An approach is developed and tested to extend discrete, source-based sensitivity results to provide a complete set of information for source-air quality impacts, including inversion of those results to develop receptor-oriented source-impact sensitivities. First, the decoupled direct sensitivity analysis method in 3D (DDM-3D) is used to calculate a finite number of forward sensitivities from discrete points. These results are then interpolated using tessellation to provide complete fields of forward, emissions-based sensitivities, i.e., how emissions in any one grid cell within the domain impact any other cell. Receptor-oriented sensitivities are then found by inverting the set of forward sensitivities and can be used to identify the area of influence (AOI). This economically provides results similar to what would be found using an adjoint model. The present approach is computationally less intensive than adjoint modeling for a large number of receptors, and provides both source-oriented and receptor-oriented pollutant response fields that can be used for air quality management and health impact analyses. The forward sensitivity interpolation procedure, as well as the receptor-oriented sensitivities, is evaluated using data withholding.