10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Positive Matrix Factorization of SEM Based Individual Particle Results from the Middle East: A Comparison of Data Sets from Kuwait Collected during Two Time Periods
Johann Engelbrecht, GARY CASUCCIO, Traci Lersch, RJ Lee Group, Inc.
Abstract Number: 1624 Working Group: Source Apportionment
Abstract Aerosol sampling and analyses programs mandated by U.S. military and government agencies provided detailed characterization of ambient particulate matter in the Middle East airshed. The U.S. Army Environmental Hygiene Agency, re-designated as the U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM), designed an investigation to produce data to be used to assess the health risk of oil well fires to U.S. troops involved in Operation Desert Storm. Sampling began in Kuwait and Saudi Arabia in early May 1991 and continued through Dec 1991. The goal was to determine the magnitude and extent of pollutants released to the atmosphere from the burning of oil wells. Fifteen years later, a study to generate information on the chemical and physical properties of aerosols collected at military deployment locations in the Middle East was initiated by the U.S. Department of Defense. The purpose was to characterize the aerosols and to provide information that could be used to assess human health effects from exposure to ambient particulate matter at Middle Eastern military bases. Aerosol and bulk dust samples were collected for evaluation over a period of approximately one year following 2005 at fifteen military sites.
For both studies, ambient particulate matter was analyzed by scanning electron microscopy (SEM). An SEM equipped with an energy dispersive X-ray spectroscopy (EDS) system was used to obtain information on the chemical and morphological composition of individual particles. This furthermore provided insight on mineralogical relationships, source identification, and other particle features such as surface coatings. Automated scanning electron microscopy (SEM) techniques were employed to measure particle size, morphology, and composition for a large number of individual particles to produce quantitative data at each location.
The automated SEM/EDS data from the Middle East ambient samples are being used to develop source factors applying positive matrix factorization (PMF). The derived mineralogical composition of the individual particles is also a signature of the region’s geology. Examples include the high quartz content of the four Kuwait sites, the high percentage of calcite in the United Arab Emirates samples, the high dolomite content of the Al Asad samples, and the titaniferous magnetite dust from Djibouti. Further, the automated SEM results also provided direct measurements on carbon chain agglomerated structures, tracers of the oil fire plumes. This investigation examines the source factors established from PMF; evaluates the impact of these emissions on the Middle East ambient environment; and compares the results obtained from multiple locations in the region over two different time periods.