicators. OPDTTV and OSGCV showed site-dependent correlations suggesting that acellular OP may not be fully representative of the intracellular oxidative stress at all sites and conditions. Cytotoxicity correlated with both OPDTTV and OSGCV at two sites out of three and the strength of the correlation was larger with OSGCV. Genotoxicity was correlated with cytotoxicity at all sites and correlated with both, OPDTTV and OSGCV, at two sites out of three. Results suggest that several toxicity indicators are useful to gain a global picture of the potential health effects of PM.
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Affiliation(s)
- Maria Rachele Guascito
- Department of Environmental and Biological Sciences and Technologies (DISTEBA), University of Salento, Lecce 73100, Italy; Institute of Atmospheric Sciences and Climate, ISAC-CNR, Str. Prv. Lecce-Monteroni km 1.2, 73100 Lecce, Italy
| | - Maria Giulia Lionetto
- Department of Environmental and Biological Sciences and Technologies (DISTEBA), University of Salento, Lecce 73100, Italy
| | - Franco Mazzotta
- Studio Effemme Chimica Applicata, s.r.l. Via Pio XII, 73018 Squinzano, Italy
| | - Marianna Conte
- Laboratory for Observations and Analyses of Earth and Climate, Agenzia Nazionale per le Nuove Tecnologie, l'Energia e lo Sviluppo Economico Sostenibile (ENEA), 00123 Roma, Italy
| | - Maria Elena Giordano
- Department of Environmental and Biological Sciences and Technologies (DISTEBA), University of Salento, Lecce 73100, Italy
| | - Roberto Caricato
- Department of Environmental and Biological Sciences and Technologies (DISTEBA), University of Salento, Lecce 73100, Italy
| | - Anna Rita De Bartolomeo
- Department of Environmental and Biological Sciences and Technologies (DISTEBA), University of Salento, Lecce 73100, Italy
| | - Adelaide Dinoi
- Institute of Atmospheric Sciences and Climate, ISAC-CNR, Str. Prv. Lecce-Monteroni km 1.2, 73100 Lecce, Italy
| | - Daniela Cesari
- Institute of Atmospheric Sciences and Climate, ISAC-CNR, Str. Prv. Lecce-Monteroni km 1.2, 73100 Lecce, Italy
| | - Eva Merico
- Institute of Atmospheric Sciences and Climate, ISAC-CNR, Str. Prv. Lecce-Monteroni km 1.2, 73100 Lecce, Italy
| | - Laura Mazzotta
- Studio Effemme Chimica Applicata, s.r.l. Via Pio XII, 73018 Squinzano, Italy
| | - Daniele Contini
- Institute of Atmospheric Sciences and Climate, ISAC-CNR, Str. Prv. Lecce-Monteroni km 1.2, 73100 Lecce, Italy.
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9
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Aldekheel M, Farahani VJ, Tohidi R, Altuwayjiri A, Sioutas C. Development and performance evaluation of a two-stage cascade impactor equipped with gelatin filter substrates for the collection of multi-sized particulate matter. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2023; 294:119493. [PMID: 36504702 PMCID: PMC9733700 DOI: 10.1016/j.atmosenv.2022.119493] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
This study presents the development and evaluation of a high flow rate gelatin cascade impactor (GCI) to collect different PM particle sizes on water-soluble gelatin substrates. The GCI operates at a flow rate of 100 lpm, and consists of two impaction stages, followed by a filter holder to separate particles in the following diameter ranges: >2.5 μm, 0.2-2.5 μm, and <0.2 μm. Laboratory characterization of the GCI performance was conducted using monodisperse polystyrene latex (PSL) particles as well as polydisperse ammonium sulfate, sodium chloride, and ammonium nitrate aerosols to obtain the particle collection efficiency curves for both impaction stages. In addition to the laboratory characterization, we performed concurrent field experiments to collect PM2.5 employing both GCI equipped with gelatin filter and personal cascade impactor sampler (PCIS) equipped with PTFE filter for further toxicological analysis using macrophage-based reactive oxygen species (ROS) and dithiothreitol consumption (DTT) assays. Our results showed that the experimentally determined cut-point diameters for the first and second impaction stages were 2.4 μm and 0.21 μm, respectively, which agreed with the theoretical predictions. Although the GCI has been developed primarily to collect particles on gelatin filters, the use of a different type of substrate (i.e., quartz) led to similar particle separation characteristics. The findings of the field tests demonstrated the advantage of using the GCI in toxicological studies due to its ability to collect considerable PM-toxic constituents, as corroborated by the DTT and ROS values for the GCI-collected particles which were 26.44 nmoles/min/mg PM and 8813.2 μg Zymosan Units/mg PM, respectively. These redox activity values were more than twice those of particles collected concurrently on PTFE filter using the PCIS. This high-flow-rate impactor can collect considerable amounts of size-fractionated PM on water-soluble filters (i.e., gelatin), which can completely dissolve in water allowing for the extraction of soluble and insoluble PM species for further toxicological analysis.
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Affiliation(s)
- Mohammad Aldekheel
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, California, USA
- Kuwait University, Department of Civil Engineering, P.O Box 5969, Safat 13060, Kuwait
| | - Vahid Jalali Farahani
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, California, USA
| | - Ramin Tohidi
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, California, USA
| | - Abdulmalik Altuwayjiri
- Department of Civil and Environmental Engineering, College of Engineering, Majmaah University, AL-Majmaah 11952, Saudi Arabia
| | - Constantinos Sioutas
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, California, USA
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10
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Faridi S, Yousefian F, Roostaei V, Harrison RM, Azimi F, Niazi S, Naddafi K, Momeniha F, Malkawi M, Moh'd Safi HA, Rad MK, Hassanvand MS. Source apportionment, identification and characterization, and emission inventory of ambient particulate matter in 22 Eastern Mediterranean Region countries: A systematic review and recommendations for good practice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 310:119889. [PMID: 35932896 DOI: 10.1016/j.envpol.2022.119889] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/16/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
Little is known about the main sources of ambient particulate matter (PM) in the 22 Eastern Mediterranean Region (EMR) countries. We designed this study to systematically review all published and unpublished source apportionment (SA), identification and characterization studies as well as emission inventories in the EMR. Of 440 articles identified, 82 (11 emission inventory ones) met our inclusion criteria for final analyses. Of 22 EMR countries, Iran with 30 articles had the highest number of studies on source specific PM followed by Pakistan (n = 15 articles) and Saudi Arabia (n = 8 papers). By contrast, there were no studies in Afghanistan, Bahrain, Djibouti, Libya, Somalia, Sudan, Syria, Tunisia, United Arab Emirates and Yemen. Approximately 72% of studies (51) were published within a span of 2015-2021.48 studies identified the sources of PM2.5 and its constituents. Positive matrix factorization (PMF), principal component analysis (PCA) and chemical mass balance (CMB) were the most common approaches to identify the source contributions of ambient PM. Both secondary aerosols and dust, with 12-51% and 8-80% (33% and 30% for all EMR countries, on average) had the greatest contributions in ambient PM2.5. The remaining sources for ambient PM2.5, including mixed sources (traffic, industry and residential (TIR)), traffic, industries, biomass burning, and sea salt were in the range of approximately 4-69%, 4-49%, 1-53%, 7-25% and 3-29%, respectively. For PM10, the most dominant source was dust with 7-95% (49% for all EMR countries, on average). The limited number of SA studies in the EMR countries (one study per approximately 9.6 million people) in comparison to Europe and North America (1 study per 4.3 and 2.1 million people respectively) can be augmented by future studies that will provide a better understanding of emission sources in the urban environment.
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Affiliation(s)
- Sasan Faridi
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Yousefian
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| | - Vahid Roostaei
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Roy M Harrison
- School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, UK; Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Faramarz Azimi
- Environmental Health Research Center, School of Health and Nutrition, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Sadegh Niazi
- International Laboratory for Air Quality and Health, School of Earth and Atmospheric Sciences, Science and Engineering Faculty, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Kazem Naddafi
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Momeniha
- Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Mazen Malkawi
- Environmental Health Exposures Centre for Environmental Health Action (CEHA), World Health Organization (WHO), Jordan
| | - Heba Adel Moh'd Safi
- Environmental Health Exposures Centre for Environmental Health Action (CEHA), World Health Organization (WHO), Jordan
| | - Mona Khaleghy Rad
- Environmental Health Exposures Centre for Environmental Health Action (CEHA), World Health Organization (WHO), Jordan
| | - Mohammad Sadegh Hassanvand
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
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11
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Farahani VJ, Altuwayjiri A, Pirhadi M, Verma V, Ruprecht AA, Diapouli E, Eleftheriadis K, Sioutas C. The oxidative potential of particulate matter (PM) in different regions around the world and its relation to air pollution sources. ENVIRONMENTAL SCIENCE: ATMOSPHERES 2022; 2:1076-1086. [PMID: 36277745 PMCID: PMC9476553 DOI: 10.1039/d2ea00043a] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/02/2022] [Indexed: 05/19/2023]
Abstract
In this study, we investigated the impact of urban emission sources on the chemical composition of ambient particulate matter (PM) as well as the associated oxidative potential. We collected six sets of PM samples in five urban location sites around the world over long time periods varying from weeks to months, intentionally selected for their PM to be dominated by unique emission sources: (1) PM2.5 produced mainly by traffic emissions in central Los Angeles, United States (US); (2) PM2.5 dominated by biomass burning in Milan, Italy; (3) PM2.5 formed by secondary photochemical reactions thus dominated by secondary aerosols in Athens, Greece; (4) PM10 emitted by refinery and dust resuspension in Riyadh, Saudi Arabia (SA); (5) PM10 generated by dust storms in Riyadh, SA, and (6) PM2.5 produced mainly by industrial and traffic emissions in Beirut, Lebanon. The PM samples were chemically analyzed and their oxidative potential were quantified by employing the dithiothreitol (DTT) assay. Our results revealed that the Milan samples were rich in water soluble organic carbon (WSOC) and PAHs, even exceeding the levels measured on Los Angeles (LA) freeways. The PM in Athens was characterized by high concentrations of inorganic ions, specifically sulfate which was the highest of all PM samples. The ambient PM in LA was impacted by the traffic-emitted primary organic and elemental carbon. Furthermore, the contribution of metals and elements per mass of PM in Riyadh and Beirut samples were more pronounced relative to other sampling areas. The highest intrinsic PM redox activity was observed for PM with the highest WSOC fraction, including Milan (biomass burning) and Athens (secondary organic aerosols, SOA). PM in areas characterized by high metal emissions including dust events, refinery and industry, such as Riyadh and Beirut, had the lowest oxidative potential as assessed by the DTT assay. The results of this study illustrate the impact of major emission sources in urban areas on the redox activity and oxidative potential of ambient PM, providing useful information for developing efficient air pollution control and mitigation policies in polluted areas around the globe.
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Affiliation(s)
- Vahid Jalali Farahani
- University of Southern California, Department of Civil and Environmental Engineering 3620 S. Vermont Ave, KAP210 Los Angeles California 90089 USA +1-213-744-1426 +1-213-740-6134
| | - Abdulmalik Altuwayjiri
- University of Southern California, Department of Civil and Environmental Engineering 3620 S. Vermont Ave, KAP210 Los Angeles California 90089 USA +1-213-744-1426 +1-213-740-6134
- Majmaah University, Department of Civil and Environmental Engineering Majmaah Riyadh Saudi Arabia
| | - Milad Pirhadi
- California Air Resources Board Sacramento California USA
| | - Vishal Verma
- University of Illinois at Urbana Champaign, Department of Civil and Environmental Engineering Urbana Illinois USA
| | | | - Evangelia Diapouli
- Environmental Radioactivity Laboratory, N.C.S.R. Demokritos 15341 Attiki Greece
| | | | - Constantinos Sioutas
- University of Southern California, Department of Civil and Environmental Engineering 3620 S. Vermont Ave, KAP210 Los Angeles California 90089 USA +1-213-744-1426 +1-213-740-6134
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12
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Tohidi R, Farahani VJ, Sioutas C. Real-time measurements of mineral dust concentration in coarse particulate matter (PM 10-2.5) by employing a novel optical-based technique in Los Angeles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156215. [PMID: 35623535 DOI: 10.1016/j.scitotenv.2022.156215] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/01/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
As a primary component of coarse particulate matter (PM), ambient mineral dust has been linked to adverse health effects. Los Angeles, the largest metropolitan urban area of the United States, is impacted by both windblown and localized sources of mineral dust, often internally mixed with black carbon. The estimation of mineral dust concentrations with a high time resolution becomes critical in improving our understanding of its sources and temporal trends. Using Aethalometers combined with a high-volume virtual impactor (VI) to enrich coarse (2.5 <dp < 10 μm) particles, the light absorption and mass concentration of mineral dust were estimated in real-time during summer, fall, and winter over 2020-2021. The concentration-enriched coarse PM was collected on Teflon filters, and its chemical composition in terms of trace elements and metals was chemically quantified. The high time-resolution measurements enabled us to calculate the absorption coefficient of enriched dust particles by subtracting the light absorption of the post-VI coarse PM from that of the PM2.5 aerosol fraction to reduce the impact of stronger light absorbers in ambient PM. Mineral dust was more prevalent during the fall and winter campaigns (i.e., 19.3 and 11.4 μg/m3, respectively), lower concentrations were observed during the summer campaign (i.e., 8.50 μg/m3). The calculated absorption Ångström exponent (AAE) was 2.18, highlighting the presence of dust particles during the sampling period. The dust mass absorption coefficient was estimated to be 2.7 ± 1.6 Mm-1 at 370 nm and 0.41 ± 0.16 Mm-1 at 880 nm wavelengths, respectively. The validation of the proposed approach was investigated by comparing the evaluated mineral dust mass concentrations in this study with the reported coarse PM concentrations by the California Air Resources Board (CARB). The results reported by the optical-based approach with high temporal resolution can provide crucial information on identifying sources of mineral dust in urban areas.
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Affiliation(s)
- Ramin Tohidi
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA
| | - Vahid Jalali Farahani
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA
| | - Constantinos Sioutas
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
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13
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Jalali Farahani V, Altuwayjiri A, Taghvaee S, Sioutas C. Tailpipe and Nontailpipe Emission Factors and Source Contributions of PM 10 on Major Freeways in the Los Angeles Basin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:7029-7039. [PMID: 35230811 DOI: 10.1021/acs.est.1c06954] [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: 06/14/2023]
Abstract
In this study, the emission factors of PM10 and its chemical constituents from various contributing sources including nontailpipe and tailpipe emissions were estimated on two interstate freeways in the Los Angeles basin. PM10 samples were collected on the I-110 and I-710 freeways as well as at the University of Southern California (USC) campus as the urban background site, while freeway and urban background CO2 levels were measured simultaneously. PM10 samples were analyzed for their content of chemical species which were used to estimate the emission factors of PM10 and its constituents on both I-110 and I-710 freeways. The estimated values were employed to determine the emission factors for light (LDV) and heavy-duty vehicles (HDV). The quantified species were also processed by the positive matrix factorization (PMF) model to produce PM10 freeway source profiles and their contribution to PM10 mass concentrations. Using the PMF factor profiles and emission factors on the two freeways, we characterized the emission factors for light-duty and heavy-duty vehicles by each nontailpipe source. Our findings indicated higher nontailpipe emission factors of PM10 and metal elements on the I-710 freeway compared to the I-110 freeway, due to the higher fraction of heavy-duty vehicles (HDVs) on that freeway. Furthermore, the generation of nontailpipe PM10 from resuspension of road dust was twice of tire and brake wear. The results of this study provide significant insights into PM10 freeway emissions and particularly the overall contribution of nontailpipe and tailpipe sources in Los Angeles, which can be helpful to modelers and air quality officials in assessing the importance of individual traffic-related emissions on the overall population exposure.
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Affiliation(s)
- Vahid Jalali Farahani
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, California 90007, United States
| | - Abdulmalik Altuwayjiri
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, California 90007, United States
- Department of Civil and Environmental Engineering, Majmaah University, Majmaah, Riyadh 15341, Saudi Arabia
| | - Sina Taghvaee
- Department of Atmospheric & Oceanic Sciences, University of California─Los Angeles, Los Angeles, California 90095, United States
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, California 90007, United States
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14
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A New Method for the Assessment of the Oxidative Potential of Both Water-Soluble and Insoluble PM. ATMOSPHERE 2022. [DOI: 10.3390/atmos13020349] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Water-soluble and insoluble fractions of airborne particulate matter (PM) exhibit different toxicological potentials and peculiar mechanisms of action in biological systems. However, most of the research on the oxidative potential (OP) of PM is focused exclusively on its water-soluble fraction, since experimental criticisms were encountered for detaching the whole PM (soluble and insoluble species) from field filters. However, to estimate the actual potential effects of PM on human health, it is essential to assess the OP of both its water-soluble and insoluble fractions. In this study, to estimate the total OP (TOP), an efficient method for the detachment of intact PM10 from field filters by using an electrical toothbrush was applied to 20 PM10 filters in order to obtain PM10 water suspensions to be used for the DCFH, AA and DTT oxidative potential assays (OPDCFH, OPAA and OPDTT). The contribution of the insoluble PM10 to the TOP was evaluated by comparing the TOP values to those obtained by applying the three OP assays to the water-soluble fraction of 20 equivalent PM10 filters. The OP of the insoluble fraction (IOP) was calculated as the difference between the TOP and the WSOP. Moreover, each PM10 sample was analyzed for the water-soluble and insoluble fractions of 10 elements (Al, Cr, Cs, Cu, Fe, Li, Ni, Rb, Sb, Sn) identified as primary elemental tracers of the main emission sources in the study area. A principal component analysis (PCA) was performed on the data obtained to identify the predominant sources for the determination of TOP, WSOP, and IOP. Results showed that water-soluble PM10 released by traffic, steel plant, and biomass burning is mainly responsible for the generation of the TOP as well as of the WSOP. This evidence gave strength to the reliability of the results from OP assays performed only on the water-soluble fraction of PM. Lastly, the IOPDCFH and IOPDTT were found to be principally determined by insoluble PM10 from mineral dust.
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