Introduction

Drinking water typically contains low levels of many chemical contaminants and is a potential source of exposure to these contaminants. While no attempt is made to present a comprehensive list of contaminants, the major chemical classes are reviewed, with emphasis on the specific contaminants for which US drinking water standards have been proposed or established. Physicochemical properties that significantly influence the occurrence of these contaminants in microenvironments as vapors or in aerosols and the likelihood of exposure and uptake by inhalation or through the skin are also discussed. The domestic activities that involve water are introduced and the data available for characterizing water-related activity patterns for a population are summarized. The working group concluded that methods are now available for modeling of microenvironments, such as the MAVRIQ model used in these case studies that offer flexible and reasonably robust approaches to estimating the extent of exposure and uptake of contaminants in drinking water through the skin and by inhalation.