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TECHNIQUES TO ASSESS CROSS-BORDER AIR POLLUTION AND APPLICATION TO A U.S.-MEXICO BORDER REGION
Citation:
Mukerjee, S, D. S. Shadwick, L. Smith, M. C. Somerville, K. E. Dean, AND J. J. Bowser. TECHNIQUES TO ASSESS CROSS-BORDER AIR POLLUTION AND APPLICATION TO A U.S.-MEXICO BORDER REGION. SCIENCE OF THE TOTAL ENVIRONMENT 276(1-3):205-224, (2001).
Impact/Purpose:
1) Assess new and standard air monitoring devices to characterize PM and gaseous air pollutants that are being used in this task.
2) Develop advanced directional analysis techniques (with receptor modeling) to assess transboundary transport of air pollutants and other source impacts. Hypothesis to be tested: Can these wind sector analysis techniques help us identify source location and contribution of transboundary and other sources.
Objectives will be achieved by development of a detailed electronic database for application in the Statistical Analysis System (SAS) to perform statistical assessments and directional techniques on measurements from Border XXI studies, namely the Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) done in and near Brownsville, TX and Ambos Nogales Air Programs on Arizona/Sonora border. Research includes analysis of submicron PM and gaseous pollutant data from El Paso as part of "Measurement and Modeling of Air Pollutants in El Paso, Texas" study.
Description:
A year-long assessment of cross-border air pollution was conducted in the eastmost section of the US-Mexico border region, known as the Lower Rio Grande Valley, in South Texas. Measurements were conducted on the US side and included fine particle mass (PM2.5) and elemental composition, volatile organic compounds (VOCs) and meteorology. Wind sector analyses of chemical tracers and diagnostic ratios, in addition to principal component analysis (PCA), were initially applied to assess cross-border and overall air shed influences. Linear-angular correlation statistics [Biometrika, 63, (1976), 403-405] and nonparametric multiple comparisons between wind sectors were computed with the particle element data using principal component scores from PCA to determine the direction of source classes. Findings suggest crustal particles and salts carried or stirred by sea breeze winds from a southerly and southeasterly direction from the Gulf of Mexico heavily influenced the elemental composition of the particulate samples. Pair-wise comparisons of wind directions for the principal component scores suggest possible oil combustion influences from utilities or boilers coming from the south and possible coal combustion influences from the north and northwest. The techniques discussed can provide a methodology to assess future ambient levels and cross-border influences in the Valley as conditions change.
The information in this document has been funded wholly or in part by the United States Environmental Protection Agency under Contracts 68-D2-0134 to QST Environmental, Inc. and 68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.