Emission factors (EFs) and results from dispersion models are key components in the air pollution regulatory process. The EPA preferred regulatory model changed from ISCST3 to AERMOD in November, 2007. Emission factors are used in conjunction with dispersion models to predict 24-hour concentrations that are compared to National Ambient Air Quality Standards (NAAQS) for determining the required control systems in permitting sources. This change in regulatory models has had an impact on the regulatory process and the industries regulated. In this study, EFs were developed for regulated particulate matter PM10 and PM2.5 from cotton harvesting. Measured concentrations of TSP and PM10 along with meteorological data were used in conjunction with the dispersion models ISCST3 and AERMOD, to determine the emission fluxes from cotton harvesting. The goal of this research was to document differences in emission factors as a consequence of the models used. The PM10 EFs developed for two-row and six-row pickers were 154 + 43 kg/km2 and 425 + 178 kg/km2, respectively. From the comparison between AERMOD and ISCST3, it was observed that AERMOD EFs were 1.8 times higher than ISCST3 EFs for Emission factors (EFs) and results from dispersion models are key components in the air pollution regulatory process. The EPA preferred regulatory model changed from ISCST3 to AERMOD in November, 2007. Emission factors are used in conjunction with dispersion models to predict 24-hour concentrations that are compared to National Ambient Air Quality Standards (NAAQS) for determining the required control systems in permitting sources. This change in regulatory models has had an impact on the regulatory process and the industries regulated. In this study, EFs were developed for regulated particulate matter PM10 and PM2.5 from cotton harvesting. Measured concentrations of TSP and PM10 along with meteorological data were used in conjunction with the dispersion models ISCST3 and AERMOD, to determine the emission fluxes from cotton harvesting. The goal of this research was to document differences in emission factors as a consequence of the models used. The PM10 EFs developed for two-row and six-row pickers were 154 + 43 kg/km2 and 425 + 178 kg/km2, respectively. From the comparison between AERMOD and ISCST3, it was observed that AERMOD EFs were 1.8 times higher than ISCST3 EFs for absence of solar radiation. Using AERMOD predictions of pollutant concentrations off property for regulatory purposes will likely affect a source?s ability to comply with limits set forth by State Air Pollution Regulatory Agencies (SAPRAs) and could lead to inappropriate regulation of the source.

Agricultural emissions are an important contributor to atmospheric aerosol. These emissions include nitrogen containing organic compounds, primarily as amines, which have not been well investigated to date. Although there have been several studies that have looked at the emission of gas phase amines, there are only a few studies that have focused on ambient amine-based aerosol. There have also only been a handful of smog chamber studies that have investigated amine aerosol chemistry. Kinetic studies have looked at the reactions of amines with OH and ozone. However, amine reactions with nitrate radical (NO3) are not well understood. Several years of measuring atmospheric particulate matter in Cache Valley, Utah, using an aerosol mass spectrometer (AMS), has shown the presence of amine aerosol in significant concentrations (0.5-6 μg/m3). Furthermore, the concentration of amine aerosol peaks at night when NO3 is the dominant oxidant. This thesis details experiments aimed at obtaining a better understanding of the underlying reactions that lead to aerosol formation in Cache Valley and is focused on amine reactivity studies, employing both field and laboratory experiments. There were two field studies performed near agricultural facilities in California. These studies provide a good comparison to the ambient chemistry observed in Utah. The detection of a small amount of amine aerosol was important in showing that amine aerosol is not unique to Utah. The results of these studies add to the previous knowledge base of ambient chemistry in California. This should help future researchers performing similar field studies in California and other locations. Smog chamber-based laboratory experiments included amine reactions with common oxidants, such as ozone and NO3. While small amounts of aerosol formation occurred with ozone (~10 μg/m3), reaction with NO3 produced the most aerosol (up to 135 μg/m3). The smog chamber studies show the importance of amine/NO3 chemistry in the formation of ambient aerosol. Researchers can use this work to aid in further understanding the ambient atmospheric chemistry occurring at various locations. The smog chamber studies also provide a knowledge base that should help guide future work into this area of research.