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PREDICTION OF FINE PARTICULATE LEVELS AT UNMONITORED LOCATIONS
Citation:
Smith, L., S Mukerjee, G A. Norris, M Gonzales, C Stallings, L Neas, AND A H. Ozkaynak. PREDICTION OF FINE PARTICULATE LEVELS AT UNMONITORED LOCATIONS. Presented at American Association for Aerosol Research, Anaheim, CA, October 20-24, 2003.
Impact/Purpose:
Overall Goal: To develop spatial analyses using limited network-based air quality and GIS and other ancillary spatial information to estimate exposures for epidemiologic studies.
Goal of NERL Contribution: To develop regression-based spatial models using said measures and ancillary information to predict such exposures at unmonitored locations.
Specific Objectives:
1. To determine whether ultrafine (<0.1 um), accumulation (0.1-0.7), and/or coarse (1-10 um) mode particle counts correlate with CO, NO2 and VOCs emitted from mobile and/or other urban sources using source apportionment modeling techniques.
2. To determine spatial associations among measured levels of NO2, VOCs, and (possibly) ultrafine/accumulation/coarse mode particle counts from mobile and other urban sources in El Paso. Spatial variability in ultrafine/accumulation/coarse mode particle concentrations will be determined using available PM, NO2, VOC and available surrogates of motor vehicle emissions. These measured or predicted spatial associations will then be used by NHEERL to ultimately assess impact of these particle counts and gaseous species on children's exposures in schools.
3. To evaluate accuracy of NO2 and VOC measurements using the passive badges to be deployed by EPA versus collocated FRM devices established by the State of Texas. In addition, to evaluate precision of collocated NO2 and VOC passive badge measurements.
4. To use spatial analysis concepts to evaluate their possible application in an EPA Region 6 study entitled "Air Toxics Data and Analysis and Development of a Predictive Model of Estimation of Ambient Vocs in Selected Census Tracts in Houston-Galveston, TX."
Description:
In November and December of 1999, air concentrations of ultrafine, fine, and coarse particulate matter were measured at two intensive sites in El Paso, Texas. The intensive sites included collocated measurements of NO2 and volatile organic compounds (VOCs) in the air from both continuous and passive samplers. Passive sampling of NO2 and VOCs was also conducted at twenty-two school locations. One of the goals of this study was to attempt to predict the fine and ultrafine particulate concentrations at a total of fifty-five schools, none of which monitored particulates.
To accomplish this, the passive samplers were first compared to the continuous monitors at the two intensive sites. Based on these results, predictive equations for particulate levels were developed as functions of the passive monitor measurements. These predictive equations were then applied at the twenty-two schools with passive monitors. These predicted particulate levels were then utilized to develop predictive equations at the twenty-two schools in terms of certain ancillary variables whose values could be obtained at all school locations.
Finally, predictions were obtained at all school locations by applying these last equations. The ancillary variables were obtained from information supplied by the El Paso school district, the city, the U. S. Census, and from application of GIS techniques to these data. The ancillary variables used were: section of the city, distance to the nearest border crossing, elevation, population density, distance to roads with certain levels of traffic, traffic intensity around the schools, and distance to the nearest petroleum facility. It is envisioned that the results are to be used in a qualitative basis in an epidemiological study of El Paso school children.
The information in this document has been funded wholly or in part by the U.S. Environmental Protection Agency under Contracts Contract 68-D0-0206 to ManTech Environmental Technology, Inc. and 68-D-99-012 to Research Triangle Institute. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.