CalTOX: A multimedia total-exposure model for hazardous-wastes sites. Part 3, The multiple-pathway exposure model.

摘要

Multimedia, multiple pathway exposure models are used in the CalTOX model to estimate average daily doses within a human population in the vicinity of a hazardous-substances-release site. The models encompass twenty-three exposure pathways. This report describes these model and specifies methods, assumptions, and inputs for making exposure and dose assessments. The end product of an exposure assessment for contaminants at hazardous-waste sites is typically an estimation of the distribution of potential dose among the population whose air, water, and soil have been contaminated by the hazardous-waste-substances-release site. The exposure analysis begins with the assumption that, through models or measurements, concentrations are available for ambient air (gas and particle phases), surface water, ground water, surface soil, and root-zone soil at a hazardous-waste-substances-release site. The exposure-assessment process consists of relating contaminant concentrations in these environmental media to contaminant concentrations in the media with which a human population has contact (personal air, tap water, foods, household dusts, soils, etc.). The average daily dose is the product of the exposure concentrations in these contact media and an intake or uptake factor that relates the concentrations to the distributions of potential dose within the population.