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CORRELATION OF FINE AND ULTRAFINE PARTICULATE MATTER WITH METEOROLOGICAL CONDITIONS AND CRITERIA POLLUTANTS IN EL PASO, TEXAS
Citation:
Noble, C. A., C. E. Rodes, P. A. Lawless, S. Natarajan, E. A. Myers, S Mukerjee, A H. Ozkaynak, M Gonzales, AND L Neas. CORRELATION OF FINE AND ULTRAFINE PARTICULATE MATTER WITH METEOROLOGICAL CONDITIONS AND CRITERIA POLLUTANTS IN EL PASO, TEXAS. Presented at American Association for Aerosol Research, Portland, OR, October 15-19, 2001.
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:
Because the harmful health effects of airborne particulate matter (PM) are not well understood, various researchers are investigating ambient PM in order to assess its hazardous components. Current hypotheses acknowledge that PM related morbidity and mortality may be a result of both physical and chemical properties of the aerosol. Among potential PM indicators are ultrafine particles (those smaller than approximately 01.um). Previous epidemiological and toxicological research has suggested that there is a correlation between ultrafine particle number concentration and human health end points.
To investigate ambient ultrafine PM, continuous measurements of aerosol size distributions were made in El Paso, Texas, a city along the US/Mexico border. Sampling was conducted over a twenty-one day period in winter 1999. Size distribution measurements were performed at two urban locations using two coupled pairs of the scanning mobility particle sizer (SMPS) and the aerodynamic particle sizer (APS). Complementary measurements also were performed for gas phase pollutants and meteorological conditions. The data were analyzed as hourly averages.
Throughout the study, the mean ultrafine particle number concentration in El Paso was 14,400 particles per cubic centimeter. Most pollutants were found to vary on diurnal cycles and to follow one of two different trends, either vehicular traffic schedules or sunlight intensity. Wind direction was found to have a significant influence not only on pollutant concentrations, but also on the correlation between pollutants. With southerly winds, CO, NO, and NO2 concentrations were 25-140% greater than when the wind was coming from the north. Likewise, ultrafine particle concentrations were approximately 100% greater for southerly than for northerly winds.
This is an abstract of a proposed presentation and does not necessarily reflect EPA policy. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.