Characterizing Exposure to Speciated Organic Carbon and Acute Cardiorespiratory Response in a Cohort of Daily Commuters

JEREMY A. SARNAT (1,2), Roby Greenwald (1), Fuyuen Yip (2), Michael H. Bergin (3), Colin Boswell (3), James Gooch (1), Priya Kewada (1), Tegan Boehmer (2)

(1) Emory University, Atlanta, (2) Centers for Disease Control and Prevention, Atlanta, (3) Georgia Institute of Technology, Atlanta

     Abstract Number: 234
     Last modified: November 9, 2009

Abstract
Currently, over 40 million Americans spend approximately an hour each day commuting to and from their place of work, with 3.4 million people commuting at least three hours per day. Numerous studies have indicated that specific sub-populations may be at greater risk for PM-related health effects due to their proximity and/or enhanced exposures to traffic-related pollution. A more complete understanding of in-vehicle exposures and health for commuters is becoming increasingly necessary, as commuting durations as well as roadway congestion have steadily increased throughout the U.S. during the last 20 years. To address these concerns, we are currently measuring in-vehicle pollutant concentrations and corresponding biomarkers of acute cardiorespiratory response for 40 older adults, as part of the Atlanta Commuters Exposures (ACE) Study. The study involves in vehicle real time measurements of size-resolved particulate concentration, elemental carbon, and total surface polycyclic aromatic hydrocarbons (PAHs). Time integrated filter samples are also collected and analyzed for particulate mass concentration, organic and elemental carbon, as well as a wide range of elements and major ions. A novel component of this study is the analysis of filters for specific organic compounds including hopanes, steranes, and PAHs using thermal desorption gas chromatography mass spectrometry (TD-GC/MS) analysis method. Initial analyses of filters collected under conditions similar to the proposed study commutes (i.e. roadside sampling for a one hour time period) indicate quantifiable concentrations of elemental and organic carbon as well as a broad range of organic species (appx. 50). We will present specific details on the sampling approach and methodology as well as in-vehicle speciated organic carbon measurements. Preliminary associations between these measurements with specific cardiorespiratory endpoints including heart rate, blood pressure, airway resistance and exhaled nitric oxide will also be discussed.