2011 Progress Report: Simulated Roadway Exposure Atmospheres for Laboratory Animal and Human Studies

EPA Grant Number: R834796C002
Subproject: this is subproject number 002 , established and managed by the Center Director under grant R834796
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: University of Washington Center for Clean Air Research
Center Director: Vedal, Sverre
Title: Simulated Roadway Exposure Atmospheres for Laboratory Animal and Human Studies
Investigators: McDonald, Jacob D. , Lund, Amie K.
Current Investigators: McDonald, Jacob D.
Institution: Lovelace Respiratory Research Institute
EPA Project Officer: Callan, Richard
Project Period: December 1, 2010 through November 30, 2015 (Extended to November 30, 2017)
Project Period Covered by this Report: December 1, 2010 through July 31,2011
RFA: Clean Air Research Centers (2009) RFA Text |  Recipients Lists
Research Category: Health Effects , Air

Objective:

An integral component of the Center is the development of laboratory-generated atmospheres for experimental exposures of animals and humans. This Project will develop these atmospheres, with the primary objective of simulating environments containing key components of roadway emissions and the products of environmental factors that transform them. The exposures will help determine air contaminants that cause or potentiate the toxicity of roadway emissions or confound interpretations based on exposure defined by roadway proximity alone. The work that  currently is under way is related to Aims 1 and 2 defined below.

Aim 1: Develop and characterize laboratory-generated exposure atmospheres simulating the key components of near-roadway exposures, including transformed emissions and co-exposures.
 
Aim 1 will modify and optimize existing LRRI exposure systems that have been previously utilized. We will modify the existing Motor Vehicle Emissions (MVE) exposure system to permit studies that compare atmospheres that mimic near roadway exposure to atmospheres that are physically aged or chemically transformed to mimic downwind exposures. The MVE atmospheres will be studied both as near as realistically practical to the point of emission, and after atmospheric aging simulating time-related particle nucleation and agglomeration. Next, the atmospheres will be chemically transformed in an irradiation (smog) chamber. The ability of a representative background pollutant mix to potentiate the toxic effects of roadway emissions will then be determined. The background mix will be simulated by combining inorganic ions, metals, secondary organics volatile hydrocarbons and ozone in realistic proportions.
 
Aim 2: Conduct inhalation exposures of laboratory animals.
 
Aim 2 will integrate with the animal toxicology project. Building on previous findings that show synergistic increases in mouse vascular response when gasoline and diesel emissions are combined, we will investigate permutations to assess the effects of the near-roadway scenarios developed in Aim 1 and define the biological potency based on lipid peroxidation in ApoE -/- mice (Ref: Project 3). The first phase of this work is screening potency of motor vehicle emissions under different exposure combinations that may reflect scenarios observed in Project 1.

Progress Summary:

Three separate gasoline:diesel mixtures have been developed, and the initial set of experiments (animal inhalation exposures) currently are under way. The next phase of this research will evaluate the role of physical and chemical transformations on the potency of the motor vehicle atmospheres. The dilution system has been modified to enable physical transformation/aging and agglomeration of the mixed motor vehicle exhaust, and the characterization is under way. Next, the motor vehicle exhaust system has been coupled to the irradiation chamber that will allow study of chemical transformation. Finally, a NOx denuder system has been procured from the Desert Research Institute. This denuder will remove NOx that would prohibit successful atmospheric transformation experiments.
 
Protocols and Standard Operating Procedures (SOPs) for the conduct of this work have been completed, and a quality assurance plan that describes use of SOPs and data management is being developed.

Future Activities:

The dose and mixture response studies will be completed in conjunction with Project 3. In parallel, mixed atmospheres will be generated to determine the physical and chemical transformation. These atmospheres will be characterized in collaboration with Project 1, and the results will be related to field observations from Project 1.

Journal Articles:

No journal articles submitted with this report: View all 8 publications for this subproject

Supplemental Keywords:

 air pollution, motor vehicle, mixtures, particulate matter, Scientific Discipline, Health, Air, ENVIRONMENTAL MANAGEMENT, Air Quality, air toxics, Health Risk Assessment, Risk Assessments, mobile sources, Environmental Monitoring, Biochemistry, Risk Assessment, ambient air quality, atmospheric particulate matter, particulate matter, aerosol particles, air pollutants, motor vehicle emissions, vehicle emissions, air quality models, motor vehicle exhaust, airway disease, bioavailability, air pollution, particle exposure, atmospheric aerosols, ambient particle health effects, vascular dysfunction, cardiotoxicity, atmospheric chemistry, exposure assessment

Progress and Final Reports:

Original Abstract
2012 Progress Report
2013 Progress Report
2015 Progress Report


Main Center Abstract and Reports:

R834796    University of Washington Center for Clean Air Research

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R834796C001 Exposure Mapping – Characterization of Gases and Particles for ExposureAssessment in Health Effects and Laboratory Studies
R834796C002 Simulated Roadway Exposure Atmospheres for Laboratory Animal and Human Studies
R834796C003 Cardiovascular Consequences of Immune Modification by Traffic-Related Emissions
R834796C004 Vascular Response to Traffic-Derived Inhalation in Humans
R834796C005 Effects of Long-Term Exposure to Traffic-Derived Particles and Gases on Subclinical Measures of Cardiovascular Disease in a Multi-Ethnic Cohort