Executing ECHO-AIR for analyses in California requires only estimates of emissions, which can be input as ArcGIS-compatible shapefiles or comma separated value files. ECHO-AIR is modular, enabling users to employ any ISRM, population data, and health input data, so long as they are formatted correctly ECHO-AIR is managed through a public GitHub repository to ensure transparency, to maximize usability, and to perform routine model upgrades and maintenance (see Supplementary Text for details).