2003 Progress Report: Exposure Characterization Error

EPA Grant Number: R827351C001
Subproject: this is subproject number 001 , established and managed by the Center Director under grant R827351
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: EPA NYU PM Center: Health Risks of PM Components
Center Director: N/A
Title: Exposure Characterization Error
Investigators: Ito, Kazuhiko
Institution: New York University School of Medicine
EPA Project Officer: Chung, Serena
Project Period: June 1, 1999 through May 31, 2005 (Extended to May 31, 2006)
Project Period Covered by this Report: June 1, 2003 through May 31, 2004
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air


The objectives of this project are to: (1) quantitatively characterize spatio-temporal error of particulate matter (PM) components and gaseous copollutants measured at routine regulatory-based air monitors as a function of site characteristics using the entire U.S. air monitoring network; (2) establish the relationship between the estimated error at a given monitoring site and the effect size/significance in mortality and morbidity models; and (3) evaluate the relative contribution of the error due to site-to-site and person-to-site variability. This project is testing the prevailing hypothesis that the PM and gaseous copollutant data from a single air monitoring station can adequately reflect the population exposure for the entire city and that resulting risk estimates and their significance are not biased.

This is one of the projects funded by the New York University (NYU) PM Center. The progress for the other projects is reported separately (see reports for R827351C002 through R827351C016).

Progress Summary:

We completed the analyses of monitor-to-monitor correlation for PM10 and gaseous criteria pollutants in seven North-Central States for the years 1988-1990 (Ito, et al., 2001) as well as in the nationwide data for the years 1988-1997 (Ito, et al., 2004a). In the analysis of the seven North-Central States, O3, PM10, and NO2 showed generally higher monitor-to-monitor temporal correlation (r: 0.8-0.6) than CO or SO2 (r < 0.5). In the analysis of the nationwide data, the overall rankings in monitor-to-monitor correlation on the average were: O3, NO2, and PM10, (r ~ 0.6 to 0.8) > CO (r < 0.6) > SO2 (r < 0.5). Also, the resulting median monitor-to-monitor correlation was modeled as a function of qualitative site characteristics (i.e., land-use, location-setting, and monitoring-objective) and quantitative information (e.g., median separation distance, longitude/latitude or regional indicators) for each pollutant using Generalized Additive Models (GAM). Both the separation distance and the regional variation were important predictors of the correlation. For PM10, for example, the correlation for the monitors along the East Coast was higher by approximately 0.2 than in western regions. The qualitative monitor characteristics often were significant predictors of the variation in correlation, but their impacts were not substantial in magnitude for most categories. These results suggest that the apparent regional heterogeneity in PM effect estimates, as well as the differences in the significance of health outcome associations across pollutants, may in part be explained by the differences in monitor-to-monitor correlations by region and across pollutants.

We also completed the processing of weather and mortality data for the years 1985-1997 for the 88 largest U.S. cities. To address the model specification issues that have been raised since the discovery of the GAM convergence issue in 2002, we have examined several alternative weather adjustment models in a limited subset, as was done in the re-analysis of Detroit PM components data (Ito, 2003). We plan to complete the mortality analysis in the next 2 months.

Future Activities:

We will continue to compare the magnitude of the error associated with monitor-to-monitor variability and that associated with person-to-monitor differences. In addition, we have acquired the new nationwide PM2.5 chemical speciation data and plan to characterize the regional source types of PM2.5. As of March 2004, there are more than 250 speciation monitors. Using the nationwide data, we will conduct an analysis similar to that done for the three PM2.5 chemical speciation monitors in New York City (Ito, et al., 2004b). We will examine the relative exposure error by source types and link this information to the mortality analysis.

Journal Articles on this Report : 3 Displayed | Download in RIS Format

Other subproject views: All 7 publications 7 publications in selected types All 7 journal articles
Other center views: All 112 publications 101 publications in selected types All 89 journal articles
Type Citation Sub Project Document Sources
Journal Article Ito K, Thurston GD, Nadas A, Lippmann M. Monitor-to-monitor temporal correlation of air pollution and weather variables in the North-Central U.S. Journal of Exposure Analysis & Environmental Epidemiology 2001;11(1):21-32. R827351 (Final)
R827351C001 (2000)
R827351C001 (2002)
R827351C001 (2003)
R827351C001 (Final)
R825271 (Final)
  • Abstract from PubMed
  • Full-text: JESEE-Full Text PDF
  • Abstract: JESEE-Abstract
  • Journal Article Ito K, Xue N, Thurston G. Spatial variation of PM2.5 chemical species and source-apportioned mass concentrations in New York City. Atmospheric Environment 2004;38(31):5269-5282. R827351 (2003)
    R827351 (Final)
    R827351C001 (2003)
    R827351C001 (Final)
    R827997 (2005)
    R827997 (Final)
  • Full-text: Science Direct-Full Text HTML
  • Abstract: Science Direct-Abstract
  • Other: Science Direct-Full Text PDF
  • Journal Article Ito K, De Leon SF, Thurston GD, Nadas A, Lippmann M. Monitor-to-monitor temporal correlation of air pollution in the contiguous US. Journal of Exposure Analysis and Environmental Epidemiology 2005;15(2):172-184. R827351 (2003)
    R827351 (Final)
    R827351C001 (2003)
    R827351C001 (Final)
  • Abstract from PubMed
  • Full-text: JESEE-Full Text HTML
  • Abstract: JESEE-Abstract
  • Other: JESEE-Full Text PDF
  • Supplemental Keywords:

    thoracic particles, PM10, fine particles, PM2.5, ultrafine particles, PM0.1, lung dosimetry models, human exposure models, pulmonary responses, cardiovascular responses, immunological responses, criteria air pollutants, concentrated ambient aerosols, aerosol, air pollutants, air pollution, airborne pollutants, airway disease, airway inflammation, airway variability, allergen, ambient air, ambient air quality, analytical chemistry, assessment of exposure, asthma, asthma morbidity, atmospheric monitoring, biological markers, childhood respiratory disease, children, combustion, combustion contaminants, combustion emissions, compliance monitoring, dosimetry, epidemiology, exposure, exposure and effects, health effects, heart rate variability, human exposure, human health, human health effects, incineration, lead, lung, mercury, morbidity, particulates, pulmonary, pulmonary disease, respiratory, RFA, Health, Scientific Discipline, PHYSICAL ASPECTS, Air, ENVIRONMENTAL MANAGEMENT, particulate matter, Environmental Chemistry, Health Risk Assessment, Risk Assessments, Environmental Monitoring, Physical Processes, Atmospheric Sciences, Atmosphere, Risk Assessment, ambient air quality, atmospheric particulate matter, particulates, air toxics, atmospheric particles, chemical characteristics, toxicology, ambient air monitoring, airborne particulate matter, ozone, environmental risks, exposure, Sulfur dioxide, air pollution, aerosol composition, atmospheric aerosol particles, human exposure, ozone monitoring, PM, exposure assessment

    Relevant Websites:

    http://www.med.nyu.edu/environmental/centers/epa/ Exit

    Progress and Final Reports:

    Original Abstract
  • 1999 Progress Report
  • 2000 Progress Report
  • 2001 Progress Report
  • 2002 Progress Report
  • 2004
  • Final Report

  • Main Center Abstract and Reports:

    R827351    EPA NYU PM Center: Health Risks of PM Components

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R827351C001 Exposure Characterization Error
    R827351C002 X-ray CT-based Assessment of Variations in Human Airway Geometry: Implications for Evaluation of Particle Deposition and Dose to Different Populations
    R827351C003 Asthma Susceptibility to PM2.5
    R827351C004 Health Effects of Ambient Air PM in Controlled Human Exposures
    R827351C005 Physicochemical Parameters of Combustion Generated Atmospheres as Determinants of PM Toxicity
    R827351C006 Effects of Particle-Associated Irritants on the Cardiovascular System
    R827351C007 Role of PM-Associated Transition Metals in Exacerbating Infectious Pneumoniae in Exposed Rats
    R827351C008 Immunomodulation by PM: Role of Metal Composition and Pulmonary Phagocyte Iron Status
    R827351C009 Health Risks of Particulate Matter Components: Center Service Core
    R827351C010 Lung Hypoxia as Potential Mechanisms for PM-Induced Health Effects
    R827351C011 Urban PM2.5 Surface Chemistry and Interactions with Bronchoalveolar Lavage Fluid (BALF)
    R827351C012 Subchronic PM2.5 Exposure Study at the NYU PM Center
    R827351C013 Long Term Health Effects of Concentrated Ambient PM2.5
    R827351C014 PM Components and NYC Respiratory and Cardiovascular Morbidity
    R827351C015 Development of a Real-Time Monitoring System for Acidity and Soluble Components in Airborne Particulate Matter
    R827351C016 Automated Real-Time Ambient Fine PM Monitoring System