1
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Liu F, Joo T, Ditto JC, Saavedra MG, Takeuchi M, Boris AJ, Yang Y, Weber RJ, Dillner AM, Gentner DR, Ng NL. Oxidized and Unsaturated: Key Organic Aerosol Traits Associated with Cellular Reactive Oxygen Species Production in the Southeastern United States. Environ Sci Technol 2023; 57:14150-14161. [PMID: 37699525 PMCID: PMC10538939 DOI: 10.1021/acs.est.3c03641] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/14/2023]
Abstract
Exposure to ambient fine particulate matter (PM2.5) is associated with millions of premature deaths annually. Oxidative stress through overproduction of reactive oxygen species (ROS) is a possible mechanism for PM2.5-induced health effects. Organic aerosol (OA) is a dominant component of PM2.5 worldwide, yet its role in PM2.5 toxicity is poorly understood due to its chemical complexity. Here, through integrated cellular ROS measurements and detailed multi-instrument chemical characterization of PM in urban southeastern United States, we show that oxygenated OA (OOA), especially more-oxidized OOA, is the main OA type associated with cellular ROS production. We further reveal that highly unsaturated species containing carbon-oxygen double bonds and aromatic rings in OOA are major contributors to cellular ROS production. These results highlight the key chemical features of ambient OA driving its toxicity. As more-oxidized OOA is ubiquitous and abundant in the atmosphere, this emphasizes the need to understand its sources and chemical processing when formulating effective strategies to mitigate PM2.5 health impacts.
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Affiliation(s)
- Fobang Liu
- Department
of Environmental Science and Engineering, School of Energy and Power
Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Taekyu Joo
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Jenna C. Ditto
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Maria G. Saavedra
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Masayuki Takeuchi
- School of
Civil and Environmental Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Alexandra J. Boris
- Air
Quality Research Center, University of California
Davis, Davis, California 95618, United States
| | - Yuhan Yang
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Rodney J. Weber
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ann M. Dillner
- Air
Quality Research Center, University of California
Davis, Davis, California 95618, United States
| | - Drew R. Gentner
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Nga L. Ng
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
- School of
Civil and Environmental Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
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2
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Zhang Q, Weber RJ, Luxton TP, Peloquin DM, Baumann EJ, Black MS. Metal compositions of particle emissions from material extrusion 3D printing: Emission sources and indoor exposure modeling. Sci Total Environ 2023; 860:160512. [PMID: 36442638 PMCID: PMC10259682 DOI: 10.1016/j.scitotenv.2022.160512] [Citation(s) in RCA: 5] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/26/2022] [Accepted: 11/22/2022] [Indexed: 06/14/2023]
Abstract
Material extrusion 3D printing has been widely used in industrial, educational and residential environments, while its exposure health impacts have not been well understood. High levels of ultrafine particles are found being emitted from 3D printing and could pose a hazard when inhaled. However, metals that potentially transfer from filament additives to emitted particles could also add to the exposure hazard, which have not been well characterized for their emissions. This study analyzed metal (and metalloid) compositions of raw filaments and in the emitted particles during printing; studied filaments included pure polymer filaments with metal additives and composite filaments with and without metal powder. Our chamber study found that crustal metals tended to have higher partitioning factors from filaments to emitted particles; silicon was the most abundant element in emitted particles and had the highest yield per filament mass. However, bronze and stainless-steel powder added in composite filaments were less likely to transfer from filament to particle. For some cases, boron, arsenic, manganese, and lead were only detected in particles, which indicated external sources, such as the printers themselves. Heavy metals with health concerns were also detected in emitted particles, while their estimated exposure concentrations in indoor air were below air quality standards and occupational regulations. However, total particle exposure concentrations estimated for indoor environments could exceed ambient air fine particulate standards.
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Affiliation(s)
- Qian Zhang
- Chemical Insights Research Institute, Underwriters Laboratories Inc., Marietta, GA 30067, USA.
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Todd P Luxton
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Cincinnati, OH 45224, USA
| | - Derek M Peloquin
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Cincinnati, OH 45224, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Eric J Baumann
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Cincinnati, OH 45224, USA
| | - Marilyn S Black
- Chemical Insights Research Institute, Underwriters Laboratories Inc., Marietta, GA 30067, USA
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3
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Campbell J, Battaglia M, Dingilian K, Cesler-Maloney M, St Clair JM, Hanisco TF, Robinson E, DeCarlo P, Simpson W, Nenes A, Weber RJ, Mao J. Source and Chemistry of Hydroxymethanesulfonate (HMS) in Fairbanks, Alaska. Environ Sci Technol 2022; 56:7657-7667. [PMID: 35544773 PMCID: PMC9227704 DOI: 10.1021/acs.est.2c00410] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 06/15/2023]
Abstract
Fairbanks, Alaska, is a subarctic city with fine particle (PM2.5) concentrations that exceed air quality regulations in winter due to weak dispersion caused by strong atmospheric inversions, local emissions, and the unique chemistry occurring under the cold and dark conditions. Here, we report on observations from the winters of 2020 and 2021, motivated by our pilot study that showed exceptionally high concentrations of fine particle hydroxymethanesulfonate (HMS) or related sulfur(IV) species (e.g., sulfite and bisulfite). We deployed online particle-into-liquid sampler-ion chromatography (PILS-IC) in conjunction with a suite of instruments to determine HMS precursors (HCHO, SO2) and aerosol composition in general, with the goal to characterize the sources and sinks of HMS in wintertime Fairbanks. PM2.5 HMS comprised a significant fraction of PM2.5 sulfur (26-41%) and overall PM2.5 mass concentration of 2.8-6.8% during pollution episodes, substantially higher than what has been observed in other regions, likely due to the exceptionally low temperatures. HMS peaked in January, with lower concentrations in December and February, resulting from changes in precursors and meteorological conditions. Strong correlations with inorganic sulfate and organic mass during pollution events suggest that HMS is linked to processes responsible for poor air quality episodes. These findings demonstrate unique aspects of air pollution formation in cold and humid atmospheres.
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Affiliation(s)
- James
R. Campbell
- Geophysical
Institute and Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - Michael Battaglia
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Kayane Dingilian
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Meeta Cesler-Maloney
- Geophysical
Institute and Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - Jason M. St Clair
- Atmospheric
Chemistry and Dynamics Laboratory, NASA
Goddard Space Flight Center, Greenbelt, Maryland 20771, United States
- Joint
Center for Earth Systems Technology, University
of Maryland Baltimore County, Baltimore, Maryland 21228, United States
| | - Thomas F. Hanisco
- Atmospheric
Chemistry and Dynamics Laboratory, NASA
Goddard Space Flight Center, Greenbelt, Maryland 20771, United States
| | - Ellis Robinson
- Department
of Environmental Health and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Peter DeCarlo
- Department
of Environmental Health and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - William Simpson
- Geophysical
Institute and Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - Athanasios Nenes
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
- Center for
the Study of Air Quality and Climate Change, Institute of Chemical Engineering Sciences, Foundation for Research
and Technology Hellas, Patras 26504, Greece
- Laboratory
of Atmospheric Processes and their Impacts, School of Architecture,
Civil and Environmental Engineering, École
Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Rodney J. Weber
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Jingqiu Mao
- Geophysical
Institute and Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
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4
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Tang Z, Sarnat JA, Weber RJ, Russell AG, Zhang X, Li Z, Yu T, Jones DP, Liang D. The Oxidative Potential of Fine Particulate Matter and Biological Perturbations in Human Plasma and Saliva Metabolome. Environ Sci Technol 2022; 56:7350-7361. [PMID: 35075906 PMCID: PMC9177558 DOI: 10.1021/acs.est.1c04915] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [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] [Indexed: 05/03/2023]
Abstract
Particulate oxidative potential may comprise a key health-relevant parameter of particulate matter (PM) toxicity. To identify biological perturbations associated with particulate oxidative potential and examine the underlying molecular mechanisms, we recruited 54 participants from two dormitories near and far from a congested highway in Atlanta, GA. Fine particulate matter oxidative potential ("FPMOP") levels at the dormitories were measured using dithiothreitol assay. Plasma and saliva samples were collected from participants four times for longitudinal high-resolution metabolic profiling. We conducted metabolome-wide association studies to identify metabolic signals with FPMOP. Leukotriene metabolism and galactose metabolism were top pathways associated with ≥5 FPMOP-related indicators in plasma, while vitamin E metabolism and leukotriene metabolism were found associated with most FPMOP indicators in saliva. We observed different patterns of perturbed pathways significantly associated with water-soluble and -insoluble FPMOPs, respectively. We confirmed five metabolites directly associated with FPMOP, including hypoxanthine, histidine, pyruvate, lactate/glyceraldehyde, and azelaic acid, which were implications of perturbations in acute inflammation, nucleic acid damage and repair, and energy perturbation. The unique metabolic signals were specific to FPMOP, but not PM mass, providing initial indication that FPMOP might constitute a more sensitive, health-relevant measure for elucidating etiologies related to PM2.5 exposures.
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Affiliation(s)
- Ziyin Tang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Jeremy A Sarnat
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30322, United States
| | - Armistead G Russell
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30322, United States
| | - Xiaoyue Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Zhenjiang Li
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Tianwei Yu
- School of Data Science, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Dean P Jones
- Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia 30322, United States
| | - Donghai Liang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
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5
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Tao Y, VandenBoer TC, Veres PR, Warneke C, de Gouw JA, Weber RJ, Markovic MZ, Zhao Y, Baker KR, Kelly JT, Murphy JG, Young CJ, Roberts JM. Hydrogen chloride (HCl) at ground sites during CalNex 2010 and insight into its thermodynamic properties. J Geophys Res Atmos 2022; 127:1-16. [PMID: 35586832 PMCID: PMC9109133 DOI: 10.1029/2021jd036062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Gas phase hydrogen chloride (HCl) was measured at Pasadena and San Joaquin Valley (SJV) ground sites in California during May and June 2010 as part of the CalNex study. Observed mixing ratios were on average 0.83 ppbv at Pasadena, ranging from below detection limit (0.055 ppbv) to 5.95 ppbv, and were on average 0.084 ppbv at SJV with a maximum value of 0.776 ppbv. At both sites, HCl levels were highest during midday and shared similar diurnal variations with HNO3. Coupled phase partitioning behavior was found between HCl/Cl- and HNO3/NO3 - using thermodynamic modelling and observations. Regional modeling of Cl- and HCl using CMAQ captures some of the observed relationships but underestimates measurements by a factor of 5 or more. Chloride in the 2.5-10 μm size range in Pasadena was sometimes higher than sea salt abundances, based on co-measured Na+, implying that sources other than sea salt are important. The acid-displacement of HCl/Cl- by HNO3/NO3 - (phase partitioning of semi-volatile acids) observed at the SJV site can only be explained by aqueous phase reaction despite low RH conditions and suggests the temperature dependence of HCl phase partitioning behavior was strongly impacted by the activity coefficient changes under relevant aerosol conditions (e.g., high ionic strength). Despite the influence from activity coefficients, the gas-particle system was found to be well constrained by other stronger buffers and charge balance so that HCl and Cl- concentrations were reproduced well by thermodynamic models.
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Affiliation(s)
- Ye Tao
- Department of Chemistry, York University, Toronto, Ontario, Canada
| | | | - Patrick R. Veres
- Chemical Sciences Laboratory, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA
| | - Carsten Warneke
- Chemical Sciences Laboratory, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA
| | - Joost A. de Gouw
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, USA
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado, USA
| | - Rodney J. Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Milos Z. Markovic
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
- Now at Picarro Inc., Santa Clara, California, USA
| | - Yongjing Zhao
- Air Quality Research Center, University of California, Davis, Davis, California, USA
| | - Kirk R. Baker
- Office of Air Quality Planning and Standards, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - James T. Kelly
- Office of Air Quality Planning and Standards, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Jennifer G. Murphy
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Cora J. Young
- Department of Chemistry, York University, Toronto, Ontario, Canada
| | - James M. Roberts
- Chemical Sciences Laboratory, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA
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6
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Chen Y, Guo H, Nah T, Tanner DJ, Sullivan AP, Takeuchi M, Gao Z, Vasilakos P, Russell AG, Baumann K, Huey LG, Weber RJ, Ng NL. Low-Molecular-Weight Carboxylic Acids in the Southeastern U.S.: Formation, Partitioning, and Implications for Organic Aerosol Aging. Environ Sci Technol 2021; 55:6688-6699. [PMID: 33902278 DOI: 10.1021/acs.est.1c01413] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
While carboxylic acids are important components in both particle and gas phases in the atmosphere, their sources and partitioning are not fully understood. In this study, we present real-time measurements of both particle- and gas-phase concentrations for five of the most common and abundant low-molecular-weight carboxylic acids (LMWCA) in a rural region in the southeastern U.S. in Fall 2016. Through comparison with secondary organic aerosol (SOA) tracers, we find that isoprene was the most important local precursor for all five LMWCA but via different pathways. We propose that monocarboxylic acids (formic and acetic acids) were mainly formed through gas-phase photochemical reactions, while dicarboxylic acids (oxalic, malonic, and succinic acids) were predominantly from aqueous processing. Unexpectedly high concentrations of particle-phase formic and acetic acids (in the form of formate and acetate, respectively) were observed and likely the components of long-range transport organic aerosol (OA), decoupled from their gas-phase counterparts. In addition, an extraordinarily strong correlation (R2 = 0.90) was observed between a particulate LMWCA and aged SOA, which we tentatively attribute to boundary layer dynamics.
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Affiliation(s)
- Yunle Chen
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Hongyu Guo
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Theodora Nah
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - David J Tanner
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Amy P Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Masayuki Takeuchi
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ziqi Gao
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Petros Vasilakos
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Armistead G Russell
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Karsten Baumann
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - L Gregory Huey
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Nga L Ng
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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7
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Zeng L, Zhang A, Wang Y, Wagner NL, Katich JM, Schwarz JP, Schill GP, Brock C, Froyd KD, Murphy DM, Williamson CJ, Kupc A, Scheuer E, Dibb J, Weber RJ. Global Measurements of Brown Carbon and Estimated Direct Radiative Effects. Geophys Res Lett 2020; 47:e2020GL088747. [PMID: 32728304 PMCID: PMC7380307 DOI: 10.1029/2020gl088747] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/05/2020] [Accepted: 06/08/2020] [Indexed: 05/29/2023]
Abstract
Brown carbon (BrC) is an organic aerosol material that preferentially absorbs light of shorter wavelengths. Global-scale radiative impacts of BrC have been difficult to assess due to the lack of BrC observational data. To address this, aerosol filters were continuously collected with near pole-to-pole latitudinal coverage over the Pacific and Atlantic basins in three seasons as part of the Atmospheric Tomography Mission. BrC chromophores in filter extracts were measured. We find that globally, BrC was highly spatially heterogeneous, mostly detected in air masses that had been transported from regions of extensive biomass burning. We calculate the average direct radiative effect due to BrC absorption accounted for approximately 7% to 48% of the top of the atmosphere clear-sky instantaneous forcing by all absorbing carbonaceous aerosols in the remote atmosphere, indicating that BrC from biomass burning is an important component of the global radiative balance.
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Affiliation(s)
- Linghan Zeng
- School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaGAUSA
| | - Aoxing Zhang
- School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaGAUSA
| | - Yuhang Wang
- School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaGAUSA
| | - Nicholas L. Wagner
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Joseph M. Katich
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Joshua P. Schwarz
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Gregory P. Schill
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Charles Brock
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Karl D. Froyd
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Daniel M. Murphy
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Christina J. Williamson
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Agnieszka Kupc
- Chemical Sciences LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
- Faculty of PhysicsUniversity of ViennaViennaAustria
| | - Eric Scheuer
- Institute for the Study of Earth, Oceans, and SpaceUniversity of New HampshireDurhamNHUSA
| | - Jack Dibb
- Institute for the Study of Earth, Oceans, and SpaceUniversity of New HampshireDurhamNHUSA
| | - Rodney J. Weber
- School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaGAUSA
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8
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Wong JPS, Yang Y, Fang T, Mulholland JA, Russell AG, Ebelt S, Nenes A, Weber RJ. Fine Particle Iron in Soils and Road Dust Is Modulated by Coal-Fired Power Plant Sulfur. Environ Sci Technol 2020; 54:7088-7096. [PMID: 32391689 DOI: 10.1021/acs.est.0c00483] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Transition metal ions, such as water-soluble iron (WS-Fe), are toxic components of fine particles (PM2.5). In Atlanta, from 1998 to 2013, a previous study found that WS-Fe was the PM2.5 species most associated with adverse cardiovascular outcomes. We examined this data set to investigate the sources of WS-Fe and the effects of air quality regulations on ambient levels of WS-Fe. We find that insoluble forms of iron in mineral and road dust combined with sulfate from coal-fired electrical generating units were converted into soluble forms by sulfate-driven acid dissolution. Sulfate produced both the highly acidic aerosol (summer pH 1.5-2) and liquid water required for the aqueous phase acid dissolution, but variability in WS-Fe was mainly driven by particle liquid water. These processes were more pronounced in summer when particles were most acidic, whereas in winter the relative importance of WS-Fe from combustion emissions increased. Although WS-Fe constituted a minute fraction of PM2.5 mass (0.15%), the WS-Fe-PM2.5 mass correlation was high (r = 0.67) and may be explained by these formation routes, which, in part, could account for observed associations between PM2.5 mass and adverse health seen in past studies. Similar processes are expected in many regions, implying that these unexpected benefits from coal-burning reduction may be widespread.
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Affiliation(s)
- Jenny P S Wong
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville E4L 1G8, Canada
| | - Yuhan Yang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
| | - Ting Fang
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - James A Mulholland
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30331, United States
| | - Armistead G Russell
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30331, United States
| | - Stefanie Ebelt
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Athanasios Nenes
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
- Institute of Chemical Engineering Science, Foundation for Research and Technology, Patras GR-26504, Greece
- Laboratory of Atmospheric Processes and their Impacts, School of Architecture, Civil & Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
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9
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Fang T, Lakey PSJ, Weber RJ, Shiraiwa M. Oxidative Potential of Particulate Matter and Generation of Reactive Oxygen Species in Epithelial Lining Fluid. Environ Sci Technol 2019; 53:12784-12792. [PMID: 31560535 DOI: 10.1021/acs.est.9b03823] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Reactive oxygen species (ROS) play a central role in adverse health effects of atmospheric particulate matter (PM). Respiratory deposition can lead to the formation of ROS in the epithelial lining fluid due to redox reactions of PM components with lung antioxidants. As direct quantification of ROS is challenging, PM oxidative potential is more commonly measured using antioxidant surrogates including dithiothreitol and ascorbic acid, assuming that the decay of surrogates corresponds to ROS formation. However, this assumption has not yet been validated and the lack of ROS quantification in the respiratory tract causes major limitations in evaluating PM impacts on oxidative stress. By combining field measurements of size-segregated chemical composition, a human respiratory tract model, and kinetic modeling, we quantified production rates and concentrations of different types of ROS in different regions of the epithelial lining fluid by considering particle-size-dependent respiratory deposition. The extrathoracic region is found to have higher ROS concentrations compared to the bronchial and alveolar regions. Although H2O2 and O2- production is governed by Fe and Cu ions, OH radicals are mainly generated by organic compounds and Fenton-like reactions of metal ions. In winter when affected by biomass burning, model comparisons suggest that humic-like substances (HULIS) contribute to ROS formation substantially. We found that PM oxidative potential is a good indicator of the chemical production of H2O2 and O2- but does not represent OH generation. These results provide rationale and limitations of the use of oxidative potential as an indicator of PM toxicity in epidemiological and toxicological studies.
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Affiliation(s)
- Ting Fang
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Pascale S J Lakey
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Manabu Shiraiwa
- Department of Chemistry , University of California , Irvine , California 92697 , United States
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Zhang Q, Pardo M, Rudich Y, Kaplan-Ashiri I, Wong JPS, Davis AY, Black MS, Weber RJ. Chemical Composition and Toxicity of Particles Emitted from a Consumer-Level 3D Printer Using Various Materials. Environ Sci Technol 2019; 53:12054-12061. [PMID: 31513393 DOI: 10.1021/acs.est.9b04168] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Consumer-level 3D printers emit ultrafine and fine particles, though little is known about their chemical composition or potential toxicity. We report chemical characteristics of the particles in comparison to raw filaments and assessments of particle toxicity. Particles emitted from polylactic acid (PLA) appeared to be largely composed of the bulk filament material with mass spectra similar to the PLA monomer spectra. Acrylonitrile butadiene styrene (ABS), extruded at a higher temperature than PLA, emitted vastly more particles and their composition differed from that of the bulk filament, suggesting that trace additives may control particle formation. In vitro cellular assays and in vivo mice exposure all showed toxic responses when exposed to PLA and ABS-emitted particles, where PLA-emitted particles elicited higher response levels than ABS-emitted particles at comparable mass doses. A chemical assay widely used in ambient air-quality studies showed that particles from various filament materials had comparable particle oxidative potentials, slightly lower than those of ambient particulate matter (PM2.5). However, particle emissions from ABS filaments are likely more detrimental when considering overall exposure due to much higher emissions. Our results suggest that 3D printer particle emissions are not benign and exposures should be minimized.
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Affiliation(s)
- Qian Zhang
- Chemical Safety and Human Health , Underwriters Laboratories Inc. , Marietta , Georgia 30067 , United States
| | | | | | | | - Jenny P S Wong
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Aika Y Davis
- Chemical Safety and Human Health , Underwriters Laboratories Inc. , Marietta , Georgia 30067 , United States
| | - Marilyn S Black
- Chemical Safety and Human Health , Underwriters Laboratories Inc. , Marietta , Georgia 30067 , United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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11
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Wong JPS, Tsagkaraki M, Tsiodra I, Mihalopoulos N, Violaki K, Kanakidou M, Sciare J, Nenes A, Weber RJ. Effects of Atmospheric Processing on the Oxidative Potential of Biomass Burning Organic Aerosols. Environ Sci Technol 2019; 53:6747-6756. [PMID: 31091086 DOI: 10.1021/acs.est.9b01034] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Oxidative potential (OP), which is the ability of certain components in atmospheric particles to generate reactive oxidative species (ROS) and deplete antioxidants in vivo, is a prevailing toxicological mechanism underlying the adverse health effects associated with exposure to ambient aerosols. While previous studies have identified the high OP of fresh biomass burning organic aerosols (BBOA), it remains unclear how it evolves throughout atmospheric transport. Using the dithiothreitol (DTT) assay as a measure of OP, a combination of field observations and laboratory experiments is used to determine how atmospheric aging transforms the intrinsic OP (OPmassDTT) of BBOA. For ambient BBOA collected during the fire seasons in Greece, OPmassDTT was observed to increase by a factor of 2.1 ± 0.9 for samples of atmospheric ages up to 68 h. Laboratory experiments indicate that aqueous photochemical aging (aging by UVB and UVA photolysis; as well as OH oxidation), as well as aging by ozone and atmospheric dilution can transform the OPmassDTT of the water-soluble fraction of wood smoke within 2 days of atmospheric transport. The results from this work suggest that the air quality impacts of biomass burning emissions can extend beyond regions near fire sites and should be accounted for.
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Affiliation(s)
- Jenny P S Wong
- Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , 30331 , United States
| | - Maria Tsagkaraki
- Environmental Chemical Processes Laboratory, Department of Chemistry , University of Crete , 70013 Heraklion , Crete Greece
| | - Irini Tsiodra
- Environmental Chemical Processes Laboratory, Department of Chemistry , University of Crete , 70013 Heraklion , Crete Greece
| | | | - Kalliopi Violaki
- Laboratory of Atmospheric Processes and their Impacts, School of Architecture, Civil & Environmental Engineering , École Polytechnique Fédérale de Lausanne , Lausanne , 1015 , Switzerland
| | - Maria Kanakidou
- Environmental Chemical Processes Laboratory, Department of Chemistry , University of Crete , 70013 Heraklion , Crete Greece
| | - Jean Sciare
- Energy Environment and Water Research , The Cyprus Institute , Nicosia 1645 , Cyprus
| | - Athanasios Nenes
- Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , 30331 , United States
- IERSD , National Observatory of Athens , Palea Penteli , 15236 , Greece
- Laboratory of Atmospheric Processes and their Impacts, School of Architecture, Civil & Environmental Engineering , École Polytechnique Fédérale de Lausanne , Lausanne , 1015 , Switzerland
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , 30331 , United States
| | - Rodney J Weber
- Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , 30331 , United States
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12
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Bates JT, Fang T, Verma V, Zeng L, Weber RJ, Tolbert PE, Abrams JY, Sarnat SE, Klein M, Mulholland JA, Russell AG. Review of Acellular Assays of Ambient Particulate Matter Oxidative Potential: Methods and Relationships with Composition, Sources, and Health Effects. Environ Sci Technol 2019; 53:4003-4019. [PMID: 30830764 DOI: 10.1021/acs.est.8b03430] [Citation(s) in RCA: 199] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Oxidative stress is a potential mechanism of action for particulate matter (PM) toxicity and can occur when the body's antioxidant capacity cannot counteract or detoxify harmful effects of reactive oxygen species (ROS) due to an excess presence of ROS. ROS are introduced to the body via inhalation of PM with these species present on and/or within the particles (particle-bound ROS) and/or through catalytic generation of ROS in vivo after inhaling redox-active PM species (oxidative potential, OP). The recent development of acellular OP measurement techniques has led to a surge in research across the globe. In this review, particle-bound ROS techniques are discussed briefly while OP measurements are the focus due to an increasing number of epidemiologic studies using OP measurements showing associations with adverse health effects in some studies. The most common OP measurement techniques, including the dithiothreitol assay, glutathione assay, and ascorbic acid assay, are discussed along with evidence for utility of OP measurements in epidemiologic studies and PM characteristics that drive different responses between assay types (such as species composition, emission source, and photochemistry). Overall, most OP assays respond to metals like copper than can be found in emission sources like vehicles. Some OP assays respond to organics, especially photochemically aged organics, from sources like biomass burning. Select OP measurements have significant associations with certain cardiorespiratory end points, such as asthma, congestive heart disease, and lung cancer. In fact, multiple studies have found that exposure to OP measured using the dithiothreitol and glutathione assays drives higher risk ratios for certain cardiorespiratory outcomes than PM mass, suggesting OP measurements may be integrating the health-relevant fraction of PM and will be useful tools for future health analyses. The compositional impacts, including species and emission sources, on OP could have serious implications for health-relevant PM exposure. Though more work is needed, OP assays show promise for health studies as they integrate the impacts of PM species and properties on catalytic redox reactions into one measurement, and current work highlights the importance of metals, organic carbon, vehicles, and biomass burning emissions to PM exposures that could impact health.
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Affiliation(s)
- Josephine T Bates
- Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Ting Fang
- Department of Chemistry , University of California Irvine , Irvine , California 92697 , United States
| | - Vishal Verma
- Civil and Environmental Engineering , University of Illinois at Urbana-Champaign , Champaign , Illinois 61820 , United States
| | - Linghan Zeng
- Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Rodney J Weber
- Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Paige E Tolbert
- Rollins School of Public Health , Emory University , Atlanta , Georgia 30322 , United States
| | - Joseph Y Abrams
- Center for Disease Control and Prevention, Atlanta , Georgia 30329 , United States
| | - Stefanie E Sarnat
- Rollins School of Public Health , Emory University , Atlanta , Georgia 30322 , United States
| | - Mitchel Klein
- Rollins School of Public Health , Emory University , Atlanta , Georgia 30322 , United States
| | - James A Mulholland
- Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Armistead G Russell
- Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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13
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Ng NL, Tuet WY, Chen Y, Fok S, Gao D, Tagle Rodriguez MS, Klein M, Grosberg A, Weber RJ, Champion JA. Cellular and Acellular Assays for Measuring Oxidative Stress Induced by Ambient and Laboratory-Generated Aerosols. Res Rep Health Eff Inst 2019; 2019:1-57. [PMID: 31872749 PMCID: PMC7266377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Abstract
INTRODUCTION Many studies have established associations between exposure to air pollution, or atmospheric particulate matter (PM), and adverse health effects. An increasing array of studies have suggested oxidative stress as a possible mechanism by which PM-induced health effects arise, and as a result, many chemical and cellular assays have been developed to study PM-induced oxidant production. Although significant progress has been made in recent years, there are still many gaps in this area of research that have not been addressed. Many prior studies have focused on the aerosol of primary origin (e.g., the aerosol emitted from combustion engines) although the aerosol formed from the oxidation of volatile species, secondary organic aerosol (SOA), has been shown to be the predominant type of aerosol even in urban areas. Current SOA health studies are limited in number, and as such, the health effects of SOA are poorly characterized. Also, there is a lack of perspective in terms of the relative toxicities of different SOA systems. Additionally, although chemical assays have identified some SOA constituents associated with adverse health endpoints, the applicability of these results to cellular responses has not been well established. SPECIFIC AIMS The overall objective of this study was to better understand the oxidative properties of different types and components of PM mixtures (especially SOA) through systematic laboratory chamber experiments and ambient field studies. The study had four specific aims. 1 To develop a cellular assay optimized for measuring reactive oxygen and nitrogen species (ROS/RNS) production resulting from PM exposure and to identify a robust parameter that could represent ROS/RNS levels for comparison with different endpoints. 2 To identify ambient PM components associated with ROS/RNS production and evaluate whether results from chemical assays represented cellular responses in terms of ROS/RNS production. 3 To investigate and provide perspective on the relative toxicities of SOA formed from common biogenic and anthropogenic precursors under different conditions (e.g., humidity, nitrogen oxides [NOx], and redox-active metals) and identify bulk aerosol properties associated with cellular responses. 4 To investigate the effects of photochemical aging on aerosol toxicity. METHODS Ambient PM samples were collected from urban and rural sites in the greater Atlanta area as part of the Southeastern Center for Air Pollution and Epidemiology (SCAPE) study between June 2012 and October 2013. The concentrations of water-soluble species (e.g., water-soluble organic carbon [WSOC], brown carbon [Br C], and metals) were characterized using a variety of instruments. Samples for this study were chosen to span the observed range of dithiothreitol (DTT) activities. Laboratory studies were conducted in the Georgia Tech Environmental Chamber (GTEC) facility in order to generate SOA under well-controlled photooxidation conditions. Precursors of biogenic origin (isoprene, α-pinene, and β-caryophyllene) and anthropogenic origin (pentadecane, m-xylene, and naphthalene) were oxidized under various formation conditions (dry vs. humid, NOx, and ammonium sulfate vs. iron sulfate seed particles) to produce SOA of differing chemical composition and mass loading. For the naphthalene system, a series of experiments were conducted with different initial hydrocarbon concentrations to produce aerosols with various degree of oxidation. A suite of instruments was utilized to monitor gas- and particle-phase species. Bulk aerosol properties (e.g., O:C, H:C, and N:C ratios) were measured using a high-resolution time-of-flight aerosol mass spectrometer. Filter samples were collected for chemical oxidative potential and cellular measurements. For the naphthalene system, multiple filter samples were collected over the course of a single experiment to collect aerosols of different photochemical aging. For all filter samples, chemical oxidative potentials were determined for water-soluble extracts using a semiautomated DTT assay system. Murine alveolar macrophages and neonatal rat ventricular myocytes were also exposed to PM samples extracted in cell culture medium to investigate cellular responses. ROS/RNS production was detected using the intracellular ROS/RNS probe, carboxy-2',7'-dichlorodihydrofluorescein diacetate (carboxy-H2DCFA), whereas cellular metabolic activity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Finally, cytokine production, that is, secreted levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), were measured post-exposure using an enzyme-linked immunosorbent assay (ELISA). To identify PM constituents associated with oxidative properties, linear regressions between oxidative properties (cellular responses or DTT activity) and aerosol composition (metals, elemental ratios, etc.) were evaluated using Pearson's correlation coefficient, where the significance was determined using multiple imputation and evaluated using a 95% confidence interval. RESULTS We optimized several parameters for the ROS/RNS assay, including cell density (2 × 104 cells/well for macrophages and 3.33 × 104 cells/well for cardiomyocytes), probe concentration (10 µM), and sample incubation time (24 hours). Results from both ambient and laboratory-generated aerosols demonstrate that ROS/RNS production was highly dose-dependent and nonlinear with respect to PM dose. Of the dose-response metrics investigated in this study (maximum response, dose at which the response is 10% above the baseline [threshold], dose at which 50% of the response is attained [EC50], rate at which the maximum response is attained [Hill slope], and area under the dose-response curve [AUC]), we found that the AUC was the most robust parameter whose informativeness did not depend on dose range. A positive, significant correlation was observed between ROS/RNS production as represented by AUC and chemical oxidative potential as measured by DTT for ambient samples collected in summer. Conversely, a relatively constant AUC was observed for ambient samples collected in winter regardless of the corresponding DTT activity. We also identified several PM constituents (WSOC, BrC, iron, and titanium) that were significantly correlated with AUC for summer samples. The strong correlation between organic species and ROS/RNS production highlights a need to understand the contribution of organic aerosols to PM-induced health effects. No significant correlations were observed for other ROS/RNS metrics or PM constituents, and no spatial trends were observed. For laboratory-generated aerosol, precursor identity influenced oxidative potentials significantly, with isoprene and naphthalene SOA having the lowest and highest DTT activities, respectively. Both precursor identity and formation condition significantly influenced inflammatory responses induced by SOA exposure, and several response patterns were identified for SOA precursors whose photooxidation products share similar carbon-chain length and functionalities. The presence of iron sulfate seed particles did not have an apparent effect on oxidative potentials; however, a higher level of ROS/RNS production was observed for all SOA formed in the presence of iron sulfate compared with ammonium sulfate. We also identified a significant positive correlation between ROS/RNS production and average carbon oxidation state, a bulk aerosol property. It may therefore be possible to roughly estimate ROS/RNS production using this property, which is readily obtainable. This correlation may have significant implications as aerosols have an atmospheric lifetime of a week, during which average carbon oxidation state increases because of atmospheric photochemical aging. Our results suggest that aerosols might become more toxic as they age in the atmosphere. Finally, in the context of ambient samples, laboratory-generated SOA induced comparable or higher levels of ROS/RNS. Oxidative potentials for all laboratory SOA systems, with the exception of naphthalene (which was higher), were all comparable with oxidative potentials observed in ambient samples.
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Affiliation(s)
- N L Ng
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA
| | - W Y Tuet
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Y Chen
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA
| | - S Fok
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
| | - D Gao
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA
| | - M S Tagle Rodriguez
- Department of Biomedical Engineering, University of California-Irvine, Irvine, CA
| | - M Klein
- Rollins School of Public Health, Emory University, Atlanta, GA
| | - A Grosberg
- Department of Biomedical Engineering, University of California-Irvine, Irvine, CA
| | - R J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA
| | - J A Champion
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
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14
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Lawal AS, Guan X, Liu C, Henneman LRF, Vasilakos P, Bhogineni V, Weber RJ, Nenes A, Russell AG. Linked Response of Aerosol Acidity and Ammonia to SO 2 and NO x Emissions Reductions in the United States. Environ Sci Technol 2018; 52:9861-9873. [PMID: 30032604 DOI: 10.1021/acs.est.8b00711] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Large reductions of sulfur and nitrogen oxide emissions in the United States have led to considerable improvements in air quality, though recent analyses in the Southeastern United States have shown little response of aerosol pH to these reductions. This study examines the effects of reduced emissions on the trend of aerosol acidity in fine particulate matter (PM2.5), at a nationwide scale, using ambient concentration data from three monitoring networks-the Ammonia Monitoring Network (AMoN), the Clean Air Status and Trends network (CASTNET) and the Southeastern Aerosol Research and Characterization Network (SEARCH), in conjunction with thermodynamic (ISORROPIA-II) and chemical transport (CMAQ) model results. Sulfate and ammonium experienced similar and significant decreases with little change in pH, neutralization ratio ( f = [NH4+]/2[SO42-] + [NO3-]), or nitrate. Oak Grove, MS was the only SEARCH site showing statistically significant pH changes in the Southeast region where small increases in pH (0.003-0.09 pH units/year) were observed. Of the five regions characterized using CASTNET/AMoN data, only California exhibited a statistically significant, albeit small pH increase of +0.04 pH units/year. Furthermore, statistically insignificant (α = 0.05) changes in ammonia were observed in response to emission and PM2.5 speciation changes. CMAQ simulation results had similar responses, showing steady ammonia levels and generally low pH, with little change from 2001 to 2011.
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Affiliation(s)
- Abiola S Lawal
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Xinbei Guan
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Cong Liu
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- School of Energy and Environment , Southeast University , Nanjing 210096 , China
| | - Lucas R F Henneman
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- Department of Biostatistics, Harvard T.H. Chan School of Public Health , Harvard University , Boston , Massachusetts 02115 , United States
| | - Petros Vasilakos
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Vasudha Bhogineni
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Athanasios Nenes
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- Institute for Chemical Engineering Sciences , Foundation for Research and Technology - Hellas , Patras , GR - 26504 , Greece
- Institute for Environmental Research and Sustainable Development , National Observatory of Athens, P. Penteli , Athens , GR - 15236 , Greece
| | - Armistead G Russell
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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15
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Lawal AS, Guan X, Liu C, Henneman LRF, Vasilakos P, Bhogineni V, Weber RJ, Nenes A, Russell AG. Linked Response of Aerosol Acidity and Ammonia to SO 2 and NO x Emissions Reductions in the United States. Environ Sci Technol 2018; 52:9861-9873. [PMID: 30032604 DOI: 10.1021/acs.est.8b0071110.1021/acs.est.8b00711.s001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Large reductions of sulfur and nitrogen oxide emissions in the United States have led to considerable improvements in air quality, though recent analyses in the Southeastern United States have shown little response of aerosol pH to these reductions. This study examines the effects of reduced emissions on the trend of aerosol acidity in fine particulate matter (PM2.5), at a nationwide scale, using ambient concentration data from three monitoring networks-the Ammonia Monitoring Network (AMoN), the Clean Air Status and Trends network (CASTNET) and the Southeastern Aerosol Research and Characterization Network (SEARCH), in conjunction with thermodynamic (ISORROPIA-II) and chemical transport (CMAQ) model results. Sulfate and ammonium experienced similar and significant decreases with little change in pH, neutralization ratio ( f = [NH4+]/2[SO42-] + [NO3-]), or nitrate. Oak Grove, MS was the only SEARCH site showing statistically significant pH changes in the Southeast region where small increases in pH (0.003-0.09 pH units/year) were observed. Of the five regions characterized using CASTNET/AMoN data, only California exhibited a statistically significant, albeit small pH increase of +0.04 pH units/year. Furthermore, statistically insignificant (α = 0.05) changes in ammonia were observed in response to emission and PM2.5 speciation changes. CMAQ simulation results had similar responses, showing steady ammonia levels and generally low pH, with little change from 2001 to 2011.
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Affiliation(s)
- Abiola S Lawal
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Xinbei Guan
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Cong Liu
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- School of Energy and Environment , Southeast University , Nanjing 210096 , China
| | - Lucas R F Henneman
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- Department of Biostatistics, Harvard T.H. Chan School of Public Health , Harvard University , Boston , Massachusetts 02115 , United States
| | - Petros Vasilakos
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Vasudha Bhogineni
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Athanasios Nenes
- School of Earth and Atmospheric Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- Institute for Chemical Engineering Sciences , Foundation for Research and Technology - Hellas , Patras , GR - 26504 , Greece
- Institute for Environmental Research and Sustainable Development , National Observatory of Athens, P. Penteli , Athens , GR - 15236 , Greece
| | - Armistead G Russell
- School of Civil & Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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16
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Sarnat JA, Russell A, Liang D, Moutinho JL, Golan R, Weber RJ, Gao D, Sarnat SE, Chang HH, Greenwald R, Yu T. Developing Multipollutant Exposure Indicators of Traffic Pollution: The Dorm Room Inhalation to Vehicle Emissions (DRIVE) Study. Res Rep Health Eff Inst 2018; 2018:3-75. [PMID: 31872750 PMCID: PMC7266376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Abstract
Introduction The Dorm Room Inhalation to Vehicle Emissions (DRIVE2) study was conducted to measure traditional single-pollutant and novel multipollutant traffic indicators along a complete emission-to-exposure pathway. The overarching goal of the study was to evaluate the suitability of these indicators for use as primary traffic exposure metrics in panel-based and small-cohort epidemiological studies. Methods Intensive field sampling was conducted on the campus of the Georgia Institute of Technology (GIT) between September 2014 and January 2015 at 8 monitoring sites (2 indoors and 6 outdoors) ranging from 5 m to 2.3 km from the busiest and most congested highway artery in Atlanta. In addition, 54 GIT students living in one of two dormitories either near (20 m) or far (1.4 km) from the highway were recruited to conduct personal exposure sampling and weekly biomonitoring. The pollutants measured were selected to provide information about the heterogeneous particulate and gaseous composition of primary traffic emissions, including the traditional traffic-related species (e.g., carbon monoxide [CO], nitrogen dioxide [NO2], nitric oxide [NO], fine particulate matter [PM2.5], and black carbon [BC]), and of secondary species (e.g., ozone [O3] and sulfate as well as organic carbon [OC], which is both primary and secondary) from traffic and other sources. Along with these pollutants, we also measured two multipollutant traffic indicators: integrated mobile source indicators (IMSIs) and fine particulate matter oxidative potential (FPMOP). IMSIs are derived from elemental carbon (EC), CO, and nitrogen oxide (NOx) concentrations, along with the fractions of these species emitted by gasoline and diesel vehicles, to construct integrated estimates of gasoline and diesel vehicle impacts. Our FPMOP indicator was based on an acellular assay involving the depletion of dithiothreitol (DTT), considering both water-soluble and insoluble components (referred to as FPMOPtotal-DTT). In addition, a limited assessment of 18 low-cost sensors was added to the study to supplement the four original aims. Results Pollutant levels measured during the study showed a low impact by this highway hotspot source on its surrounding vicinity. These findings are broadly consistent with results from other studies throughout North America showing decreased relative contributions to urban air pollution from primary traffic emissions. We view these reductions as an indication of a changing near-road environment, facilitated by the effectiveness of mobile source emission controls. Many of the primary pollutant species, including NO, CO, and BC, decreased to near background levels by 20 to 30 m from the highway source. Patterns of correlation among the sites also varied by pollutant and time of day. NO2 exhibited spatial trends that differed from those of the other single-pollutant primary traffic indicators. We believe this was caused by kinetic limitations in the photochemical chemistry, associated with primary emission reductions, required to convert the NO-dominant primary NOx, emitted from automobiles, to NO2. This finding provides some indication of limitations in the use of NO2 as a primary traffic exposure indicator in panel-based health effect studies. Roadside monitoring of NO, CO, and BC tended to be more strongly correlated with sites, both near and far from the road, during morning rush hour periods and often weakly to moderately correlated during other time periods of the day. This pattern was likely associated with diurnal changes in mixing and chemistry and their impact on spatial heterogeneity across the campus. Among our candidate multipollutant primary traffic indicators, we report several key findings related to the use of oxidative potential (OP)-based indicators. Although earlier studies have reported elevated levels of FPMOP in direct exhaust emissions, we found that atmospheric processing further enhanced FPMOPtotal-DTT, likely associated with the oxidation of primary polycyclic aromatic hydrocarbons (PAHs) to quinones and hydroxyquinones and with the oxidization and water solubility of metals. This has important implications in terms both of the utility of FPMOPtotal-DTT as a marker for exhaust emissions and of the importance of atmospheric processing of particulate matter (PM) being tied to potential health outcomes. The results from the personal exposure monitoring also point to the complexity and diversity of the spatiotemporal variability patterns among the study monitoring sites and the importance of accounting for location and spatial mobility when estimating exposures in panel-based and small-cohort studies. This was most clearly demonstrated with the personal BC measurements, where ambient roadside monitoring was shown to be a poor surrogate for exposures to BC. Alternative surrogates, including ambient and indoor BC at the participants' respective dorms, were more strongly associated with personal BC, and knowledge of the participants' mean proximity to the highway was also shown to explain a substantial level of the variability in corresponding personal exposures to both BC and NO2. In addition, untargeted metabolomic indicators measured in plasma and saliva, which represent emerging methods for measuring exposure, were used to extract approximately 20,000 and 30,000 features from plasma and saliva, respectively. Using hydrophilic interaction liquid chromatography (HILIC) in the positive ion mode, we identified 221 plasma features that differed significantly between the two dorm cohorts. The bimodal distribution of these features in the HILIC column was highly idiosyncratic; one peak consisted of features with elevated intensities for participants living in the near dorm; the other consisted of features with elevated intensities for participants in the far dorm. Both peaks were characterized by relatively short retention times, indicative of the hydrophobicity of the identified features. The results from the metabolomics analyses provide a strong basis for continuing this work toward specific chemical validation of putative biomarkers of traffic-related pollution. Finally, the study had a supplemental aim of examining the performance of 18 low-cost CO, NO, NO2, O3, and PM2.5 pollutant sensors. These were colocated alongside the other study monitors and assessed for their ability to capture temporal trends observed by the reference monitoring instrumentation. Generally, we found the performance of the low-cost gas-phase sensors to be promising after extensive calibration; the uncalibrated measurements alone, however, would likely not have led to reliable results. The low-cost PM sensors we evaluated had poor accuracy, although PM sensor technology is evolving quickly and warrants future attention. Conclusions An immediate implication of the changing near-road environment is that future studies aimed at characterizing hotspots related to mobile sources and their impacts on health will need to consider multiple approaches for characterizing spatial gradients and exposures. Specifically and most directly, the mobile source contributions to ambient concentrations of single-pollutant indicators of traffic exposure are not as distinguishable to the degree that they have been in the past. Collectively, the study suggests that characterizing exposures to traffic-related pollutants, which is already difficult, will become more difficult because of the reduction in traffic-related emissions. Additional multi-tiered approaches should be considered along with traditional measurements, including the use of alternative OP measures beyond those based on DTT assays, metabolomics, low-cost sensors, and air quality modeling.
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Affiliation(s)
- J A Sarnat
- Department of Environmental Health, Rollins School of Public Health of Emory University, Atlanta, Georgia
| | - A Russell
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta
| | - D Liang
- Department of Environmental Health, Rollins School of Public Health of Emory University, Atlanta, Georgia
| | - J L Moutinho
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta
| | - R Golan
- Department of Epidemiology, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - R J Weber
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta
| | - D Gao
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta
| | - S E Sarnat
- Department of Environmental Health, Rollins School of Public Health of Emory University, Atlanta, Georgia
| | - H H Chang
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - R Greenwald
- Department of Environmental Health, Georgia State University, Atlanta
| | - T Yu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia
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17
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Verma V, Sioutas C, Weber RJ. Oxidative Properties of Ambient Particulate Matter - An Assessment of the Relative Contributions from Various Aerosol Components and Their Emission Sources. ACS Symposium Series 2018. [DOI: 10.1021/bk-2018-1299.ch019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, United States
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Rodney J. Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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18
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Affiliation(s)
| | - Howard H Chang
- 1 Rollins School of Public Health Emory University Atlanta, Georgia and
| | - Rodney J Weber
- 2 School of Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta, Georgia
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19
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Abrams JY, Weber RJ, Klein M, Sarnat SE, Chang HH, Strickland MJ, Verma V, Fang T, Bates JT, Mulholland JA, Russell AG, Tolbert PE. Erratum: Associations between Ambient Fine Particulate Oxidative Potential and Cardiorespiratory Emergency Department Visits. Environ Health Perspect 2017; 125:129001. [PMID: 29212063 PMCID: PMC5963574 DOI: 10.1289/ehp3048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 11/04/2017] [Indexed: 05/06/2023]
Abstract
[This corrects the article DOI: 10.1289/EHP1545.].
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20
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Abrams JY, Weber RJ, Klein M, Sarnat SE, Chang HH, Strickland MJ, Verma V, Fang T, Bates JT, Mulholland JA, Russell AG, Tolbert PE. Associations between Ambient Fine Particulate Oxidative Potential and Cardiorespiratory Emergency Department Visits. Environ Health Perspect 2017; 125:107008. [PMID: 29084634 PMCID: PMC5933307 DOI: 10.1289/ehp1545] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 08/04/2017] [Accepted: 08/12/2017] [Indexed: 05/19/2023]
Abstract
BACKGROUND Oxidative potential (OP) has been proposed as a measure of toxicity of ambient particulate matter (PM). OBJECTIVES Our goal was to address an important research gap by using daily OP measurements to conduct population-level analysis of the health effects of measured ambient OP. METHODS A semi-automated dithiothreitol (DTT) analytical system was used to measure daily average OP (OPDTT) in water-soluble fine PM at a central monitor site in Atlanta, Georgia, over eight sampling periods (a total of 196 d) during June 2012-April 2013. Data on emergency department (ED) visits for selected cardiorespiratory outcomes were obtained for the five-county Atlanta metropolitan area. Poisson log-linear regression models controlling for temporal confounders were used to conduct time-series analyses of the relationship between daily counts of ED visits and either the 3-d moving average (lag 0-2) of OPDTT or same-day OPDTT. Bipollutant regression models were run to estimate the health associations of OPDTT while controlling for other pollutants. RESULTS OPDTT was measured for 196 d (mean=0.32 nmol/min/m3, interquartile range=0.21). Lag 0-2 OPDTT was associated with ED visits for respiratory disease (RR=1.03, 95% confidence interval (CI): 1.00, 1.05 per interquartile range increase in OPDTT), asthma (RR=1.12, 95% CI: 1.03, 1.22), and ischemic heart disease (RR=1.19, 95% CI: 1.03, 1.38). Same-day OPDTT was not associated with ED visits for any outcome. Lag 0-2 OPDTT remained a significant predictor of asthma and ischemic heart disease in most bipollutant models. CONCLUSIONS Lag 0-2 OPDTT was associated with ED visits for multiple cardiorespiratory outcomes, providing support for the utility of OPDTT as a measure of fine particle toxicity. https://doi.org/10.1289/EHP1545.
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Affiliation(s)
- Joseph Y Abrams
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Mitchel Klein
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Stefanie E Sarnat
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Howard H Chang
- Department of Biostatistics, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | | | - Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
| | - Ting Fang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Josephine T Bates
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - James A Mulholland
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Armistead G Russell
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Paige E Tolbert
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
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21
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Bates JT, Weber RJ, Abrams J, Verma V, Fang T, Ivey C, Liu C, Klein M, Strickland MJ, Sarnat SE, Chang HH, Mulholland JA, Tolbert PE, Russell AG. Source Impacts on and Cardiorespiratory Effects of Reactive Oxygen Species Generated by Water-Soluble PM2.5 Across the Eastern United States. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/978-3-319-57645-9_79] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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22
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Abstract
Brown carbon (BrC) consists of those organic compounds in atmospheric aerosols that absorb solar radiation and may play an important role in planetary radiative forcing and climate. However, little is known about the production and loss mechanisms of BrC in the atmosphere. Here, we study how the light absorptivity of BrC from wood smoke and secondary BrC generated from the reaction of ammonium sulfate with methylglyoxal changes under photolytic aging by UVA radiation in the aqueous phase. Owing to its chemical complexity, BrC is separated by molecular weight using size exclusion chromatography, and the response of each molecular weight fraction to aging is studied. Photolytic aging induced significant changes in the light absorptivity of BrC for all molecular weight fractions; secondary BrC was rapidly photoblenched, whereas for wood smoke BrC, both photoenhancement and photobleaching were observed. Initially, large biomass burning BrC molecules were rapidly photoenhanced, followed by slow photolysis. As a result, large BrC molecules dominated the total light absorption of aged biomass burning BrC. These experimental results further support earlier observations that large molecular weight BrC compounds from biomass burning can be relatively long-lived components in atmospheric aerosols, thus more likely to have larger impacts on aerosol radiative forcing and could serve as biomass burning tracers.
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Affiliation(s)
| | - Athanasios Nenes
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology-Hellas , Patras GR-26504, Greece
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens , Palea Penteli GR-15236, Greece
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23
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Fang T, Zeng L, Gao D, Verma V, Stefaniak AB, Weber RJ. Ambient Size Distributions and Lung Deposition of Aerosol Dithiothreitol-Measured Oxidative Potential: Contrast between Soluble and Insoluble Particles. Environ Sci Technol 2017; 51:6802-6811. [PMID: 28548846 PMCID: PMC5994611 DOI: 10.1021/acs.est.7b01536] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Ambient particulate matter may upset redox homeostasis, leading to oxidative stress and adverse health effects. Size distributions of water-insoluble and water-soluble OPDTT (dithiothreitol assay, measure of oxidative potential per air volume) are reported for a roadside site and an urban site. The average water-insoluble fractions were 23% and 51%, and 37% and 39%, for fine and coarse modes at the roadside and urban sites, respectively, measured during different periods. Water-soluble OPDTT was unimodal, peaked near 1-2.5 μm due to contributions from fine-mode organic components plus coarse-mode transition metal ions. In contrast, water-insoluble OPDTT was bimodal, with both fine and coarse modes. The main chemical components that drive both fractions appear to be the same, except that for water-insoluble OPDTT the compounds were absorbed on surfaces of soot and non-tailpipe traffic dust. They were largely externally mixed and deposited in different regions in the respiratory system, transition metal ions predominately in the upper regions and organic species, such as quinones, deeper in the lung. Although OPDTT per mass (toxicity) was highest for ultrafine particles, estimated lung deposition was mainly from accumulation and coarse particles. Contrasts in the phases of these forms of OPDTT deposited in the respiratory system may have differing health impacts.
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Affiliation(s)
- Ting Fang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Linghan Zeng
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Dong Gao
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois Urbana–Champaign, Champaign, Illinois 61801, United States
| | - Aleksandr B. Stefaniak
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, United States
| | - Rodney J. Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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24
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Di Lorenzo RA, Washenfelder RA, Attwood AR, Guo H, Xu L, Ng NL, Weber RJ, Baumann K, Edgerton E, Young CJ. Molecular-Size-Separated Brown Carbon Absorption for Biomass-Burning Aerosol at Multiple Field Sites. Environ Sci Technol 2017; 51:3128-3137. [PMID: 28199090 DOI: 10.1021/acs.est.6b06160] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Biomass burning is a known source of brown carbon aerosol in the atmosphere. We collected filter samples of biomass-burning emissions at three locations in Canada and the United States with transport times of 10 h to >3 days. We analyzed the samples with size-exclusion chromatography coupled to molecular absorbance spectroscopy to determine absorbance as a function of molecular size. The majority of absorption was due to molecules >500 Da, and these contributed an increasing fraction of absorption as the biomass-burning aerosol aged. This suggests that the smallest molecular weight fraction is more susceptible to processes that lead to reduced light absorption, while larger-molecular-weight species may represent recalcitrant brown carbon. We calculate that these large-molecular-weight species are composed of more than 20 carbons with as few as two oxygens and would be classified as extremely low volatility organic compounds (ELVOCs).
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Affiliation(s)
- Robert A Di Lorenzo
- Department of Chemistry, Memorial University , St. John's, Newfoundland A1B 3X5, Canada
| | - Rebecca A Washenfelder
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder , Boulder, Colorado 80309, United States
- Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration , Boulder, Colorado 80305, United States
| | - Alexis R Attwood
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder , Boulder, Colorado 80309, United States
- Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration , Boulder, Colorado 80305, United States
| | | | | | | | | | - Karsten Baumann
- Atmospheric Research & Analysis Inc. , Cary, North Carolina 27513, United States
| | - Eric Edgerton
- Atmospheric Research & Analysis Inc. , Cary, North Carolina 27513, United States
| | - Cora J Young
- Department of Chemistry, Memorial University , St. John's, Newfoundland A1B 3X5, Canada
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25
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Fang T, Guo H, Zeng L, Verma V, Nenes A, Weber RJ. Highly Acidic Ambient Particles, Soluble Metals, and Oxidative Potential: A Link between Sulfate and Aerosol Toxicity. Environ Sci Technol 2017; 51:2611-2620. [PMID: 28141928 DOI: 10.1021/acs.est.6b06151] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Soluble transition metals in particulate matter (PM) can generate reactive oxygen species in vivo by redox cycling, leading to oxidative stress and adverse health effects. Most metals, such as those from roadway traffic, are emitted in an insoluble form, but must be soluble for redox cycling. Here we present the mechanism of metals dissolution by highly acidic sulfate aerosol and the effect on particle oxidative potential (OP) through analysis of size distributions. Size-segregated ambient PM were collected from a road-side and representative urban site in Atlanta, GA. Elemental and organic carbon, ions, total and water-soluble metals, and water-soluble OP were measured. Particle pH was determined with a thermodynamic model using measured ionic species. Sulfate was spatially uniform and found mainly in the fine mode, whereas total metals and mineral dust cations were highest at the road-side site and in the coarse mode, resulting in a fine mode pH < 2 and near neutral coarse mode. Soluble metals and OP peaked at the intersection of these modes demonstrating that sulfate plays a key role in producing highly acidic fine aerosols capable of dissolving primary transition metals that contribute to aerosol OP. Sulfate-driven metals dissolution may account for sulfate-health associations reported in past studies.
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Affiliation(s)
- Ting Fang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Hongyu Guo
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Linghan Zeng
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign , Champaign, Illinois 61801, United States
| | - Athanasios Nenes
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology , GR-26504, Patras, Greece
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens , GR-15236, Palea Penteli, Greece
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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Xu L, Guo H, Weber RJ, Ng NL. Chemical Characterization of Water-Soluble Organic Aerosol in Contrasting Rural and Urban Environments in the Southeastern United States. Environ Sci Technol 2017; 51:78-88. [PMID: 27997132 DOI: 10.1021/acs.est.6b05002] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We developed a novel system for direct and online characterization of water-solubility of organic aerosol (OA) by coupling a Particle Into Liquid Sampler (PILS) to a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). We showed that approximately 88% and 77% of OA are water-soluble in rural Centreville, Alabama and urban Atlanta, Georgia, respectively. The water-solubility of OA factors, resolved with Positive Matrix Factorization analysis of AMS data, is directly investigated for the first time. Above 80% of isoprene-derived OA is water-soluble and its water-soluble fraction has the least variability among all OA factors. This is consistent with that the majority of this factor represents OA formed through the aqueous-phase reaction of isoprene epoxydiols. More-oxidized oxygenated OA is dominantly water-soluble, consistent with this factor representing highly oxidized compounds. Less-oxidized oxygenated OA has the lowest water-solubility among all secondary OA factors, which agrees with the hypothesis that this factor in the southeastern U.S. includes contributions from organic nitrates. While hydrocarbon-like OA is largely water-insoluble, biomass burning OA and cooking OA have the largest range of water-soluble fraction. This study on the water-solubility of OA factors provides insights for interpretation of OA factors and improves understanding of the complex OA sources in the atmosphere.
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Affiliation(s)
- Lu Xu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Hongyu Guo
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Nga Lee Ng
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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27
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Rattanavaraha W, Chu K, Budisulistiorini SH, Riva M, Lin YH, Edgerton ES, Baumann K, Shaw SL, Guo H, King L, Weber RJ, Neff ME, Stone EA, Offenberg JH, Zhang Z, Gold A, Surratt JD. Assessing the impact of anthropogenic pollution on isoprene-derived secondary organic aerosol formation in PM 2.5 collected from the Birmingham, Alabama, ground site during the 2013 Southern Oxidant and Aerosol Study. Atmos Chem Phys 2017; 16:4897-4914. [PMID: 30245702 PMCID: PMC6145830 DOI: 10.5194/acp-16-4897-2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In the southeastern US, substantial emissions of isoprene from deciduous trees undergo atmospheric oxidation to form secondary organic aerosol (SOA) that contributes to fine particulate matter (PM2.5). Laboratory studies have revealed that anthropogenic pollutants, such as sulfur dioxide (SO2), oxides of nitrogen (NO x ), and aerosol acidity, can enhance SOA formation from the hydroxyl radical (OH)-initiated oxidation of isoprene; however, the mechanisms by which specific pollutants enhance isoprene SOA in ambient PM2.5 remain unclear. As one aspect of an investigation to examine how anthropogenic pollutants influence isoprene-derived SOA formation, high-volume PM2.5 filter samples were collected at the Birmingham, Alabama (BHM), ground site during the 2013 Southern Oxidant and Aerosol Study (SOAS). Sample extracts were analyzed by gas chromatography-electron ionization-mass spectrometry (GC/EI-MS) with prior trimethylsilylation and ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-QTOFMS) to identify known isoprene SOA tracers. Tracers quantified using both surrogate and authentic standards were compared with collocated gas- and particle-phase data as well as meteorological data provided by the Southeastern Aerosol Research and Characterization (SEARCH) network to assess the impact of anthropogenic pollution on isoprene-derived SOA formation. Results of this study reveal that isoprene-derived SOA tracers contribute a substantial mass fraction of organic matter (OM) (~ 7 to ~ 20 %). Isoprene-derived SOA tracers correlated with sulfate ( SO42- ) (r2 = 0.34, n = 117) but not with NO x . Moderate correlations between methacrylic acid epoxide and hydroxymethyl-methyl-α-lactone (together abbreviated MAE/HMML)-derived SOA tracers with nitrate radical production (P[NO3]) (r2 = 0.57, n = 40) were observed during nighttime, suggesting a potential role of the NO3 radical in forming this SOA type. However, the nighttime correlation of these tracers with nitrogen dioxide (NO2) (r2 = 0.26, n = 40) was weaker. Ozone (O3) correlated strongly with MAE/HMML-derived tracers (r2 = 0.72, n = 30) and moderately with 2-methyltetrols (r2 = 0.34, n = 15) during daytime only, suggesting that a fraction of SOA formation could occur from isoprene ozonolysis in urban areas. No correlation was observed between aerosol pH and isoprene-derived SOA. Lack of correlation between aerosol acidity and isoprene-derived SOA is consistent with the observation that acidity is not a limiting factor for isoprene SOA formation at the BHM site as aerosols were acidic enough to promote multiphase chemistry of isoprene-derived epoxides throughout the duration of the study. All in all, these results confirm previous studies suggesting that anthropogenic pollutants enhance isoprene-derived SOA formation.
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Affiliation(s)
- Weruka Rattanavaraha
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kevin Chu
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sri Hapsari Budisulistiorini
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- now at: Earth Observatory of Singapore, Nanyang Technological University, Singapore
| | - Matthieu Riva
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ying-Hsuan Lin
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- now at: Michigan Society of Fellows, Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | | | | | | | - Hongyu Guo
- Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, GA, USA
| | - Laura King
- Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, GA, USA
| | - Rodney J Weber
- Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, GA, USA
| | - Miranda E Neff
- Department of Chemistry, University of Iowa, Iowa City, IA, USA
| | | | - John H Offenberg
- Human Exposure and Atmospheric Sciences Division, United States Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Zhenfa Zhang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Avram Gold
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jason D Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Bates JT, Weber RJ, Abrams J, Verma V, Fang T, Klein M, Strickland MJ, Sarnat SE, Chang HH, Mulholland JA, Tolbert PE, Russell AG. Reactive Oxygen Species Generation Linked to Sources of Atmospheric Particulate Matter and Cardiorespiratory Effects. Environ Sci Technol 2015; 49:13605-12. [PMID: 26457347 DOI: 10.1021/acs.est.5b02967] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Exposure to atmospheric fine particulate matter (PM2.5) is associated with cardiorespiratory morbidity and mortality, but the mechanisms are not well understood. We assess the hypothesis that PM2.5 induces oxidative stress in the body via catalytic generation of reactive oxygen species (ROS). A dithiothreitol (DTT) assay was used to measure the ROS-generation potential of water-soluble PM2.5. Source apportionment on ambient (Atlanta, GA) PM2.5 was performed using the chemical mass balance method with ensemble-averaged source impact profiles. Linear regression analysis was used to relate PM2.5 emission sources to ROS-generation potential and to estimate historical levels of DTT activity for use in an epidemiologic analysis for the period of 1998-2009. Light-duty gasoline vehicles (LDGV) exhibited the highest intrinsic DTT activity, followed by biomass burning (BURN) and heavy-duty diesel vehicles (HDDV) (0.11 ± 0.02, 0.069 ± 0.02, and 0.052 ± 0.01 nmol min(-1) μg(-1)source, respectively). BURN contributed the largest fraction to total DTT activity over the study period, followed by LDGV and HDDV (45, 20, and 14%, respectively). DTT activity was more strongly associated with emergency department visits for asthma/wheezing and congestive heart failure than PM2.5. This work provides further epidemiologic evidence of a biologically plausible mechanism, that of oxidative stress, for associations of adverse health outcomes with PM2.5 mass and supports continued assessment of the utility of the DTT activity assay as a measure of ROS-generating potential of particles.
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Affiliation(s)
| | | | | | - Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Champaign, Illinois 61801, United States
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29
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Verma V, Fang T, Xu L, Peltier RE, Russell AG, Ng NL, Weber RJ. Organic aerosols associated with the generation of reactive oxygen species (ROS) by water-soluble PM2.5. Environ Sci Technol 2015; 49:4646-56. [PMID: 25748105 DOI: 10.1021/es505577w] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We compare the relative toxicity of various organic aerosol (OA) components identified by an aerosol mass spectrometer (AMS) based on their ability to generate reactive oxygen species (ROS). Ambient fine aerosols were collected from urban (three in Atlanta, GA and one in Birmingham, AL) and rural (Yorkville, GA and Centerville, AL) sites in the Southeastern United States. The ROS generating capability of the water-soluble fraction of the particles was measured by the dithiothreitol (DTT) assay. Water-soluble PM extracts were further separated into the hydrophobic and hydrophilic fractions using a C-18 column, and both fractions were analyzed for DTT activity and water-soluble metals. Organic aerosol composition was measured at selected sites using a high-resolution time-of-flight AMS. Positive matrix factorization of the AMS spectra resolved the organic aerosol into isoprene-derived OA (Isop_OA), hydrocarbon-like OA (HOA), less-oxidized oxygenated OA, (LO-OOA), more-oxidized OOA (MO-OOA), cooking OA (COA), and biomass burning OA (BBOA). The association of the DTT activity of water-soluble PM2.5 (WS_DTT) with these factors was investigated by linear regression techniques. BBOA and MO-OOA were most consistently linked with WS_DTT, with intrinsic water-soluble activities of 151 ± 20 and 36 ± 22 pmol/min/μg, respectively. Although less toxic, MO-OOA was most widespread, contributing to WS_DTT activity at all sites and during all seasons. WS_DTT activity was least associated with biogenic secondary organic aerosol. The OA components contributing to WS_DTT were humic-like substances (HULIS), which are abundantly emitted in biomass burning (BBOA) and include highly oxidized OA from multiple sources (MO-OOA). Overall, OA contributed approximately 60% to the WS_DTT activity, with the remaining probably from water-soluble metals, which were mostly associated with the hydrophilic WS_DTT fraction.
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Affiliation(s)
- Vishal Verma
- †School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ting Fang
- †School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Lu Xu
- ‡School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Richard E Peltier
- §Department of Environmental Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Armistead G Russell
- ∥School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Nga Lee Ng
- ‡School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Rodney J Weber
- †School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Verma V, Fang T, Xu L, Peltier RE, Russell AG, Ng NL, Weber RJ. Organic aerosols associated with the generation of reactive oxygen species (ROS) by water-soluble PM2.5. Environ Sci Technol 2015; 49:4646-4656. [PMID: 25748105 DOI: 10.1021/es505577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We compare the relative toxicity of various organic aerosol (OA) components identified by an aerosol mass spectrometer (AMS) based on their ability to generate reactive oxygen species (ROS). Ambient fine aerosols were collected from urban (three in Atlanta, GA and one in Birmingham, AL) and rural (Yorkville, GA and Centerville, AL) sites in the Southeastern United States. The ROS generating capability of the water-soluble fraction of the particles was measured by the dithiothreitol (DTT) assay. Water-soluble PM extracts were further separated into the hydrophobic and hydrophilic fractions using a C-18 column, and both fractions were analyzed for DTT activity and water-soluble metals. Organic aerosol composition was measured at selected sites using a high-resolution time-of-flight AMS. Positive matrix factorization of the AMS spectra resolved the organic aerosol into isoprene-derived OA (Isop_OA), hydrocarbon-like OA (HOA), less-oxidized oxygenated OA, (LO-OOA), more-oxidized OOA (MO-OOA), cooking OA (COA), and biomass burning OA (BBOA). The association of the DTT activity of water-soluble PM2.5 (WS_DTT) with these factors was investigated by linear regression techniques. BBOA and MO-OOA were most consistently linked with WS_DTT, with intrinsic water-soluble activities of 151 ± 20 and 36 ± 22 pmol/min/μg, respectively. Although less toxic, MO-OOA was most widespread, contributing to WS_DTT activity at all sites and during all seasons. WS_DTT activity was least associated with biogenic secondary organic aerosol. The OA components contributing to WS_DTT were humic-like substances (HULIS), which are abundantly emitted in biomass burning (BBOA) and include highly oxidized OA from multiple sources (MO-OOA). Overall, OA contributed approximately 60% to the WS_DTT activity, with the remaining probably from water-soluble metals, which were mostly associated with the hydrophilic WS_DTT fraction.
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Affiliation(s)
- Vishal Verma
- †School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ting Fang
- †School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Lu Xu
- ‡School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Richard E Peltier
- §Department of Environmental Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Armistead G Russell
- ∥School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Nga Lee Ng
- ‡School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Rodney J Weber
- †School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Staudt S, Kundu S, Lehmler HJ, He X, Cui T, Lin YH, Kristensen K, Glasius M, Zhang X, Weber RJ, Surratt JD, Stone1 EA. Aromatic organosulfates in atmospheric aerosols: synthesis, characterization, and abundance. Atmos Environ (1994) 2014; 94:366-373. [PMID: 24976783 PMCID: PMC4071301 DOI: 10.1016/j.atmosenv.2014.05.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Aromatic organosulfates are identified and quantified in fine particulate matter (PM2.5) from Lahore, Pakistan, Godavari, Nepal, and Pasadena, California. To support detection and quantification, authentic standards of phenyl sulfate, benzyl sulfate, 3-and 4-methylphenyl sulfate and 2-, 3-, and 4-methylbenzyl sulfate were synthesized. Authentic standards and aerosol samples were analyzed by ultra-performance liquid chromatography (UPLC) coupled to negative electrospray ionization (ESI) quadrupole time-of-flight (ToF) mass spectrometry. Benzyl sulfate was present in all three locations at concentrations ranging from 4 - 90 pg m-3. Phenyl sulfate, methylphenyl sulfates and methylbenzyl sulfates were observed intermittently with abundances of 4 pg m-3, 2-31 pg m-3, 109 pg m-3, respectively. Characteristic fragment ions of aromatic organosulfates include the sulfite radical (•SO3-, m/z 80) and the sulfate radical (•SO4-,m/z 96). Instrumental response factors of phenyl and benzyl sulfates varied by a factor of 4.3, indicating that structurally-similar organosulfates may have significantly different instrumental responses and highlighting the need to develop authentic standards for absolute quantitation organosulfates. In an effort to better understand the sources of aromatic organosulfates to the atmosphere, chamber experiments with the precursor toluene were conducted under conditions that form biogenic organosulfates. Aromatic organosulfates were not detected in the chamber samples, suggesting that they form through different pathways, have different precursors (e.g. naphthalene or methylnaphthalene), or are emitted from primary sources.
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Affiliation(s)
- Sean Staudt
- Department of Chemistry, University of Iowa, Iowa City, IA 52242, United States
| | - Shuvashish Kundu
- Department of Chemistry, University of Iowa, Iowa City, IA 52242, United States
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Xianran He
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Tianqu Cui
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ying-Hsuan Lin
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kasper Kristensen
- Department of Chemistry and iNANO, Aarhus University, 8000 Aarhus C, Denmark
| | - Marianne Glasius
- Department of Chemistry and iNANO, Aarhus University, 8000 Aarhus C, Denmark
| | - Xiaolu Zhang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Rodney J. Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Jason D. Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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De Santiago A, Longo AF, Ingall ED, Diaz JM, King LE, Lai B, Weber RJ, Russell AG, Oakes M. Characterization of selenium in ambient aerosols and primary emission sources. Environ Sci Technol 2014; 48:8988-8994. [PMID: 25075640 DOI: 10.1021/es500379y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Atmospheric selenium (Se) in aerosols was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the oxidation state and elemental associations of Se in common primary emission sources and ambient aerosols collected from the greater Atlanta area. In the majority of ambient aerosol and primary emission source samples, the spectroscopic patterns as well as the absence of elemental correlations suggest Se is in an elemental, organic, or oxide form. XRF microscopy revealed numerous Se-rich particles, or hotspots, accounting on average for ∼16% of the total Se in ambient aerosols. Hotspots contained primarily Se(0)/Se(-II). However, larger, bulk spectroscopic characterizations revealed Se(IV) as the dominant oxidation state in ambient aerosol, followed by Se(0)/Se(-II) and Se(VI). Se(IV) was the only observed oxidation state in gasoline, diesel, and coal fly ash, while biomass burning contained a combination of Se(0)/Se(-II) and Se(IV). Although the majority of Se in aerosols was in the most toxic form, the Se concentration is well below the California Environmental Protection Agency chronic exposure limit (∼20000 ng/m(3)).
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Affiliation(s)
- Arlette De Santiago
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , 311 Ferst Drive, Atlanta, Georgia 30332-0340, United States
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Cheng Y, Engling G, He KB, Duan FK, Du ZY, Ma YL, Liang LL, Lu ZF, Liu JM, Zheng M, Weber RJ. The characteristics of Beijing aerosol during two distinct episodes: impacts of biomass burning and fireworks. Environ Pollut 2014; 185:149-157. [PMID: 24275313 DOI: 10.1016/j.envpol.2013.10.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/16/2013] [Accepted: 10/19/2013] [Indexed: 06/02/2023]
Abstract
The chemical composition of Beijing aerosol was measured during summer and winter. Two distinct episodes were identified. Water-soluble potassium (K(+)) increased significantly during the firework episode in winter with an episode to non-episode ratio of 4.97, whereas the biomass burning (BB) episode in summer was characterized by high episode to non-episode ratios of levoglucosan (6.38) and K(+) (6.90). The BB and firework episodes had only a minor influence on the water-soluble OC (organic carbon) to OC ratio. Based on separate investigations of episode and non-episode periods, it was found that: (i) sulfate correlated strongly with both relative humidity and nitrate during the typical winter period presumably indicating the importance of the aqueous-phase oxidation of sulfur dioxide by nitrogen dioxide, (ii) oxalate and WSOC during both winter and summer in Beijing were mainly due to secondary formation, and (iii) high humidity can significantly enhance the formation potential of WSOC in winter.
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Affiliation(s)
- Yuan Cheng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China.
| | - Guenter Engling
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Ke-bin He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, China.
| | - Feng-kui Duan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Zhen-yu Du
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Yong-liang Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Lin-lin Liang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Zi-feng Lu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Jiu-meng Liu
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Mei Zheng
- College of Environmental Sciences and Engineering, Peking University, Beijing, China
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States
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Zheng M, Zhao X, Cheng Y, Yan C, Shi W, Zhang X, Weber RJ, Schauer JJ, Wang X, Edgerton ES. Sources of primary and secondary organic aerosol and their diurnal variations. J Hazard Mater 2014; 264:536-544. [PMID: 24262212 DOI: 10.1016/j.jhazmat.2013.10.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 06/08/2013] [Revised: 10/11/2013] [Accepted: 10/21/2013] [Indexed: 06/02/2023]
Abstract
PM(2.5), as one of the criteria pollutants regulated in the U.S. and other countries due to its adverse health impacts, contains more than hundreds of organic pollutants with different sources and formation mechanisms. Daytime and nighttime PM2.5 samples from the August Mini-Intensive Gas and Aerosol Campaign (AMIGAS) in the southeastern U.S. were collected during summer 2008 at one urban site and one rural site, and were analyzed for organic carbon (OC), elemental carbon (EC), water soluble organic carbon (WSOC), and various individual organic compounds including some important tracers for carbonaceous aerosol sources by gas chromatography-mass spectrometry. Most samples exhibited higher daytime OC concentration, while higher nighttime OC was found in a few events at the urban site. Sources, formation mechanisms and composition of organic aerosol are complicated and results of this study showed that it exhibited distinct diurnal variations. With detailed organic tracer information, sources contributing to particulate OC were identified: higher nighttime OC concentration occurring in several occasions was mainly contributed by the increasing primary emissions at night, especially diesel exhaust and biomass burning; whereas sources responsible for higher daytime OC concentration included secondary organic aerosol (SOA) formation (e.g., cis-pinonic acid and non-biomass burning WSOC) together with traffic emissions especially gasoline engine exhaust. Primary tracers from combustion related sources such as EC, polycyclic aromatic hydrocarbons, and hopanes and steranes were significantly higher at the urban site with an urban to rural ratio between 5 and 8. However, this urban-rural difference for secondary components was less significant, indicating a relatively homogeneous distribution of SOA spatially. We found cholesterol concentrations, a typical tracer for meat cooking, were consistently higher at the rural site especially during the daytime, suggesting the likely additional sources for this tracer at rural site and that it should be used with caution as meat cooking tracer in rural areas in the future.
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Affiliation(s)
- Mei Zheng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Xiuying Zhao
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Yuan Cheng
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Caiqing Yan
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Wenyan Shi
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Xiaolu Zhang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Rodney J Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | | | - Xinming Wang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
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Balachandran S, Pachon JE, Lee S, Oakes MM, Rastogi N, Shi W, Tagaris E, Yan B, Davis A, Zhang X, Weber RJ, Mulholland JA, Bergin MH, Zheng M, Russell AG. Particulate and gas sampling of prescribed fires in South Georgia, USA. Atmospheric Environment 2013; 81:125-135. [DOI: 10.1016/j.atmosenv.2013.08.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
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Verma V, Rico-Martinez R, Kotra N, Rennolds C, Liu J, Snell TW, Weber RJ. Estimating the toxicity of ambient fine aerosols using freshwater rotifer Brachionus calyciflorus (Rotifera: Monogononta). Environ Pollut 2013; 182:379-384. [PMID: 23981648 DOI: 10.1016/j.envpol.2013.07.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [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: 11/29/2012] [Revised: 04/30/2013] [Accepted: 07/29/2013] [Indexed: 06/02/2023]
Abstract
The toxicity of atmospheric fine particulate matter (PM2.5) in Atlanta is assessed using freshwater rotifers (Brachionus calyciflorus). The PM-laden quartz filters were extracted in both water and methanol. Aerosol extracts were passed through a C-18 column to separate the PM components into hydrophobic and hydrophilic fractions. Toxicity data reported in the units of LC50 (concentration that kills 50% of the test population in 24 h) shows that ambient particles are toxic to the rotifers with LC50 values ranging from 5 to 400 μg of PM. The methanol extract of the aerosols was substantially more toxic (8 ± 6 times) to the rotifers compared to the water extracts. A sizeable fraction (>70%) of toxicity was found to be associated with the hydrophobic fraction of PM. However, none of the bulk aerosol species was strongly correlated with the LC50 values suggesting a complicated mechanism of toxicity probably involving synergistic interactions of various PM components.
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Affiliation(s)
- Vishal Verma
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, USA
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Zhang X, Lin YH, Surratt JD, Weber RJ. Sources, composition and absorption Ångström exponent of light-absorbing organic components in aerosol extracts from the Los Angeles Basin. Environ Sci Technol 2013; 47:3685-93. [PMID: 23506531 DOI: 10.1021/es305047b] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We investigate the sources, chemical composition, and spectral properties of light-absorbing organic aerosol extracts (i.e., brown carbon, or BrC) in the Los Angeles (LA) Basin during the CalNex-2010 field campaign. Light absorption of PM2.5 water-soluble components at 365 nm (Abs365), used as a proxy for water-soluble BrC, was well correlated with water-soluble organic carbon (WSOC) (r(2) = 0.55-0.65), indicating secondary organic aerosol (SOA) formation from anthropogenic emissions was the major source of water-soluble BrC in this region. Normalizing Abs365 to WSOC mass yielded an average solution mass absorption efficiency (MAE365) of 0.71 m(2) g(-1) C. Detailed chemical speciation of filter extracts identified eight nitro-aromatic compounds that were correlated with Abs365. These compounds accounted for ∼4% of the overall water-soluble BrC absorption. Methanol-extracted BrC in LA was approximately 3 and 21 times higher than water-soluble BrC at 365 and 532 nm, respectively, and had a MAE365 of 1.58 m(2) g(-1) C (Abs365 normalized to organic carbon mass). The water-insoluble BrC was strongly correlated with ambient elemental carbon concentration, suggesting similar sources. Absorption Ångström exponent (Å(a)) (fitted between 300 and 600 nm wavelengths) was 3.2 (±1.2) for the PILS water-soluble BrC measurement, compared to 4.8 (±0.5) and 7.6 (±0.5) for methanol- and water-soluble BrC from filter extracts, respectively. These results show that fine particle BrC was prevalent in the LA basin during CalNex, yet many of its properties and potential impacts remain unknown.
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Affiliation(s)
- Xiaolu Zhang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
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Verma V, Rico-Martinez R, Kotra N, King L, Liu J, Snell TW, Weber RJ. Contribution of water-soluble and insoluble components and their hydrophobic/hydrophilic subfractions to the reactive oxygen species-generating potential of fine ambient aerosols. Environ Sci Technol 2012; 46:11384-92. [PMID: 22974103 DOI: 10.1021/es302484r] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Relative contributions of water- and methanol-soluble compounds and their hydrophobic/hydrophilic subfractions to the ROS (reactive oxygen species)-generating potential of ambient fine aerosols (D(p) < 2.5 μm) are assessed. ROS-generating (or oxidative) potential of the particulate matter (PM) was measured by the dithiothreitol (DTT) assay. Particles were collected on quartz filters (N = 8) at an urban site near central Atlanta during January-February 2012 using a PM(2.5) high-volume sampler. Filter punches were extracted separately in both water and methanol. Hydrophobic and hydrophilic fractions were then subsequently segregated via a C-18 solid phase extraction column. The DTT assay response was significantly higher for the methanol extract, and for both extracts a substantial fraction of PM oxidative potential was associated with the hydrophobic compounds as evident from a substantial attenuation in DTT response after passing PM extracts through the C-18 column (64% for water and 83% for methanol extract; both median values). The DTT activities of water and methanol extracts were correlated with the water-soluble (R = 0.86) and water-insoluble organic carbon (R = 0.94) contents of the PM, respectively. Brown carbon (BrC), which predominantly represents the hydrophobic organic fraction (referred to as humic-like substances, HULIS), was also correlated with DTT activity in both the water (R = 0.78) and methanol extracts (R = 0.83). Oxidative potential was not correlated with any metals measured in the extracts. These findings suggest that the hydrophobic components of both water-soluble and insoluble organic aerosols substantially contribute to the oxidative properties of ambient PM. Further investigation of these hydrophobic organic compounds could help identify sources of a significant fraction of ambient aerosol toxicity.
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Affiliation(s)
- Vishal Verma
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Liu J, Zhang X, Parker ET, Veres PR, Roberts JM, de Gouw JA, Hayes PL, Jimenez JL, Murphy JG, Ellis RA, Huey LG, Weber RJ. On the gas-particle partitioning of soluble organic aerosol in two urban atmospheres with contrasting emissions: 2. Gas and particle phase formic acid. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017912] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zhang X, Liu J, Parker ET, Hayes PL, Jimenez JL, de Gouw JA, Flynn JH, Grossberg N, Lefer BL, Weber RJ. On the gas-particle partitioning of soluble organic aerosol in two urban atmospheres with contrasting emissions: 1. Bulk water-soluble organic carbon. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017908] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wang LH, Dong HB, Yan CQ, Zeng LM, Zheng M, Zhang YJ, Liu JM, Weber RJ. [Improvement and application of the method for determination of OCEC split]. Huan Jing Ke Xue 2012; 33:2946-2952. [PMID: 23243843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Aerosol samples were collected in Beijing (BD) and Atlanta (GT) from July to August in 2011 using a Micro-Orifice Uniform Deposit Impactor (MOUDI) (0.18-18 microm, eight-stage) for organic carbon (OC) and elemental carbon (EC) measurement (Sunset Laboratory Inc, USA). The laser intensity of blank filters decreased with temperature in the process of OC & EC analysis because the structure of quartz filters was changed when burned which largely affected the determination of low concentration samples' splits. It would increase the accuracy of OC & EC split to determine it manually after the change of blank filter's laser intensity was recouped. The concentrations and size distributions of OC & EC using the improved method were different from taking the moment when oxygen was introduced as the split. The split may appear before oxygen addition, when the sample was rich in metal or substances that can be decomposed after heated. The concentrations of carbonaceous components were higher at BD than those at GT. The size distributions of OC showed a bimodal pattern with peaks appeared in the particles with size of (0.56-1.0) microm and (3.2-5.6) microm. The peak concentrations of OC were (2.82 +/- 1.59) microg x m(-3) and (1.95 +/- 0.76) microg x m(-3) at BD, and (1.28 +/- 0.41) microg x m(-3) and (0.64 +/- 0.19) microg x m(-3) at GT. EC showed a bimodal pattern at BD with peaks in particles with size of (0.56-1.0) microm and (3.2-5.6) microm, while showed a trimodal pattern at GT. The peak concentrations at BD were (0.32 +/- 0.24) microg x m(-3) and (0.26 +/- 0.19) microg x m(-3). EC at GT was preferably enriched in particles with size of (0.18-0.56) microm, the mass concentrations of EC in this size accounted for 44.6%. The OC and EC were more concentrated in accumulation mode at GT than those at BD, the reason may be that the main pollution source of GT is motor vehicle emission, while there are more industrial gas emissions at BD.
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Affiliation(s)
- Li-Hua Wang
- State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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Oakes M, Ingall ED, Lai B, Shafer MM, Hays MD, Liu ZG, Russell AG, Weber RJ. Iron solubility related to particle sulfur content in source emission and ambient fine particles. Environ Sci Technol 2012; 46:6637-44. [PMID: 22621615 DOI: 10.1021/es300701c] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The chemical factors influencing iron solubility (soluble iron/total iron) were investigated in source emission (e.g., biomass burning, coal fly ash, mineral dust, and mobile exhaust) and ambient (Atlanta, GA) fine particles (PM2.5). Chemical properties (speciation and mixing state) of iron-containing particles were characterized using X-ray absorption near edge structure (XANES) spectroscopy and micro-X-ray fluorescence measurements. Bulk iron solubility (soluble iron/total iron) of the samples was quantified by leaching experiments. Major differences were observed in iron solubility in source emission samples, ranging from low solubility (<1%, mineral dust and coal fly ash) up to 75% (mobile exhaust and biomass burning emissions). Differences in iron solubility did not correspond to silicon content or Fe(II) content. However, source emission and ambient samples with high iron solubility corresponded to the sulfur content observed in single particles. A similar correspondence between bulk iron solubility and bulk sulfate content in a series of Atlanta PM2.5 fine particle samples (N = 358) further supported this trend. In addition, results of linear combination fitting experiments show the presence of iron sulfates in several high iron solubility source emission and ambient PM2.5 samples. These results suggest that the sulfate content (related to the presence of iron sulfates and/or acid-processing mechanisms by H(2)SO(4)) of iron-containing particles is an important proxy for iron solubility.
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Affiliation(s)
- M Oakes
- Department of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States.
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Kane-Gill SL, Kowiatek JG, Weber RJ. A comparison of voluntarily reported medication errors in intensive care and general care units. Qual Saf Health Care 2012; 19:55-9. [PMID: 20172884 DOI: 10.1136/qshc.2008.027961] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Few institutions currently track intensive care unit (ICU)-specific medication safety data. A comparison of medication error data for intensive care and general care units may determine if ICU-specific surveillance is needed. OBJECTIVE To compare the type, cause, contributing factors, level of staff initiating an error, medication use process node, drug classes and patient outcomes for voluntarily reported medication errors occurring in ICUs and general care units. DESIGN Retrospective evaluation of voluntarily reported medication errors over 4.5 years at a 647-bed academic medical centre containing greater than 120 ICU beds. Adult patients with a reported medication error in intensive care and general care units were included. Medication error data were compared for ICUs with general care units. MAIN MEASURES AND RESULTS There were a total of 3252 medication errors reported with 541 and 2711 occurring in ICUs and general care units, respectively. Primary types of medication errors were prescribing in the ICUs and omission in the general care units. Leading causes of medication errors were procedure/protocol not followed and knowledge deficit in the ICU and general care units. More frequently there was no contributing factor identified for medication errors in the ICUs. The top three drugs associated with medication errors in the ICUs were opioid analgesics, beta-lactam antimicrobials and blood coagulation modifiers compared with anti-asthma/bronchodilators, narcotic analgesics and vaccines in the general care units. The level of care provided after the error was observation increased/initiated in ICUs and no additional care in general care units. Prolonged hospitalisation was a result of medication errors in 1% of ICU cases and 0.4% of general care unit errors (p = 0.056). Medication errors were associated with harm in 12% and 6% of cases in the ICUs and general care units, respectively (p<0.001). CONCLUSION Type, contributing factors, drug classes and patient outcomes associated with voluntarily reported medication errors differ in intensive care and general care units so it is important to develop surveillance systems that analyse ICU-specific data allowing systematic changes for this patient population.
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Affiliation(s)
- S L Kane-Gill
- Center for Pharmacoinformatics and Outcomes Research, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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Duong HT, Sorooshian A, Craven JS, Hersey SP, Metcalf AR, Zhang X, Weber RJ, Jonsson H, Flagan RC, Seinfeld JH. Water-soluble organic aerosol in the Los Angeles Basin and outflow regions: Airborne and ground measurements during the 2010 CalNex field campaign. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016674] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hanh T. Duong
- Department of Chemical and Environmental Engineering; University of Arizona; Tucson Arizona USA
| | - Armin Sorooshian
- Department of Chemical and Environmental Engineering; University of Arizona; Tucson Arizona USA
- Department of Atmospheric Sciences; University of Arizona; Tucson Arizona USA
| | - Jill S. Craven
- Departments of Environmental Science and Engineering and Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - Scott P. Hersey
- Departments of Environmental Science and Engineering and Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - Andrew R. Metcalf
- Departments of Environmental Science and Engineering and Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - Xiaolu Zhang
- School of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta Georgia USA
| | - Rodney J. Weber
- School of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta Georgia USA
| | - Haflidi Jonsson
- Center for Interdisciplinary Remotely-Piloted Aircraft Studies; Naval Postgraduate School; Monterey California USA
| | - Richard C. Flagan
- Departments of Environmental Science and Engineering and Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - John H. Seinfeld
- Departments of Environmental Science and Engineering and Chemical Engineering; California Institute of Technology; Pasadena California USA
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Asa-Awuku A, Moore RH, Nenes A, Bahreini R, Holloway JS, Brock CA, Middlebrook AM, Ryerson TB, Jimenez JL, DeCarlo PF, Hecobian A, Weber RJ, Stickel R, Tanner DJ, Huey LG. Airborne cloud condensation nuclei measurements during the 2006 Texas Air Quality Study. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd014874] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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46
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Oakes M, Rastogi N, Majestic BJ, Shafer M, Schauer JJ, Edgerton ES, Weber RJ. Characterization of soluble iron in urban aerosols using near-real time data. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd012532] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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47
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Padró LT, Tkacik D, Lathem T, Hennigan CJ, Sullivan AP, Weber RJ, Huey LG, Nenes A. Investigation of cloud condensation nuclei properties and droplet growth kinetics of the water-soluble aerosol fraction in Mexico City. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd013195] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
SYNOPSIS The drying stresses that develop in stratum corneum (SC) are crucial for its mechanical and biophysical function, its cosmetic feel and appearance, and play a central role in processes of dry skin damage. However, quantitative methods to characterize these stresses are lacking and little understanding exists regarding the effects of drying environment, chemical exposures and moisturizing treatments. We describe the application of a substrate curvature technique adapted for biological tissue to accurately characterize SC drying stresses as a function of time following environmental pre-conditioning and chemical treatment in a range of drying environments. SC stresses were observed to increase to stress levels of up to approximately 3 MPa over periods of 8 h depending on pretreatment and drying environment. A unique relationship between the SC stress and water in the drying environment was established. The effect of glycerol on lowering SC stresses and damaging surfactants on elevating SC stresses were quantified. Extensions of the method to continuous monitoring of SC stresses in response to changes in environmental moisture content and temperature are reported. Finally, a biomechanics framework to account for the SC drying stress as a mechanical driving force for dry skin damage is presented.
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Affiliation(s)
- K Levi
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
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Weber RJ, Gomez-Flores R, Smith JE, Martin TJ. Neuronal adaptations, neuroendocrine and immune correlates of heroin self-administration. Brain Behav Immun 2009; 23:993-1002. [PMID: 19467321 DOI: 10.1016/j.bbi.2009.05.057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 05/19/2009] [Accepted: 05/19/2009] [Indexed: 11/19/2022] Open
Abstract
Opioid receptor-mediated action in the central nervous system (CNS) has been consistently shown to trigger changes in the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS) and suppress a variety of parameters of immune function in investigator-delivered paradigms. Overwhelming evidence supports the concept that the CNS undergoes numerous and complex neuronal adaptive changes in addicts, and in animal models of heroin addiction as a result of the training of drug stimuli to serve as reinforcers, altering the function of individual neurons and the larger neural circuits within which the neurons operate. Taken together, these advances suggest that since plastic neuronal changes occur in drug addiction and related animal model paradigms, profiles of neuroendocrine and immune function would differ in a rat model of heroin self-administration compared to passive infusion of drug. Self-administration of heroin induces neuronal circuitry adaptations in specific brain regions that may be related to alterations in neuroendocrine and T lymphocyte function also observed. Animals self-administering (SA) heroin exhibit increased mu-opioid receptor agonist ([D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO))-stimulated guanosine-5'-O-(gamma-thio)-triphosphate ([(35)S]GTPgammaS) binding in the anterior hypothalamus (50% and 33%) and rostral medial thalamus (33% and 36%) compared with control animals receiving identical non-contingent injections of yoked-heroin (YH) or yoked-saline (YS), respectively. No changes in agonist-stimulated G-protein sensitization were observed in 14 other brain regions studied. No changes in mu-opioid receptor density, ((3)H-DAMGO binding) were seen in all brain regions examined. The neuronal changes in SA animals were correlated with elevated adrenocorticotrophic hormone (ACTH) (64% and 104%) and glucocorticoid production (198% and 79%) compared with YH and YS groups, respectively. Neuroendocrine adaptive changes in SA animals were associated with thymic hypoplasia. Splenic T lymphocytes from animals that had self-administered heroin showed a profoundly reduced ability to proliferate in response to concanavalin A (50% and 48% compared with YH and YS controls, respectively; Fig. 1A), or a monoclonal antibody (R73) to the CD3/T-cell receptor complex (anti-TCR) plus IL-2 (55% and 59% compared with YH and YS controls, respectively; Fig. 1B). Self-administration of heroin selectively alters T lymphocyte function, as no effects on natural killer cell activity or macrophage functions were observed. These findings may have relevance to the acquisition and documented increased incidence of infectious diseases, including HIV, in heroin addicts, due to a pre-existing T-cell immunodeficient state.
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Affiliation(s)
- R J Weber
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, IL 61656, USA.
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Yan B, Zheng M, Hu Y, Ding X, Sullivan AP, Weber RJ, Baek J, Edgerton ES, Russell AG. Roadside, urban, and rural comparison of primary and secondary organic molecular markers in ambient PM2.5. Environ Sci Technol 2009; 43:4287-4293. [PMID: 19603636 DOI: 10.1021/es900316g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
PM2.5 filter samples (12-h and 24-h) were collected in urban Atlanta, GA, next to a freeway and 400 m away, as well as at a rural site, with particular focus on exploring on-road emissions, regional transport, and biogenic effects. Detailed speciation of PM2.5 carbonaceous aerosols was conducted by GC/ MS. Diurnal, seasonal, and spatial variations of PM2.5 organic composition were investigated. Primary organic compounds usually exhibit different attributes of day vs night while secondary organic tracers varied little. Much higher concentrations of automotive-related primary organic compounds are observed at the highway site, including n-alkanes, hopanes, steranes, and polycyclic aromatic hydrocarbons (PAHs). Season-specific on-road mobile source primary OC profiles were developed by using differences in organic species concentrations between the highway site and the nearby site. Calculated on-road source profiles differ from mobile source profiles measured in the lab. Significant seasonal differences are observed for 2-methyltetrols, cis-pinonic acid, and pinic acid, organic tracers of biogenic secondary organic aerosols (SOA). Little correlation is found between 2-methyltetrols and cis-pinonic or pinic acid, though cis-pinonic and pinic acids are strongly correlated.
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Affiliation(s)
- Bo Yan
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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