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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. Atmos Environ (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] [What about the content of this article? (0)] [Affiliation(s)] [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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Tohidi R, Altuwayjiri A, Sioutas C. Investigation of organic carbon profiles and sources of coarse PM in Los Angeles. Environ Pollut 2022; 314:120264. [PMID: 36162557 DOI: 10.1016/j.envpol.2022.120264] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/17/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Source apportionment analyses are essential tools to determine sources of ambient coarse particles (2.5 <dp < 10 μm) and to disentangle their association and contribution from other pollutants, particularly PM2.5 (<2.5 μm). A semi-continuous sampling campaign was conducted using two virtual impactors/concentrators to enhance coarse particulate matter concentrations coupled with an online thermal-optical EC/OC monitor to quantify coarse PM-bound organic carbon volatility fractions (OC1-OC4) in central Los Angeles during the winter, spring, and summer of 2021. The total OC and its volatility fraction concentrations, meteorological parameters (i.e., wind speeds and relative humidity), vehicle miles traveled (VMT), and gaseous source tracers (i.e., O3 and NO2) were used as inputs to positive matrix factorization (PMF) model. A 3-factor solution identified vehicular emissions (accounting for 46% in the cold phase and 26% in the warm phase of total coarse OC concentrations), secondary organic carbon (27% and 37%), and re-suspended dust (27% and 37%) as the primary organic carbon sources of coarse PM. The re-suspended dust factor showed a higher contribution of more volatile organic carbons (i.e., OC1 up to 77%) due to their re-distribution on dust particles, whereas the SOA factor was the dominant contributor to less volatile organic aerosols (i.e., OC4 up to 54%), which are the product of reactions at high relative humidity (RH). Our findings revealed that the total OC concentrations in the coarse size range were comparable with those of previous studies in the area, underscoring the challenges in curtailing coarse PM-bound OC sources and the necessity of developing effective emission control regulations on coarse PM. The results from the current study provide insights into the seasonal and temporal variation of total OC and its volatility fractions in Los Angeles.
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Affiliation(s)
- Ramin Tohidi
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA
| | - Abdulmalik Altuwayjiri
- Majmaah University, Department of Civil and Environmental Engineering, Majmaah, Riyadh, Saudi Arabia
| | - Constantinos Sioutas
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
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Aldekheel M, Altuwayjiri A, Tohidi R, Jalali Farahani V, Sioutas C. The Role of Portable Air Purifiers and Effective Ventilation in Improving Indoor Air Quality in University Classrooms. Int J Environ Res Public Health 2022; 19:14558. [PMID: 36361438 PMCID: PMC9658982 DOI: 10.3390/ijerph192114558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/30/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
In this study we investigated the effectiveness of air purifiers and in-line filters in ventilation systems working simultaneously inside various classrooms at the University of Southern California (USC) main campus. We conducted real-time measurements of particle mass (PM), particle number (PN), and carbon dioxide (CO2) concentrations in nine classrooms from September 2021 to January 2022. The measurement campaign was carried out with different configurations of the purifier (i.e., different flow rates) while the ventilation system was continuously working. Our results showed that the ventilation systems in the classrooms were adequate in providing sufficient outdoor air to dilute indoor CO2 concentrations due to the high air exchange rates (2.63-8.63 h-1). The particle penetration coefficients (P) of the investigated classrooms were very low for PM (<0.2) and PN (<0.1), with the exception of one classroom, corroborating the effectiveness of in-line filters in the ventilation systems. Additionally, the results showed that the efficiency of the air purifier exceeded 95% in capturing ultrafine and coarse particles and ranged between 82-88% for particles in the accumulation range (0.3-2 µm). The findings of this study underline the effectiveness of air purifiers and ventilation systems equipped with efficient in-line filters in substantially reducing indoor air pollution.
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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, Kuwait City 13060, Kuwait
| | - Abdulmalik Altuwayjiri
- Department of Civil and Environmental Engineering, College of Engineering, Majmaah University, Al-Majmaah 11952, Saudi Arabia
| | - Ramin Tohidi
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Vahid Jalali Farahani
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089, USA
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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. Environ Sci Atmos 2022; 2:1076-1086. [PMID: 36277745 PMCID: PMC9476553 DOI: 10.1039/d2ea00043a] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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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. Environ Sci Technol 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Altuwayjiri A, Pirhadi M, Kalafy M, Alharbi B, Sioutas C. Impact of different sources on the oxidative potential of ambient particulate matter PM 10 in Riyadh, Saudi Arabia: A focus on dust emissions. Sci Total Environ 2022; 806:150590. [PMID: 34597581 PMCID: PMC8907835 DOI: 10.1016/j.scitotenv.2021.150590] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 05/08/2023]
Abstract
In this study, we employed Principal Component Analysis (PCA) and Multi-Linear Regression (MLR) to identify the most significant sources contributing to the toxicity of PM10 in the city center of Riyadh. PM10 samples were collected using a medium-volume air sampler during cool (December 2019-March 2020) and warm (May 2020-August 2020) seasons, including dust and non-dust events. The collected filters were analyzed for their chemical components (i.e., water-soluble ions, metals, and trace elements) as well as oxidative potential and elemental and organic carbon (EC/OC) contents. Our measurements revealed comparable extrinsic oxidative potential (P-value = 0.30) during the warm (1.2 ± 0.1 nmol/min-m3) and cool (1.1 ± 0.1 nmol/min-m3) periods. Moreover, we observed higher extrinsic oxidative potential of PM10 samples collected during dust events (~30% increase) compared to non-dust samples. Our PCA-MLR analysis identified soil and resuspended dust, secondary aerosol (SA), local industrial activities and petroleum refineries, and traffic emissions as the four sources contributing to the ambient PM10 oxidative potential in central Riyadh. Soil and resuspended dust were the major source contributing to the oxidative potential of ambient PM10, accounting for 31% of the total oxidative potential. Secondary aerosols (SA) were the next important source of PM10 toxicity in the area as they contributed to about 20% of the PM10 oxidative potential. Results of this study revealed the major role of soil and resuspended road dust on PM10 toxicity and can be helpful in adopting targeted air quality policies to reduce the population exposure to PM10.
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Affiliation(s)
- Abdulmalik Altuwayjiri
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA; Majmaah University, Department of Civil and Environmental Engineering, Majmaah, Riyadh, Saudi Arabia
| | - Milad Pirhadi
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA
| | - Mohammed Kalafy
- Saudi Envirozone, Air Quality Monitoring Department, Riyadh, Saudi Arabia
| | - Badr Alharbi
- National Center for Environmental Technology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Constantinos Sioutas
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
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Altuwayjiri A, Soleimanian E, Moroni S, Palomba P, Borgini A, De Marco C, Ruprecht AA, Sioutas C. The impact of stay-home policies during Coronavirus-19 pandemic on the chemical and toxicological characteristics of ambient PM 2.5 in the metropolitan area of Milan, Italy. Sci Total Environ 2021; 758:143582. [PMID: 33213922 PMCID: PMC7833074 DOI: 10.1016/j.scitotenv.2020.143582] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 10/10/2020] [Accepted: 11/02/2020] [Indexed: 05/03/2023]
Abstract
The goal of this study was to characterize changes in components and toxicological properties of PM2.5 during the nationwide 2019-Coronavirus (COVID-19) lockdown restrictions in Milan, Italy. Time-integrated PM2.5 filters were collected at a residential site in Milan metropolitan area from April 11th to June 3rd at 2020, encompassing full-lockdown (FL), the followed partial-lockdown (PL2), and full-relaxation (FR) periods of COVID-19 restrictions. The collected filters were analyzed for elemental and organic carbon (EC/OC), water-soluble organic carbon (WSOC), individual organic species (e.g., polycyclic aromatic hydrocarbons (PAHs), and levoglucosan), and metals. According to online data, nitrogen dioxide (NO2) and benzene (C6H6) levels significantly decreased during the entire COVID-19 period compared to the same time span in 2019, mainly due to the government-backed shutdowns and curtailed road traffic. Similarly, with a few exceptions, surrogates of tailpipe emissions (e.g., traffic-associated PAHs) as well as re-suspended road dust (e.g., Fe, Mn, Cu, Cr, and Ti) were relatively lower during FL and PL2 periods in comparison with year 2019, whereas an increasing trend in mass concentration of mentioned species was observed from FL to PL2 and FR phases due to the gradual lifting of lockdown restrictions. In contrast, comparable concentrations of ambient PM2.5 and black carbon (BC) between lockdown period and the same time span in 2019 were attributed to the interplay between decreased road traffic and elevated domestic biomass burning as a result of adopted stay-home strategies. Finally, the curtailed road traffic during FL and PL2 periods led to ~25% drop in the PM2.5 oxidative potential (measured via 2',7'-dichlorodihydrofluorescein (DCFH) and dithiothreitol (DTT) assays) with respect to the FR period as well as the same time span in 2019. The results of this study provide insights into the changes in components and oxidative potential of PM2.5 in the absence of road traffic during COVID-19 restrictions.
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Affiliation(s)
- Abdulmalik Altuwayjiri
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA
| | - Ehsan Soleimanian
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA
| | - Silvia Moroni
- Agenzia Mobilità Ambiente e Territorio - AMAT srl, Mobility, Environment and Territory Agency, Milan, Italy
| | - Paolo Palomba
- Agenzia Mobilità Ambiente e Territorio - AMAT srl, Mobility, Environment and Territory Agency, Milan, Italy
| | - Alessandro Borgini
- Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; Associazione Medici per l'Ambiente ISDE Italia, International Society of Doctors for the Environment (ISDE), Italy
| | - Cinzia De Marco
- Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; Associazione Medici per l'Ambiente ISDE Italia, International Society of Doctors for the Environment (ISDE), Italy
| | - Ario A Ruprecht
- Associazione Medici per l'Ambiente ISDE Italia, International Society of Doctors for the Environment (ISDE), Italy
| | - Constantinos Sioutas
- University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
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Altuwayjiri A, Taghvaee S, Mousavi A, Sowlat MH, Hassanvand MS, Kashani H, Faridi S, Yunesian M, Naddafi K, Sioutas C. Association of systemic inflammation and coagulation biomarkers with source-specific PM 2.5 mass concentrations among young and elderly subjects in central Tehran. J Air Waste Manag Assoc 2021; 71:191-208. [PMID: 32758070 DOI: 10.1080/10962247.2020.1806140] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 05/20/2023]
Abstract
In this study, we investigated the association between short-term exposure to different sources of fine particulate matter (PM2.5) and biomarkers of coagulation and inflammation in two different panels of elderly and healthy young individuals in central Tehran. Five biomarkers, including white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF) were analyzed in the blood samples drawn every 8 weeks from the subjects between May 2012 and May 2013. The studied populations consisted of 44 elderly individuals at a retirement home as well as 40 young adults residing at a school dormitory. Positive Matrix Factorization (PMF)-resolved source-specific PM2.5 mass concentrations and biomarker levels were used as the input to the linear mixed-effects regression model to evaluate the impact of exposure to previously identified PM sources at retirement home and school dormitory in two time lag configurations: lag 1-3 (1-3 days before the blood sampling), and lag 4-6 (4-6 days before the blood sampling). Our analysis of the elderly revealed positive associations of all biomarkers (except hsCRP) with particles of secondary origin in both time lags, further corroborating the toxicity of secondary aerosols formed by photochemical processing in central Tehran. Moreover, industrial emissions, and road dust particles were positively associated with WBC, sTNF-RII, and IL-6 among seniors, while vehicular emissions exhibited positive associations with all biomarkers in either first- or second-time lag. In contrast, most of the PM2.5 sources showed insignificant associations with biomarkers of inflammation in the panel of healthy young subjects. Therefore, findings from this study indicated that various PM2.5 sources increase the levels of inflammation and coagulation biomarkers, although the strength and significance of these associations vary depending on the type of PM sources, demographic characteristics, and differ across the different time lags. Implications: Tehran, the capital of Iran with a population of more than 9 million people, has been facing serious air pollution challenges as a result of extensive vehicular, and industrial activities in the previous years. Among various air pollutants in Tehran, fine particulate matters (PM2.5, particles with aerodynamic diameters < 2.5 µm) are known as one of the most important critical pollutants, causing several adverse health impacts including lung cancer, respiratory, cardiovascular, and cardiopulmonary diseases. Therefore, a number of studies in the area have tried to investigate the adverse health impacts of exposure to PM2.5. However, no studies have ever been conducted in Tehran to examine the association between specific PM2.5 sources and biomarkers of coagulation and systemic inflammation as indicators of cardiovascular disorders. Indeed, this is the first study in the area investigating the association of source-specific PM2.5 with biomarkers of inflammation including white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF). Our results have important implications for policy makers in identifying the most toxic sources of PM2.5, and in turn designing schemes for mitigating adverse health impacts of air pollution in Tehran.
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Affiliation(s)
- Abdulmalik Altuwayjiri
- Department of Civil and Environmental Engineering, University of Southern California , Los Angeles, CA, USA
| | - Sina Taghvaee
- Department of Civil and Environmental Engineering, University of Southern California , Los Angeles, CA, USA
| | - Amirhosein Mousavi
- Department of Civil and Environmental Engineering, University of Southern California , Los Angeles, CA, USA
| | - Mohammad H Sowlat
- Advanced Monitoring Technologies, Science and Technology Advancement Division, South Coast Air Quality Management District , Diamond Bar, CA, USA
| | - Mohammad Sadegh Hassanvand
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences , Tehran, Iran
| | - Homa Kashani
- Department of Research Methodology and Data Analysis, Institute for Environmental Research (IER), Tehran University of Medical Sciences , Tehran, Iran
| | - 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
| | - Masud Yunesian
- Department of Research Methodology and Data Analysis, 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
| | - 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
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, University of Southern California , Los Angeles, CA, USA
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Altuwayjiri A, Pirhadi M, Taghvaee S, Sioutas C. Long-term trends in the contribution of PM 2.5 sources to organic carbon (OC) in the Los Angeles basin and the effect of PM emission regulations. Faraday Discuss 2020; 226:74-99. [PMID: 33241815 DOI: 10.1039/d0fd00074d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study aimed to investigate the long-term variations in the contributions of emission sources to ambient PM2.5 organic carbon (OC) in central Los Angeles (CELA) and Riverside using the Chemical Speciation Network (CSN) database in the 2005-2015 period, during which several federal and state PM-based regulations were implemented to reduce tailpipe emissions in the region. The measured concentrations of OC, OC volatility fractions (i.e., OC1, OC2, and OC3), elemental carbon (EC), ozone (O3), sulfate, the ratio of potassium ion to potassium (K+/K), and selected metal elements were used as the input to the positive matrix factorization (PMF) model. PMF resolved tailpipe emissions, non-tailpipe emissions, secondary organic aerosols (SOA), biomass burning, and local industrial activities as the main sources contributing to ambient OC at both sampling sites. Vehicular exhaust emissions, non-tailpipe emissions, and SOA were dominant sources of OC across our sampling sites, accounting cumulatively for more than 80% of total OC mass throughout the study period. Our findings showed a significant reduction in the absolute and relative contributions of tailpipe emissions to the ambient OC levels in CELA and Riverside over the time period of 2005-2015. The contribution of exhaust emissions to total OC in CELA decreased from 3.5 µg m-3 (49%) in 2005 to 1.5 µg m-3 (34%) in 2015, while similar trends were observed at Riverside during this period. These reductions are mainly attributed to the implementation of several federal, state, and local air quality regulations targeting tailpipe emissions in the area. The implementation of these regulations furthermore reduced the emissions of primary organic precursors of secondary aerosols, resulting in an overall decrease (although not statistically significant, P values ranging from 0.4 to 0.6) in SOA mass concentration in both locations over the study period. In contrast to the tailpipe emissions, we observed an increasing trend (by ∼4 to 14%) in the relative contribution of non-tailpipe emissions to OC over this time period at both sites. Our results demonstrated the effectiveness of air quality regulations in reducing direct tailpipe emissions in the area, but also underpinned the need to develop equally effective mitigation policies targeting non-tailpipe PM emissions.
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Affiliation(s)
- Abdulmalik Altuwayjiri
- University of Southern California, Department of Civil and Environmental Engineering, 3620 S. Vermont Ave. KAP210, Los Angeles, CA 90089, USA.
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