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Traffic Source Exposures and Health: Studies from the Harvard EPA Particle Center.

Society for Risk Analysis New England Chapter. Traffic Source Exposures and Health: Studies from the Harvard EPA Particle Center. John J. Godleski , MD Department of Environmental Health Deputy Director, Harvard EPA Particle Center. Harvard/EPA PM Center.

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Traffic Source Exposures and Health: Studies from the Harvard EPA Particle Center.

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  1. Society for Risk Analysis New England Chapter Traffic Source Exposures and Health: Studies from the Harvard EPA Particle Center. John J. Godleski, MD Department of Environmental Health Deputy Director, Harvard EPA Particle Center

  2. Harvard/EPA PM Center Novel Exposure Scenarios to Define the Health Effects of Particle Sources PetrosKoutrakis, PI: Center Director John Godleski, Deputy Director Harvard University University of Toronto University of Michigan Brigham & Women’s Hospital Veteran’s Administration

  3. Center Strategy • A multi-faceted exposure approach encompassing ambient, Concentrated Ambient Particles (CAPs), and specific-source exposures • Assessing a large array of biological responses, in humans and animals, focusing on pulmonary and cardiovascular outcomes

  4. Center Projects and Cores • P1: Normative Aging Study (Yrs 1-5) • P2: Human CAPs Study (Yrs 1-5) • P3: Animal CAPs Study (Yrs 1-2.5) • P4: TERESA Study (Yrs 2.5-5) • C1: Administrative Core (Yrs 1-5) • C2: Particle Technology Core (Yrs 1-5) • C3: Biostatistical Core (Yrs 1-5)

  5. Project 1Cardiovascular Responses in the Normative Aging Study: Exploring the Pathways of Particle Toxicity PI: Joel Schwartz Project 2 Cardiovascular Toxicity of Concentrated Ambient Fine, Ultrafine and Coarse Particles in Controlled Human Exposures PI: Frances Silverman Project 3 Assessing Toxicity of Local and Transported Particles Using Animal Models Exposed to CAPs PI: John Godleski Project 4 Toxicological Evaluation of Realistic Emission Source Aerosol (TERESA): Investigation of Vehicular Emissions PIs: PetrosKoutrakis and John Godleski

  6. Study Design Project 4 • A mixture of primary particles and gases from a vehicular traffic source will be studied. • These emissions will also undergo photochemical oxidation to form secondary PM derived from traffic emissions. • A large tunnel in the Northeast will be used as the source of primary emissions • Exposure scenarios will be assessed vs filtered air controls: • Primary gas and particle emissions • Primary plus secondary particles • Secondary particles formed in the absence of primary particles

  7. Figure 1. The TERESA Source-Specific Emission Exposure System (SEES)

  8. The TERESA Photochemical Reaction Simulation System

  9. Parallel Plate Diffusion Denuder Ruiz et al, Environmental Science & Technology 2006: 40(16): 5058-5063.

  10. Biological Outcomes • Sprague Dawley Rats will be studied. Biological measurements will include: • pulmonary, systemic, and cardiovascular effects • continuous measurements of blood pressure and pulmonary function • Selected scenarios will be further investigated using animal models of disease to assess susceptibility

  11. Status of Project 4 Experiments • Many necessary preliminary studies have been completed in preparation for these tunnel studies. • On site inspection of our mobile laboratory by the Harvard Medical Area Standing Committee on Animals was just completed in the past two weeks. • Animal exposures to these atmospheres are just beginning.

  12. Integration of Center Projects 1-3in Relationship to Blood PressureMechanisms and Outcomes The studies in the literature on blood pressure changes as an outcome in relationship to ambient air pollution have been inconsistent.

  13. From Project 1 Environmental Health Perspectives 2009: 117:1767–1772.

  14. Black Carbon was significantly associated with increases in systolic and diastolic blood pressure, but PM2.5 was not. There was no associated effect modification by gene variants related to oxidative stress. Mordukhovich et al Environmental Health Perspectives 2009: 117:1767–1772

  15. From Project 2 Hypertension 2009: 54: 659-667

  16. Harvard Ambient Fine Particle Concentrator

  17. University of Toronto location is an urban setting along a heavily traveled street – Concentrator inlet is about 25’ from the street Brook et al Hypertension 2009: 54: 659-667

  18. Brook et al Hypertension 2009: 54: 659-667

  19. CAPs + Ozone CAPs Alone Brook et al Hypertension 2009: 54: 659-667

  20. From Project 3 Environmental Health Perspectives 2009: 117(3): 361-366.

  21. Harvard Ambient Particle Concentrator • CAPs: • PM2.5 • Concentration is ~30x ambient • Composition is same as ambient Inlet about 75 meters from Huntington Ave. Godleski et al HEI Report 91,2000

  22. Systolic and Diastolic Blood Pressure increased Significantly with CAPs exposure over 6 hours Bartoli et al. Environmental Health Perspectives 2009: 117(3): 361-366.

  23. Bartoli et al . Environmental Health Perspectives 2009: 117(3): 361-366.

  24. Rat studies of Blood pressure over 5 hours of exposure Caps Filter Air

  25. Hours of Exposure

  26. Barorecptor Reflex Sensitivity (BRS) – A potential mechanism • Baroreceptors (or baroceptors) in thebodydetect the pressure of blood flowing through them, and send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output. • Baroreceptor reflex is one of the body's homeostatic mechanisms for maintaining blood pressure. It provides a negative feedback loop in which an elevated blood pressure reflexively causes blood pressure to decrease; similarly, decreased blood pressure depresses the baroreflex, causing blood pressure to rise

  27. BRS Studies • We evaluated pre- and post-exposure BRS following intravenous injection of phenylepherine (10µg/kg), Heart rate and BP after the injection of agonist are plotted to determine whether the BRS set point has changed.

  28. Bartoli et al . Environmental Health Perspectives 2009: 117(3): 361-366.

  29. BRS Interpretation • The findings suggest a compensatory response takes place during the exposure.

  30. Alpha Adrenergic Blockers Prevent CAPs Effect on Blood Pressure Bartoli et al . Environmental Health Perspectives 2009: 117(3): 361-366.

  31. Summary • In all studies of our Center, blood pressure increased significantly, and associations were strongest with markers of urban traffic. • The timing of measuring blood pressure in relationship to exposure is important in assessing the magnitude of change. • Homeostatic mechanisms control increases in blood pressure and limit the amount of change during longer exposures. • The sympathetic nervous system plays a role in the change in blood pressure with exposure.

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