Analysis of Temporal and Spatial Dichotomous PM Air Samples in the El Paso-Cd. Juarez Air Quality Basin |
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| Authors: | Wen-Whai Li Ruben Orquiz Jose H Garcia Tania T Espino Nicholas E Pingitore Jorge Gardea-Torresdey |
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| Institution: | 1. Department of Civil Engineering and Environmental Science and Engineering Program , University of Texas at El Paso wli@utep.edu;3. Department of Civil Engineering , University of Texas at El Paso;4. Environmental Science and Engineering Program , University of Texas at El Paso;5. Department of Geological Sciences and Environmental Science and Engineering Program, , University of Texas at El Paso;6. Department of Chemistry and Environmental Science and Engineering Program , University of Texas at El Paso |
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| Abstract: | ABSTRACT This paper presents and discusses the results obtained from the gravimetric and chemical analyses of the 24-hr average dichotomous samples collected from five sites in the El Paso-Cd. Juarez air quality basin between August 1999 and March 2000. Gravimetric analysis was performed to determine the temporal and spatial variations of PM2.5 (particulate matter less than 2.5 um in diameter) and PM2.5-10 (particulate matter less than 10 μm but greater than 2.5 μm in diameter) mass concentrations. The results indicate that ~25% of the PM10 (i.e., PM2.5 + PM2.5-10) concentration is composed of PM2.5. Concurrent measurements of hourly PM concentrations and wind speed showed strong diurnal patterns of the regional PM pollution. Results of X-ray fluorescence (XRF) elemental analyses were compared to similar but limited studies performed by the Texas Natural Resource Conservation Commission (TNRCC) in 1990 and 1997. Major elements from geologic sources—Al, Si, Ca, Na, K, Fe, and Ti—accounted for 35% of the total mass concentrations in the PM2.5-10 fraction, indicating that geologic sources in the area are the dominant PM sources. Levels of toxic trace elements, mainly considered as products of anthropogenic activities, have decreased significantly from those observed in 1990 and 1997. |
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