Anthropogenic emissions to the atmosphere can result in substantial adverse impacts to human health and the environment. Understanding the nature and magnitude of these impacts requires knowledge of pollutant source emissions, the transport and physical/ chemical transformation of those emissions in the atmosphere, and sinks for their eventual removal. This session will focus broadly on these topics for primary and secondary gas and particle phase pollutants. Modeling and observational studies of local to regional scale air quality are invited. Topics of interest include pollutant emissions, secondary pollutant formation, air pollution effects, deposition, and air pollution regulation. Presentations reporting improvements to and evaluation of air quality models are of interest as are studies reporting new and improved measurement techniques, including the use of low-cost sensors.