EAF collaborates with many universities and private sector consultants to complement their expertise in air quality management, permitting, and assessment. Some of our projects, ongoing and completed, are listed here.
NPS Interagency Monitoring of PROtected Visual Environments (IMPROVE) (1987-current)
DRI has performed carbon analyses on quartz-fiber filters for IMPROVE since the program’s inception in 1988. Since then, DRI has worked closely and reliably with the program’s Particulate Monitoring Coordination Contractor (PMCC), to cost-effectively analyze over 150,000 filters for OC, EC, and carbon fractions, using custom-designed DRI/OGC thermal-optical reflectance analyzers following the IMPROVE protocol (Chow et al., 1993).
DRI procures, prepares, and ships the quartz-fiber filters to the PMCC for distribution to ~180 sites, at present. DRI then receives the sampled filters and blanks from the PMCC, analyzes the filters, and sends the analytical results and uncertainty evaluations to the PMCC.
With the expansion of the IMPROVE network during mid-2000, and the change in sampling frequency from twice-per-week to every-third-day during the summer and fall of 2000, DRI began to analyze more than ~20,000 filters per year.
DRI has continuously updated the SOP and QA/QC procedure to improve data precision and consistency. This includes the transition from the IMPROVE to the IMPROVE_A protocol (Chow et al., 2007) in 2005, and the completion of over 130,000 IMPROVE carbon analyses.
For more information see: vista.cira.colostate.edu/improve/
South Eastern Aerosol Research and Characterization (SEARCH) Study (1999-current)
The South Eastern Aerosol Research and Characterization (SEARCH) network began air quality monitoring in early 1998. It contains eight urban/rural and urban/non-urban pair sites in the states of Alabama, Florida, Georgia, and Mississippi.
DRI Environmental Analysis Facility (EAF) is providing the Electrical Power Research Institute (EPRI) with the following services in support of the SEARCH study since 1999: 1) filter procurement and acceptance testing; 2) filter shipping and receiving; 3) thermal/optical carbon analysis for quartz-fiber filters; and 4) data processing, validation, and reporting.
For more information see: www.atmospheric-research.com
Texas Commission on Environmental Quality (TCEQ) (2004-current)
In 1999, the U.S. EPA established the national monitoring network for PM2.5. This includes 1,500 Federal Reference Method (FRM) or Federal Equivalent Method (FEM) monitoring sites, with more than 50 sites in Texas, to determine PM2.5 mass concentrations and ensure compliance with the PM2.5 NAAQS.
In 2000, EPA established the PM2.5 Chemical Speciation Network (CSN) of ~225 sites nationally, including ~23 sites in Texas, to assess the chemical composition of PM2.5. The Texas Commission on Environmental Quality (TCEQ) air quality network is now the largest state-run monitoring program in the U.S.
DRI also completed a study of PM2.5 levels and composition in Houston and four other Texas cities during 1997-98. DRI has been supplying the TCEQ with laboratory support and analysis services for its statewide PM2.5 Federal Reference Method (FRM) and chemical speciation program since 2004.
The objectives of this project are: 1) procurement and logistics for PM2.5 FRM filter sampling and analysis; 2) procurement and logistics for PM2.5 chemical speciation filter sampling and analysis following the same EPA STN/CSN protocol; 3) data management and reporting; 4) project management and quality assurance; and 5) training TCEQ personnel.
For more information see: www.tceq.state.tx.us
Port of Los Angeles (POLA) Air Quality Monitoring Program (2005-current)
The Port of Los Angeles (POLA) instituted a four-site monitoring program in 2005 to provide a long-term database that can be used to detect trends in PM2.5 mass, chemical components, and source contributions that might be related to emission reduction activities at POLA.
Downward trends have been detected in response to emission controls that have been gradually phased in at POLA. This has required multi-year data to capture changes in meteorology and to evaluate the effectiveness of control measures. The PM2.5 network includes light scattering as a surrogate to evaluate PM2.5 diurnal variations under different meteorological conditions.
In 2008, this network was supplemented with compliance monitoring of NO (nitric oxide), NO2 (nitrogen dioxide), O3 (ozone), and SO2 (sulfur dioxide) levels. The objectives of this network are to: 1) examine spatial and temporal variations in PM2.5 levels; 2) quantify Port and non-Port PM2.5 contributions to nearby neighborhoods; 3) identify the dominant sources of Port PM2.5 contributions; 4) determine the effectiveness of emission-reduction measures on ambient PM2.5; 5) evaluate and improve the POLA emission inventory; and 6) validate dispersion model estimates exposures to air toxics.
For more information see: www.portoflosangeles.org/environment/air_quality.asp
Carbon Analysis of Chemical Speciation Network (CSN) Samples (2006-current)
Since its inception in 1999, the Speciation Trend Network (STN; now the Chemical Speciation Network [CSN]) used the NIOSH thermal/optical transmittance (TOT) protocol to analyze OC and EC in PM2.5. To establish data comparability between the STN and IMPROVE networks, while maintaining the overall program objectives of the STN to support control strategy development for the PM2.5 NAAQS, U.S. EPA started to convert all of the Trends and supplemental sites (such as State and Local Air Monitoring Stations [SLAMS]) in the STN (about 200 sites total) to IMPROVE-like carbon sampling and analysis protocols in the summer of 2006.
DRI has been performing carbon analysis for all the converted STN sites through a subcontract with the Research Triangle Institute (RTI). The carbon analysis protocol and QA/QC procedure are identical to those applied to the IMPROVE network following the IMPROVE_A protocol (Chow et al., 2007).
Source Characterization for the Athabasca Oil Sands Region (2008-current)
The Athabasca Oil Sands Region (AOSR) of northern Alberta, Canada hosts the second largest oil reserve in the world. Air pollutants are emitted during the oil mining, extraction, and upgrading processes and are not well characterized. Major emitters include large stationary sources through vents and ducts, engine exhaust (e.g., large haulers and land-moving equipment), and fugitive dust from unpaved roads, mining pits, and tailings piles.
This project quantifies emissions from major pollution sources in the AOSR under real-world conditions with the following objectives: 1) evaluate and apply modern real-world testing methods that represent the equipment, feed stocks, and operating conditions in actual use; 2) develop source profiles and emission factors that allow identification and quantification of source contributions at receptors; and 3) integrate site-specific activities, emission factors, and source profiles to provide consistent, documented, transparent, and easily accessible information for different uses.
For more information see: www.wbea.org
Qin Terra-Cotta Museum Air Pollution Study (2005-2010)
Funded in part by: the Nazir and Mary Ansari Foundation for Entrepreneurialism and Science
The discovery of terra-cotta figures in Xi’an, China, in 1974 is one of the most important archeological finds of the 20th century; it has led to the city becoming one of the most popular tourist attractions in China.
The Museum of the Qin Terra-cotta Warriors and Horses (34o44’N, 109o49’E) is located 50 km east of Xi’an, covers an area of 16,000 square meters (m2), and contains more than 7,000 pottery soldiers, horses, chariots, and weapons dating from the Qin Dynasty (211-246 BC).
These terra-cotta artifacts have not received adequate environmental protection since they were unearthed. They are being discolored by air pollution, coupled with large variations in temperature and relative humidity, after 30 years of exposure in the exhibition halls (Cao et al., 2005; Hu et al., 2006).
In 2005, a systematic study was undertaken to:
- Summarize existing knowledge of air pollutant levels in museums, their interactions with precious antiquities, methods to measure and model their concentrations and effects, and remedial measures to minimize their impacts.
- Quantify indoor and outdoor concentrations and deposition of particulate matter (PM), gas concentrations, and other atmospheric variables (e.g., temperature, humidity) that might cause adverse effects on the surfaces of antiquities, and to the extent possible, determine how these vary during the day and between seasons.
- Elucidate the physical and chemical mechanisms by which pollutants cause degradation of the antiquities and recommend methods to minimize that degradation.
California Air Resources Board (CARB) Characterization of Black Carbon (2004-2008)
The goal of this project was to improve black carbon (BC) emissions inventories applicable to global climate change by understanding what is currently available, by better characterizing measurement methods, and by measuring emission rates and chemical profiles from BC-emitting sources.
Uncertainties and differences were assessed among inventories with respect to activity levels, emission factors, and BC content.
Specific project objectives were to:
- Identify, compile, evaluate, and summarize existing information on BC inventories, combustion processes, emission factors, source profiles, and source/ambient measurement methods.
- Develop and apply BC analysis methods to determine causes of differences among concentrations in source emissions and in ambient monitoring networks.
- Develop relationships among different BC measurement methods and light-absorbing properties of emitted particles.
- Measure organic carbon (OC) and BC emission factors for selected combustion processes.
- Compile and compare OC and BC emission factors relevant to California, U.S., and global inventories.
- Evaluate and quantify emissions inventory uncertainties and describe how the results of this study might reduce them.
This project compared and contrasted results from laboratory tests and an ambient field study of particulate organic carbon (OC), elemental carbon (EC), and black carbon (BC) using in situ and integrated filter samples with optical and thermal analysis methods.
For more information see: http://www.arb.ca.gov/research/apr/single-project.php?row_id=64592
Minnesota PM2.5 Source Apportionment Study (2007-2008)
The Minnesota PM2.5 Source Apportionment Study was undertaken to explore the utility of PM2.5 mass, element, ion, and carbon measurements from the IMPROVE and STN monitoring sites for pollution source attribution.
A weight-of-evidence approach was taken for the first time that combined data from IMPROVE and STN sites across a state; reconciled differences among the data sets; applied the effective variance (EV) chemical mass balance (CMB), positive matrix factorization (PMF), and UNMIX solutions to available data; estimated source regions using back trajectories; and evaluated uncertainties for local and regional PM2.5 source contributions.
Several measures were taken to reconcile the difference in measurements between the IMPROVE network and STN. Analytical results (ambient concentration equivalent) were retrieved from EPA databases for retroactive blank correction. Measurement uncertainties of the STN samples and field blanks were estimated and outliers were removed from analysis. To obtain representative geological source profiles, nine bulk samples of five types (i.e., paved road dust, surface soil, de-icing material [road salt], Ca-rich trackout [from a ready-mix concrete facility], and taconite dust) were collected near Minnesota source areas and surround the sampling sites. These samples were air-dried in the laboratory, sieved to 400 mesh (38 mm geometric diameter), suspended into a chamber, and sampled through PM2.5 and PM10 size-selective inlets onto Teflon-membrane and quartz-fiber filters for chemical analyses similar to those applied to the IMPROVE samples (Chow et al., 1994).
Fresno Supersite Phase II (2000-2006)
The Fresno Supersite is jointly supported by the National Oceanic and Atmospheric Administration (NOAA) in Boulder, CO, the California Air Resources Board (ARB), and the U.S. EPA in Research Triangle Park, NC. It is a cooperative effort between DRI and ARB. The Fresno Supersite is one of seven such supersites that were operated throughout the U.S.
The objectives of the Fresno Supersite project were to:
- Test and evaluate non routine monitoring methods, with the intent to establish their comparability with existing methods and determine their applicability to air quality planning, exposure assessment, and health impact determination.
- Increase the knowledge base of aerosol characteristics, behavior, and sources so regulatory agencies can develop standards and strategies that protect public health.
- Acquire measurements that can be used to evaluate relationships between aerosol properties, co factors, and observed health end points.
For more information see: http://www.epa.gov/ttnamti1/ssfresno.html
EPA STAR Grant: Understanding Thermal and Optical Carbon Analysis Methods (2003-2006)
The project was sponsored by the U.S. EPA National Center for Environmental Research as part of the FY2003 Science to Achieve Results (STAR) Program. The goal is to improve understanding of atmospheric carbon and its sources. The project developed and evaluated carbonaceous PM2.5 measurement methods, emissions sources, and ambient concentrations.
The objectives of this study were to:
- Determine which OC, EC, and carbonate carbon (CC) compounds evolve at different temperatures.
- Specify how optical properties differ and change between particles in the air, particles on a filter, and particles undergoing changes owing to thermal analysis.
- Quantify the difference in carbon fractions determined by commonly used thermal and optical analysis methods.
- Optimize thermal and optical monitoring methods to meet the multiple needs of health, visibility, global climate, and source apportionment.
This study advanced knowledge about the conditions that affect carbon measurements currently in use at IMPROVE and STN sites. It identified the potential for more refined temperature fractions and non-destructive Raman scattering measurements to relate carbon concentrations to their source emissions. It will provide a technical basis for further refinement of other thermal evolution methods that use more specific detectors to better quantify specific compounds and carbon fractions.
For more information see: http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/6232/report/0
Lake Tahoe Source Characterization Study (2002-2005)
This study quantified the emission rates and chemically characterized the emission profiles of potential sources that might affect water quality of Lake Tahoe. Integrated PM2.5 filter samples were taken for OC/EC analysis by TOR. In addition, real time measurements of residential wood combustion and vehicle emissions were taken using the in-plume system.
Big Bend Regional Aerosol Visibility and Observation (BRAVO) Study (1998-2004)
The study was designed to understand the long range, trans-boundary, transport of particles from regional sources in the US and Mexico and to quantify the source contributions and source types responsible for poor visibility at the Big Bend National Park in Texas.
An important component of this study was the source sampling of paved and unpaved road dust, soil dust, vehicle (gasoline and diesel) exhaust, vegetative burning, coal-fired power plants oil refinery catalytic cracker, cement kilns and residential meat cooking, resulting in a total of 145 source profiles. The thermally evolved carbon fractions (TOR) of these source samples were found to be useful in distinguishing and differentiating the different sources.
For more information see: http://vista.cira.colostate.edu/improve/studies/BRAVO/Studybravo.htm
California Regional Particulate Air Quality Study (CRPAQS) (1999-2001)
The CRPAQS programmatic goal was to provide additional and more comprehensive information than is currently available to explain the nature and causes of particulate concentrations and visibility impairment in and around central California. This information is especially needed within the San Joaquin Valley, where the highest particle concentrations have been measured in the past.
PM2.5 sampling was conducted during the annual (12/99 to 02/01), fall (10/00 to 11/00) and winter (12/00 to 02/01) intensive studies at five (5) anchor and ~27 satellite sites. In addition, dilution source sampling was also conducted to acquire source profiles for vehicle (gas/diesel) exhaust, tire and brake wear, residential wood combustion and agricultural burning.
Specific field study objectives were to:
- Generate a validated data set, with appropriate data qualification statements, that is suitable for characterizing the nature and causes of particulate concentrations and visibility impairment in and around central California by supporting modeling and data analysis activities.
- Study PM concentrations under a variety of emissions and meteorological conditions. Evaluate the extent to which long-term PM monitoring networks represent the levels of exposure of large populations.
- Document the current spatial distribution, temporal variation, and intensity of PM concentrations and visibility impairment within central California.
- Measure and characterize the structure and evolution of the boundary layer and the nature of regional circulation patterns that determine the transport and diffusion of PM and its precursors in central California.
- Further characterize the source zones of influence and quantify source contributions to community exposure for PM chemical components, including particles that are directly emitted and those that form from directly emitted gases.
- Quantify source contributions to secondary aerosol, identify the limiting precursors, and assess the extent to which reductions in nitrogen oxides, ammonia, sulfur oxides, and volatile organic compounds would be effective in reducing PM concentrations.
- Refine conceptual models that explain the causes of elevated PM concentrations and interactions between emissions, meteorology, and ambient PM concentrations.
- Evaluate and improve the performance of emissions, meteorological, and air quality simulations. Apply simulation methods to estimate PM concentrations at receptor sites and to test potential emissions reduction strategies.
For more information see: http://arb.ca.gov/airways/CRPAQS/