ABSTRACT
The risk assessment process has become an integral element in the evaluation and management of contaminated sites. This chapter identifies the various aspects of exposure assessment that contribute to the clear and accurate characterization of potential human health risks associated with contaminated soils. In order to accurately assess the impact of chemicals in soil on human health, the potentially exposed subpopulations must be identified. In an uncontrolled site, there may be multiple important exposure routes. One should consider among these the inhalation of gaseous emissions in residential or occupational indoor air due to contaminated soil or groundwater. In conducting risk assessments, selection of exposure parameter values that represent the conditions of human exposure is critical. In assessing exposure to petroleum contaminated soils, the key exposure parameters include soil ingestion, dermal absorption, and inhalation of vapors, dusts, and soil. A relatively new factor which should be considered in exposure assessments is the bioavailability of a substance in various environmental media.
