Research Agenda - Year 6 Continuation

Objectives/ Hypotheses:
1. The nature and severity of PM health effects observed in susceptible populations reflects differences in PM potency related to differences in PM composition.
2. Organic constituents of fine PM emitted from transportation and vegetative burning sources comprise a major fraction of PM mass in NW airsheds, in contrast to most eastern US airsheds that are dominated by secondary inorganic aerosols.
3. These regional differences combined with detailed characterization of NW aerosol composition and characteristics, source-receptor relationships, and patterns of exposures provide an opportunity to assess PM potency as a function of variations in PM composition.

RESEARCH PLAN:
Approach and Expected Results:

In the 4.5 year span of the NW PM Center, considerable evolution of research effort has occurred: one project continues along its original lines, three projects have substantially shifted focus, two projects have been completed and phased out, and two new projects were launched in prior years. In Year 6, we propose to continue and complete six of these ongoing projects and to initiate (and complete) two new efforts. One ongoing project involves epidemiologic studies of the contribution of long-term PM exposure to cardiopulmonary outcomes in susceptible populations (elderly, cystic fibrosis, infants, and diabetics) using existing data sets. We also propose continuing research to complete our analyses of data from our intensive panel studies that were carried out during Years 1-4.

Specifically, we propose to examine associations between various PM exposure metrics and exhaled nitric oxide (eNO), lung function decrements, blood pressure, and 8-isoprostane in these susceptible panel subjects; the exposure metrics include hourly and daily fine PM, particle size fraction (fine versus ultrafine particle levels), and light absorbing carbon (a surrogate of combustion-derived PM). Additional analyses will also provide a better understanding of infiltration efficiency and exposures to ambient originated PM of different sizes, constituents, and sources, not only in Seattle, but also in two other major cities. We also propose to continue three recently launched projects. These include: 1) a new study of age-dependent sensitivity in genetically altered mice with compromised glutathione synthesis; 2) research into statistical methods to provide a deeper understanding of the statistical properties of estimates from exposure models that are incorporated into health effects analyses; and 3) relative toxicity of size fractionated PM from Seattle and other locations in an ApoE-/- mouse model.

Finally, we are proposing two new initiatives: 1) examination of using F2-isoprostanes and nitro-tyrosine as useful and sensitive biomarkers to monitor oxidative stress in vivo, in the context of PM exposures; and 2) a pilot study of commuting school children examining associations between in-transit DEP exposures and in-vivo oxidative stress markers as well as eNO.

Center research and related research will continue to be assisted by five resource cores: Admin, Controlled Exposure Facility/Health, Exposure, Biostatistics, and Biomarker. These cores will each provide expertise, services, and resources to assist projects and to maximize the cross-project benefits of shared data and methods.

Research Agenda - Project Summary (Years 1 through 5)

Objectives/ Hypotheses: The proposed Northwest Research Center for Particulate Air Pollution and Health will integrate the efforts of a multi-disciplinary team of scientists with expertise in environmental exposure assessment, toxicology, epidemiology, and biostatistics, whose combined efforts will address critical aspects of the health effects related to particulate matter (PM) air pollution. The theme of this Center is combustion-derived fine particulate composition, exposures, and health effects. Atmospheric fine particulate components vary regionally as a result of climate, industry, and resources. Elucidation of relationships among ambient air quality, population exposures, and population health (and study of these regional differences as a strategic approach to uncovering causative agents and mechanisms of effect) will provide crucial information to understand and prevent PM-associated health effects.

Approach and Expected Results: The Northwest PM Center is well-positioned to advance understanding of population exposures to atmospheric PM and resulting health effects, by linking and building on the following aspects of Northwest PM activity: (1) the innovative programs of PM measurement in Northwest states carried out by the University of Washington, Washington State University and local air agencies, together with ongoing and anticipated enhancements such as the PM_2.5 network; (2) the expertise and progress to date by academic and local air agencies in characterization of sources, atmospheric transport and transformation models, ambient impacts, and personal or community exposures to fine PM; (3) the University and affiliated resources for research in related biomedical areas such as toxicology, epidemiology, biostatistics and biomarkers. The Center will accomplish its aims by providing administrative infrastructure, research funding, and technical support to help focus and link studies of PM that address aerosol characterization for exposure assessment, population studies aimed at establishing the role of PM exposures in cardiopulmonary morbidity and mortality, and toxicological studies that seek to establish causative agents and physiological processes. The research projects are focused on epidemiology, exposure assessment, health effects, dosimetry, and toxicology. Center research and related research will be assisted by three resource service cores: Health, Exposure, and Biostatistics. These cores will each provide expertise, services, and resources to assist projects and to maximize the cross-project benefits of shared data and methods.

Major emphasis in Center activities aimed at collaboration and information exchange with other PM Centers, Supersites, and with PM researchers generally will be an objective of the Administrative Core. An annual cycle of Center-directed meetings and planning activities will continually update and refocus the Center research agenda. Three other resource cores will assist with the research; a Health Effects core will provide consultation for health aspects of proposed studies; an Exposure and Dosimetry core will serve as an air quality, exposure monitoring and chemistry laboratory resource for proposed studies; and a Statistics and Data resource core will oversee data management , data analysis, and data quality issues.

Improvements in Risk Assessment or Risk Management: While several Northwest programs of research are already established in areas ranging from meteorology to biomarkers, this Center will provide critical elements to apply expertise and to leverage existing activities to address PM topics. This Center will serve as a significant regional and national resource that will generate important new information on the magnitude and mechanisms of health consequences of particulate air pollution, which is needed to develop scientifically-based environmental standards and risk management strategies. Specific research project findings will lead to improved exposure assessment and population dosimetric models, and improved dose-response information.

Year 1 Progress Report

Year 2 Progress Report

Year 3 Progress Report

Year 4 Progress Report

Year 5 Progress Report