Conventional Weapons Demilitarization: A Health and Environmental Effects Data Base Assessment. Methods for Estimating Multi-Pathway Exposures to Environmental Contaminants. Phase 2

摘要

This report describes a model that expresses human expo sure using multiple exposure pathways linked to multiple environmental media. Starting with contaminant concentrations in air (as gases or attached to particles), water, and soil; the model links human exposure through inhalation, ingestion, and dermal absorption to concentrations in each environmental compartment. The concentration in a specific compartment is linked to exposure through a specific pathway using a pathway exposure factor (PEF). The PEF is a numerical expression that incorporates information on human physiology and lifestyle together with models of environmental partitioning into an expression that translates a unit concentration (mg/m3 in air, mg/l in water, or mg/kg in soil) into a daily exposure in mg/kg-d for a specific pathway. Human, animal, and environmental data used in calculating PEFs are presented and discussed. The report provides a detailed derivation of PEF's for air/inhalation, air/ingestion, soil/inhalation, soil/ingestion, soil/dermal absorption, water/inhalation, water/ingestion, and water/dermal absorption pathways. The model is illustrated by sample applications of hypothetical arsenic, benzene, and trinitrotoluene (TNT) contamination. Keywords: Exposure modeling, Multimedia pollution, Pathway exposure factors, Inhalation exposure, Ingestion exposure, Dermal exposure; Exposure physiology. (KT)