Biographies and Abstracts
Mr. James A. “Jac” Capp is a 17-year veteran of Georgia’s Environmental Protection Division (EPD) and currently serves as the organization’s Air Protection Branch chief. He is responsible for the state’s air programs, including Ambient Monitoring, Mobile & Area Sources, Planning & Support, Industrial Source Monitoring, Stationary Source Compliance, and Stationary Source Permitting. Prior to this appointment, Capp was manager of the Air Protection Branch Stationary Source Permitting Program, where he supervised the review and issuance of new and modified industrial permits for stationary sources of air pollution. Capp also managed the Air Protection Branch Industrial Source Monitoring Program with EPD. Capp holds a Master of Science degree in Mechanical Engineering from the Georgia Institute of Technology and a Bachelor of Science degree in Mechanical Engineering from the University of Illinois.
Mr. Jimmy Johnston has almost 24 years of air quality regulatory experience since joining Georgia EPD’s Air Protection Branch in 1985. He has worked in or managed the majority of the tasks in the Air Branch including permitting, compliance and enforcement, emergency response, air toxics, information management, planning, and financial management and is familiar with all of the remaining aspects of the Branch through collaborative work in these various positions. He received his Bachelors Degree in Chemical Engineering from Georgia Tech in 1985 and is a registered Professional Engineer. He is currently the manager of the Air Protection Branch’s Planning & Support Program which is responsible for SIP development, air quality planning and rulemaking, dispersion modeling and photochemical modeling, and financial management of the Air Protection Branch.
Pam Earl (moderator) EPD, Air Protection Branch, Mobile and Area Sources Manager
AQ planning and analysis
Jim Kelly (EPD, mod) Air Quality, NAAQS, ozone and PM2.5 attainment designations, and SIPs
Dr. Jim Boylan has over 14 years of atmospheric modeling experience and has been working for Georgia EPD’s Air Protection Branch since 2002. He received his B.S. in Chemical Engineering from the University of Notre Dame in 1990, M.S. in Chemical Engineering from Auburn University in 1993, M.S. in Environmental Engineering from Georgia Tech in 1999, and his Ph.D. in Environmental Engineering from Georgia Tech in 2002. His Ph.D. work included the development and application of the first “one-atmosphere” modeling system to simultaneously model ozone, particulate matter, and acid deposition in the Southern Appalachian Mountains. He is currently the manager of the Air Protection Branch’s Data & Modeling Unit and is responsible for dispersion modeling to support the air permitting process and photochemical modeling to support Georgia’s State Implementation Plans for ozone, PM 2.5, and regional haze.
PM 2.5 Attainment Modeling in Georgia
Georgia has four areas currently designated nonattainment for the annual PM 2.5 NAAQS (15 mg/m 3). Three of these areas should come into attainment by 2010 without additional emission controls. However, Atlanta will likely remain in nonattainment in 2010 and additional emission controls will be needed. Additional controls include the replacement of 30 railyard switches with Gensets by 2012. Modeling of these aggressive emission reductions is likely to bring Atlanta into attainment by 2013. In addition, GA EPD has investigated the importance of NO x emission reductions on annual average PM 2.5 concentrations in Georgia and has concluded that the impacts are insignificant.
Dr. Daniel Cohan is an Assistant Professor in the Department of Civil and Environmental Engineering at Rice University. His research specializes in the development of photochemical models and their application to air quality management, uncertainty analysis, energy policy, and health impact studies. Before joining Rice, Dr. Cohan worked for the Air Protection Branch of the Georgia Environmental Protection Division. He received a B.A. in Applied Mathematics from Harvard University, a Ph.D. in Atmospheric Chemistry from Georgia Tech, and served as a Fulbright Scholar to Australia at the Cooperative Research Centre for Southern Hemisphere Meteorology. Dr. Cohan is principal investigator of a U.S. EPA STAR grant that is developing methods for systematically considering uncertainty in air pollution control strategy development, and a recent recipient of a National Science Foundation CAREER young investigator award.
Considering Uncertainty in Air Quality Management
The modeling and other analyses that inform air quality management contain significant uncertainties, yet those uncertainties are rarely quantified or considered directly in the development of attainment plans. This talk will present ongoing work for a U.S. EPA STAR grant that is exploring how uncertainty analysis of air pollution models and other factors can be incorporated into attainment planning. The research is specifically considering ozone and particulate matter in Georgia as case studies for the development of innovative methods to represent uncertainties.
Prof. Armistead (Ted) Russell is the Georgia Power Professor of Environmental Engineering. At Georgia Tech, his research is aimed at better understanding the dynamics of ozone and particulate matter at urban and regional scales, and to develop approaches to design strategies to improve air quality. He earned his M.S. and Ph.D. degrees in Mechanical Engineering at the California Institute of Technology in 1980 and 1985, conducting his research at Caltech’s Environmental Quality Laboratory. His B.S. is from Washington State University. Dr. Russell is a member of EPA’s Clean Air Science Advisory Committee (CASAC) and the National Research Council’s Board on Environmental Studies and Toxicology.
Considerations on Combined NO x-SO x Secondary National Ambient Air Quality Standards
The United States EPA is currently considering revising the National Ambient Air Quality Standards (NAAQS) for Nitrogen Oxides (NO x)and Sulfur Oxides (SO x). Unlike prior reviews of criteria pollutant standards, EPA has decided to conduct a joint review of the secondary standards for SO x and NO x, and that combined review is separate from the reviews for possible revisions of the primary standards. As part of the review of the secondary standards, EPA is considering how a standard might consider the combined impacts of both SO x and NO x, as well as the role of reduced nitrogen (e.g., ammonia) on the environment. The reasons for having a standard that considers NO x and SO x together, as well as considering reduced nitrogen, is driven by the science in that both of those pollutants, and products of their atmospheric chemistry, combine to increase acidic deposition. Further, reduced nitrogen and NO x can both lead to excess nutrient loadings which, among other effects, can lead to eutrophication. A combined standard can address both of these concerns in a more scientifically appropriate fashion, but potentially will be more complex. An additional complexity is that it is the depositional loads, not the atmospheric concentrations, which are important for both acid deposition and excess nutrient loadings. However, the NAAQS are specified as atmospheric concentrations. EPA is now exploring approaches for how to approach these issues, and as part of their recent Integrated Science Assessments and Risk and Exposure Assessments are providing the basis for what could be a truly novel approach to the associated National Ambient Air Quality Standards.
Airshed Characterization and Emissions Studies
Mr. William Smith is a biology graduate of the University of Georgia. He completed his Bachelor of Science in August 2007 and began working with the Georgia Environmental Protection Division in June of 2008. Will works with the Air Protection Branch, Ambient Monitoring Program, Data Analysis Unit validating continuous data and assisting to produce the Unit’s documents.
Ms. Crystal Romeo joined the Georgia EPD in September of 2007 and currently serves as an Environmental Specialist. Prior to joining EPD, she worked for a year at the New Jersey Department of Environmental Protection in the Site Remediation program. Crystal is a graduate of Spelman College with a B.S. degree in Environmental Science. Crystal works with the Air Protection Branch, Ambient Monitoring Program, Data Analysis Unit assisting in data analysis projects to produce the Unit’s documents.
Georgia Environmental Protection Division Ambient Air Monitoring Network Assessment
Contributors: William Smith, Crystal Romeo, Ahmed Dura, Susan Zimmer-Dauphinee, Janet Aldredge-Byars (GA EPD)
In order to comply with EPA regulations [40CFR58.10(e)] and evaluate Georgia’s current ambient air monitoring network on a five-year basis, Georgia EPD is conducting an assessment of the network with a variety of data analyses techniques. Following EPA guidance documents, five different data analyses are being performed on the current ambient air monitoring network and presented at this point in the research. The assessment includes a comparison of the number of parameters monitored at each site, longevity of parameters monitored and resulting trends, measured concentrations of criteria pollutants with values above National Ambient Air Quality Standards (NAAQS), how criteria pollutants at each site deviate from the NAAQS, and how concentrations of different monitors compare by performing monitor-to-monitor correlations. Using these assessments as tools, Georgia EPD will prioritize existing monitoring sites, and recommend possible changes to the network to improve efficiency, eliminate redundancy, and ensure monitoring objectives are met.
Prof. Rodney Weber is a professor in the School of Earth and Atmospheric Sciences at Georgia Institute of Technology. He was previously an assistant scientist at Brookhaven National Laboratory. Dr. Weber earned a B.A.Sc. in Mechanical Engineering from the University of Waterloo, and an M.S. and Ph.D. in Mechanical Engineering from the University of Minnesota. His research interests are in atmospheric aerosols, sources and fates of air pollutants, aerosol dynamics, regional air quality and health effects, particle radiative and cloud activation properties, and development of advanced measurement systems. More information is available at http://www.aerosols.eas.gatech.edu/, and two papers related to this study are available: "Weber et al" and "Hennigan et al"
Secondary organic aerosol in the Southeastern US
Fine particles over the southeastern US are known to have adverse health impacts and regional effects on climate. Secondary organic aerosol (SOA) is a large fraction of this fine PM, (only sulfate is more important), yet SOA remains one of the least understood components of ambient particles. Recent work has shown that SOA formed within anthropogenic emissions produce vastly (x10 or so) more organic aerosol than can be explained by currently known mechanisms. It has recently been suggested that anthropogenic SOA may even dominate over regions with high biogenic VOC emissions, like the southeast. Radiocarbon dating of SOA in the southeast does not support the idea that SOA is mainly from anthropogenic VOCs, indicting instead that SOA is largely (70 to 80 percent) composed of biogenic VOCs. One way to reconcile these observations is that biogenic VOCs form SOA much more effectively in anthropogenic plumes. Currently, a physicochemical mechanism that may explain most of the SOA is lacking. This talk will summarize findings and possibly new research that may provide insight into the source and routes to SOA formation in Atlanta and the surrounding region. These issues have significant implications for regulating PM in the southeastern US.
Dr. Mei Zheng joined Georgia Institute of Technology in 2000 and is currently a Senior Research Scientist at the School of Earth and Atmospheric Sciences. She received her training in environmental science and earned degrees from Chinese Academy of Sciences, Hong Kong University of Science and Technology, and University of Rhode Island. Her expertise includes chemical characterization of particulate matter with gas chromatography/mass spectrometry (GC/MS) for organic air pollutants and inductively coupled plasma/mass spectrometry (ICP/MS) for inorganic air pollutants, and applying chemical tracers in receptor models for PM2.5 source apportionment. She has been analyzing the primary and secondary organic tracers in PM2.5 from the Southeastern Aerosol Research and Characterization program (SEARCH) since 2000. She is interested in developing quantitative ways of understanding the origin of air pollutants and the impacts of these pollutants on human health.
Sources of Primary and Secondary Organic Aerosol in the Southeastern United States
Mei Zheng a*, Xiang Ding a, Xiaolu Zhang a, Rodney J. Weber a, Ted Russell b, and Eric Edgerton c
a School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA
b School of Civil and Environmental Engineering, Georgia Institute of Technology, GA
c Atmospheric Research & Analysis, Inc., Cary, NC
Particles suspended in the atmosphere can be directly emitted from various primary sources or formed through secondary formation. There is an urgent need to expand knowledge in secondary organic aerosols (SOA) including their abundances in the atmosphere, formation mechanisms, and spatial and seasonal variations. Fine particulate matter (PM2.5) samples collected over one-year period (from May 2004 to April 2005) at one rural site and three urban sites of the Southeastern Aerosol Research and Characterization Program (SEARCH) were examined for both biogenic SOA tracers using gas chromatography/mass spectrometry (GC/MS), and water-soluble organic carbon (WSOC). As a first study to investigate the seasonal variations of biogenic SOA tracers in the Southeast, tracers such as isoprene-derived 2-methylthreitol and 2-methylerythritol and pinene-derived cis-pinonic acid were measured in 123 PM2.5 samples. All tracers exhibited distinct but similar spatial distributions with the highest concentration observed at the rural site and the lowest level at a coastal site. Isoprene SOA makes an important contribution to WSOC as shown by significant correlation between WSOC and 2-methyltetrols during summer. During summer when high temperature, intense solar radiation and high ozone level occurred, 2-methyltetrols also reached the highest level. However, no obvious seasonal variation was found for cis-pinonic acid. Based on this study, we found that SOA especially biogenic-derived SOA contributed significantly to PM2.5 in the southeastern US, especially during summer.
Besides primary and secondary tracers for organic aerosol, these filters were also analyzed for carbon isotopes. We estimated the fossil secondary organic carbon (SOCF) and the contemporary secondary organic carbon (SOCC) in these samples, ranging from 0.56 to 3.20 mgC/m3 and 0.82 to 4.09 mgC/m3, respectively. SOCF was higher at urban sites and exhibited small seasonal variation at all sites, probably resulting from higher fossil precursor emissions in urban areas. In contrast, SOCC was higher at the rural site and exhibited obvious seasonal variation at all sites. It is interesting to note that the secondary items, including SOCF, SOCC, secondary sulfate, and secondary ammonium, exhibited significant correlations between the monitoring sites, suggesting the regional impact of secondary aerosol in the southeastern United States.
Prof. Athanasios Nenes is an Affiliated Scientist at the Foundation for Research and Technology, Greece, and an Associate Professor in the Schools of Earth & Atmospheric Sciences and Chemical & Biomolecular Engineering at the Georgia Institute of Technology, Atlanta, GA, USA. He has a Diploma in Chemical Engineering from the National Technical University of Athens, Greece (1993), a MSc in Atmospheric Science from the Rosenstiel School of Marine and Atmospheric Sciences, University of Miami (1997) and a PhD in Chemical Engineering from the California Institute of Technology (2002). Prof. Nenes’ research has resulted in 65 ISI-indexed publications (1775 citations, h-index of 20) with 4 publications in press and 18 in review. Prof. Nenes is co-inventor of the commercially-available Continuous-Flow Streamwise Thermal-Gradient CCN Counter, and is author of the ISORROPIA aerosol thermodynamics model. He has received an NSF CAREER Award (2004), a NASA New Investigator Award (2004), the Blanchard-Milliken Young Faculty Chair (2005), a Friedlander award by the American Association for Aerosol Research (2005), a Sigma-Xi Young Faculty Award from the Georgia Institute of Technology (2007), and the Henry G. Houghton Award from the American Meteorological Society (2009). Prof. Nenes serves on the Pacific Northwest National Laboratory Aerosol-Climate Initiative External Advisory Board, the US Department of Energy Radiation Measurement Climate Research Facility Science Board, and is Editor of the journal Atmospheric Chemistry and Physics.
Mixing State, CCN Activity And Droplet Activation Kinetics Of Atlanta Aerosol
Athanasios Nenes, Luz-Teresa Padró, Richard H. Moore, Xialou Zhang, Neeraj Rastogi, Wenyan Shi, Mei Zheng and Rodney J. Weber (Georgia Institute of Technology)
The effect of organic species on the cloud droplet formation process constitutes a large source of uncertainty in aerosol-cloud-climate interactions studies. In-situ size-resolved measurements of the Cloud Condensation Nucleus (CCN) activity of ambient aerosol can unravel such complex chemical effects, and were carried out at the Southern Company Jefferson Street site in Atlanta, GA during the AMIGAS campaign (August-September, 2008). The daily trend of the mixing state, CCN activity, and droplet growth kinetic of the size-resolved CCN are presented and compared to chemical composition measurements. Inferences about the impact of photochemistry and mixing on CCN activity, hygroscopic uptake and droplet activation kinetics are carried out. We also quantify the predictive uncertainty associated with simplifying compositional assumptions (e.g., size-invariant composition, organic insoluble/soluble with constant hygroscopicity) used for predicting CCN concentrations in global climate models.
Dr. Christian E. Lindhjem, a Senior Consultant at ENVIRON International Corporation, is an expert on emissions from highway and nonroad vehicles and engines and fuels used in those engines. With ENVIRON for 11 years and with EPA’s Office of Transportation and Air Quality (previously named Office of Mobile Sources) for 8 years, Dr. Lindhjem has worked on on-road and off-road mobile source regulation development, emission measurements and analysis, emission control strategies, and emission inventory modeling including regulated pollutants and chemical compositional analysis to estimate toxic emissions and other components of concern. Dr. Lindhjem has evaluated and continues to consult on a broad range local and national mobile source emission issues including both emission estimates and potential emissions reductions. He works with local, regional and national officials and private clients to improve on-road and off-road emission inventories for at the national scale, metropolitan areas, and individual facilities including ports and rail yards. Dr. Lindhjem continues to work closely with and review mobile emission models including peer review of MOBILE and MOVES model frameworks providing one of the first detailed methodological reviews of MOVES in the Coordinating Research Council’s Project E-68, “Analysis Of EPA’s Draft Plan For Emissions Modeling In MOVES.” Dr. Lindhjem holds a Ph.D. degree in Chemical Engineering from the Rensselaer Polytechnic Institute and a M.S. degree in Chemical Engineering from the University of Michigan.
Link Level On-Road Emission Estimation
ENVIRON is engaged in providing EPRI and EPA link level on-road emission modeling inventories for several cities including Atlanta. In order to model emissions by individual link, ENVIRON has developed the CONCEPT model. This is a free and publicly available open source software tool that currently incorporates MOBILE6 for modeling of emissions by individual link, for individual speeds and temperatures unique to that link, and hour of day. The current modeling effort combines the travel demand model data with temporal adjustments for vehicle mix of heavy and light-duty determined from automatic traffic recorders (ATR). Given appropriate trip data, the start emissions can also be temporally and spatially allocated, such as by traffic analysis zones (TAZ). EPA provided ENVIRON PM adjustment factors to convert MOBILE6 emissions into approximate MOVES emission factors for starts and running emissions. Those adjustments have been incorporated into CONCEPT. The results to date for link level modeling in Atlanta and Detroit will be presented. ENVIRON has funding to begin the full conversion of CONCEPT to MOVES once the output formats have been determined and due out later this year.
Ann Xu is a PhD candidate in Transportation Systems Engineering at Georgia Tech. She is writing her dissertation on effective sample size for GPS-based panel surveys, in the context of various travel studies such as congestion pricing, air quality, and fuel consumption. Ann came to Atlanta from China in 2006, with a BS degree in Environmental Science and a dual BS degree in Statistics at Peking University.
Ann is presenting David Kall and Dr. Randall Guensler’s work on “Effect of High Occupancy Toll Lanes (HOT) on Mass Vehicle Emissions: An Application to I-85in Atlanta”. David graduated from Georgia Tech in 2008 with a Master’s degree in Civil Engineering and another Master’s degree in City Planning. This presentation summarizes his Master’s thesis and some extended analysis. David now works for Cambridge Systematics in Atlanta. Randall Guensler is a professor in Georgia Tech’s School of Civil and Environmental Engineering. Dr. Guensler specializes in instrumented vehicle fleet monitoring, travel behavior, and motor vehicle emissions analysis.
Effect of High Occupancy Toll Lanes (HOT) on Mass Vehicle Emissions: An Application to I-85 in Atlanta
A demonstration High Occupancy Toll (HOT) lane will be opening on I-85 in Atlanta in January 2011 as a way to relieve congestion and provide reliable commute times for carpools and for single occupant drivers that are willing to pay a toll. It is important to evaluate the air quality impacts of such a proposal to meet environmental regulations, such as the National Environmental Policy Act (NEPA) and Transportation Conformity Regulations. A number of factors affect mass vehicle emissions, such as vehicle activity, vehicle speeds, vehicle age distributions, and vehicle class distributions. These factors are incorporated into a base scenario, which models the current condition on I-85 with HOV lanes using data collected in the corridor during the summer of 2007, and a future scenario, which models the implementation of HOT lanes on this corridor using information from other cities that have already implemented HOT lanes.
The MOBILE-Matrix modeling tool, recently developed by Georgia Tech, is used to run the emissions analysis using the input factors described above. This tool calculates mass emissions for five pollutants: HC, NOx, CO, PM2.5, and PM10 as a function of fleet composition and onroad operating conditions. The modeling work predicts extremely small increases in mass emissions for CO, PM2.5, and PM10, and extremely small decreases in mass emissions for NOx and HC. In addition, the post-implementation emissions changes fall well within the motor vehicle emissions budgets for the facility that are used in air quality planning. Therefore, the implementation of HOT lanes on I-85 in Atlanta should not violate the emissions budget requirements of the Transportation Conformity Rule. For NEPA purposes, this analysis could be used to make the case that air quality impacts are not significant, and therefore further detailed analyses are not required.
Health Effects and Mitigation
Mr. William Cook is the Engines and Fuels Unit Manger in the Mobile and Area Sources Program in the Air Protection Branch of the Georgia Environmental Protection Division. He graduated from the Georgia Institute of Technology in 1991 with a Bachelor’s Degree in Mechanical Engineering. He began work with the Environmental Protection Division in April 1993 as an Environmental Engineer and became the Engines and Fuels Unit manager in July 2000. His primary responsibilities include the implementation of the Georgia School Bus Retrofit Program, Georgia Low RVP and Sulfur Gasoline Program, Vapor Recovery, Clean Fueled Fleets Program, Alternative Fuels, Idling Reduction, and other Heavy-Duty Diesel Engine Programs.
Dr. Matt Strickland is Assistant Professor in the Department of Environmental & Occupational Health and in the Department of Epidemiology at the Rollins School of Public Health, Emory University. His research interests center on the health effects of environmental exposures on fetuses and children. He has conducted investigations of the health effects of ambient air pollutant concentrations in metropolitan Atlanta on the risk of congenital heart defects, preterm delivery, and pediatric asthma exacerbations.
Acute Associations between Ambient Air Pollutants and Pediatric Asthma Emergency Department Visits
Rationale : Certain ambient air pollutants cause asthma exacerbations in children. To advance understanding of these relationships, further characterization of the dose-response and pollutant lag effects are needed, as are investigations of pollutant species beyond the commonly measured criteria pollutants.
Objectives : Investigate acute associations between ambient air pollutant concentrations and emergency department visits for pediatric asthma.
Methods : Daily counts of emergency department visits for asthma or wheeze among children age 5–17 were collected from 41 Metropolitan Atlanta hospitals during 1993–2004 (n = 91,386 visits). Ambient concentrations of gaseous pollutants and detailed measurements of particulate matter were obtained from stationary monitors. Rate ratios for the warm season (May–October) and cold season (November–April) were estimated using Poisson generalized linear models in the framework of a case-crossover analysis.
Measurements and Main Results : Ozone was strongly associated with emergency department visits during both seasons, and we observed associations with several pollutants from traffic sources during the warm season; in multipollutant models we observed evidence for independent effects of both ozone and traffic pollutants. These associations were present at relatively low ambient concentrations and tended to be of the highest magnitude for concentrations on the day of the emergency department visit. We also observed associations with sulfate particles during the warm season and coarse thoracic particles during the cold season.
Conclusions : Even at relatively low ambient concentrations, ozone and pollutants from traffic sources independently contributed to the burden of emergency department visits for pediatric asthma in Atlanta.
Dr. Jeremy Sarnat is currently an assistant professor of environmental health at the Rollins School of Public Health of Emory University. He conducts exposure science research, measuring air pollution exposures in various populations, in particular sensitive cohorts such as children, seniors and individuals with cardiopulmonary disease. A specific focus of his work examines how exposure assessment informs environmental epidemiology and the impact of exposure misclassification and confounding on air pollution epidemiologic findings. Dr. Sarnat holds an ScD in environmental exposure assessment and an MS in risk assessment from Harvard University.
Fine Particle Sources and Cardiorespiratory Morbidity: An Application of Chemical Mass Balance and Factor Analytical Source Apportionment Methods.
Jeremy A. Sarnat 1 , Amit Marmur 2 , Mitchel Klein 1 , Eugene Kim 3 , Armistead G. Russell 2 , Stefanie E. Sarnat 1, James A. Mulholland 2 , Philip K. Hopke 4 , Paige E. Tolbert 1
1 Emory University, Atlanta, Georgia
2 Georgia Institute of Technology, Atlanta, Georgia
3 California Air Resources Board, California
4 Clarkson University, Potsdam, New York
Interest in PM health effects has focused on identifying sources of particulate matter (PM) that may be associated with adverse health. Few epidemiologic studies, however, have included source apportionment estimates in their examinations of PM health effects. We analyzed a time-series of chemically-speciated PM measurements in Atlanta, GA, and conducted an epidemiologic analysis using data from three distinct source apportionment methods. Atlanta is a unique location for conducting this type of health effects study given the existence of an extensive time-series of daily speciated PM 2.5 measurements and corresponding hospital records. The key objective of this analysis was to compare epidemiologic findings generated using both factor analysis and mass balance source apportionment methods. We analyzed data collected between November 1998 and December 2002 using positive-matrix factorization (PMF), modified chemical mass balance (CMB-LGO), and a tracer approach. Emergency department (ED) visits for a combined cardiovascular (CVD) and respiratory disease (RD) group were assessed as endpoints. Results. There were significant, positive associations between PM 2.5 concentrations to mobile sources (RR range: 1.018 - 1.025) and biomass combustion, (RR range: 1.024 – 1.033) source categories and CVD-related ED visits. Associations between the source categories and RD visits were not significant for all models with the exception of sulfate-rich secondary PM 2.5 (RR range: 1.012 – 1.020). Generally, the epidemiologic results were robust to the selection of source apportionment method. Conclusions. Despite differences among the source apportionment methods, these findings suggest that modeled source apportioned data can produce robust estimates of acute health risk. In Atlanta, there were consistent associations across methods between PM 2.5 from mobile sources and biomass burning with both cardiovascular and respiratory ED visits and between sulfate-rich secondary PM 2.5 with respiratory visits. Moreover, combining multiple source apportionment methods adds information that compensates for limitations of relying on any single method. The implications of using one or several methods for understanding the sources of PM 2.5-mediated health risks will also be addressed.
Dr. Roby Greenwald is a Research Assistant Professor in the Department of Environmental and Occupational Health in the Rollins School of Public Health at Emory University and is engaged in research examining the relationship between ambient air quality and human health. Roby received a PhD in Environmental Engineering from Georgia Tech, a BS in Civil Engineering from Clemson University, and previously served as a Peace Corps Volunteer in Benin, West Africa.
Two Atlanta Studies: Highway Commuters Exposures and Examining the Influence of Air Pollution on Asthma in Children
Asthma and Air Pollution:
The Study of Asthma and Air Pollution (SAAP) examines the effects of exposure to concentrated ambient particles for two hours on respiratory symptoms, lung function, and airway and systemic redox variables in children. The study was designed to test the hypothesis that inhalation of ambient particles at a concentration comparable to an elevated natural exposure increases the magnitude of systemic and airway redox stress in children with asthma. Twenty participants with well-controlled asthma were recruited from the Emory Pediatrics Asthma Center. Prior to exposure experiments, participants underwent a complete characterization of lung function, atopic status and an assessment of their personal exposure to airborne particles in their home environment. On the day of experimental exposure, participants were exposed in random order to either concentrated ambient particles or filtered air. Participants returned two weeks later for the corresponding second exposure. Immediately prior to exposure and at intervals during the 48 hours post-exposure, we assessed asthma symptom control, airway and systemic redox variables and lung function. The primary outcome indicators were changes in exhaled nitric oxide (NO) and breath condensate pH and composition, nitration products, glutathione, oxidation/reduction potential (ORP), and inflammatory cytokines as indices of particle-induced inflammation.
Atlanta Commuters Study:
Exposure to gas-phase and particle-phase pollutants in the ambient atmosphere is known to have a negative effect on human health. Furthermore, results of many epidemiological and laboratory studies suggest that combustion-generated pollutants associated with motor vehicle traffic are of particular concern. We have therefore established the Atlanta Commuters Exposures (ACE) Study to examine in more detail the exposure to potentially harmful pollutants by commuters following a scripted route through zones of high traffic volume on Atlanta highways. This study will include in-vehicle monitoring of chemically- and seize-resolved particulate matter (PM) concentrations. We will also assess the influence of factors such as engine performance, vehicle ventilation rate and traffic congestion on in-cabin pollutant levels and will examine the relative contribution of emissions from the subject's own vehicle as compared to surrounding vehicular traffic as well as ambient PM sources. In addition, we will monitor several health outcomes that have previously been identified as potentially important by PM-related epidemiology, including heart rate and heart rate variability, systemic markers of inflammation and oxidative stress, and exhaled nitric oxide and other markers of airway inflammation. We will also monitor potential confounding factors such as in-vehicle noise levels and elevated stress levels experienced by participants operating vehicles in situations of high traffic volume. Finally, data analysis will include general descriptive statistics, fixed and mixed effects regression models to identify factors influencing in-cabin pollutant concentrations, and an examination of associations between pollutant exposure and health outcomes, including both a priori models to examine previously-reported associations and exploratory models to examine novel hypotheses.
Dr. Tegan Boehmer has worked as an epidemiologist with the Air Pollution and Respiratory Health Branch, National Center for Environmental Health, CDC for the past year. Prior to this, she completed a two-year field assignment as a CDC Epidemic Intelligence Service officer at the Tri-County Health Department in Denver, Colorado. Dr. Boehmer received an MPH and PhD degree from Saint Louis University School of Public Health. Her research interests include the impact of urban design and transportation on community health, particularly respiratory and cardiovascular disease, obesity, and physical activity.
Paying a Higher Price: Association between Gas Price, Vehicle Travel, and Air Quality
Tegan K. Boehmer, PhD, MPH; W. Dana Flanders, PhD; Fuyuen Y. Yip, PhD, MPH
Background: Exposure to traffic emissions is associated with adverse health. Motor vehicles contribute >50% to urban air pollution, and the number of vehicle miles traveled (VMT) continues to rise. This study sought to determine if elevated gas prices experienced in 2008 were associated with a reduction in VMT and traffic-related air pollution in metropolitan Atlanta.
Methods: Monthly data on price/gallon of unleaded gasoline, VMT, and ambient concentration of particulate matter with a diameter ≤2.5μm (PM2.5), ozone, and nitrogen oxides (NOx) were obtained for five Atlanta counties (VMT data only available for all Georgia urban areas) from 1/1/2006 to 9/30/2008. Wilcoxon rank sum test was used to determine if gas price, VMT, and air pollutant levels were significantly different between 2008 and 2006. Generalized estimating equations (GEE) with an autoregressive correlation structure were used to assess the relationship between gas price and VMT and between VMT and PM2.5, ozone, and NOx over the 33-month period, adjusting for season.
Results: In 2008, the price of unleaded gasoline was 30% higher and VMT was 5% lower compared with 2006. Likewise, ambient concentrations of PM2.5, ozone, and NOx were significantly lower in 2008 than 2006. Preliminary GEE models indicate that increased gas price was associated with a reduction in VMT. Three single-pollutant GEE models demonstrated that reduced VMT was associated with a reduction in the ambient concentrations of PM2.5, ozone, and NOx.
Conclusions: These preliminary data suggest that higher gas prices might be associated with reduced VMT and improved air quality in metropolitan Atlanta. Future analyses will incorporate additional variables to enhance our understanding of this relationship and its impact on health.
Climate Change and Sustainability
Mr. Chuck Mueller is a senior policy advisor at the Georgia Environmental Protection Division. He was hired about 4 years ago to focus on Energy and Environmental Policy issues and worked very closely with the staff of the state energy office, within GEFA, to develop the first comprehensive State Energy Strategy for Georgia. He is the Division’s point on Climate Change and Air policy issues. He currently supports Georgia’s role on the Board of Directors for The Climate Registry, a non-profit organization consisting of 41 states working to establish the first national Greenhouse Gas reporting registry. Prior to coming to Georgia, Chuck worked for the Texas Commission on Environmental Quality for 13 years where he held senior policy level and management positions directing Air, Water and Energy programs. During that time Chuck also represented the state on numerous Federal Clean Air Act Advisory Committee subcommittees, the National Association of Clean Air Agencies and served as Chairman of the Central States Air Resource Agencies.
Preparing for Future Climate Change Policy
Climate change policy is changing rapidly. This presentation give an overview of Federal, Regional, and State-level activities that are or may impact Georgia. In particular, requirements related to the Waxman-Markey Bill (H.R. 2454), the EPA Endangerment Finding , and the Greenhouse Gas ( GHG) Reporting Rule is discussed. Regional initiatives and regional and state-level GHG emissions targets outside of Georgia are presented, and activities within Georgia, including how the GA Environmental Protection Division is meeting the goals of the State Energy Strategy, are described.
Ms. Elaine Olivares is a Senior Planner in the Transportation Planning division of the Atlanta Regional Commission. Her work at ARC mainly involves technical air quality analyses to support emission reductions within the region and air quality planning of transportation conformity detailed forecast emission inventories for inclusion into the State Implementation Plan. More recently she has led climate change modeling and planning. Her previous background has been varied, including work in engineering support in the aerospace sector. Her educational degrees include a bachelor's degree in mechanical engineering from the University of California Riverside and a master's degree in environmental engineering from Georgia Tech.
Transportation Planning and Greenhouse Gases
The Atlanta region is facing many factors that drive a rise in greenhouse gas emissions at a time when national policies are considering strategies for reducing all GHG emissions. The Atlanta Regional Commission (ARC) has begun to look at reductions of transportation-based GHG emissions and has developed a white paper exploring possible effects of increased levels of greenhouse gases on the region. Envision6, the current RTP, contains strategies that lead to reductions of primary pollutants as well as CO2 emissions.
Dr. Michael E. Chang is the Deputy Director of the Brook Byers Institute for Sustainable Systems at Georgia Tech. His research focuses on the complexity of the urban and regional environment, and how nature, technology, economics, and culture lead to both environmental problems and solutions. Previously, Dr. Chang was an air quality modeler with the Georgia Environmental Protection Division; and prior to that, he was an aerospace engineer at the McDonnell Douglas Corporation (now Boeing). He holds degrees in atmospheric chemistry (MS, Ph.D.), environmental policy (MS), and aerospace engineering (BAE) all from Georgia Tech. Among other service activities, he is a Trustee of the Georgia Conservancy and an Editorial Board Member of the Journal of Environmental Management. He lives in Peachtree City, GA with his wife and two children.
Now what?
In 1979, Georgia was declared to have its first air quality nonattainment area. In due time, other areas in Georgia would follow. Now after 30 years of regulation and management, Georgia's air quality is better even if some nonattainment designations persist. In 30 years we built a regulatory agency, passed laws, discovered a southern strategy for air, and cleaned up smokestacks and tailpipes everywhere. So what's next? More of the same? Less of the same? Or something entirely different? Not since 1979 has there been this wide of a window of opportunity to develop a new approach for addressing our air resource needs and desires here in Georgia. So now what?
