Cardiovascular Effects of Mobile Source Exposures: Effects of Particles and Gaseous Co-pollutants

EPA Grant Number: R832416C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R832416
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Harvard Particle Center
Center Director: Koutrakis, Petros
Title: Cardiovascular Effects of Mobile Source Exposures: Effects of Particles and Gaseous Co-pollutants
Investigators: Suh, Helen H. , Gold, Diane R.
Institution: Harvard University
EPA Project Officer: Chung, Serena
Project Period: October 1, 2005 through September 30, 2010 (Extended to September 30, 2011)
RFA: Particulate Matter Research Centers (2004) RFA Text |  Recipients Lists
Research Category: Health Effects , Air


The independent and joint effects of particles and gases on acute autonomic function and inflammation changes are poorly defined, especially when the particles and gases originate from the same source. To improve our understanding about pollutant mixtures and source-specific effects, we propose to use a crossover study to examine whether particulate and/or gaseous pollutants emitted from motor vehicles are associated with autonomic dysfunction and pulmonary and systemic inflammation.


Thirty-six older adults will be exposed repeatedly either to particulate plus gaseous motor vehicle pollution or to only gaseous motor vehicle pollution. For both exposure scenarios, participants will be exposed through 5-hr long field trips via diesel-powered buses. Participants will include older adults who may be more sensitive to particulate pollution and will likely include individuals with coronary artery disease. Selected participants will live in or near retirement facilities located in suburban Boston. Project 2 will be conducted in Years 3 through 5 of the Center. Field trips will occur in the fall and spring, when regional pollution is low, so that motor vehicle pollution comprises a larger fraction of particulate mass. Twelve subjects, randomly divided into two groups of six, will participate in each field trip, with groups riding on separate buses that will follow the same route. On one bus, the air will be unmodified, thus naturally exposing its riders to elevated concentrations of particles and gases from the bus and surrounding vehicles. Air in the second bus will be filtered to remove all particles. Thus, individuals traveling on the second bus will be exposed only to gaseous pollution, predominately from vehicles. Exposure scenarios for the groups will be alternated in a second field trip, which will occur one-to-two weeks later to prevent carryover of any effect from the first trip while minimizing differences in weather and ambient particle composition. Study participants will be randomized to the sequence of exposures to avoid bias. A total of 72 person-trips will be made (six groups and six trips). Health and exposure monitoring will be identical to methods used in our precursor St. Louis Bus study, which was performed as part of our existing Center. Before, during, and after each trip, participants will be monitored for heart rate variability (HRV) as a measure of autonomic function, exhaled NO (eNO) as a measure of pulmonary inflammation, and blood markers as a measure of systemic inflammation. In addition, oxygen saturation and blood pressure will be measured repeatedly, as potentially inter-related intermediate markers of cardiac morbidity. Personal group-level measures of black carbon (BC) and particle counts (PC) will also be measured before, during and after each trip to assess exposures to mobile source pollution, along with measures of PM2.5 and PM2.5-10, ozone (O3), carbon monoxide (CO), nitrogen oxide (NO), and total nitrogen oxides (NOx).

Expected Results:

Results from this study will provide critical information about the roles of pollution mixtures and motor vehicle pollution in cardiac dysfunction. Through its crossover design and use of bus trips to elevate motor vehicle exposures, this study provides a novel, efficient and effective means to examine the combined and separate effects of particulate and gaseous motor vehicle pollution. The crossover design not only allows separation of the effects of gases from those of both particles and gases, but also allows these effects to be examined both by group and by individual. Furthermore, the use of bus trips to elevate exposures allows us to study "frail" older adults, who for ethical reasons cannot be examined in controlled human studies.

Supplemental Keywords:

pollutant mixtures, confounding, traffic-related air pollution,, RFA, Health, Scientific Discipline, Air, particulate matter, Health Risk Assessment, Risk Assessments, ambient air quality, atmospheric particulate matter, chemical characteristics, human health effects, cardiovascular vulnerability, automobile exhaust, airborne particulate matter, chemical composition, biological mechanisms, biological mechanism , traffic related particulate matter, human exposure, mobile sources, ambient particle health effects, autonomic dysfunction, human health risk

Progress and Final Reports:

  • 2006
  • 2007
  • 2008
  • 2009
  • 2010
  • Final

  • Main Center Abstract and Reports:

    R832416    Harvard Particle Center

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R832416C001 Cardiovascular Responses in the Normative Aging Study: Exploring the Pathways of Particle Toxicity
    R832416C002 Cardiovascular Toxicity of Concentrated Ambient Fine, Ultrafine and Coarse Particles in Controlled Human Exposures
    R832416C003 Assessing Toxicity of Local and Transported Particles Using Animal Models Exposed to CAPs
    R832416C004 Cardiovascular Effects of Mobile Source Exposures: Effects of Particles and Gaseous Co-pollutants
    R832416C005 Toxicological Evaluation of Realistic Emission Source Aerosol (TERESA): Investigation of Vehicular Emissions