2000 Progress Report: Hazardous Air Pollutant Mixtures: Measuring and Modeling Complex ExposureEPA Grant Number: R827928
Title: Hazardous Air Pollutant Mixtures: Measuring and Modeling Complex Exposure
Investigators: Adgate, John L. , Pratt, Greg , Ramachandran, Gurumurthy , Sexton, Ken , Zhang, Junfeng
Current Investigators: Adgate, John L. , Church, Timothy , Pratt, Greg , Ramachandran, Gurumurthy , Sexton, Ken , Zhang, Junfeng
Institution: University of Minnesota , Minnesota Pollution Control Agency , University of Medicine and Dentistry of New Jersey
EPA Project Officer: Chung, Serena
Project Period: December 20, 1999 through December 19, 2002 (Extended to June 19, 2004)
Project Period Covered by this Report: December 20, 1999 through December 19, 2000
Project Amount: $510,012
RFA: Urban Air Toxics (1999) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air
Objective:The proposed research, which builds upon a previous U.S. EPA STAR grant (R825241: Measurement and Source Apportionment of Human Exposures to Toxic Air Pollutants in the Minneapolis - St. Paul Metropolitan Area) and University of Minnesota-funded studies in the Minneapolis-St. Paul Metropolitan area, has two objectives: (1) to examine the relationships between ambient monitoring (i.e., outdoor central sites), indoor air monitoring, and personal exposure monitoring for a mixture of selected hazardous air pollutants (HAPS), i.e., 8 volatile organic compounds (VOCs) and 6 particle-bound metals in the PM2.5 size fraction; and (2) examine the relationships between ambient dispersions modeling results and monitoring results for exposures to VOCs and metals.
In the course of attaining these objectives, the study will test several related hypotheses, including: (1) central site measurements of metal concentrations in the PM2.5 fraction provide reasonable estimates (i.e., within a factor of 2) of indoor concentrations for these particle-bound metals; (2) central site measurements of metal concentrations in the PM2.5 fraction provide reasonable estimates (i.e., within a factor of 2) of personal exposure concentrations for these particle-bound metals; (3) the variability in personal metals concentrations in the PM2.5 fraction is related to the variability in indoor at-home metals concentrations in the PM2.5 fraction; (4) the variability in personal exposure to metals in the PM2.5 fraction is related to the variability in indoor at home and personal VOC levels; (5) for the general population of adults, personal exposure concentrations for a complex mixture of metals and VOCs can be predicted based on time activity profiles and ambient dispersion modeling of these HAPs; (6) for the general population of adults, the primary sources contributing to indoor and personal exposure to a complex mixture of metals and VOCs can be predicted based on source apportionment modeling results; and (7) continuous measures of indoor PM2.5 levels can be used to characterize and explain day-to-day variability in 24-hour gravimetric samples.
Progress Summary:The following tasks were completed or initiated in year 1 of this project: (1) x-ray fluorescence analysis of more than 300 outdoor PM2.5 central site filters was completed; (2) digestion of outdoor, indoor, and personal PM2.5 filters for trace metal analysis was initiated; (3) data clean up, quality assurance checks, and development of an integrated database of all outdoor, indoor, and personal VOC and PM measurements from the HAPS study was largely completed; and (4) the development of a new VOC source inventory to facilitate updating dispersion modeling performed using a 1995 source inventory was initiated.
Future Activities:The proposed schedule for completion of the this research in the next 2 years is as follows:
? Year 2: Conduct trace metal analyses and laboratory QA/QC of personal, indoor, and outdoor filters; begin first stage of complex exposure modeling.
? Year 3: Continue exposure modeling and comparisons with dispersion modeling results; communicate results to study participants, prepare papers for publication in peer-reviewed journals.