INHALATION EXPOSURE MODEL FOR VOLATILE CHEMICALS FROM INDOOR USES OF WATER

An indoor air quality model, MAVRIQ, has been developed for use with a personal computer (PC) to simulate the air concentration of organic compounds due to volatilization of chemicals originating in the domestic water supply. MAVRIQ also simulates the inhalation exposure of individuals based on their location and water use behavior. An application of MAVRIQ, presented in this paper, demonstrates the effect of various water uses on the air concentrations in a test house, and on the inhalation exposure of the inhabitants. The occupants' activities, location and water-use patterns are shown to affect their inhalation exposure. In the case of a person who spends the majority of his or her time in a home (such as the primary child-care adult) with contaminated water supply, the daily inhalation exposure is likely to exceed the exposure from ingestion of the same water. A large part of the inhalation exposure occurs during showering and post-showering activities, but other water uses also contribute. In addition, it is shown that a simple remedial action, the installation of a bathroom exhaust fan, can result in significant reductions of the inhalation exposure.