In a private residence using benzene contaminated groundwater (about 300 micrograms/l), a series of experiments were performed to assess the benzene exposures that occur in the shower stall, bathroom, master bedroom, and living room as a result of a single 20 minute shower. Sampling methodologies used in the assessment included: fixed site Summa-polished canisters and Tenax GC cartridges; personal Tenax GC devices; and, grab samples collected with glass gas-tight syringes. Integrated Summa and Tenax GC samples were collected from the target microenvironments over 20, 60, and 240 minute periods; these results are contrasted with the long-term personal samples and grab samples that were collected at 0, 10, 18, 20, 25, 25.5, and 30 minutes. Results indicate that maximum benzene concentrations occurred in the shower stall (758-1673 micrograms/cu m) and bathroom (366-498 micrograms/cu m). The total dermal and inhalation dose resulting from a single 20 minute shower was estimated to be equivalent to the inhalation dose which would occur during 6 h of occupation of the house (about 135 micrograms). The benzene dose relating to a single shower and continuous occupancy of the residence was shown to be approximately 551 micrograms/day, with the shower accounting for 25% of the daily total (4% dermal and 21% inhalation), and the remaining 75% relating to respiration in the house for the balance of the day.