Modern agriculture depends on the use of nitrogen fertilizers to obtain maximum crop yields. Most grain crops (e.g., corn, wheat) are used to sustain animal production, resulting in the translocation and accumulation of nitrogen (via animal wastes) in specific regions of the country (e.g., Sampson and Duplin counties, NC). Enhanced production of animal waste leads to enhanced emission of ammonia (NH3), which in turn can influence ambient atmospheric chemistry and air quality. Since 1998, annular denuder technology has been used to measure ambient atmospheric concentrations of ammonia and ammonium (NH4+) aerosols across eastern NC. On average, NH3 comprises 72% of total NH3 + NH4+ in regions with relatively high animal densities, thus increasing the relative importance of acid gases with respect to fine particulate matter (PM2.5) formation. Aerosol equilibrium modeling (ISORROPIA) shows that ammonium-based PM2.5 formation is most sensitive, in these regions with relatively high animal densities, to sulfur dioxide (SO2) emission reductions during the warm months, and is approximately equally sensitive to SO2 and nitric oxide (NOx) emission reductions during the cold months. Moving away from areas with high animal densities results in a corresponding change in atmospheric ammonia chemistry, suggesting a relatively localized impact of the enhanced ammonia emissions on air quality. However, further study and monitoring using annular denuder technology is needed across eastern NC to fully understand the impacts of enhanced ammonia emissions on regional air quality, and to accurately predict the changes that will result with the adoption of alternative technologies for handling animal waste.