Evaluating Heterogeneity in Indoor and Outdoor Air Pollution Using Land-Use Regression and Constrained Factor Analysis

EPA Grant Number: R834677C152
Subproject: this is subproject number 152 , established and managed by the Center Director under grant R834677
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Health Effects Institute (2010 — 2015)
Center Director: Greenbaum, Daniel S.
Title: Evaluating Heterogeneity in Indoor and Outdoor Air Pollution Using Land-Use Regression and Constrained Factor Analysis
Investigators: Levy, Jonathan
Institution: Harvard T.H. Chan School of Public Health , Health Effects Institute (HEI)
EPA Project Officer: Hunt, Sherri
Project Period: April 1, 2010 through March 31, 2015
RFA: Health Effects Institute (2010) RFA Text |  Recipients Lists
Research Category: Health Effects , Air Quality and Air Toxics , Air


Epidemiologic studies of exposure to air pollution have typically relied on data from centrally located ambient air quality monitors. However, such data are not sufficient for capturing the spatial variability of pollutant concentrations at the local scale, in particular at the within-city, or intra-urban, scale at which traffic-related air pollution is both highest and most variable. The ideal approach would be to measure each individual’s personal exposure to traffic-specific pollutants over time, but this is difficult, intrusive, expensive, and generally not feasible for very large populations. Investigators have consequently sought ways to predict, or to model, individual-level exposures from more readily available data.

Dr. Jonathan I. Levy of the Harvard School of Public Health has proposed an approach to extend and improve upon existing GIS-based methods for predicting intra-urban exposures. An underlying goal of his study was therefore to explore ways to reduce exposure-measurement error and to improve the accuracy and precision of the associations reported in epidemiologic studies of air pollution.


The investigators will conduct a study linked to a prospective birth cohort study of factors that might contribute to the development of asthma, the Asthma Coalition for Community, Environment, and Social Stress study in Boston, Massachusetts. Among the several factors under investigation will be indoor and outdoor exposures to air pollutants, including those potentially related to traffic. Investigators will collect detailed air quality measurements at a set of homes selected to reflect a range of potential exposures to traffic and of neighborhoods broadly representative of Boston. Investigators will collect short-term NO2 and PM2.5 samples simultaneously indoors and outdoors at each home. 

Investigators will also collected additional types of data to support development of their Land Use Regression (LUR) models. They will utilize existing GIS data on road networks, traffic counts, and population density to characterize proximity to and potential density of traffic in the vicinity of each home. They will obtain additional data on local land use and on the age of each home, its living area, building materials, heating system, and whether or not it had air conditioning. Investigators will administer a standardized questionnaire to participants at each home to obtain data on occupant behaviors and home characteristics that have been shown previously to indicate indoor sources of pollutants or to influence ventilation in the home.

Expected Results:

Investigators will explore how land-use regression and source-apportionment techniques can be used to characterize individual-level exposure to both indoor and outdoor air pollution sources. Investigators will utilize health and air monitoring data from an ongoing prospective cohort study on childhood asthma in Boston, Massachusetts to model variability in outdoor and indoor residential air pollution, identify potential sources, and evaluate the effectiveness of various indoor exposure surrogates for predicting childhood asthma development. This study will also evaluate how these approaches might reduce error in individual exposure assessment and thereby improve epidemiologic estimates of the effects of traffic-related air pollution on health.

Supplemental Keywords:

Health Effects, Air Toxics,  epidemiology, exposure models, inhalation exposure, land use regression model, GIS, source apportionment analysis

Relevant Websites:

http://pubs.healtheffects.org/getfile.php?u=604 Exit

Main Center Abstract and Reports:

R834677    Health Effects Institute (2010 — 2015)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R834677C149 Development and Application of a Sensitive Method to Determine Concentrations of Acrolein and Other Carbonyls in Ambient Air
R834677C150 Mutagenicity of Stereochemical Configurations of 1,3-Butadiene Epoxy Metabolites in Human Cells
R834677C151 Biologic Effects of Inhaled Diesel Exhaust in Young and Old Mice: A Pilot Project
R834677C152 Evaluating Heterogeneity in Indoor and Outdoor Air Pollution Using Land-Use Regression and Constrained Factor Analysis
R834677C153 Improved Source Apportionment and Speciation of Low-Volume Particulate Matter Samples
R834677C155 The Impact of the Congestion Charging Scheme on Air Quality in London
R834677C156 Concentrations of Air Toxics in Motor Vehicle-Dominated Environments
R834677C158 Air Toxics Exposure from Vehicle Emissions at a U.S. Border Crossing: Buffalo Peace Bridge Study
R834677C159 Role of Neprilysin in Airway Inflammation Induced by Diesel Exhaust Emissions
R834677C160 Personal and Ambient Exposures to Air Toxics in Camden, New Jersey
R834677C162 Assessing the Impact of a Wood Stove Replacement Program on Air Quality and Children’s Health
R834677C163 The London Low Emission Zone Baseline Study
R834677C165 Effects of Controlled Exposure to Diesel Exhaust in Allergic Asthmatic Individuals
R834677C168 Evaluating the Effects of Title IV of the 1990 Clean Air Act Amendments on Air Quality
R834677C172 Potential Air Toxics Hot Spots in Truck Terminals and Cabs
R834677C173 Detection and Characterization of Nanoparticles from Motor Vehicles
R834677C174 Cardiorespiratory Biomarker Responses in Healthy Young Adults to Drastic Air Quality Changes Surrounding the 2008 Beijing Olympics