Receptor methods provide estimates of the impacts of sources on ambient air, primarily from the inter-relationships of measured ambient concentrations of individual air pollutant species, using only minimal meteorological and emissions inventory information. The article summarizes recent results from applying receptor methods (principally Chemical Mass Balance) to ambient Volatile Organic Compounds (VOC) data from Atlanta, Georgia, USA, an ozone non-compliance area. A novel feature of the analysis is the extraction of source profiles from the ambient data themselves. Recent results on applying radiocarbon measurements to determine the biogenic fraction of ambient VOC are also being discussed.