Decades of research and regulatory efforts have resulted in a robust understanding of primary exposure pathways to aquatic environments. Some pathways, however, remain understudied and unquantified. These understudied pathways include airborne dispersion, deposition, and transport mechanisms that are harder to measure, such as air deposition to aquatic systems or transport from groundwater into surface water. Currently, these pathways are assumed to contribute a relatively small proportion of the total pollutants to ecosystems. However, these understudied pathways also pose a challenge to quantify, resulting in uncertainty around whether they truly are minor pathways, or simply harder to measure or predict. To extend the understanding of pollution sources and exposure pathways, we aimed to: 1.) survey the current knowledge on atmospheric deposition as an aquatic environment exposure pathway; and 2.) describe key findings, information gaps, and considerations for future work. Several anthropogenic and non-anthropogenic air contaminant sources (e.g., organics, metals, inorganics) occur in the particulate and vapor phases that may contribute to this understudied pathway. Most research for this pathway focuses on monitoring air quality parameters, characterizing particulate matter and pollutants in ambient air, or testing the effects of air pollution constituents in laboratory-based toxicity tests. A targeted review indicates that this exposure pathway’s relative contribution to pollutant concentrations and their toxic effects in aquatic organisms has not been fully evaluated. Few studies have confidently quantified the amount of particulate matter or other airborne pollutant deposited into aquatic systems, or determined if the constituents are bioavailable, both of which are important considerations for exposure characterization. Current biogeochemistry research offers atmospheric aerosol deposition and metal leaching models for oceans, but these typically focus on global scales rather than the local or regional approach needed for a conceptual site model appropriate for risk assessment. To fully evaluate atmospheric deposition risk and inform regulatory action, additional research is needed to characterize and quantify this understudied exposure pathway.