Indoor-air models for the transfer of contaminants from tap water to air typically rely on physical properties such as Henry's law constant, diffusion coefficients and so forth, and on roomair exchange rates to determine personal-air concentrations. These models do not address other potential sinks or sources for airborne contaminants that could affect exposure. A study was conducted to examine the buildup and decay of trichloroethylene (TCE) in the air of a 1 m3 shower chamber into which water containing 210 μg/L TCE flowed through nozzles producing different flow rates (3 to 6 L/min) and droplet sizes (300 to 1500 μm). The concentrations of TCE in the air of the chamber and in the drain water were measured and the water-to-air transfer efficiency for the three nozzles was determined. The aerosol concentration and size distribution of aerosols generated by the nozzles were measured. Significant differences were observed between the measured air concentrations and the concentrations predicted by the transfer efficiencies and air exchange rate. These differences are observed to depend on the aerosol concentrations for the three nozzles. Consideration is given to processes such as deposition, incomplete mixing, scavenging, and measurement precision as explanations for these differences.