ABSTRACT

Exposure to contaminants in drinking water occurs not only via ingestion but also via inhalation, when the contaminants volatilize or are aerosolized, and via dermal absorption from direct contact with the water. Showering not only results in a direct inhalation exposure to the individual showering while in the shower stall and in the bathroom while the shower water is running, but it also increases the air concentration throughout the home, causing exposure to others within the residence. This chapter discusses the major processes leading to inhalational aerosol exposure and summarizes the little available information about showering and use of humidifiers. It considers droplet size distributions reported in the literature as a background for later sections on settling and evaporation. The chapter provides an overview of the modeling topics and concepts that should be considered when conducting a model-based exposure assessment.