Measured and estimated air concentrations of chloroform in showers: Effects of water temperature and aerosols

Air concentrations of chloroform (CHCl 3) in an experimental shower chamber were compared with estimates predicted by determining CHCl 3 loss between the shower nozzle and drain and treating the shower chamber as a single, well-mixed compartment. CHCl 3 water-to-air transfer efficiencies for experimental nozzles producing droplets of 1800 and 300 μm diameters were 0.90 and 0.80, respectively, and 0.65 for a standard domestic shower nozzle. Significant differences were observed in the transfer efficiencies when the experimental nozzles were operated at 35 and 45°C but not when the standard nozzle was operated in either jet or spray flow at 40°C. Aerosol concentrations were measured continuously with a hot-wire probe and ranged between 3000 and 17,000 aerosols/cm3 for the three nozzles. Measured air concentrations showed variable agreement with predicted values; under certain conditions, air concentrations were between 10 and 50% less than the predicted values. These discrepancies were observed at the highest aerosol concentrations and when peak aerosol concentrations occurred between 2 and 4 min of the 10 min shower.