Data was provided by EPA from an air quality model (the Community Multiscale Air Quality or "CMAQ" model) that predicts surface level atmospheric concentrations of air pollutants. These data were provided in the form of shape files and are available from the corresponding author upon request. Specific data include predictions of total primary organic aerosol concentrations, as well as individual fractions of primary organic aerosol from key sources like onroad vehicles and cooking sources. This dataset is associated with the following publication: Saha, P., A. Presto, S. Hankey, B. Murphy, C. Allen, W. Zhang, J. Marshall, and A. Robinson. National Exposure Models for Source-Specific Primary Particulate Matter Concentrations Using Aerosol Mass Spectrometry Data. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 56(20): 14284-14295, (2022).