1999 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, 1999 through May 31, 2000
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 research project are to: (1) characterize quantitatively the spatiotemporal error of particulate matter (PM) components and gaseous copollutants measured at the 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 of size/significance in mortality and morbidity models; and (3) evaluate the relative contribution of the error resulting from site-to-site and person-to-site variability. This project will test the prevailing hypothesis that the PM and gaseous copollutants 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. We will first characterize spatiotemporal variation of PM at metropolitan and regional scales for the entire United States. The site-to-site correlation of temporal variation will be modeled as a function of qualitative (e.g., location setting) and quantitative (e.g., distance to and quantity of emission sources) variables. The second stage of this project will investigate the relationship between the estimated exposure characterization error associated with a given site’s data and its effect size/significance in health effects models for metropolitan statistical areas (MSAs) or regions where numerous (10-30 sites) monitors are available (approximately 20 regions covering more than 70 million residents).

Progress Summary:

Because we could obtain mortality records for 3 more years (1995-1997) than originally planned (10 years, 1985-1994), we extended our study period to 13 years. We have processed much of the nationwide air pollution and mortality records, and have conducted initial characterization of the pollution data. The daily PM10 data and hourly O3, SO2, and CO data for all of the sites in the contiguous U.S. states for the 13-year study period have been retrieved and processed. For the gaseous pollutants, daily 24-hour averages were computed for all of the sites. There were 2,368 sites for PM10, 1,544 sites for O3, 1,473 sites for SO2, and 904 sites for CO for the entire study period. Although PM10 had the largest number of sites, a smaller number of sites had a large number of available days because of the every-6th-day sampling schedule used at most sites. However, 25 percent of the PM10 sites (590 sites) had at least 565 days available (enough daily data to conduct time-series study with a reasonable statistical power), and 10 percent (236 sites) had more than 900 days of observations available. As the gaseous pollutants (O3, SO2, and CO) were collected on a daily basis, larger numbers of daily observations were available. For example, 25 percent of O3 (386 sites), SO2 (368 sites), and CO (226 sites) had at least 3,100 days of observations. We currently are choosing the cities (or MSAs) for the main data analyses, based on the number of multiple sites, population size, and available sample days.

We also conducted an initial analysis of the pollution data to restrict the core database to the urban and suburban sites. The air pollution levels of all of the sites were first examined by qualitative site characteristics such as land use (e.g., industrial, commercial, residential, and agricultural), location setting (e.g., urban, suburban, and rural), and monitoring objective (e.g., maximum concentration, population exposure, etc.). In the nationwide data, the PM10 levels did not vary appreciably by land use (median = 26.2, 26.5, and 26.3 μm/m3 for residential, commercial, and industrial sites, respectively), or by monitoring objective (median = 27.5 and 25.7 μm/m3 for maximum concentration and population exposure sites, respectively). By location setting, PM10 levels were comparable for urban (median = 27.6 μm/m3) and suburban (median = 26.3 μg/m3) sites, but lower in the rural sites (median = 20.8 μg/m3). In contrast, the gaseous air pollution levels were more dependent on the qualitative site characteristics. For example, CO levels were higher at maximum concentration sites (median = 1.2 ppm) than at population exposure sites (median = 0.80 ppm). These factors will be further examined by regions (e.g., Air Quality Control Regions or AQCR).

The nationwide multiple cause of death records (approximately 2 million deaths per year) have been processed for the 13-year period to reduce the data size. We reduced the record length from the original 440 characters per record to 69 characters per record by extracting only the relevant variables for our purpose, including state, country, MSA, city of residence identifiers, race, sex, age, underlying cause, and five contributing causes of death. We also have developed a data processing routine so that daily counts for a given geographic boundary for the 13-year period can be constructed easily from these records.

Future Activities:

We will retrieve and process all of the daily PM10 data, hourly O3, SO2, and CO data for all the sites for the 13-year study period. We will compute daily 24-hour averages for the gaseous pollutants for all the sites (2,368 sites for PM10, 1,544 sites for O3, 1,473 sites for SO2, and 904 sites for CO). We will begin analyzing the data for PM10 and gaseous pollutants in some of the larger cities (e.g., Detroit, Chicago). We also will retrieve and process nationwide PM 2.5 data for the period 1999-2000.

Journal Articles:

No journal articles submitted with this report: View all 7 publications for this subproject

Supplemental Keywords:

thoracic particles, particulate matter, PM, 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, air, health, waste, biochemistry, biology, chemical engineering, chemistry, children’s health, civil engineering, environmental engineering, environmental chemistry, physics, analytical chemistry, epidemiology, health risk assessment, immunology, incineration, combustion, combustion contaminants, combustion emissions, air toxics, tropospheric ozone, aerosol, air pollutants, air pollution, airborne pollutants, airway disease, airway inflammation, airway variability, allergen, ambient air, ambient air quality, assessment of exposure, asthma, asthma morbidity, atmospheric monitoring, biological markers, childhood respiratory disease, children, compliance monitoring, dosimetry, exposure, exposure and effects, health effects, heart rate variability, human exposure, human health, human health effects, lead, lung, mercury, morbidity, pulmonary, pulmonary disease, respiratory, Air Quality Control Regions, AQCRs, metropolitan statistical areas, MSAs, clinical, toxicology, spatiotemporal, error, air monitor, mortality, sulfur dioxide, aerosol composition, airborne particulate matter, ambient air monitoring, atmospheric aerosol particles, atmospheric particles, atmospheric particulate matter, chemical characteristics, environmental risks, exposure assessment, human health risk, ozone, ozone monitoring, particulates,, RFA, Health, PHYSICAL ASPECTS, Scientific Discipline, Air, ENVIRONMENTAL MANAGEMENT, particulate matter, Environmental Chemistry, Health Risk Assessment, Risk Assessments, Physical Processes, Environmental Monitoring, 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
  • 2000 Progress Report
  • 2001 Progress Report
  • 2002 Progress Report
  • 2003 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