AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Aerosol Precursors from Agricultural Emissions
PHILIP SILVA, USDA - Agricultural Research Service
Abstract Number: 586 Working Group: Aerosol Chemistry
Abstract Aerosol influences on the environment from agriculture are usually considered to be dominated by coarse mode dust with some secondary component in the fine mode from the impact of ammonia emissions. However, agricultural emissions include many reactive volatile organic compounds that potentially contribute to secondary aerosols as well. Emissions inventories are more uncertain regarding area sources like agriculture compared to mobile and point sources. In a number of locations, measured ammonia is either significantly higher or lower than modeling would predict and most reactive organic compounds are not adequately accounted for. Is this because different management practices contribute emissions different than specified inventory values? Are there missing sources in emissions inventories? We have performed field sampling experiments at poultry, dairy, and a hog farms to find answers to these questions. We will show evidence from field work that ammonia and volatile organic compounds react close to source to produce aerosol and discuss potential formation mechanisms. Data suggest that agricultural emissions may be underestimated as a source for new particulate matter in rural areas and that emissions inventories and air quality models may be missing important information.