Grantee Research Project Results

Final Report: A Pilot Geospatial Analysis of Exposure to Air Pollutants (with Special Attention to Air Toxics) and Hospital Admissions in Harris County, Texas

EPA Grant Number: R828678C011
Subproject: this is subproject number 011 , established and managed by the Center Director under grant R824834
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Mickey Leland National Urban Air Toxics Research Center (NUATRC)
Center Director: Beskid, Craig
Title: A Pilot Geospatial Analysis of Exposure to Air Pollutants (with Special Attention to Air Toxics) and Hospital Admissions in Harris County, Texas
Investigators: Hamilton, William P.
Institution: Baylor College of Medicine
EPA Project Officer: Chung, Serena
Project Period: January 2, 2001 through December 31, 2005 (Extended to December 31, 2008)
RFA: Targeted Research Center (2004) Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research , Air Toxics

Objective:

The investigators' research in this pilot study was organized around the hypothesis that the rate of Harris County residents hospitalized during the study period differs geographically among 337 4x4 kilometer domains, and correlates with exposure to air pollutants estimated using the EPA's Community Multiscale Air Quality with Air Toxics (CMAQ-AT) model. They used the CMAQ model and model inputs (meteorology and emissions) developed by the University of Houston as part of previous ozone modeling for Houston's TexAQS field study to estimate pollutant concentrations; this project then used ArcGIS (ESRI, Redlands, CA) geospatial modeling software to extract and/or combine the estimated exposure, admissions, and demographic data for each of the domains for subsequent analysis. The investigators hypothesized that the CMAQ model would allow air toxic concentrations to be determined to a more comprehensive extent than can be accomplished using fixed site monitors.

Investigators concluded that preliminary findings suggested spatial differences in predicted hospitalization rates, but acknowledged that the pilot study raised significant concerns about the ability of the current model to usefully estimate exposure and other methodological issues that need to be addressed. The SAP believes that conclusions drawn from the study are fraught with methodological and interpretation challenges as they relate to evaluation of the model to develop the needed exposure estimates. The investigators acknowledge in their report that the chief numerical conclusions raise concerns about the exposure estimates computed from the CMAQ output and the instability of the resultant risk estimates. However, the SAP believes that the authors have not adequately addressed these issues, leaving the reader to evaluate its conclusions and interpretation based only on the summary of methods and application. The SAP therefore relayed their concerns in a “Statement of the NUATRC Scientific Advisory Panel” that was published along with the investigators’ report.

Summary/Accomplishments (Outputs/Outcomes):

• The study was funded in response to RFA 2003, “Small Grants Program on Exposures and Health Effects of Urban Air Toxics.”
• The study is in compliance with Institutional Review Board of the Baylor College of Medicine, Houston. The study provided and followed appropriate quality control and quality assurance procedures.
• The study started in April 2005 and was scheduled to be completed in March 2007.
• Investigators discussed their progress with NUATRC at a workshop in September 2005.
• Additional funds were provided biostatistical support.
• A no-cost extension was given to this project through August 2007.
• A draft final report was submitted to the NUATRC in September 2007. A revised final report was received by the Center in October 2008.
• The SAP and Board of Directors approved publication of the report after a Statement by the SAP, which provides alternate interpretation of the study results presented by Dr. Hamilton.
• The Center Research Report Number 15, “A Pilot Geospatial Analysis of Exposure to Air Pollutants (with Special Attention to Air Toxics) and Hospital Admissions in Harris County, Texas,” was published in December 2009.

 

Supplemental Keywords:

RFA, Health, PHYSICAL ASPECTS, Scientific Discipline, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, HUMAN HEALTH, Aquatic Ecosystems & Estuarine Research, Genetics, Health Risk Assessment, State, Risk Assessments, Aquatic Ecosystem, Health Effects, Physical Processes, Biochemistry, asthma, particulate matter, adolescents, morbidity, airway disease, allergic airway disease, exposure, ozone, respiratory disease, air pollution, Texas (TX), human exposure, cigarette smoke, water quality, environmental tobacco smoke, urban environment, airborne urban contaminants

Progress and Final Reports:

Original Abstract

2001

2002

2003

2004

2005 Progress Report

2006 Progress Report

2007 Progress Report

Main Center Abstract and Reports:

R824834    Mickey Leland National Urban Air Toxics Research Center (NUATRC)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R824834C001 Air Toxics Exposures Among Teenagers in New York City and Los Angeles - A Columbia-Harvard Study (TEACH)
R824834C002 Cardiopulmonary Response to Particulate Exposure
R824834C003 VOC Exposure in an Industry Impacted Community
R824834C004 A Study of Personal Exposure to Air Toxics Among a Subset of the Residential U.S. Population (VOC Project)
R824834C005 Methods Development Project for a Study of Personal Exposures to Toxic Air Pollutants
R824834C006 Relationship Between Indoor, Outdoor and Personal Air (RIOPA)
R824834C007 Development of the "Leland Legacy" Air Sampling Pump
R824834C008 Source Apportionment of Indoor Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Residences
R824834C009 Development of a Personal Cascade Impactor Sampler (PCIS)
R824834C010 Testing the Metals Hypothesis in Spokane
R828678C001 Air Toxics Exposures Among Teenagers in New York City and Los Angeles—A Columbia-Harvard Study (TEACH)
R828678C002 Cardiopulmonary Effects of Metal-Containing Particulate Exposure
R828678C003 VOC Exposure in an Industry Impacted Community
R828678C004 A Study of Personal Exposure to Air Toxics Among a Subset of the Residential U.S. Population (VOC Project)
R828678C005 Oxygenated Urban Air Toxics and Asthma Variability in Middle School Children: A Panel Study (ATAC–Air Toxics and Asthma in Children)
R828678C006 Relationship between Indoor, Outdoor and Personal Air (RIOPA). Part II: Analyses of Concentrations of Particulate Matter Species
R828678C007 Development of the “Leland Legacy” Air Sampling Pump
R828678C008 Source Apportionment of Indoor PAHs in Urban Residences 98-03B
R828678C009 Development of a Personal Cascade Impactor Sampler (PCIS)
R828678C010 Testing the Metals Hypothesis in Spokane
R828678C011 A Pilot Geospatial Analysis of Exposure to Air Pollutants (with Special Attention to Air Toxics) and Hospital Admissions in Harris County, Texas
R828678C012 Impact of Exposure to Urban Air Toxics on Asthma Utilization for the Pediatric Medicaid Population in Dearborn, Michigan
R828678C013 Field Validation of the Sioutas Sampler and Leland Legacy Pump – Joint Project with EPA’s Environmental Technology Validation Program (ETV)
R828678C014 Performance Evaluation of the 3M Charcoal Vapor Monitor for Monitor Low Ambient Concentrations of VOCs
R828678C015 RIOPA Database Development
R828678C016 Contributions of Outdoor PM Sources to Indoor and Personal Exposures: Analysis of PM Species Concentrations” Focused on the PM Speciation and Apportioning of Sources
R828678C017 The Short and Long-Term Respiratory Effects of Exposure to PAHs from Traffic in a Cohort of Asthmatic Children