2011 Progress Report: A Multi-City Time-Series Study of Pollutant Mixtures and Acute Morbidity

EPA Grant Number: R834799C004
Subproject: this is subproject number 004 , 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: A Multi-City Time-Series Study of Pollutant Mixtures and Acute Morbidity
Investigators: Sarnat, Stefanie Ebelt , Bilonick, Richard , Darrow, Lyndsey , Klein, Mitchel , Mulholland, James , Russell, Armistead G. , Talbott, Evelynn , Tolbert, Paige , Winquist, Andrea
Institution: Emory University , Georgia Institute of Technology
EPA Project Officer: Chung, Serena
Project Period: January 1, 2011 through December 31, 2016
Project Period Covered by this Report: October 1, 2011 through September 30,2011
RFA: Clean Air Research Centers (2009) RFA Text |  Recipients Lists
Research Category: Health Effects , Air


Although associations between ambient air pollution and acute cardiorespiratory outcomes have been observed in numerous studies, questions remain about the degree to which these findings are generalizable between locations and whether the observed health effects are due to the individual pollutants measured or to pollutants acting in combination with other pollutants. In Project 4, we are conducting a multi-city time-series study to clarify the impacts of air quality on acute cardiorespiratory morbidity in five U.S. cities using novel mixture characterization metrics. Our overarching hypothesis is that factors related to air pollution mixtures, seasonality and climate, concentration-response functions, exposure measurement error, and population susceptibility and vulnerability can help explain apparent between-city heterogeneity in short-term associations between air quality measures and cardiorespiratory emergency department (ED) visits and hospitalizations.

Progress Summary:

During the current reporting period (1/1/2011-7/31/2011), work on Project 4 has focused on development of the project QAPP and associated data management activities, assessment of the specific cities to be included in the study, and initiation of the health and air quality data collection phase of the project. The specific cities proposed for this study were largely chosen based on availability of at least 2 years of daily speciated particulate matter (PM) data and availability of individual-level ED visit and/or hospitalization data for the corresponding time period. We have ongoing studies in Atlanta, GA; Dallas, TX; and St. Louis, MO-IL that meet these criteria. Data collection for these cities has progressed throughout the reporting period. For Atlanta, GA, existing ED visit and HA databases covering the 1993-2004 time period were extended through 2009 with data acquired from the Georgia Hospital Association. These data are currently being processed and validated for use in epidemiologic analyses. Air quality (AQ) monitoring data for the extended time period have been acquired from state and federal monitoring networks, and data from local intensive monitoring programs (e.g., the SouthEastern Aerosol Research and Characterization [SEARCH] network) has been requested. For St. Louis, MO-IL, all ED visit, hospitalization, and AQ monitoring data have been acquired previously. The AQ data have been shared among the project team for use in the mixture characterization metrics development. For Dallas, TX, negotiations with a central health data source have progressed and a data use agreement is currently under review. Data transfer to Emory investigators is anticipated by September 2011. All relevant AQ data for Dallas have been acquired and population-weighted metrics have been created. Pittsburgh, PA, was selected as a city of interest because of a relevant ongoing study conducted by the University of Pittsburgh. Progress has been made on developing the required collaboration with the University of Pittsburgh investigators and assessing the feasibility of including data from this study in the current project (e.g., with respect to anticipated data availability, timeline, and data sharing matters). Finally, Birmingham, AL was proposed as a city of interest due to its contrasting pollution mix from Atlanta, availability of detailed daily speciated AQ measurements conducted as part of the SEARCH network, and feasibility of ED visit and HA data collection from hospitals. Progress has been made on acquiring the relevant AQ monitoring data and initiation of hospital recruitment activities. These five cities may be characterized as distinct, non-coastal major urban population centers with varying degrees of contribution from traffic, industrial sources, coal-fired power plants, and secondary pollutant formation. We are considering the feasibility of including a limited number of additional cities in this study, which may provide increased power and generalizability of study findings.

Future Activities:

Over the coming year, we will finalize the selection of cities to be included in this study and will continue with data collection activities. Specifically, ED visit and hospitalization data will be compiled from all cities, which will entail a combination of hospital recruitment activities and negotiations and contracts to be initiated with centralized data sources or collaborators. Air quality monitoring data for all cities and relevant study periods will be compiled and population-weighted averages will be computed when possible. Work will commence on developing the proposed mixture characterization metrics, including source-resolved PM metrics in each city. Throughout the coming year, we also willdevelop focused hypotheses and epidemiologic approaches for the planned multi-city analyses.

Journal Articles:

No journal articles submitted with this report: View all 101 publications for this subproject

Supplemental Keywords:

ambient air, health effects, sensitive populations, dose-response, cumulative effects, epidemiology, exposure, air quality modeling, PM2.5, organics, elemental carbon, metals, oxidants, sulfates, source characterization, Health, Scientific Discipline, Health Risk Assessment, Risk Assessments, Biochemistry, Environmental Monitoring, children's health, particulate matter, ambient air monitoring, morbidity, climate change, air pollution, airshed modeling, ambient particle health effects, susceptibility, human health risk

Relevant Websites:

www.scape.gatech.edu Exit

Progress and Final Reports:

Original Abstract
  • 2012 Progress Report
  • 2013 Progress Report
  • 2014 Progress Report
  • 2015 Progress Report
  • Final Report

  • Main 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