Grantee Research Project Results
2014 Progress Report: Development and Deployment of an Instrumentation Suite for Comprehensive Air Quality Characterization Including Aerosol ROS
EPA Grant Number: R834799C001Subproject: this is subproject number 001 , established and managed by the Center Director under grant R834799
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: The Southeastern Center for Air Pollution and Epidemiology: Multiscale Measurements and Modeling of Mixtures
Center Director: Tolbert, Paige
Title: Development and Deployment of an Instrumentation Suite for Comprehensive Air Quality Characterization Including Aerosol ROS
Investigators: Weber, Rodney J. , Sarnat, Stefanie Ebelt , Strickland, Matthew J , Nenes, Athanasios , Mulholland, James , Sarnat, Jeremy , Bergin, Michael
Institution: Georgia Institute of Technology , Emory University
Current Institution: Georgia Institute of Technology , Duke University , Emory University , University of Nevada - Reno
EPA Project Officer: Chung, Serena
Project Period: January 1, 2011 through December 31, 2016
Project Period Covered by this Report: October 1, 2013 through September 30,2014
RFA: Clean Air Research Centers (2009) RFA Text | Recipients Lists
Research Category: Human Health , Air
Objective:
To provide a chemically comprehensive data set on ambient particle composition at various sites relative to roadway emissions that will be used by other SCAPE Projects. As a part of this effort, our goal is to develop new instruments and analytical methods to quantify concentrations of particle-bound reactive oxygen species (ROS) and the ability of aerosols to catalyze the production of ROS through interactions with antioxidants. These techniques were deployed during SCAPE to provide a data set for investigating ROS sources, atmospheric processing and health impacts.
Progress Summary:
Project 1 ambient sampling program was completed in the third year, including three out-of-state sites (Centreville, AL; Birmingham, AL; and St. Louis, MO), and an additional September 2013 deployment at Roadside/GIT as part of the CCAR collaboration. This has produced a data set of roughly 310 days of sample collection. In addition to the online data collected, analysis of the 23-hour integrated filters also has been completed. This includes:
- ROS via DTT assay of water and methanol extracts. The hydrophilic fraction was isolated for each of these solvents and DTT activity measured. Roughly 2,400 DTT measurements were performed.
- A suite of water-soluble elements (e.g., water-soluble metals) was measured in conjunction with all DTT analyses (i.e., 2,400 samples). This was based on the development of an automated method that utilized an online XRF metals instrument (Xact 625 Monitoring System, Cooper Environmental Systems). The method’s performance was verified, all high-volume filters were analyzed (total water-soluble and hydrophilic water-soluble), data quality assured and submitted to data archive.
- Deployment of an Aerosol Mass Spectrometer (AMS) was completed providing detailed aerosol chemical characterization for 8 of the Project 1 deployment sites. The AMS data has been analyzed, including PMF for organic speciation/source tracers. All data are archived.
- WSOC, BrC (Brown Carbon), a suite of ions, OC and EC analyses was completed.
- GC-MS analysis was completed on a subset of the high-volume filters for a suite of PAHs and quinones.
In addition to the integrated filters, roughly 50 Whole Air Samples have been analyzed for suite of VOCs and the data archived.
All data have undergone preliminary quality checks and are archived on ftp site for use by other SCAPE investigators.
In addition, we have modified the automated DTT analytical system for Ascorbate-depletion Assay (AA), verified its performance and begun analysis of all high-volume filters.
We participated in CCAR-SCAPE collaborative project, Sept 2013, which involved our standard simultaneous deployments at two sites; in this case Road-side and GIT. The data have been analyzed and archived.
All ROS analysis for Project 2 in-vehicle filters has been completed via the DTT assay. Data are in the process of being analyzed.
In the past year, significant instrumental issues were discovered for the Aerodyne Cavity Ring Down NO2 instrument. The instrument was repaired and additional measurements of NO2 were made, after the main SCAPE sampling had been completed. NOx, NO2 and O3 were measured at the Road-side spring 2013 and a 1-month inter-comparison was conducted at the SEARCH JST site comparing two NO2 instrument from differing manufacturers.
We deployed online elements instrument (Xact 625 Monitoring System, Cooper Environmental Systems) at JST for a 3-month comparison of PM2.5 and PM10 metals to SEARCH filter-based collection method and offline ICPMS analyses.
A significant effort was made in the latter part of the third year of the project on data analysis and development of manuscripts.
Future Activities:
- Ascorbate-depletion assay (AA) will be measured on all high-volume filters for both the water-soluble extract and hydrophilic fraction of the water-soluble extracts. This will provide a large data set for direct comparisons between ROS measurements by the DTT (sensitive to organics) and Ascorbate assays (sensitive to metals). Water-soluble metals, quantified on the same filters, will provide further data for this comparison. We will test the hypothesis that these two assays, when combined, provide a broad measure of the aerosol ROS activity. The results will be published.
- In the next year we hope to finish the collaboration with EPA (Bob Devlin), including DTT analysis of ultrafine, fine and coarse particle filters provided to us by the EPA. These results will be combined with CAPS DTT data already generated and the results published.
- All data analysis will be completed and publications submitted by the end of the project. In addition to the publications in progress, listed above, we plan to publish papers on the following:
- King, et al., Chemiluminescence measurements of NOx and NO versus cavity ring down NO2 at various sites in the southeastern US.
- King, et al., On the spatial and seasonal distribution of a suite of air quality parameters based on paired measurements to investigate roadway emissions
- Xu, et al., Characterization of the organic aerosol in the Southeastern US by Aerosol Mass Spectrometry
- Wang/Verma, et al., Spatial and seasonal variation of the chemical composition of the HULIS fraction in ambient PM: implications for the source of DTT activity
- Verma/Devlin, et al., PM generated ROS species associated with biological changes in humans exposed to fine concentrated air pollutants
Depending on availability of funds, the following projects may be attempted.
- Although the filter-based system has provided major new insights, it is recognized that online measurements of ROS by acellular assays, such as DTT and AA, could provide substantially greater insights into sources, atmospheric processing and health impacts of aerosols. An online system would provide much larger data sets, allow better integration with state-of-the art online aerosol chemical speciation instrumentation, a better assessment of variability in ROS and what drives it, and an assessment of possible artifacts associated with filter-based methods. A goal is to undertake preliminary laboratory work to assess the potential of developing an online DTT and AA assay based on PILS technology and our expertise gained through developing automated DTT and AA analytical systems used for filter extract analyses.
- To date, our work has focused on the water- and methanol-soluble components that contribute to fine particle ROS. Other studies have shown that solid particles, especially soot, can also be effective at generating ROS and are highly DTT active. Quantifying the ROS activity of soot and other insoluble components on the same integrated filter samples that have already undergone extensive analyses would provide a more complete assessment of the fine particle ROS potential. The approach would be to modify the automated DTT/AA analysis system so that the redox chemistry can be done on an immersed filter, instead of in the filter extract. The system will be assessed by comparison to published diesel exhaust DTT intrinsic activities and contrasts between road-side to other sites (comparison between sites with high EC versus low EC concentrations).
Journal Articles on this Report : 5 Displayed | Download in RIS Format
Other subproject views: | All 62 publications | 17 publications in selected types | All 17 journal articles |
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Other center views: | All 338 publications | 139 publications in selected types | All 135 journal articles |
Type | Citation | ||
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King LE, Weber RJ. Development and testing of an online method to measure ambient fine particulate Reactive Oxygen Species (ROS) based on the 2’,7’-dichlorofluorescin (DCFH) assay. Atmospheric Measurement Techniques 2013;6(7):1647-1658. |
R834799 (2013) R834799 (2014) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2013) R834799C001 (2014) R834799C001 (2015) R834799C001 (Final) |
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Liu J, Bergin M, Guo H, King L, Kotra N, Edgerton E, Weber RJ. Size-resolved measurements of brown carbon in water and methanol extracts and estimates of their contribution to ambient fine-particle light absorption. Atmospheric Chemistry and Physics 2013;13(24):12389-12404. |
R834799 (2014) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2013) R834799C001 (2014) R834799C001 (2015) R834799C001 (Final) |
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Liu J, Scheuer E, Dibb J, Ziemba LD, Thornhill KL, Anderson BE, Wisthaler A, Mikoviny T, Devi JJ, Bergin M, Weber RJ. Brown carbon in the continental troposphere. Geophysical Research Letters 2014;41(6):2191-2195. |
R834799 (2014) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2014) R834799C001 (2015) R834799C001 (Final) R835039 (Final) |
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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. Environmental Science & Technology 2012;46(20):11384-11392. |
R834799 (2012) R834799 (2013) R834799 (2014) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2012) R834799C001 (2013) R834799C001 (2014) R834799C001 (2015) R834799C001 (Final) |
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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). Environmental Pollution 2013;182:379-384. |
R834799 (2014) R834799 (2015) R834799 (2016) R834799 (Final) R834799C001 (2013) R834799C001 (2014) R834799C001 (2015) R834799C001 (Final) |
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Supplemental Keywords:
reactive oxygen species, ROS, oxidative stress, oxidative potential, Health, Scientific Discipline, Health Risk Assessment, Risk Assessments, Biochemistry, Environmental Monitoring, children's health, particulate matter, ambient air monitoring, climate change, air pollution, airshed modeling, ambient particle health effects, human health riskRelevant Websites:
Southeastern Center for Air Pollution & Epidemiology - Emory/Georgia Tech EPA Clean Air Research Center ExitProgress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R834799 The Southeastern Center for Air Pollution and Epidemiology: Multiscale Measurements and Modeling of Mixtures Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R834799C001 Development and Deployment of an Instrumentation Suite for Comprehensive Air Quality Characterization Including Aerosol ROS
R834799C002 Examining In-Vehicle Pollution and Oxidative Stress in a Cohort of Daily Commuters
R834799C003 Novel Estimates of Pollutant Mixtures and Pediatric Health in Two Birth Cohorts
R834799C004 A Multi-City Time-Series Study of Pollutant Mixtures and Acute Morbidity
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
17 journal articles for this subproject
Main Center: R834799
338 publications for this center
135 journal articles for this center