Polychlorinated biphenyls (PCBs) continue to be contaminants of concern across the Great Lakes. It is unclear whether current concentrations are driven by on-going primary emissions from their original uses, or whether ambient PCBs are dominated by their environmental cycling. Feely dissolved PCBs in air and water were measured using polyethylene passive samplers across Lakes Erie and Ontario during summer and fall, 2011 to investigate their spatial distribution, determine and apportion their sources and to asses the air-water exchange gradients. Average gaseous and freely dissolved ∑29 PCB concentrations ranged from 5.0 to 160 pg/m3 and 2.0 to 55 pg/L respectively. Gaseous concentrations were significantly correlated (R2 = 0.80) with the urban area within a 20 km radius. Fugacity ratio calculations indicated that the majority of PCBs are volatilizing from the water thus acting as a secondary source for the atmosphere. Dissolved PCBs were probably linked to direct PCB emissions from areas of concern. Positive Matrix Factorization indicated that although volatilized Aroclors (gaseous PCBs) and unaltered Aroclors (dissolved PCBs) dominate in some samples, on-going non-Aroclor sources such as paints/pigments (PCB 11) and coal/wood combustion showed significant contributions across the lower Great Lakes. Accordingly, control strategies should give further attention to PCBs emitted from current use sources.